Staff Reporter

Health experts say rain is the reason

Thiruvananthapuram: The summer showers may have brought respite from the sweltering heat, but it has resulted in a slight increase in the number of dengue cases in the district.

Following intensive preventive and control activities, dengue incidence has been showing a downward trend in the district since February-end. The number of cases has come down from 207 in January to 133 in February.

Apart from intensified vector-control measures, the high summer temperature has helped to keep the vector density down. Public health experts had warned that the health system needed to continue vigil as one spell of rain could change the picture.

The declining trend would have continued as hardly two or three cases were reported in March. But after this lull, five cases were reported from various Corporation areas last Tuesday.

Health Department officials attribute this to the summer showers received in the city the week before.

The breeding habits of the Aedes Aegypti species of mosquito make this vector virtually impossible to be destroyed. The female of the species lays eggs on any wet surface and it does not even require a water pool. These eggs have the capacity to stay alive for up to a year or more even in dry conditions.

The eggs come alive and hatch as soon as the first summer shower occurs. If the eggs are virus-laden, as soon as the adult mosquito emerges, it is ready to transmit the virus. Thus, a spurt in dengue cases is to be expected after summer showers.

Slackening of control activities in the field can thus lead to a public health issue again. Health officials have warned the public to be on continuous vigil and to ensure that water does not stagnate in coconut shells, unused plastic vessels or tyres after the rain.

Eliminating a single source of breeding is as good as destroying thousands of mosquitoes, the District Medical Officer said. Till now, 350 cases of dengue fever and one dengue-related death has been reported in the district.