Report of the CSA advisory group on onchocerciasis elimination

African Programme for Onchocerciasis Control (APOC) Programme africain de lutte contre I'onchocercose JAF-FACNT ACTION FORUM fice of the Chairman JOINT ACTION FORUM Seventeenth session Kuwait Citv. Kuwait. 12-14 December 2011 FORUM D'ACTION COMMUNE Bureau du Pr6sident JAFl7.7 (ii) ORIGINAL: ENGLISH October 2011 REPORT OF THE CSA ADVISORY GROUP ON ONCHOCERCIASIS ELIMINATTON t Rsponr oF rHE CSA AnvrsoRY Gnoup oru ONCHocERCrAsrs EUMTNATToN t ,L4 October 2011 Summary The Advisory Group on Elimination has undertaken a detailed analysis of ivermectin treatment history and progress towards elimination in APOC projects. The results were used in a model to predict for each project when ivermectin treatment can be safely stopped. Based on this analysis, the advisory group arrived at the following conclusions and recommendations. Extensive epidemiological evaluation data show good progress towards elimination in advanced APOC projects. ln 60% of these projects the prevalence of infection is already close to zero. Some projects within some countries will be able to stop treatment by 2015, but no APOC country will be ready to achieve national elimination by 2015. lf APOC is prolonged lo 2O2O, 12 APOC countries may achieve national elimination protecting more than 50 million people. Accordingly, the committee recommends extension of APOC from 2015 to 2020. Five APOC countries will not achieve elimination by 2020 because of loiasis, or because of problems with treatment coverage in post-conflict areas with high onchocerciasis endemicity levels and insufficient managerial capacity. These countries should be supported with strengthening CDT|, prevention of cross border transmission, and evaluation of the long term impact of treatment. lf the ex-OCP countries are also considered, preliminary estimates indicate that another 11 countries may reach national elimination by 2020. Most ex-OCP countries are close to elimination and the main support they require is support for evaluations and decision-making on when and where to stop treatment, Hence, which adequate support, a total of 23 African countries may achieve national onchocerciasis elimination by 2020. Among the main challenges are problems with treatment coverage in some projects where coverage has been lower than reported. lndependent monitoring should be introduced to confirm coverage on a regular basis for more accurate projections. ln order to cover all areas where there is local transmission, the total target population for treatment may need to be extended by 5-2O%. ln these extension areas, endemicity levels are low and interruption of transmission will be relatively easy to achieve. Further surveys are urgently needed to establish exact treatment boundaries. Twice per year treatment and intensified efforts to improve compliance might be indicated in areas with very high pre-control endemicity levels, or in projects that began treatment late or had low treatment coverage. Cross-border foci and long-distance vector migration require close coordination of treatment and evaluation activities between countries. Research priorities include exploring alternative interventions for areas with low onchocerciasis endemicity that are co-endemic with Loa loa, and evaluating the use of new diagnostics. The required steps towards certifying and maintaining elimination status have been defined by the Committee. The WHO guidelines for national certification of onchocerciasis elimination need to be updated. ln areas where onchocerciasis and lymphatic filariasis are co-endemic, close collaboration is required between the two elimination programs because both programs require post treatment surveillance, and neither program can come to conclusion if the other program is continuing ivermectin treatment in the same area. ln most APOC countries, LF treatment coverage is low but if the LF program was to scale up, most untreated onchocerciasis areas would be covered by the LF programme. L Report The advisory group on elimination has undertaken a detailed review of available information on ivermectin treatment and progress towards elimination in APOC projects, and has used this information in a model-based analysis to predict when ivermectin treatment can be safely stopped in each project area (see Annex 1). Based on the results of this review and analysis, the advisory group arrived at the following conclusions and recommendations. Progress and timeline towards elimination o APOC has evaluated progress towards elimination in 27 APOC projects that have had 8 or more years of ivermectin treatment. The results showed good progress towards elimination in 23 projects while the prevalence of infection was already close to zero in 15 projects. o Some foci within some countries will be able to stop treatment by 2015 (Figure 1), but APOC funding for elimination will not be enough to do full post treatment surveillance in these foci. o No country will be ready to achieve national elimination by 2015. Figure 1: Predicted End Year of Treatment for APOC Proiects Legend to Figure 1: The end year of treatment was predicted for each APOC project using the simulation model ONCHOSIM, taking into account the precontrol endemicity level in the project area and the reported coverage and duration of ivermectin treatment in the project. lf APOC is prolonged to 2020, 12 APOC countries (Angola, Burundi, Cameroon, Chad, Congo Brazzaville, Ethiopia, Malawi, Mozambique, Nigeria, Sudan, Tanzania, and Uganda) may achieve elimination protecting more than 60 million people (Table L). As stated above, this is compared to having no country ready to achieve this goal if APOC were to close in 2015. 