Global rotavirus and pediatric diarrhea surveillance: meeting report, WHO Regional Office for the Western Pacific, Manila, Philippines, 11-13 December 2023

Global rotavirus and pediatric diarrhea surveillance Meeting report WHO Regional Office for the Western Pacific Manila, Philippines 11–13 December 2023 Global rotavirus and pediatric diarrhea surveillance Meeting report WHO Regional Office for the Western Pacific Manila, Philippines 11–13 December 2023 Global rotavirus and pediatric diarrhea surveillance: meeting report, WHO Regional Office for the Western Pacific, Manila, Philippines, 11-13 December 2023 ISBN 978-92-4-009364-5 (electronic version) ISBN 978-92-4-009365-2 (print version) © World Health Organization 2024 Some rights reserved. This work is available under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo). Under the terms of this licence, you may copy, redistribute and adapt the work for non-commercial purposes, provided the work is appropriately cited, as indicated below. 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The responsibility for the interpretation and use of the material lies with the reader. In no event shall WHO be liable for damages arising from its use. iii Contents Meeting objectives 1 Session summaries 1 Agenda 24 List of participants 27 iv 1 Global rotavirus and pediatric diarrhea surveillance Meeting report WHO Regional Office for the Western Pacific, Manila, Philippines 11–13 December 2023 Meeting objectives • Review data from Global Rotavirus and Pediatric Diarrhea Surveillance networks • Discuss priorities and future activities for rotavirus and pediatric diarrhea surveillance Session summaries Day 1, Session 2: Global Rotavirus and Pediatric Diarrhea Surveillance updates Presenters: Heidi Soeters (World Health Organization [WHO]) and James Platts-Mills (University of Virginia [UVA]) Rotavirus remains the top cause of hospitalized diarrhea among children <5 years. Currently 120 countries have introduced rotavirus vaccine across the world. Globally, rotavirus last dose coverage is at 51%, but coverage varies by WHO region. Rotavirus vaccine has a complicated product market space where countries are often faced with difficult decisions regarding product switches. WHO updated the rotavirus vaccine position paper in July 2021, which replaces the 2013 version and adds recent developments in the rotavirus vaccine field. The Global Rotavirus Surveillance Network (GRSN) is being conducted in all 6 WHO regions with the objective of estimating rotavirus burden and describing circulating genotypes. In both 2021 and 2022, 41 countries reported data to the network. Overall rotavirus positivity is consistently lower in countries that have introduced the vaccine compared to countries that have not. GRSN remains a critical global platform for rotavirus surveillance that contributes towards the evidence base to introduce and evaluate rotavirus vaccines. The Global Pediatric Diarrheal Surveillance (GPDS) network builds on GRSN to identify additional causes of diarrhea, addressing a substantial data gap. In both 2021 and 2022, 25 and 26 countries reported data to the network, respectively. It is important to maintain the same countries and sites as much as possible to be able to interpret changing epidemiologic trends of diarrheal diseases over time. During this period, the major findings to report include: Despite the substantial impact of rotavirus vaccine introduction, rotavirus remained the leading cause of pediatric diarrhea hospitalizations. Ongoing vaccine introductions as well as improving the efficacy and coverage of rotavirus vaccination could further reduce diarrhea morbidity and mortality. Shigella (with a burden of diarrhea similar to rotavirus in countries that have introduced rotavirus vaccine), norovirus (now the leading cause of hospitalized diarrhea in South America) and adenovirus 40/41 (now the leading cause of hospitalized diarrhea in India) are other important causes of diarrhea requiring hospitalization in these settings. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 2 Discussion and Action Points • Testing of fatal cases might not be feasible in African Region, as not all deaths may have the fatal outcome captured by surveillance and testing the additional fatal cases may overcomplicate the logistics. • Building regional capacity for interpreting and communicating GPDS results is important. • In presence of rotavirus proportion going down, other attributable fractions for other pathogens have stayed consistent. A question worth exploring. • Genotyping data from GRSN has declined (~1000 results per year, majority from Western Pacific Region). Need to improve genotype reporting to GRSN, and compare genotype data to TAC genotypes. • How confident are we that the Taqman Array Cards (TAC) are catching the major pathogens? GPDS has a fairly comprehensive list of pathogens. Open to adding more if needed. But majority of samples are getting identified with current TAC cards. • Should attempt to stratify GPDS and GRSN analyses by rotavirus vaccination coverage level, or which rotavirus vaccine is used. One challenge may be that national vaccination coverage estimates may not represent the coverage at the sentinel sites, in which case sub-national coverage would be better (if available). Day 1, Session 3: Global Rotavirus Surveillance Network & Global Pediatric Diarrheal Surveillance: context & importance Presenter: Carl Kirkwood (The Bill and Melinda Gates Foundation) GRSN and GPDS are incredibly important and valuable surveillance networks. They provide critical data in diarrheal surveillance. The key to using these data effectively is timeliness. The window from sample collection to data analyses must be as short as possible. Day 1, Session 4: Western Pacific Region & country experiences Western Pacific Region Presenter: Varja Grabovac Currently in the Western Pacific Region, 17 countries have introduced the vaccine with 19 countries in the region remaining. The main challenge currently is low vaccine coverage. 4 countries are currently conducting rotavirus surveillance, this is a decline from 7 in 2019. There has also been decline in surveillance sites from 18 in 2019 to 10 in 2023. However, there is good genotyping data from the region. Labs have been participating in the External Quality Assurance (EQA) program with overall excellent performance. No specific remediations were noted from 2022. 4 countries are participating in GPDS. Surveillance significantly reduced during COVID-19 and slowly recovering. Delays in sending samples, staff turnover, need for training. China Presenter: Dandi Li & Fengfeng Liu (Chinese Center for Disease Control and Prevention [China CDC]) Currently, 33 provinces participate in sentinel surveillance in children under 5 as part of the viral diarrhea surveillance network; 3 of these sites additionally participate in GPDS. Acute gastroenteritis mainly caused by rotavirus in China with a seasonal peak observed from Oct to March. Challenges Session summaries 3 include lack of advanced data collection systems, insufficient training for newly added sites, limited human resources and high turnover, and limited resources to conduct vaccine impact studies. To address these challenges, relevant trainings, and meetings will be conducted in 2024. Fiji Presenter: Reema Kumar Fiji implemented rotavirus surveillance in 2012 by Fiji Centre for Disease Control (Fiji CDC) and it joined GRSN within 2 years. Initially, the country had 2 sites, however, one site was dropped after WHO evaluation. Fiji participated in GPDS in 2017-2018 and 2020-2021. The Ministry of Health (MoH) has decided to support rotavirus surveillance as part of routine system. Fiji also serves as the Regional Reference Laboratory (RRL) to confirm rotavirus outbreaks for other Pacific Island nations. Challenges include: stock-outs of supplies, incorrect or incomplete case information data, and turnover of healthcare staff. The surveillance unit is conducting annual site visits to improve surveillance quality, providing continuing medical education (CME), and providing additional supplies for specimen collection. Priorities moving forward include, participating in EQA, timely reporting of data, effective surveillance, and successful interventions. Lao People’s Democratic Republic Presenter: Sysamay Souksavanh Currently, 2 sites are conducting rotavirus surveillance, one of which also participates in GPDS. The COVID-19 pandemic affected sites’ ability to effectively conduct surveillance. There are ongoing difficulties in collecting samples due to late presentation and competing priorities. Philippines Presenters: Eunice P. Guzman-Andrade, Joseph M. Bonifacio Philippines has decentralized reference laboratories for serologic testing of vaccine-preventable diseases (VPDs) including rotavirus. Testing results are fed from regional laboratories to national level health departments to WHO. Historical data show rotavirus is endemic in the country. Rotavirus testing is consistently low throughout the country, even in regions where testing facilities are available. Philippines started participating in GPDS in 2022. Low numbers of bloody specimens are being referred, as some cases are missed and not investigated. Other challenges include: need to sustain human resources and technical capacity, kits and protocols for confirmatory testing, and low referral of samples for GPDS. Moving forward, there are plans to integrate different surveillance and information systems, provide contingency support for genotyping, utilize available local and international funding opportunities, capacitate and enhance skills of surveillance personnel, and expand VPD referral sites across the country in addition to rotavirus