Short Note-1
Aedes aegypti survey of Chennai∗ Port/Airport, India Kuldip Singh Gill, Sushil Kumar Sharma, Rakesh Katyal and Kaushal Kumar National Institute of Communicable Diseases,22, Shamnath Marg, Delhi-110054, India By
Introduction The International Health Regulations, 1969, enjoin upon national governments to keep international ports/airports and peripheral areas up to 400 metres free of Aedes aegypti in its adult and immature stages and the mosquito vectors of malaria and other diseases of epidemiological significance(1). The Ministry of Health, Government of India, set up Aedes control units in all major international ports/airports in the country. Periodic monitoring of the successful implementation of Aedes control programme is undertaken by the National Institute of Communicable Diseases (Directorate General of Health Services, Government of India). Present finding relates to an assessment carried out in Chennai port/airport during March 1998.
the Bay of Bengal. The total land area of the port is 551 acres, and the water spread area is 420 acres. The port area is divided into north, central and south zones and fishing harbours. Slum colonies surround the port area.
Airport The airport has both international and domestic terminals, covering an area of 1.5 and 1.8 sq km respectively. The airport is divided into two circles, with five zones each, for administrative conveniences.
Aedes control activities Port area Mosquito control in the port area is being undertaken by two agencies; (i) The Chennai Port Trust (CPT); and (ii) the Port Health Organization (PHO). Anti-mosquito measures are undertaken by CPT while the
Port area The Chennai International Seaport is situated at a latitude 130 6N and longitude 800 8E in ∗ Formerly known as Madras
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issuance of yellow fever certificates, ship deratting and overall supervision of mosquito control is undertaken by PHO.
Airport At the airport also, mosquito control is the responsibility of the airport health officer, while the fumigation of incoming and outgoing aircrafts is undertaken by the Airport Authority of India.
index in this area varied from 10.20% in the new airport area to 5.71% in old airport area. Used aircraft tyres lying in the open and holding rainwater were again the major breeding sites. Table 2. Aedes aegypti index and container index in different zones of Chennai Seaport Area Aedes aegypti index Container Index Percent
Premi- Premi- Premi- ContaFound ses ses ses iners posisearc- searc- searc- search tive hed hed hed ed
Survey results Tables 1 and 2 include data on Aedes aegypti index and container index in the airport and port areas respectively. Table 1. Aedes aegypti index and container index in different zones of Chennai Airport Aedes aegypti index Area Container index Percent
South zone Central zone North zone Total
18 17 15 60
2 1 1 4
11.1 5.8 6.6 6.6
48 71 32 151
10 18 1 29
20.8 25.35 3.1 19.20
Premi- PremiContaPremiFound ses ses iners ses posisearc- posisearch index tive hed tive ed
Cowl Bazar Area Old Airport Area New Airport Area Total
22
6
27.2
33
7
21.2
18
1
5.5
35
2
5.71
In the Port area, the Aedes aegypti index was found to be maximum (11.1%) in the South zone and minimum (5.8%) in the Central zone, whereas the container index was found to be maximum (25.35%) in the Central zone and minimum (3.1%) in the North zone. Used automobile tyres holding rainwater were identified as the key breeding sites. High Aedes aegypti indices observed during the dry months in both the port and airport areas, hint at a worsening situation by the monsoon period. This necessitated the need for more vigilance and further strengthening of ecology-based control measures.
19
1
5.26
49
5
10.20
59
8
3.55
117
14
11.96
In the airport area, the Aedes aegypti index was found to be maximum in the Cowl Bazar area (21.2%), which is a residential colony adjoining the airport area, in which breeding was promoted due to high water storage practices compelled by intermittent water supply. The container
Acknowledgements The authors are grateful to the Director, NICD, for providing an opportunity to
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undertake Aedes survey at the Chennai air/seaport areas. Thanks are also due to Dr S. R. Reddy, Port Health Officer, Dr Selvaraj, Airport Health Officer, Dr V. V. Sai Ram Babu, CMO, and his staff for their active cooperation and help during the survey. Thanks are also due to Mr N. A. Khan, technician and Mr Subash Chand, Lab. Attendant, NICD, Delhi, for the technical assistance provided by them.
References 1. World Health Organization/International Health Regulations, Third Annotated Edition. WHO/HQ, Geneva (1983).
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