Experts are still wary although fewer cases of H1N1 virus (swine flu) are being reported this year, while scientists at the National Institute of Virology (NIV) are encouraging more studies on immunity against the virus.
Be it climatic conditions in which the virus can thrive or the immunity of the population, theories have been doing the rounds for some time now about how the virus has firmly entrenched itself in the city and surrounding areas. Experts have said swine flu has become endemic to Pune region and is now part of seasonal flu infections.
In the past five years, since the pandemic hit Pune in 2009, the city has seen 250 deaths and 4,187 positive cases of H1N1. This year, the Pune Municipal Corporation (PMC) has registered 11 cases and one death. At NIV, scientists has registered a 3.4 per cent positivity for the virus among 387 samples received from across the state.
Dr M S Chadda, deputy director, NIV, who has conducted a study that assessed the burden of influenza hospitalisations said there were ‘small mutations’ in the H1N1 virus and it has now become endemic to the region. “But they are not significant which means that the vaccine strain has not changed and is effective,” said Chadda. “There is no way to predict how the virus is going to behave and hence it is now being treated as part of the seasonal flu infections,” Chadda said.
The drugs are still effective against the virus, she said, adding that only a few cases of resistance to the drugs had been detected. However, the workload at NIV has been immense as the apex virological institute has tested as many as 52,000 throat swab samples in the last five years with a positivity of about 20 per cent for pandemic influenza.
“Of course the cost of these tests have gone into crores,” Chadda said, adding that there were some rapid tests but these have several issues of specificity and sensitivity. “Real time RT-PCR is the gold standard,” she added.
Dr S T Pardeshi, acting chief medical officer, PMC, said that in the past five years in Pune ,a total of 25,734 throat swab samples underwent tests at NIV and Religare and a total of 4,187 persons were found to be H1N1 positive.
While 250 persons died at various hospitals in Pune, a total of 162 were from the city. This year, a total of 5,986 persons have been given Tamiflu tablets while only 11 were positive with the virus. In June, only one positive case of H1N1 virus was reported. A 43-year-old woman from Lonikand died.