sentinel sites. Viet Nam Presenter: Nguyen Thi Loan Rotavirus sentinel surveillance was established since 2000s in 4 sites. In 2012, the system was transferred to the Expanded Program on Immunization (EPI) to assess disease burden prior to vaccine introduction. Reported 100% of cases with stool specimen collected. One site also participates in GPDS. Rotavirus vaccine is locally produced in Viet Nam. Since 2018, the proportion of rotavirus-positive cases has been declining, however rotavirus burden still remains high. The proportion of children vaccinated Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 4 against rotavirus is higher in the north than in central and southern regions. However, surveillance was affected by the COVID-19 pandemic. Challenges include shortage of lab testing supplies, human resources, and training. Request from country to continue supporting GRSN/GPDS in order to assess vaccine effectiveness (VE) in the near future, expand surveillance, identify new emerging pathogens of pediatric diarrhea, and support lab capacity building. Discussion and action points from the Western Pacific Region and country presentations: • In Western Pacific Region countries that have not yet introduced rotavirus vaccine, how do we advocate for vaccine introduction? For middle-income countries (MICs), funding is a key barrier. There is also no particular champion in the region that advocates for rotavirus vaccine introduction, and there are many competing priorities (e.g., japanese encephalitis, pneumococcal conjugate vaccine, human papillomavirus vaccine are higher priorities). Should list out remaining 19 Western Pacific Region countries and outline which need what type of help to advocate for rotavirus vaccine introduction, so partners can help support. In particular, we could focus on advocating for rotavirus vaccine introduction in the Western Pacific Region GPDS countries that have not yet introduced (China, Viet Nam, Philippines, Laos People’s Democratic Republic). • Do the G9 (VP7 genotpying) primers work to accurately identify infections with G9 strains? Western Pacific Region countries are reporting a large number of G9 infections, and there are concerns about the mispriming or inaccurately reporting G9 instead of the true strain. Day 1, Session 5: Regional experiences with GRSN/GPDS South-East Asia Region Presenter: Emmanuel Tondo To date, 6 countries in the region have introduced rotavirus vaccine, 2 countries are planning to introduce, and 3 countries (Bhutan, Democratic People’s Republic of Korea, Sri Lanka) have no plans or not considering introducing the vaccine. 7 countries in the region perform rotavirus surveillance; only India currently participates in the GPDS network. There is high proportion of specimens collected and ELISA performed from enrolled cases. India and Nepal have seen a decrease in rotavirus positivity as vaccine coverage has increased. South-East Asia Region provides both financial support and technical support to countries, including training for clinicians and laboratory staff for new countries starting rotavirus surveillance, development of surveillance and laboratory manuals, and data management support. Several regional workshops have taken place since 2022 that focus on rotavirus/GPDS or new vaccine introduction. Challenges to rotavirus surveillance in South-East Asia Region include reduction in samples collected due to COVID-19 pandemic, sample storage and testing difficulties, challenges to data collection and management, and reduced capacity due to sites closing or transferring. South-East Asia Region has taken active steps to address a lot of the challenges through direct support as well as through targeted workshops. Session summaries 5 Region of the Americas Presenter: Gloria Rey-Benito To date, 23 countries in the region have introduced rotavirus vaccine. The COVID-19 pandemic affected rotavirus sentinel surveillance, but it is starting to bounce back. Currently, 6 countries in Region of the Americas participate in GPDS. Stool samples are collected from a high proportion of cases. The region has carried out remote meetings to assess surveillance performance, trained new staff, and provided laboratory support. Challenges to pediatric diarrhea surveillance at sentinel sites include the need to improve case enrollment, vaccine coverage, completeness of data, laboratory testing, and reporting of ELISA results. African Region Presenters: Jason Mwenda, Goitom Weldegebriel, Joseph Biey To date, 35 countries in African Region participate in rotavirus surveillance, of which 12 countries also participate in GPDS. Rotavirus VE and impact studies have been completed in 17 countries. 15 countries have had to switch rotavirus vaccines. Data collection and management has transitioned from EpiInfo to REDCap. This transition allows for near real-time data availability for decision-making, provides data security, data entry at point of generation, and ease of data linking and sharing. Current challenges include delayed sample shipments and testing and data completeness and quality. A key highlight of 2023 was the 14th African Rotavirus Symposium in Abuja, Nigeria. Priorities moving forward including continuing to support countries for full utilization of REDCap, conducting refresher trainings on all procedures (surveillance, lab, data, etc.), following-up with countries not regularly reporting data, supporting new surveillance sites and VE/impact studies, enhancing data use for decision-making, and ensuring timely availability of TAC/GPDS data. Eastern Mediterranean Region Presenter: Kamal Fahmy Currently Afghanistan, Pakistan, and Yemen are conducting rotavirus surveillance and Pakistan is also participating in GPDS. Achievements include continuing country support by providing mid- and end-year surveillance performance reports, securing laboratory kits, supporting Yemen in lab testing, supporting a second GPDS site in Pakistan, and designation of a new rotavirus RRL in Pakistan. Challenges include shortage of funds to cover operational costs, inability to supply lab kits to Yemen, difficulty in integrating epi and lab data at the national level, high turnover of personnel in Afghanistan, challenges in starting new GPDS sites in Eastern Mediterranean Region, and difficulty in sites registering for IRR. Moving forward, questions remain regarding how long countries should continue rotavirus surveillance following vaccine introduction, where and when vaccine impact analysis is needed, and how to support establishing rotavirus surveillance and GPDS in non-Gavi countries European Region Presenters: Roberta Pastore, Dovile Videbaek, Simarjit Singh 31 of 53 countries in the European Region have introduced rotavirus vaccine with vaccine coverage ranging from 20%-98% in 2022. Currently, no plans for vaccine introduction among the MICs that haven’t yet introduced the vaccine. The only low- or middle-income country that has not yet introduced rotavirus vaccine is Ukraine, due to programmatic considerations and ongoing conflict. For high-income Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 6 countries, reasons for non-introduction include prioritization of other vaccines, no donor support and/or long-term funding secured, and poor availability of cost-benefit analysis. GRSN and GPDS are established in Gavi eligible countries, with the RRL based in Minsk, Belarus. COVID-19 pandemic affected surveillance in most countries except Republic of Moldova (2 sites). Preliminary enrolment data suggest that not all sites have fully restored to pre-pandemic performance in 2022-2023. Rotavirus and norovirus have the highest attributable fractions identified by TAC testing. While no trainings or no laboratory assessments have been conducted since 2018, national labs are keen on continuing to get support from the RRL for genotyping. All 3 national labs that participated in the 2022 rotavirus EQA scored 100%. In 2022, due logistics constraints to ship specimens, TAC cards and reagents to Minsk, the RRL could not perform TAC testing and genotyping on 2020-2021 specimens. The temporary solution included shipping 2020-2022 specimens to the global reference lab at the U.S. Centers for Disease Control and Prevention (U.S. CDC) for TAC testing and genotyping. The Minsk RRL can resume its role once shipment logistics are resolved. Successes from the region included GRSN/GPDS supporting disease burden estimates to inform vaccine introduction decision. Surveillance data now are being collected in standardized format using WHO European Region software. Challenges included extensive paperwork to enroll diarrhea cases and complete lab investigation forms, high staff turnover, and challenges related to graduation from GAVI support and the sustainability of sentinel surveillance due to limited resources and competing priorities. In December 2022, the European Technical Advisory Group of Experts on Immunization concluded that GRSN has been instrumental in supporting decision-making for vaccine introduction and that due to GRSN sites reducing, GPDS can leveraged to inform development and introduction of new enteric vaccines. Countries are encouraged to continue conducting rotavirus surveillance using their own resources and increase ownership and domestic funding for GPDS within overall investments in VPD surveillance. WHO can consider supporting more countries in conducting pediatric diarrhea surveillance based on common standards, regardless of income level, donor funding and participation in GPDS network. The Regional Office for Europe plans to conduct a landscape analysis to better understand pediatric diarrhea surveillance gaps in European Region and liaise with existing regional networks for data use to estimate disease