KOZHIKODE: Around 40 encephalitis cases in north Kerala in the recent past and four related deaths — two of them highly mysterious — were instrumental in health officers zeroing in on a ‘virus’ possibility right at the beginning of the Nipah outbreak in Kozhikode.
Early this year, a team comprising Additional Director of Health Services (ADHS) Dr Reena K J, renowned virologist Dr G Arun Kumar and other experts had conducted detailed investigations after two mysterious brain fever-related deaths were reported in Malappuram. A mother and son had died of brain fever symptoms in a gap of 14 days, similar to the time period between deaths of Nipah index case Muhammed Sabith and his brother Muhammed Salih in Kozhikode.
Though the cause of the mother’s death was concluded as suspected ‘TB meningitis’, the unlikely death of her son with the same symptoms perplexed health officials and gave rise to suspicion that it was a case of viral encephalitis.
ADHS Dr Reena, being a microbiologist, was the first to notice the peculiarity of the two deaths. Though she suspected the involvement of a highly virulent virus, inadequate test samples taken from the child’s brain couldn’t prove that suspicion.Besides, the result of the tests conducted by Dr G Arun Kumar and team at Manipal remained inconclusive.
“At 9.40 pm on May 17, the DMO of Kozhikode informed me about the death of one person (Sabith) due to high fever and that his brother (Salih) was highly critical in ICU with similar symptoms after 14 days. I suddenly drew a parallel between this case and the case in Malappuram,” said Dr Reena. Immediately after Salih’s death a day later at a private hospital, Dr Reena reminded Dr Arun of the suspected viral deaths in Malappuram.
“After running the tests on samples from Salih, Dr Arun informed me on May 18 that a virus has been isolated and that he was working on it. On the morning of June 19, I texted Dr Arun and inquired whether the virus was ‘Hendra’ or ‘Nipah’. He replied ‘N’ indicating Nipah. But we kept it under wraps till further confirmation from NIV, Pune, and official announcement a day later,” she added.
Dr Arun Kumar admitted that not all encephalitis cases in the past were correctly diagnosed. But he ruled out a Nipah angle in the earlier deaths in north Kerala.“If Nipah virus is present, the chances of spread is very high. Had such a scenario existed during the recent encephalitis deaths in Malappuram, we would have seen a spate of infections,” he clarified.“However, our surveillance mechanism against diseases such as encephalitis need to be strengthened,” the virologist cautioned.
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“On the ground, the virus can be considered as fully contained at the moment. But the source still remains a mystery. Hence, it will take several days before we announce Kozhikode as fully free of Nipah. It depends on no new positive cases or deaths being reported for a period of 42 days from May 30 - the day when the last Nipah-related death occurred.”