Since the past few weeks, the usually staid looking website of the Delhi municipal corporation has been flashing a multi-coloured poster. The message of the graphic is grim. It warns people about vector-borne diseases like malaria, dengue and chikungunya and urges them to prevent such diseases by not allowing mosquitoes to breed. The municipal body, however, believes there is no reason to worry. Its authorities have been reported to have said only 40-50 cases of the disease have occurred in the capital since July. These figures are at odds with those of the AIIMS, which has reported more than 350 chikungunya cases in the same period. AIIMS gets patients from areas beyond the jurisdiction of the Delhi municipality and it is possible that a fair number of those being treated for chikungunya in the hospital are not from the city. That may absolve Delhi’s municipal corporation, but 350-400 chikungunya cases in areas in the capital’s vicinity cast serious questions on the public health system.
The first case of chikungunya was reported in Calcutta in 1963. There were a few outbreaks in the next eight years and the disease was believed to have disappeared from the country after 1971. It made a re-appearance about 35 years later. Chikungunya cases were reported from Andhra Pradesh in late 2005 and some months later from Karnataka, Maharashtra and Tamil Nadu. In the next five years, the disease had spread to most parts of the country. Monitoring it is, arguably, tough. The virus that causes the disease is known to mutate fast and finds a host in the Aedes aegypti mosquito, that breeds rapidly in stagnant water. The vector’s ubiquity leads municipal authorities to believe that educating people through messages, such as the one displayed on the Delhi municipal commission website, is among the better ways to deal with chikungunya. Municipal authorities also conduct checks for the parasite in localities, and, at times, at the household level as well.
Such measures, though, have very little impact. The mosquito breeds way too rapidly and the once-in-a-few-days monitoring by municipal authorities is no match for the parasite’s fecundity. The WHO has been advocating early monitoring systems that make use of GIS tools. The French-administered Reunion Island that saw a chikungunya outbreak a few months before the disease resurfaced in India used data on mosquito density and simulation models that predict chikungunya’s local trajectories. Some western countries also follow similar models. It may well be argued that in a country where geographical features vary every few kilometres such models would be difficult to implement. But in times when we proclaim success of homegrown information technology systems, it would seem utterly stupid to have been beaten by a mosquito.