burden due to enteropathogens. Discussion and action points from the regional presentations: • What was the reasoning for all European Region countries to move to GPDS? Its more about withdrawal of WHO European Region support for GRSN and consolidation to the GPDS countries. Rotavirus information from GPDS will be sufficient for the region. • Region of the Americas interested to know more about the GPDS pathogen distribution by age groups in Region of the Americas. • Can we estimate the causative pathogen for each individual case in GPDS? We have raw cycle threshold (Ct) values for each pathogen for each case. We could agree to use a Ct cut-off value for each pathogen to estimate whether the detected pathogen was potentially a causative etiology. WHO, U.S. CDC & UVA will explore this idea to see what could be done, and how it could be interpreted. Session summaries 7 Day 1, Session 6: Data management and quality Presenter: Sébastien Antoni (WHO) Rotavirus surveillance data flow from regions to WHO headquarters: African Region: Data in RedCAP; Region of the Americas: data in VINUVA casos; Eastern Mediterranean Region: adhoc data sharing; European Region: adhoc data sharing; South-East Asia Region: adhoc data sharing; Western Pacific Region: data uploaded to WIISE Mart. It is critical for all to make sure data are reported by countries within GRSN timelines. GPDS random selection involves 120 samples shipped each year, of which 100 are tested by TAC. Random selection takes place at HQ (Region of the Americas, Eastern Mediterranean Region, European Region, South-East Asia Region, and Western Pacific Region) or at Regional Office (African Region). Risks to random selection include: performing it on incomplete surveillance dataset, randomizing only 100 samples and not including a buffer, using a previous approach of 25 samples per quarter, not using a randomization function from a statistical software, including data from non-GPDS sites, and including duplicate case IDs. Day 2, Session 7: Laboratory – Rotavirus Presenters: Shilpa Iyer, Rashi Gautam, Mick Mulders, and Heidi Soeters The presenters shared the current situation of national, regional, and global reference labs that support the GRSN/GPDS networks. Currently, there is one global reference lab and eight RRLs. WHO headquarters and Eastern Mediterranean Region are working together to designate the National Institutes of Health in Islamabad, Pakistan as the GRSN RRL for the Eastern Mediterranean Region. Aga Khan University, Pakistan will remain the Eastern Mediterranean Region GPDS RRL for the region. In addition to the global reference lab and RRLs, there are 34 national reference labs and 51 site-level labs participating in GRSN. External quality assurance (EQA) program: In total, across the six WHO regions, there are 100 and 33 labs in GRSN with ELISA and genotyping capacities, respectively. Of these labs, only 61% and 64% participated in the 2022 ELISA and genotyping EQA program, respectively. Overall, the participating labs performed well, with >95% of them scoring between 90–100 points (with 100 points being the maximum score, and 80 points the threshold for passing). Four key challenges were identified during the 2022 EQA program and strategies have been developed to address them. These challenges and their corresponding strategies were: • Challenging logistics of shipping of proficiency testing (PT) panels from CDC-Atlanta to RRLs for further distribution to the national and site-level labs. o For the 2023 EQA program, the PT panel kits preparation was outsourced to the American Type Culture Collection (ATCC) and released to the International Reagent Resources (IRR) website for ordering in September 2023. IRR is an established resource used by many RRLs and site-level labs for disease programs like measles and polio. As of December 2023, 54 of the 65 labs registered for IRR have ordered 2023 EQA PT panels from IRR. • Unavailability of kits and reagents to perform EQA testing by the participating labs. o There is a list of kits and reagents for ELISA testing, extraction, detection by qRT-PCR, genotyping by qRT-PCR or conventional RT-PCR, and PT panel samples available on IRR. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 8 If labs have exhausted the regular channels for procuring kits and reagents, they may order kits available on IRR. However, to test the EQA panels, laboratories are encouraged to utilize kits and reagents routinely used for testing surveillance samples for rotavirus, and to avoid using alternative kits or reagents for the purpose of testing the EQA panel. • Manual grading and reporting of PT panel testing results. o The RotaEQA Webtool should now be used to submit PT panel results to facilitate automated grading at the global reference lab (U.S. CDC) and reporting to submitting labs. o To register for RotaEQA Webtool initially, labs must first order the PT panel kit through IRR and then the U.S. CDC will send an invitation for registration. ▪ The same login information can be used for enrollment and submission of results for future EQA program years. o Resources (screenshots and video recordings) for registering and entering results have been shared with RRL coordinators. Please contact them to receive these resources. • Accounting for 36 labs that did not submit their PT testing results in 2022 EQA program: o WHO, U.S. CDC and RRLs are working together to understand the reasons behind the labs not submitting results from PT testing, and working to update the list of participating laboratories to ensure active laboratories participate and submit results on time. Due to challenges related to panel production and logistics costs, unavailability of kits and reagents to perform testing, and the size of the network, the network could consider moving to a biennial (once every 2 years) EQA program, which would provide an opportunity to dedicate the off year to follow-up on quality control results and implement remediation. Diagnostic kits: The number of samples tested as part of GRSN are projected to increase in 2024 (~20,000). However, the price of the ProSpecT ELISA kits, which is part of the WHO catalog, has increased by 80% and this price has not been accepted by the WHO Contract Review Committee (CRC). The CRC made a 1-year exception for the new price, but this exception will expire in April 2024. WHO HQ plans to order ProSpecT kits before the exception expires and is working with procurement to explore both a new agreement on ProSpecT kit pricing and potentially adding kits by other manufacturers to the WHO catalog. • U.S. CDC has published a comparison of the ProSpecT, Rotaclone, and RIDASCREEN kits (Comparison of Premier™ Rotaclone®, ProSpecT™, and RIDASCREEN® rotavirus enzyme immunoassay kits for detection of rotavirus antigen in stool specimens - ScienceDirect. Clin Virol. 2013 September; 58(1): 292–294). • Most labs (81%) that responded to the Rotavirus Diagnostic Survey use the ProSpecT kits and the average ELISA score for 2022 EQA program among ProSpecT-using labs was 96%; the average score was 100% for the remaining labs and they used 5 other ELISA kits. Genotyping data: Globally, the number of countries contributing genotyping data to GRSN is relatively small (2021: n=10; 2022: n=12) with only 1–4 countries contributing genotyping data from each region. The genotype data are important for understanding circulating strains, informing the EQA PT panel composition, and comparing agreement between conventional/qRT-PCR-based and TAC-based methods Session summaries 9 for genotyping. Genotyping data are available at the RRLs and Regional Offices. WHO headquarters is working with the WHO regions to ensure that all existing genotype data are collated at the global level and integrated into the GRSN surveillance database. Rotavirus diagnostic survey results: A survey was conducted to determine the regional diagnostic kit and reagent preferences across the GRSN network. Among the labs that responded, 78% of labs used ELISA while 22% used PCR to detect and diagnose Rotavirus. Testing activities are primarily funded by WHO followed by national governments, U.S. CDC, and others (e.g., academic or grants). Over 70% of labs would need a diagnostic kit to be validated before adoption. Only 27% of labs had ordered kits for 2024 at the time of the survey—WHO encourages labs to order ProSpecT kits as soon as possible before the 1-year price exception expires in April 2024 and they are working to increase the variety of kit manufacturers included in the WHO catalog. Rotavirus lab manual revision: The current rotavirus lab manual needs updating as it was published in 2009. Regional experts have been identified to contribute to the revision and a writing group has been formed—the first informal meeting occurred during the Manila meeting and subsequent meetings will be held monthly. Updates will include updated genotyping methods, quality assurance procedures, and guidance on broader pediatric diarrhea surveillance. Discussion and action points • Reconvene the GRSN/GPDS lab working group of WHO headquarters and Regional Lab Coordinators • Regions are planning for lab refresher training sessions and training on updated lab methods. • Suggestions for the rotavirus lab manual revision: o Identify the PCR methods used within GRSN to inform the laboratory manual revision o Include approaches to identify non-typable strains, potentially in the form of appendices o There should be considerations to include region-specific genotyping protocols and primer sequences in the manual. o Include the list of approved kits and reagents in the manual to facilitate national labs' ability to self-procure kits. • Considerations for diagnostic testing including transition to new