Containing chikungunya

Intermittent rains before and after the monsoon's onset have led to a big increase in mosquito numbers in Kerala. Strains of the Aedes mosquito, which need just a little water for their eggs and larvae to develop, have bred prolifically. These mosquitoes, which bite during the day, have also been spreading the virus that causes chikungunya, a disease that is coming to be dreaded for the severe joint pain it produces and which sometimes takes months to disappear. Worse still, it is a disease for which there is as yet no effective cure or vaccine. Over 5,000 cases of chikungunya were reported during May 2007 from various parts of Kerala (where the month before there had been only 26 reported cases), and more than 2,600 suspected cases in the first 12 days of June. The State government is going all out to reach medical care to the affected people, with armed forces personnel lending a helping hand.

When dealing with a mosquito-borne infection like chikungunya, the best way to prevent periodic recurrence of the disease is to give the insect as few opportunities as possible to breed. Last year when chikungunya suddenly reappeared in the country after an interval of over 30 years, Kerala was one of the 15 States and Union Territories where the virus spread. More than 70,000 people in Kerala were diagnosed with the disease in 2006; nearly 1.4 million people were infected countrywide. On that occasion too there was widespread panic in the State and the government moved swiftly to contain the disease. But the fact that the virus is circulating yet again must serve to drive home the point that mosquito control cannot be a sporadic activity that is seriously undertaken only during an epidemic. The Aedes mosquito strains, which also spread dengue, have successfully adapted to survive around human habitation. Plastic and disposable ware that are carelessly thrown away, uncovered water containers of various kinds, abandoned vehicle tyres, and even coconut shells can hold sufficient water for these mosquitoes to breed. The week-long cleanliness drive launched on June 12 is a step in the right direction. It must lead to a year-round campaign so that the people take responsibility for not allowing mosquitoes to breed on their premises. The types of containers that breed the most mosquitoes need to be identified and then effectively targeted. The thoughtless littering of streets must be ended. Mosquito control is not a matter for the government alone. For its success, the programme requires the whole-hearted and sustained participation of the public.

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