The State’s Zika virus (ZIKV) tally rose to 23 on Tuesday with four new cases being reported from scattered urban locales within the capital district.
Of the 23 ZIKV cases reported so far, three have been in pregnant women.
On Tuesday, a 35-year-old woman at Poonthura, a 41-year-old pregnant woman at Sasthamangalam, a 38-year-old doctor at a private hospital and a 16-year-old girl at Karikkakam were diagnosed with the infection. These are all samples sent by clinicians in the city.
Geographic spread
The fact that isolated cases are being reported from various geographic points in the district is not just worrying, but it has made the task of epidemiologists, who are trying to trace the origin and the spread of the outbreak, harder. “It is more or less given that the virus would have been in circulation in the district for the past few months. It is also possible that there were several undetected cases which never reached a clinician, because ZIKV mostly manifests as a mild or asymptomatic infection which resolves itself in two or three days. We have no way of knowing the extent of the geographic spread of the disease unless new cases come up. A retrospective mapping of the infection through sero surveillance is impractical, costly and almost impossible because the Elisa antibody (IgG) test would show cross reactivity in people who had prior dengue infection. We can only look ahead and take prospective action, which includes ante-natal screening and surveillance and intensive mosquito- control measures,” an epidemiologist said.
District health officials said that while a cluster of epidemiologically linked cases have been found around a private hospital in the city, the new cases which have come up, need to be investigated.
The city Corporation has been asked to do intensive vector- control measures within a radius of the hospital, including spraying of larvicides in all breeding sites found in the construction sites and fogging to kill adult mosquitoes.
Central team
The Central team, which is investigating the outbreak, visited more field sites, including Parassala from where the first case was reported. They are expected to visit Poonthura on Wednesday.