2 ll il (\D s { kedicted End Yar ol TEatmnt I 2005 - 2015 2016 - 2020 ,-::- 2021 - 2025 -20x-20pslntensifed Rx o t l' i-'. t a I , t I c aTable 1: Projected elimination status of APOC countries by 2015 and 2020 Accordingly, the committee recommends extension of APOC from 2015 to 2O2O to achieve elimination in these 12 countries. The Democratic Republic of Congo, the Central African Republic, Equatorial Guinea (mainland), Gabon and South Sudan will not achieve elimination by 2020. ln Equatorial Guinea and Gabon, onchocerciasis endemicity levels are low while loiasis is hyperendemic, and this combination precludes the use of CDT| in these two countries. The Democratic Republic of Congo, the Central African Republic and South Sudan are post conflict countries with high endemicity levels of onchocerciasis and/or Loo loa, insufficient managerial capacity and having had poor treatment coverage. Because of these challenges, national elimination will not be possible by 2020 even though local elimination may be achieved in some areas The advisory group recommends continued strong APOC support for these countries through 2015 which should be covered under the current APOC approved budget. After 2015, continued APOC support is required to assist with the establishment of sustainable CDTi for the control of onchocerciasis as a public health problem, to prevent cross border transmission, and to evaluate the long term impact on onchocerciasis infection and transmission in these countries. a 3 Angola Burundi Cameroon Chad Congo Ethiopia Malawi Mozambique Nigeria Sudan Tanzania Uganda Subtotal 950,345 1,406,983 6,473,620 r,877,774 759,799 7,644,144 7,979,306 0 33,283,450 4M,655 2,207,L32 3,248,975 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No No No No No No No No No No No No 60,267,984 Central African Republic Democratic Republic of Congo Eq. Guinea Gabon South Sudan Subtotal 1,4o8,824 27,737,104 80,206 0 5,605,726 N N N N N No No No No No o o o 34,23L,85O Population of CDT| projects National Elimination by the year 2015 2020 Country i aFigure 2: National Onchocerciasis Elimination in APOC and OCP Countries Predictions for 2015 and 2020 20L5 2020 The list of countries where onchocerciasis could be eliminated by 2020 will be much longer than given above when the ex-OCP countries are also considered. ln early 2012, the working group will collate and analyze data from ex-OCP countries and Liberia in order to prepare plans, timelines and budget for elimination in this West African bloc. ln the mean time, a provisional classification with respect to national elimination by 2015 and 2020 has been provided by experts who are familiar with onchocerciasis control in these countries. This provisional classification is shown in table 2 and the West African part of the maps in figure 2. Most ex-OCP countries are close to elimination and the main support they require is support with evaluations and decision-making on when and where to stop treatment. Table 2: Provisional projection of elimination status of OCP countries and Liberia by 2015 and 2020 o o lto tr l3flJr.** I gf,#'*yGr*ri.rd I lr"fs';:s*i.l; Benin Burkina Faso Cote d'lvoire Ghana Guinea Guinea Bissau Liberia Mali Niger Senegal Sierra Leone Togo Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes No No No No No Yes No No Yes No No No National Elimination by the year 2015 2020 Country J 4 t tuoE\ rc E )Iic lr -\J lrio f@ rrtt {w aChallenges i) Treatment coverqge o Elimination projections in Figure 1 are based on reported treatment coverage data, but studies have shown that these reported data may be inaccurate in some areas. Treatment coverage has been low in some projects due to poor project management, low compliance due to fear of adverse events in onchocerciasis and loiasis co-endemic areas, and lack of skilled personnel. lndependent monitoring should be performed to confirm coverage on a regular basis for more accurate projections. a From the point of view of transmission elimination, treatment may require extension to cover all areas where there is local transmission (the so called 'transmission zones'). The committee reviewed all the current treatment boundaries in APOC countries and estimates that current treatment areas may need extension by 4-L5% (or by 5-2O% in terms of target population; see Annex 1). These additional areas are in general areas with low endemicity levels where interruption of transmission will be relatively easy to achieve. Further epidemiological and entomological surveys in those areas, including the use of new diagnostic techniques, are required to establish exact treatment boundaries. i i) I ntensifi e d tre otment o Duration of treatment to reach an elimination goal will be longest in those areas having the highest pre-control endemicity levels. Twice a year (six-monthly)treatments with ivermectin should be considered in such transmission zones to shorten the period