Kerala case raises fears over incubation period

nTHIRUVANANTHAPURAM: A man who returned from Dubai on March 18 tested positive for Covid-19 on Thursday, 29 days after what health officials say was his likely exposure to an infection source, raising concerns that the disease could take longer to manifest and quarantine periods as short as 14 days may not be enough.

The man’s brother – both living in Kozhikode – tested positive on March 28, following which he was put under special observation. “Chances of him being infected during observation period are nil... We have noticed a couple of such instances from other districts also. It could be that the onset was delayed because of his immunity. We can’t say virus works in a uniform pattern in all bodies,” said

Kozhikode medical officer Dr V Jayashree.

Kerala has a 28-day mandatory isolation period for those with close contact with a confirmed patient or with a history of travel.covid-19, has an average incubation period (the time it takes for the disease to manifest itself) of around 5 days but has been established to last longer (up to 14 days). An incubation period of 29 days, as was in the case of the Kozhikode man, is rare. “True, Kozhikkode man’s case is a peculiar one. We have asked medical experts and scientists to study his case separately,” said state health minister K K Shailaja. “It is possible as there are studies to suggest that. We are also conducting studies to check the incubation period,” said a microbiologist at one of the viral research and diagnostic labs of ICMR, requesting anonymity.