ELISA kits and PCR: o Testing by ELISA should continue as it performs well in detecting clinically relevant rotavirus infections and the ELISA kits are simpler and cheaper to operate compared to PCR. o For the implementation of any new ELISA kits, RRLs should participate in the validation, SOPs should be revised to account for the new kits, and site-level lab staff should be trained. These implementation costs of introducing a new ELISA kit should be included in the cost analysis when considering switching ELISA kits. o Transitioning from ELISA to PCR, where needed and appropriate, should be conducted in phases as reagents are expensive and training is needed. Should also compare the cost per test of PCR vs ELISA. o If using qRT-PCR to detect rotavirus, it is recommended that a cycle threshold (Ct) cut-off be used to classify results as positive or negative because qRT-PCR is more sensitive than ELISA and likely to detect asymptomatic infections or vaccine shedding. Several Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 10 published reports using data from different WHO regions have shown that a Ct value cutoff of <27.0 from qRT-PCR is comparable to ELISA test results. • EQA program: o RRL coordinators should work with the national and site-level labs to submit results online to improve participation in the EQA program and response time. WHO HQ is available to help RRLs if needed. o If the frequency of the EQA submission shifts from annual to biennial (once every 2 years) because of cost and logistic reasons, then there should be considerations for a quality control program including one between RRLs in the off-cycle years. o For 2023 EQA, all labs should register with IRR to receive PT panel; non-IRR registered labs should provide a reason for not registering to be able to receive PT panels via direct shipment from CDC. This provision is available for the 2023 Rota EQA round only. o Customs costs and clearance can be a major hurdle. Partnering with other programs like measles and polio to order kits/reagents and for cross-border specimen transport may facilitate customs processes and create program efficiencies. Consider having an intermediate consignee to then redistribute to other laboratories. Regions should support countries/labs in planning for or reimbursing customs clearance expenses incurred as part of participating in GRSN/GPDS. o Currently some labs participating in EQA do not provide data to GRSN. While we won’t drop these labs right now, we should encourage all labs participating in EQA to be associated with corresponding surveillance sites that submit data to GRSN. o Some countries would like to get certificates of participation for EQA. • Some regions/labs have restarted quality control (QC) efforts, but the network should try in 2024 to restart all QC, including potentially QC between the RRLs. Day 2, Session 8: Laboratory – GPDS Presenter: James Platts-Mills Composition of TAC card: There are 16 primary pathogens including rotavirus, norovirus, shigella, and salmonella on the GPDS TAC cards. There have not been changes to the TAC card since 2021. Automated post-run analysis (Shiny App): the network used a machine learning prediction model to automate post-run analysis to improve reproducibility, reduce time consumption, and address training needs associated with manual post-run analysis of results. The model performed very well when its ability to predict amplification of the cycle threshold using the GPDS data (internal validation) and MAL- ED data (external validation) was evaluated. Now, after the RRLs complete their TAC testing they upload their files onto an interactive web application based on the Shiny package (Shiny App). Correlation between rotavirus ELISA and qRT-PCR using GPDS 2017–2018 data from WHO African Region: The qPCR cycle threshold (Ct) cutoff value for good correspondence with ELISA results was 31.5 (sensitivity: 88%; specificity: 90%). Comparison between rotavirus typing at RRLs using qRT-PCR vs TAC cards using 2019 GPDS data from all regions: P-type agreement was 92% and G-type agreement was 81%. Session summaries 11 Discussion and action points • TAC layout: o Could consider adding the Rotavac and RotaSiil vaccine-type strains, though not getting many detections of the existing Rotarix and RotaTeq targets already on the TAC cards. • Rotavirus typing comparison between qRT-PCR vs TAC: o Regional laboratories are encouraged to share all genotyping results with HQ, integrate all existing genotype results into the surveillance dataset shared with HQ, so the genotyping data are centrally located for analysis and further comparisons. o The lower (81%) agreement for G-type may be driven by differences in the sensitivity of the typing methods. o Suggestions for future analyses: include additional data currently at RRLs but not in the WHO headquarters database in the analysis; use a lower cycle threshold value cutoff (e.g., <25) as part of the inclusion criteria to limit the potential impact of differences in the sensitivity of the typing methods; use Sanger sequencing as the gold standard to compare the typing methods based on a subset of the entire dataset or just the discordant results; combine G- and P-types because it is artificial to separate them; stratify results by WHO region. • GPDS data cannot be used for typhoid burden or vaccine impact monitoring because it is not designed to capture the appropriate clinical case definition for typhoid. Day 2, Session 9: Regional Reference Laboratory (RRL) Experiences with GRSN and GPDS Region of the Americas—U.S. CDC Presenter: Rashi Gautam U.S. CDC serves as the GRSN and GPDS RRL for Region of the Americas and the Global Reference Lab for GRSN. GRSN 2020–2022 testing is pending. For GPDS, testing of the 2020 and 2021 samples (except for Honduras in 2021) has been completed, but testing of the 2021 Honduras samples and the samples from all three countries in 2022 is pending. U.S. CDC is unable to upload TAC run files to the Shiny App because of a CDC firewall so these files have been shared with the University of Virginia (UVA) for them to upload. Genotyping by conventional RT-PCR and Sanger sequencing assays is pending for 2020 and 2021 samples. Norovirus and other enteric virus-positive samples will be transferred to Dr. Jan Vinje’s team for genotyping. All 10 Region of the Americas labs that participated in the 2022 ELISA or genotyping EQA program passed. Of the 14 total Region of the Americas labs, 13 are IRR registered and 10 of those registered have ordered 2023 RotaEQA PT panel. EQA WebTool resources (screenshots and videos) have been shared with RRLs. U.S. CDC identified a few challenges related to sample shipments: Samples from multiple years are shipped together in the same box and included on the same list or the number of samples sent in the box does not match with the list provided. Discussion and action points • Regional Office for the Americas should inform U.S. CDC if any QC testing results, TAC results, or genotyping comparisons are pending for samples collected before 2020. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 12 Western Pacific Region—Murdoch Children’s Research Institute (MCRI) Presenter: Sarah Thomas MCRI serves as a GRSN and GPDS regional reference laboratory for the Western Pacific Region, testing samples from Fiji, Lao People’s Democratic Republic, Philippines, and Viet Nam. All 2021 and 2022 GPDS samples (n=494) received at MCRI were tested and results were uploaded to the Shiny App. In 2023, MCRI received 314 samples collected during 2021–2023 for GRSN, and 254 of these sample were genotyped. The dominant genotype varied across years and countries/sites. MCRI noted several challenges and shared their strategies or suggestions for addressing them: (i) primer inaccuracies (G9 primer binds to G12 or both G3 equine-like and G9)—sequence all G9; (ii) vaccine and wildtype genotype differentiation—sequence all G1P[8]; (iii) unable to see samples previously uploaded to the Shiny App—would be helpful to view or download information generated by the Shiny App. Discussion and action points • Complete GPDS norovirus PCR testing and sequencing after receiving the list of norovirus- positive samples. • Follow up with U.S. CDC to obtain protocol for Rotarix vaccine-type strain detection. Western Pacific Region—China CDC Presenters: Dandi Li & Fengfeng Liu In 2022, eight sites from China reported rotavirus surveillance results to WHO. Rotavirus percent positivity was 16% and G9 (75%) and P[8] (38%) were the dominant strains. Overall, 31/32 rotavirus surveillance sites in China participated in the 2022 RotaEQA program, and the average ELISA and genotype score was 100%. Regarding quality control, the lab showed that ELISA testing performance improved from 2020 (97%) to 2022 (100%), but there is a need to improve genotyping performance (G- type: ~89%; P-type: ~ 91%). To improve testing capacity and performance, China CDC conducted online and in-person training and supervision visits to sites. China CDC developed the Group A Rotavirus Fluorescence Quantitative Typing Kit, which is now used for viral diarrheal surveillance nationwide, resulting in improved quality of rotavirus genotyping. Additionally, the lab translated the RotaEQA guidance document and Webtool instructions into Chinese. Western Pacific Region—Korea Disease Control and Prevention Agency (KDCA) Presenters: Deog-Yong Lee & Sun-Whan Park KDCA received and tested samples from Mongolia and Lao People’s Democratic Republic during 2017– 2019 as part of their GRSN RRL role, performing ELISA confirmation testing and genotyping. However, they did not receive samples from these countries or Cambodia during 2020–2023. KDCA still maintains technical capacity and testing