With the urban areas of the district recording more cases of dengue, particularly the Coimbatore Corporation wards, the Department of Public Health has stepped up its follow-up surveillance, over what the civic bodies’ health wings do.
The aim is to ensure that dengue-prone areas and mosquito breeding sources are not missed. More than 50 per cent of the dengue cases are from the Corporation area alone, health officials say. From August to October-end, the total number of cases is 334 in the district. Of these, 175 are from within the Corporation limits, as per figures available with the department.
“Reaching the Unreached” is the new strategy, says Deputy Director of Public Health R. Damodaran. While the standard door-to-door surveillance for fever cases and potential breeding sources in the houses and surroundings will be done by the Corporation, the health department’s teams will go to construction sites and small industrial units where fresh water stagnation or storage is unsafe enough to provide breeding space for the Aedes aegypti mosquitoes that transmit the dengue-causing flavivirus.
Removal of objects such as coconut shells and discarded plastic items has reduced the mosquito index, he says. The density of virus infected mosquitoes in a locality indicates the risk of dengue.
“Three months ago, it was 85. Source reduction and anti-larval measures brought it down to 40.2 a fortnight ago. It is only three now,” he says. “Less than 10 is low risk situation, 10 to 15 is high risk and 50 plus is a public health danger, with possibility of death,” he explains.
Dr. Damodaran appealed to general physicians – the first stop for fever cases – to pick the early signs such as severe headache, eye and stomach pain and refer such cases for an immediate platelet count test.
If the platelet count is less than one lakh, these cases must be put through an ELISA (enzyme-linked immuno sorbent assay) test.
On testing positive, appropriate treatment can be followed. The situation is not alarming in Coimbatore, Dr. Damodaran contends, when pointed out that August and September reported 22 and 29 cases respectively, but it was 133 in October.
The three-digit reading in October does not suggest a spurt, he says. In August and September, only the Coimbatore Medical College Hospital was treated as the referral unit. In October, cases that reported at 52 hospitals were recorded.
Dengue has always had sporadic occurrence in Coimbatore and it continues to be so. Only if more than five cases are reported from a locality, it is an outbreak. “Right now, we do not have this situation,” he explains. “The district’s occurrence rate is only 1.3 per cent. It is in double digits in the other districts where alerts have been sounded”.
Since Coimbatore is endemic to dengue, the occurrence is throughout the year and sporadic. Therefore, it is not enough if preventive measures are just seasonal – restricted to monsoon. As long as fresh water is stored in open containers, Aedes aegypti mosquitoes will pose the threat of dengue. In addition to safe storage, the other preventive measure is to use nets on doors, windows and ventilators to keep the mosquitoes out of the houses, Dr. Damodaran advises.