to elimination. Twice per year treatment and intensified efforts to improve treatment compliance might also be indicated in areas that began treatment late, or that had low treatment coverage, to bring progress towards elimination in those areas in 'phase' with the surrounding areas. Several of those zones have been identified by the sub committee, such as Central Province in Cameroon, Benue State in Nigeria, Ruvuma project in Tanzania and Kitgum/Pader in Northern Uganda (seq "intensified treatment" in figure 1). Other areas are likely to be determined by new epidemiological and entomological surveys. iii) Co-endemicity onchocerciasis and loiasis o ln onchocerciasis meso to hyper-endemic areas where the disease is co-endemic with loo loo, the current guidelines for ivermectin treatment in loiasis endemic areas should be followed. ln certain hypo-endemic areas which are part of areas targeted for elimination and which are co-endemic with Loa loo, ivermectin mass treatment may not be given, but alternative interventions are indicated. Consideration should be given to the use alternative drugs (e.g. doxycycline) or local Simulium vector control. One such zone identified by the committee was East Province, Cameroon. iv) Cross-border challenges o There are several cross-border onchocerciasis foci where the rivers that contain the blackfly breeding sites also form natural borders between neighbouring countries. ln addition, some rivers flow through different countries with the possibility of some fly species crossing the borders following the watercourse. Elimination in such cross-border foci will require very close coordination of treatment and evaluation activities on both sides of the border. ln the savanna zones of APOC countries, long-distance migration of vectors using dominant winds might present another cross-border challenge where effective treatment in the source area of the migrant vector may be essential for onchocerciasis elimination in target areas in another country. To better understand critical vector migration patterns and take appropriate measures to minimize the impact of such migration, APOC has launched entomological studies in several countries. ln forest areas, long-distance vector migration may not be a major problem but further entomological studies are required to confirm this. 5 Alternative strategies o ln hypo-endemic onchocerciasis areas where there is co-endemicity with Loa loa, alternative strategies should be tested using vector control, doxycycline treatment or strategies to test and treat only individuals who have onchocerciasis. o The use of new diagnostics (DEC patch test or OV L6 antibody testing) should be evaluated for (i) delineation of transmission zones, (ii) post treatment monitoring and (iii) decision - making on when to stop treatment. Guidelines and criteria for elimination APOC has developed operational guidelines for stopping treatment and countries are working towards these guidelines to stop treatment. There are guidelines and criteria published by WHO in 2001focused on national certification of elimination. These guidelines are outdated and WHO should update these guidelines at the appropriate time and operationalize them for use in different epidemiological settings. Steps towards certifying and maintaining elimination status 1. Determine full limit of the area (transmission zone) requiring treatment 2. lnitiate and consolidate treatments a. To full transmission zone b. lncrease to twice per year (5 monthly) treatment where indicated c. Conduct special interventions in hypoendemic oncho areas where Loa loa is endemic d. Enhance coverage to attain and sustain 80% therapeutic and 100% geographic coverage, including expansion of coverage where necessary to reach the entire transmission zone. 3. Monitoring progress a. of treatment figures to assure accuracy b. epidemiological and entomological trends 4. Conduct stop treatment exercises (decide stop treatment based on entomological and epidemiological data collected in number 3) 5. Stop ivermectin in the treatment area (prepare communities etc) 6. Conduct 3 year post treatment monitoring 7. Confirmation of elimination and documentation of the treatment area that will be included in the national archive/dossier for future certification process 8. Routine surveillance in the transmission zone after elimination 9. National level certification through submission of a compilation of dossiers of all national treatment areas. Areas where onchocerciasis and lymphatic filariasis are co-endemic o Neither LF nor Oncho elimination programs can succeed in co-endemic areas without close coordination. This is because both programs require post treatment surveillance, and neither program can come to conclusion if the other program is continuing ivermectin treatment in the same area. a a I a LF mapping has not been completed in most APOC countries where LF is co-endemic with onchocerciasis. Furthermore, in most of these countries, LF geographical and therapeutic coverage is low (below 50%) due to lack of LF funds. However, if the LF programme was to scale up, most onchocerciasis hypo-endemic areas would be covered by the LF programme. Harmonization of planning, mapping and implementation of the two programmes at country and district levels is critically important. 5 a