platforms to support GRSN and GPDS testing and is ready and willing to provide this support if needed. Discussion and action points • Western Pacific Region will work with Lao People’s Democratic Republic to share referral samples with KDCA to resume RRL functions. • Western Pacific Region is working to revive rotavirus surveillance in Mongolia, but Cambodia has stopped surveillance. Session summaries 13 South-East Asia Region—Christian Medical College (CMC), Vellore Presenter: Tintu Varghese For GRSN, CMC Vellore has tested all 2020–2022 samples from India, Timor Leste, and Nepal that were received. For GPDS, only the three sites in India sent samples and CMC Vellore has tested the 2020 and 2021 samples; 2022 sample testing is in progress. Genotyping results were available from India (2020– 2022) and Nepal (2021). G3P[8] is the most common genotype detected in both countries. CMC Vellore conducted a virtual training on ELISA testing for the Nepal National Public Health Laboratory’s Surveillance Team (2021), a virtual workshop to strengthen data management and GPDS in Myanmar, Indonesia, and Nepal, and a laboratory training on surveillance protocol (2022), ELISA testing and genotyping for Bhutan (2023). CMC Vellore noted several challenges and provided suggestions for addressing them: (i) staff turnover at all levels is leading to a lack of communication and a need for training—contingency plans in the case of staff turnover would be helpful; (ii) confusion in the GRSN and GPDS case definitions—need to review surveillance protocols with sites & countries; (iii) confusion regarding sample shipments; (iv) reluctance for countries to share the data on the samples shipped; and (v) delays in procurement of kits/reagents results in delays in QC testing and TAC testing. Discussion and action points • Follow-up on 2022 EQA program results. • Complete quality control testing for Myanmar and Timor Leste once samples are received. • Procure funds for GPDS in India, which was previously funded as part of the vaccine impact evaluation. • Support other countries in South-East Asia Region, especially those that were previously in GRSN/GPDS (Indonesia, Myanmar, Nepal, and Bangladesh), to restart surveillance. If the countries are initiating/restarting surveillance, the GPDS expanded case definition should be used from the beginning to avoid challenges related to expanding the case definition, and sufficient training on data collection and lab testing with regular follow-up in the initial phase of surveillance should be provided. African Region—Noguchi Memorial Institute for Medical Research, University of Ghana Presenters: Francis Dennis & George Armah Noguchi serves as the GRSN and GPDS RRL for countries in West Africa and conducts genotyping for the Central African Republic. ELISA QC testing of samples collected in 2020 for GRSN is complete. However, the ELISA QC and genotyping were mostly incomplete for samples collected during 2021–2022 because they were only received in the laboratory in November 2023 and ELISA kits were not available at that time. The ELISA QC testing of the 2020 samples revealed that several of the site-level labs are underperforming and require refresher training. For GPDS, testing is complete for 2020 and results have been uploaded to the Shiny App. The testing of 2021 and 2022 samples is ongoing, and they anticipate completing this testing in the first quarter of 2024. Noguchi noted several challenges: lack of responsive communication with some site-level labs, insufficient sample volumes among received samples, delays in sample shipment, and underperformance of ELISA testing. Noguchi suggested that hands-on training and improved availability of ELISA kits at site-level labs will help address some of these challenges because staff turnover and delayed reception of ELISA kits are the underlying causes of these challenges. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 14 Discussion and action points • Complete quality control testing, genotyping, and TAC testing for 2021 and 2022 samples. • Timeliness of test results is critical to understand circulating pathogens, guide decisions on the vaccines, and advocate for resources. Thus, timely sample shipments are critical to the network. • Conduct a hands-on lab training workshop to address QC challenges and provide training. African Region—Sefako Makgatho Health Sciences University, Pretoria, South Africa Presenters: Kebareng Rakau and Mapaseka Seheri RRL-SA supports Eastern and Southern African countries. During 2020–2022, RRL-SA received samples (n=2,996) from nine countries. The 2021–2022 ELISA rotavirus-positive samples have been genotyped and results have been uploaded to the African Region REDCap database. Genotype distribution varied by country and year. Site-level labs performed well (>85% concordance) on ELISA QC, and RRL-SA scored >90% for ELISA and genotyping on the 2022 EQA proficiency test. For GPDS, TAC testing is complete for the 2021 samples and ongoing for the 2022 samples. The results of the completed TAC tests have been uploaded to the Shiny App. RRL-SA, in collaboration with the University of Free State Next Generation Sequencing Unit, also tests (conventional RT-PCR) and sequences other TAC-detected enteric viruses (i.e., adenovirus, astrovirus, norovirus, and sapovirus). RRL-SA identified timely sample shipment, surveillance disruptions, and data management as the challenges they faced. Discussion and action points • Follow up with Uganda to send the final shipment of the 2021 and 2022 samples and Zambia to sort out the line list by fixing patient IDs. • Complete genotyping and TAC testing for 2021 and 2022 samples. • Conduct a hands-on lab training workshop to address QC challenges and provide training to labs with suboptimal performance in the 2022 EQA. • Publish GPDS/GRSN data and support countries to publish their data. Region of the Americas—Oswaldo Cruz Foundation (FIOCRUZ), Brazil Presenter: Tulio Fumian RRL-FIOCRUZ supports Bolivia, Ecuador, and Peru. As part of GRSN in 2021, RRL-FIOCRUZ received, genotyped, and sequenced 68 rotavirus-positive samples collected during 2016-2019 from Ecuador, and found that G3P[8] was the dominant genotype during this period. Although Brazil is not part of GRSN, genotype results from Brazil collected during 2020–2022 showed a shift in the dominant genotype from G3P[8] to G6P[8]. For GPDS, the 2021 samples from Bolivia and Ecuador have been TAC tested and uploaded. Peru plans to send their 2021 GPDS samples in January 2024. The 2022 samples have not been received as of this meeting (December 2023). RRL-FIOCRUZ is also testing and genotyping other TAC-detected enteric viruses (adenovirus, astrovirus, norovirus, and sapovirus). Discussion and action points • Complete genotyping and TAC testing for 2021 and 2022 samples. Session summaries 15 • Improve communication between sentinel sites (Bolivia, Ecuador, and Peru) by conducting 1–2 remote meetings between AMRO (Region of the Americas), RRL-FIOCRUZ, and sentinel sites. • Expand QC as RRL-FIOCRUZ only receives samples from Ecuador. • Explore the potential for exchanging genotyping expertise between RRL-FIOCRUZ and site-level labs as the sites possess the capacity and equipment to conduct genotyping. Eastern Mediterranean Region—Aga Khan University (AKU), Pakistan Presenter: Furqan Kabir AKU supports GPDS for two sites in Pakistan. In 2023, AKU received 400 samples (200 samples from each of the two sites) that were collected in 2021 and 2022. These samples have been tested by TAC and results have been uploaded. Discussion and action points • Recommends the creation of an interactive dashboard to visualize TAC results previously uploaded. European Region—Minsk, Belarus Presenters: Elena Samoilovich & Galina Semeiko For GRSN, RRL-Minsk received 10,672 samples during 2008–2019 from 8 countries and genotyped 6,782 samples. Although the annual genotype distribution fluctuated, the dominant genotypes were G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8]. The number of GRSN countries sending samples decreased to four after 2019. For GPDS, the lab received and tested 1,400 samples from 5 countries during 2017–2019. The also sequenced 163 samples that had tested positive for norovirus via TAC from 2017-2019. Due to logistical reasons, RRL-Minsk is currently unable to participate in GPDS testing, so the team focused on TAC testing samples from children hospitalized in Minsk with acute diarrhea and hemolytic uremic syndrome. RRL-Minsk has maintained technical capacity and GRSN and GPDS equipment. They are ready to fulfill all previously assumed obligations once logistics improve. Discussion and action points • RRL-Minsk participated in the WHO measles, rubella, and polio EQA programs, with panels/reagents ordered via IRR; would also like to participate in GRSN/GPDS EQA. African Region—University of Free State, Next Generation Sequencing Unit (UFS-NGS), South Africa Presenter: Martin Nyaga UFS-NGS is a designated WHO Collaborating Center for VPD Surveillance and Pathogen Genomics serving as the sequencing laboratory for the African Enteric Viruses Genome Initiative and is affiliated with the Africa CDC. In this role, UFS-NGS provides whole genome-level data on rotavirus and other enteric viruses (adenovirus, astrovirus, norovirus, and sapovirus) in selected African countries including Cameroon, Ghana, Kenya, Malawi, Rwanda, South Africa, and Zambia to support vaccine impact, rotavirus evolution, selection pressure, and interspecies transmission studies. Other UFS-NGS initiatives include the production of metagenomics data for respiratory diseases and training and capacity development in bioinformatics. