No confirmatory evidence available

Three probable cases of infection due to hantavirus, including a death, have been reported in the district from Kallara, Nedumangad area, giving rise to fears that this could be another emerging virus that the State’s public health system is ill-equipped to handle.

All three cases have tested positive for scrub typhus too. This is not the first time that suspected hantavirus cases are being reported in Kerala, the earliest one being reported in2002 from Ernakulam. Despite serological evidence from the population in many parts of the country, there is yet to be any confirmatory evidence because reliable test kits are not available here, microbiologists say.

Scrub typhus

The three blood samples which tested positive for both hantavirus and scrub typhus were part of the bunch of samples referred to the Rajiv Gandhi Centre for Biotechnology (RGCB) from the Medical College Hospital to test for scrub typhus between December 2013 and early January this year.

“We found some 272 blood samples to be positive for scrub typhus. We tested these samples for hantavirus also as rodents or bandicoots are a common host for both these pathogens. Once we found the three samples IgM positive for hanta, we asked for a second sample from the patients, to be collected after 7 to 20 days, which showed that antibody levels were going up. We can only say that this is a probable hantavirus infection, because PCR testing and gene sequencing alone will confirm the diagnosis,” Head of Laboratory Medicine, RGCB, R. Radhakrishnan, says.

RGCB has already placed orders for the specific reagents and primers needed for polymerase chain reaction (PCR) testing for hantavirus, he says. From the clinician’s point of view, all the patients had severe pulmonary and renal infection, pointing to classical symptoms of hantavirus infection. Additional Director of Public Health A.S. Pradeepkumar says these symptoms are the same for scrub typhus and leptospirosis also.

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