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 16 Day 2, Session 10: Additional Typing Activities Norovirus, adenovirus, astrovirus, sapovirus typing of archived GPDS specimens Presenter: Jan Vinjé (U.S. CDC) Norovirus: There are several norovirus vaccine candidates including two that are in Phase 2 clinical trials. To inform the development of vaccines and assess their impact and effectiveness post-implementation, it is important to estimate the baseline burden and describe circulating norovirus strains. During 2017– 2019, 894 norovirus sequences were generated from GPDS countries (lower income) and non-GPDS countries (higher income) through the global network for norovirus surveillance among children (NoroSurv). The top 5 norovirus strains were the same in GPDS and non-GPDS countries. The data can be visualized by region, country, year, and age group at norosurv.org. Other enteric viruses: In some contexts, including the US, adenovirus, astrovirus, and sapovirus are important causes of acute gastroenteritis. Genotype data for these viruses will help understand the baseline burden of these viruses among children aged <5 years hospitalized with acute gastroenteritis and can be used to inform mRNA-based pan-viral gastroenteritis vaccine development. A retest of norovirus GII positive nucleic acid from TAC-tested GPDS samples after 5 years of storage at -70˚C revealed that nucleic acid was preserved. Based on the results, the GPDS archived nucleic acid samples positive for these pathogens were genotyped. Using data from CMC-Vellore, genotyping was successful for 90% and 97% of the adenovirus-positive and astrovirus-positive samples, respectively, but only 29% of sapovirus-positive samples were successfully genotyped. These patterns were similar for the African Region samples although successful genotyping for adenovirus-positive and astrovirus-positive samples from the eastern and southern Africa subregion was lower (70-78%), which may be due to lower viral load. CDC-Atlanta has redesigned the sapovirus assay to improve genotyping detection and the protocol has been shared with the RRLs. Discussion and action points • Complete norovirus, adenovirus, astrovirus, sapovirus typing for 2017-2019 samples. • Make plans for typing of 2020-2024 samples • Jan to send complete typing data back to Seb, to combine into one central database and we can incorporate into GPDS country reports. Jan could also send the link to the Norosurv portal so countries can visualize their own data. Molecular epidemiology and characteristic of Shigellosis in the Global Pediatric Diarrhea Surveillance Network, 2019-2022 Presenter: James Platts-Mills Among the four Shigella species, Shigella flexneri and Shigella sonnei are the most common causes of endemic Shigellosis. However, data on the distribution of serotypes, especially from diverse geographical settings, are limited. GPDS can be leveraged to provide additional serotype data to support vaccine development and efficacy studies. In 2019, new assays were designed and included on the TAC card to help identify S. flexneri and S. sonnei serotypes. In the available data, there were 785 children hospitalized with acute gastroenteritis who had a shigella primary assay with Ct <30 (this cutoff allows for greater sensitivity). Most of these children were aged 1–5 years (74%) and reported vomiting (73%) Session summaries 17 and dehydration (84%). Overall, 21% had bloody diarrhea, which was higher than the overall GPDS population (~4%). At least one serotype was identified in 63% of the samples. S. sonnei, and S. flexneri 2a, S. flexneri 3a, and S. flexneri 6 serotypes accounted for 78% of the serotypes identified, which are the 4 serotypes included in the shigella quadrivalent vaccine under development. The distribution of the serotypes varied by region, but the quadrivalent vaccine has good coverage of the serotypes identified across the regions. S. flexneri was associated with more bloody diarrhea, while S. sonnei was associated with more vomiting/dehydration. Discussion and action points • Explore the distribution of S. flexneri by HIV status or seroprevalence. Day 3, Session 11: Analytic updates Recent GRSN/GPDS publications Key findings and highlights from seven manuscripts using GRSN or GPDS data published since the 2019 GRSN/GPDS meeting in Rio de Janeiro, Brazil were presented. The network has generated significant data and shared insights on the etiology of pediatric diarrhea globally. • Antoni et al. Rotavirus genotypes in children under five years hospitalized with diarrhea in low and middle-income countries: Results from the WHO-coordinated Global Rotavirus Surveillance Network. PLOS Glob Public Health. 2023 Nov 28;3(11):e0001358. • Clark et al. Estimating the global impact of rotavirus vaccines on child mortality. Int J Infect Dis. 2023 Oct 18:137:90-97. • Kraay et al. Predicting the long-term impact of rotavirus vaccination in 112 countries from 2006 to 2034: A transmission modeling analysis. Vaccine. 2022; 40(46):6631-6639. • Cohen et al. Aetiology and incidence of diarrhoea requiring hospitalization in children under 5 years of age in 28 low- and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network. BMJ Glob Health. 2022;7:e009548. • Hartman et al. Risk factors for mortality among children under 5 years of age with severe diarrhea in low- and middle-income countries: Findings from the WHO-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks. Clin Infect Dis. 2022;ciac561. • Peck et al. Global Rotavirus and Pneumococcal Conjugate Vaccine Introductions and the Association With Country Disease Surveillance, 2006–2018. J Infect Dis. 2021; 224(Supplement_3):S184–S193. • Murray et al. Multicountry Analysis of Spectrum of Clinical Manifestations of Children <5 Years of Age Hospitalized with Diarrhea. Emerg Infect Dis. 2019; 25(12):2253-2256. Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 18 Etiology of diarrheal hospitalizations following rotavirus vaccine implementation and association of enteric pathogens with malnutrition among under-five children in India Presenter: Tintu Varghese As a creative use of extra GPDS TAC cards, samples from 482 children with and without malnutrition were tested from 3 GPDS sites in India from 2019. This was also the first country-level GPDS analysis. Overall, adenovirus 40/41 was the leading etiology detected (attributable fraction [AF] 16.9%), followed by rotavirus (AF 12.6%), Shigella (AF 10.9%), sapovirus (AF 4.7%), norovirus (AF 4.1%), and astrovirus (AF 3.4%). Among infants, adenovirus 40/41 and rotavirus were the most common pathogens. Shigella accounted for nearly 47% of diarrhea in children above age 2 years. Acutely malnourished children were more likely to develop severe diarrhea. Attribution of diarrhea to specific etiologies was not significantly associated with either acute or chronic malnutrition. Strategies to improve the performance of rotavirus vaccines are needed, as are interventions addressing malnutrition, adenovirus 40/41 and Shigella. Discussion • Given the bidirectional relationship between malnutrition and diarrheal infection, it’s hard to assess causality. This analysis is cross-sectional, but ideally a cohort could better explore this. • There was some variability across the GPDS sites in India in terms of income, education, etc. Changes in Age Distribution of Children Hospitalized with Acute Gastroenteritis Testing Positive for Rotavirus Before and After Rotavirus Vaccine Introduction, 2008–2022 Presenter: Oumar Diallo (U.S. CDC) This analysis aimed to describe the impact of rotavirus vaccines on the age distribution of children (<5 years) hospitalized with AGE before and after rotavirus vaccine introduction using GRSN data (2008– 2022) stratified by WHO region and under-5 mortality rate quintiles. Additionally, the annual trend in age distribution by test results (positive vs. negative) was described, as was the residual rotavirus burden by age in countries with rotavirus vaccine. Overall, nearly half of rotavirus-positive hospital admissions occurred among children aged ≥12 months. The proportion of children aged 24-59 months was ≥15% in most years, and varied by WHO region. The median age at hospitalization of rotavirus- positive cases increased by 2 months from the pre-vaccination period to the post-vaccination period. This shift in age distribution towards older children highlights the importance of catch-up vaccination for missed doses and the need to consider alternative vaccination schedules. Discussion and action points • The age shifts were smaller than expected. • Consider categorizing the findings according to rotavirus vaccine coverage level (ex. <60, 60-90, >90%) • Should rotavirus catch-up vaccination policy be extended to a higher catch-up age range? Would need to look at the burden/severity of rotavirus in children aged >24 months (mortality, duration of hospitalization, etc.) • If we had better vaccination history data, it would have been valuable to incorporate vaccination status and impartial vaccination in this analysis. Can cite this as a limitation. Session summaries 19 Mortality attribution modeling Presenter: Jackie Tate The last published WHO/CDC estimates of rotavirus mortality in children aged <5 years were published in 2016 and included data from GRSN and published studies from 2000-2013. WHO/CDC plan to update these estimates using the same approach – estimating the proportion of severe diarrhea due to rotavirus in each country and multiplying this by the number of diarrheal deaths. Literature review currently underway, with aim to complete data abstraction and analysis by December 2024. Estimates would then be sent for country review in early 2025. Other planned GRSN/GPDS analyses & outputs Presenter: Heidi Soeters • Planned outputs for 2024: o GRSN ▪ Bulletins (1-2/year) ▪ Rotavirus age distribution analysis ▪ Updated rotavirus mortality attribution models ▪ Updated rotavirus vaccine impact analysis ▪ Rotavirus EQA / PT panel manuscript ▪ Updated rotavirus lab manual o GPDS ▪ Bulletins (1-2/year) ▪ GPDS country reports (updated as each year finalized) ▪ 2019-2020 main analysis ▪ 2021-2022 main analysis ▪ Rotavirus genotyping – TAC vs PCR ▪ Norovirus genotyping ▪ Astro/sapo/adeno typing ▪ 2019-2020 shigella typing ▪ Mixed infections • Planned feedback of GPDS data to GPDS collaborators o To countries and surveillance sites: ▪ Country reports ▪ Share data with immunization programs and National Immunization Technical Advisory Groups – use data for vaccine advocacy ▪ Nice example from Fiji: CME sessions to give hospital staff updates/feedback on GPDS o To RRLs: ▪ Access to automatic post-run analysis portal ▪ Can share back cleaned TAC dataset o To WHO Regional Offices: ▪ Country GPDS reports, with regional comparison data ▪ Regional GPDS reports ▪ Final clean TAC data linked with surveillance data o To the global community: ▪ GRSN/GPDS bulletins – 2x/year Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 20 ▪ Seb has final clean dataset – any collaborators can request • GPDS data availability to external partners: o GPDS data feeds into global burden estimates – Institute for Health Metrics (IHME), Maternal and Child Epidemiology Estimation (MCEE) ▪ Need to set up regular data sharing agreements, and share data annually in alignment with IHME & MCEE timelines o GRSN/GPDS bulletins – 2x/year o Will plan to make all manuscripts available as pre-prints o Will consider putting GRSN/GPDS data on WHO website Discussion and action points • If collaborators from Regions, Countries, or RRLs are planning GRSN or GPDS analysis or would like to get involved in any of the described analysis, please let WHO headquarters team know. • Could consider organizing a journal supplement Additional proposed GPDS analyses Presenter: James Platts-Mills Global diarrheal death estimates use hospitalized diarrhea as a proxy (IHME, MCEE, GPDS), however the pathogens associated with mortality may differ according to whether a child had access to medical care or not. Additionally, access to care is improving but is still highly variable geographically. Therefore, a proposed revised approach to estimating diarrheal deaths using GPDS was presented, incorporating data on health care access. Another proposed use of GPDS data is The Planetary Child Health & Enterics Observatory (Plan-EO), a project led by the University of Virginia which aims to measure the impact of climate change on the etiology of diarrhea. Incorporating published GPDS data into these estimates would greatly improve the geographic diversity of the data used in the models. Additionally, prospective GPDS data could be used to validate these predictions, taking advantage of the breadth and longitudinal nature of the GPDS data. Discussion and action points • Consider accounting for how early after symptom onset children present to care. For rotavirus, mortality tends to happen on the day of presentation or next day. Sometimes, if children arrive severely sick, it is harder to approach and enroll them in surveillance and to get a specimen. • Need to be careful about minimizing the impact of rotavirus on mortality, as this could inadvertently lead to less emphasis on rotavirus vaccination. • If climate shifts the etiologies of diarrhea, this knowledge will help us prioritize interventions Day 3, Session 12: GPDS Coordination Presenter: Heidi Soeters As the GPDS network gets caught up from COVID-19 impact, it would be ideal to get on a regular annual cycle for GPDS testing and results reporting. This would help the network better plan sample shipment and testing cycles, and improve data timeliness. Therefore, a draft GPDS annual cycle was presented for feedback. Session summaries 21 Discussion and action points • There was broad agreement that an ideal annual cycle is necessary to ensure timelines of GPDS results. Even if this timeline is ideal, and we know realities often more challenging, we should still collectively decide to do our best to maintain the timeline. • Suggestions were made to lengthen the lab testing timelines, and to incorporate the rotavirus surveillance steps into the GPDS annual cycle to better show how the surveillance is integrated. • A revised cycle based on this feedback will be circulated with the meeting report. • Ideally, we would finalize the data each year in time to analyze and then share at the annual rota/GPDS meeting. • The overall GPDS network is only as fast as the slowest site or lab. Preliminary analyses and reports can be produced, but the final results can only be produced and disseminated once the last samples from each surveillance year are received, tested, uploaded, and linked. • Some regions may need to adapt this annual cycle to be more specific for this timeline, but we all should aspire to the same end goal and see what we can do to reduce unnecessary delays at each step. Day 3, Session 13: Future directions for Rotavirus and Pediatric Diarrhea Surveillance Discussion topics and action points Rotavirus test kits • Labs running of rotavirus test kits has been a major challenge and source of delay. How can we better anticipate and address rotavirus test kit needs? WHO procurement system can be challenge, so much advance planning is needed. • Western Pacific Region orders kits every 3 months and distributes them, with regular assessment of country needs. Western Pacific Region also keeps a stockpile of kits and distributes them as needed, then donates the kits to Philippines if they are close to expiry. • African Region could consider ordering kits more regularly to address the long shipping times, large orders, and expiry dates. • We need to diversify kit products, so we are not over-reliant on one manufacturer. • WHO headquarters will keep a small stock of kits on Geneva, to help address stockouts. Can we test all fatal cases via TAC? • There are challenges with making sure all deaths are documented, and challenges with assuming the death was due to the diarrheal illness. There are also logistic challenges associated with shipping samples from fatal cases not randomly selected, and documenting this in the surveillance dataset. Therefore, we have decided not to pursue this idea. If later, we decide to test these cases as a block (instead of including in the regular GPDS cycle), that is still an option as the RNA should be stable. What other GRSN/GPDS analyses are needed? • Could do an in-depth analysis of mixed infections or multiple etiologies within GPDS. • Regional analyses/manuscripts would be of value, and could include more country-level data. Could also look at pre/post vaccine introduction at the country level. • Could consider a journal supplement Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 22 • Could look at the trends and prevalence of antimicrobial resistance genes over 6 years, as well as ETEC colonization factors • Could model seasonality. Look at severity among hospitalized children using a Vesikari-type score. How can GPDS better build capacity at the regional or country level? • We should produce regional-level GPDS reports in addition to the country reports • Need to build capacity in countries that have high staff turn-over, in order to ensure staff know the surveillance protocols, case definitions, enrollment criteria, case investigation. (note: European Region does not have capacity to do refresher trainings, and looks to WHO HQ and partners to assist). • Need guidance for countries who want to conduct pediatric diarrheal surveillance but are not part of the GPDS network. These countries could self-finance, but need guidance and assistance. o There is a brief section in the rotavirus surveillance standards on expanded surveillance for other enteric pathogens, and a proposed chapter in the lab manual update may help provide additional guidance to countries. o We need to alert countries to these resources, to increase awareness of standards of surveillance. • Regional and country colleagues would like to better understand how GPDS data are analyzed, how to interpret attributable fractions, and how to use the data in a meaningful way, especially at the program level. • Regional capacity building for the RRLs would be valuable, especially on the technology behind TAC. Session summaries 23 Based on this meeting, some priorities that have emerged for 2024 are: GRSN • Complete & disseminate planned publications & outputs • Continue to encourage ELISA testing and genotyping, & incorporating into surveillance databases • Increase participation of GRSN labs in EQA & QC, and implement remediation measures • Reconvene GRSN/GPDS lab working group • Trainings for lab staff & surveillance staff • Update lab assessment tools • GRSN data on WHO website or data portal • Arrange team visits to RRLs • Work on ELISA kit procurement (supply, price, multiple manufacturers, etc.) • Work with Eastern Mediterranean Region, European Region, South-East Asia Region to improve data flow GPDS • Get back on schedule with GPDS timeline • Support regions, countries, sites with GPDS data interpretation • Complete & disseminate planned publications & outputs (supplement?) • Add sites in South-East Asia Region & Eastern Mediterranean Region • Explore making a final etiologic determination at the individual level • Make plans for data sharing, including data sharing agreements & data access • GPDS data on WHO website or data portal • Disseminate additional typing data (via country reports, or online dashboard?) • Add dashboard to Shiny App to see status/results of post-run analysis 24 Agenda Monday, 11 December 2023 Chair: Jackie Tate Rapporteur: Jaymin Patel 8h30-9h00 Registration 9h00-9h30 1. Welcome and introduction and objectives of the meeting • Opening remarks • Welcoming remarks • Self-introduction of participants • Nomination of chairs • Administrative announcement • Introduction and objectives of meeting WHO HQ DDC Western Pacific Region All WHO HQ Western Pacific Region Chair 9h30-11h00 2. Global Rotavirus and Pediatric Diarrhea Surveillance Update • Background, Methods, Network status/updates • Updated GRSN results • Updated GPDS results • Future directions for Rotavirus and Pediatric Diarrhea Surveillance • Discussion Heidi Soeters (2.1) James Platts-Mills (2.2) Heidi Soeters (2.3) All 11h00-11h30 Coffee/tea break (and group photo) 11h30-11h35 3. GRSN/GPDS: context & importance BMGF 11h35-13h00 4. Western Pacific Region & country experience • Western Pacific Region (15 min) • China (10 min) • Fiji (10 min) • Lao People’s Democratic Republic (10 min) • Philippines (10 min) • Viet Nam (10 min) • Discussion Western Pacific Region (4.1) China (4.2) Fiji (4.3) Lao People’s Democratic Republic (4.4) Philippines (4.5) Viet Nam (4.6) All 13h00-14h00 Lunch break 14h00-15h30 5. Regional experience with GRSN/GPDS • South-East Asia Region (10 min) • Region of the Americas (10 min) • African Region (20 min) • Eastern Mediterranean Region (10 min) • European Region (10 min) • Discussion South-East Asia Region (5.1) Region of the Americas (5.2) African Region (5.3) Eastern Mediterranean Region (5.4) European Region (5.5) All 15h30-16h00 Coffee/tea break 16h00-17h00 6. Data management and quality • Current status & challenges • Proposed solutions • Discussion Sébastien Antoni (6.1) All 17h00-17h15 Discussion and Day 1 wrap-up All Agenda 25 Tuesday, 12 December 2023 Chair: Rashi Gautam Rapporteur: Oumar Diallo 9h00-10h30 7. Laboratory - Rotavirus • Laboratory network update • Future of the Rotavirus EQA program • Rotavirus EQA program (2022): results and remediation • Rotavirus test kits – procurement updates • Rotavirus lab manual • Rotavirus genotyping and lab assessment • Rotavirus EQA 2023: Updates and data reporting • IRR updates (EQA, reagent supply, other) • Discussion Mick Mulders (7.1) Shilpa Iyer (7.1) Rashi Gautam (7.2) 10h30-11h00 Coffee/tea break 11h00-12h00 8. Laboratory - GPDS • Composition of GPDS TAC card layout • New automated post-run analysis • Comparison of TAC manual vs automated post-run analysis • Rotavirus TAC genotyping validation • Rotavirus ELISA compared with Rotavirus TAC • Discussion James Platts-Mills (8.1) 12h00-13h00 Lunch break 13h00-15h15 9. GRSN/GPDS RRLs • U.S. CDC (10 min) • MCRI (10 min) • China CDC (10 min) • Korea Diseases Control and Prevention Agency (10 min) • CMC Vellore (10 min) • Ghana - Noguchi (10 min) • South Africa - Sefako Makgatho HSU (10 min) • Brazil - Fiocruz (10 min) • Aga Khan University (10 min) • Minsk (10 min) • University of the Free State (10 min) • Discussion U.S. CDC (9.1) MCRI (9.2) China CDC (9.3) Korea DCA (9.4) CMC Vellore (9.5) Ghana (9.6) South Africa (9.7) Brazil – Fiocruz (9.8) AKU (9.9) Minsk (9.10) UFS (9.11) All 15h15-15h45 Coffee/tea break 15h45-16h45 10. Additional typing activities • Norovirus genotyping by TAC and sequencing • Astro/sapo/adeno typing • Shigella typing • Discussion Jan Vinjé (10.1) James Platts-Mills (10.2) 16h45-17h00 Discussion and Day 2 wrap-up All Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 26 Wednesday, 13 December 2023 Chair: Carl Kirkwood Rapporteur: Sara Mirza 9h00-10h30 11. Analytic updates • Recent GRSN/GPDS publications • Etiology of diarrheal hospitalizations and association with malnutrition among under-five children in India • Rotavirus age distribution • Mortality attribution modeling • Improving diarrhea mortality estimates • Analyses on climate & diarrheal diseases • Other planned analyses & outputs • Discussion Heidi Soeters (11.1) Tintu Varghese (11.2) Oumar Diallo (11.3) Jackie Tate (11.4) James Platts-Mills (11.5) Heidi Soeters (11.6) All 10h30-11h00 Coffee/tea break 11h00-12h00 12. GPDS coordination • GPDS annual cycle, and roles & responsibilities • GPDS protocol • Discussion Heidi Soeters (12.1) All 12h00-13h00 Lunch break 13h00-14h15 13. Future directions for Rotavirus and Pediatric Diarrhea Surveillance • Discussion questions • Discussion Heidi Soeters (13.1) All 14h15-14h30 GRSN/GPDS meeting closure Heidi Soeters 14h30-15h00 Coffee/tea break 15h00-17h00 WHO Closed Session *virtual attendee 27 List of participants Country Rotavirus/GPDS Surveillance *Carren Bocaling National Reference Laboratory for Rotavirus and Other Enteric Viruses Manila, Philippines Joseph Bonifacio National Reference Laboratory for Rotavirus and Other Enteric Viruses Manila, Philippines Eunice P. Guzman Epidemiology Bureau Department of Health Manila, Philippines *Ma. Regina de Jesus Valdez Disease Control and Prevention Bureau Department of Health Manila, Philippines Reema Kumar National Public Health Laboratory Suva, Fiji Nguyen Thi Loan National Expanded Immunization Program Hanoi, Viet Nam *Sysamay Souksavanh National Center for Maternal and Child Health Vientiane, Lao People’s Democratic Republic Luyu Yu National Disease Control and Prevention Administration Beijing, China Rotavirus/GPDS Regional Reference Labs George Armah Noguchi Memorial Institute for Medical Research College of Health Sciences, University of Ghana Accra, Ghana Francis Dennis Noguchi Memorial Institute for Medical Research College of Health Sciences, University of Ghana Accra, Ghana Tulio Fumian Oswaldo Cruz Foundation Ministry of Health Rio de Janeiro, Brazil Irene Trigueiros de Araujo Maciel Oswaldo Cruz Foundation Ministry of Health Rio de Janeiro, Brazil *Furqan Kabir Aga Khan University Karachi, Pakistan Deog-Yong Lee Korea Diseases Control and Prevention Agency Seoul, Republic of Korea Sun-Whan Park Korea Diseases Control and Prevention Agency Seoul, Republic of Korea *Dandi Li Chinese Center for Disease Control and Prevention Beijing, China Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 *virtual attendee 28 *Fengfeng Liu Chinese Center for Disease Control and Prevention Beijing, China Martin Nyaga University of the Free State and WHO Collaborating Centre for Vaccine Preventable Diseases Surveillance and Pathogen Genomics Bloemfontein, South Africa Elena Samoilovich Laboratory of Vaccine-Preventable Diseases Republican Research and Practical Center for Epidemiology and Microbiology Minsk, Belarus Galina Semeiko Laboratory of Vaccine-Preventable Diseases Republican Research and Practical Center for Epidemiology and Microbiology Minsk, Belarus Mapaseka Seheri Sefako Makgatho Health Sciences University Pretoria, South Africa Kebareng Rakau-Nondela Sefako Makgatho Health Sciences University Pretoria, South Africa Sarah Thomas Murdoch Children’s Research Institute The Royal Children’s Hospital Melbourne, Australia Tintu Varghese Christian Medical College Vellore, India Partners Carl Kirkwood Bill & Melinda Gates Foundation Seattle, WA, United States of America (USA) Oumar Diallo Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA Rashi Gautam Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA Sara Mirza Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA *Umesh Parashar Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA Jaymin Patel Global Immunization Division Centers for Disease Control and Prevention Atlanta, GA, USA Jacqueline Tate Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA Jan Vinjé Division of Viral Diseases Centers for Disease Control and Prevention Atlanta, GA, USA List of Participants *virtual attendee 29 Emily Goldfarb CDC Foundation Atlanta, GA, USA James Platts-Mills Division of Infectious Diseases and International Health University of Virginia Health System Charlottesville, VA, USA *Jie Liu University of Virginia & Qingdao University Charlottesville, VA, USA / Qingdao, China WHO Country Office Darwin Operario WHO Country Office - Fiji Suva, Fiji Achyut Shrestha WHO Country Office - Philippines Manila, Philippines WHO Regional Office Jason Mwenda WHO Regional Office for Africa Brazzaville, Congo Joseph Biey WHO Regional Office for Africa Ouagadougou, Burkina Faso Keith Shaba WHO Regional Office for Africa Brazzaville, Congo Goitom Weldegebriel WHO Regional Office for Africa Harare, Zimbabwe Archibald Worwui WHO Regional Office for Africa Brazzaville, Congo Deepak Dhongde WHO Regional Office for South-East Asia Delhi, India Lucky Sangal WHO Regional Office for South-East Asia Delhi, India Emmanuel N. Tondo WHO Regional Office for South-East Asia Delhi, India Kamal Fahmy WHO Regional Office for the Eastern Mediterranean Cairo, Egypt Varja Grabovac WHO Regional Office for the Western Pacific Manila, Philippines Josephine Logronio WHO Regional Office for the Western Pacific Manila, Philippines Hardeep Sandhu WHO Regional Office for the Western Pacific Manila, Philippines Claudia Ortiz Pan American Health Organization WHO Regional Office for the Americas Washington DC, United States of America Global rotavirus and pediatric diarrhea surveillance: meeting report, 11-13 December 2023 *virtual attendee 30 Gloria Rey-Benito Pan American Health Organization WHO Regional Office for the Americas Washington DC, United States of America Roberta Pastore WHO Regional Office for Europe Copenhagen, Denmark Simarjit Singh WHO Regional Office for Europe Copenhagen, Denmark Dovile Videbaek WHO Regional Office for Europe Copenhagen, Denmark WHO headquarters, Geneva Sébastien Antoni *Anindya Bose Melanie Bouveret Shilpa Iyer Mick Mulders Heidi Soeters Department of Immunization, Vaccines and Biologicals World Health Organization 20, Avenue Appia 1211 Geneva 27 Switzerland Email: vpdata@who.int Website: https://immunizationdata.who.int