Experts across the city have warned a surge in influenza A H3N2 cases during winter as there have been 2.8 times rise in cases reported in the last four months (June to September), while there was also 20 per cent drop in swine flu or H1N1 during the same period.
However, the surge have been to the change in weather condition and intermittent rainfall was favourable conditions for influenza virus to spread. Moreover, doctors have urged or warned people with low immunity level to take extra care as there will be rise in upper respiratory tract infection during upcoming winter.
Data Reveals H3N2 Dominance with 1906 Cases Detected in 9 Months
As per the data, 1906 H3N2 cases were detected across the state since January to September 30, of which 1,388 were recorded between June to September, while only 518 cases were witnessed between January to May.
Similarly there were 962 H1N1 cases during the same period, of which 425 were reported in the last four months compared to 537 cases recorded between January to May.
“This year has been totally differently in terms of diseases or virus in Maharashtra compared to the last year. We have seen rise in all kind of diseases and viruses includes dengue, influenza A H3N2, conjunctivitis, Malaria and others. The influenza strain has been dominating due to which cases have tripled in just four months and it is expected to increase more during winters,” said a senior health official from the state health department.
H3N2 Spreading Faster Among People with Low Immunity
However the infection of H1N1 (swine flu) and H3N2 which comes under influenza-A, continues to persist among the people of Maharashtra including Mumbai. The data clearly a shows influenza A strain H3N2 has been spreading rapidly among the people with low immunity compared to H1N1.
Dr Pratit Samdani, Internal Medicine Specialist, Breach Candy Hospital, said there is a possibility of cases might start to increase post monsoon as winter is also nearing when upper respiratory tract infections are more at that time.
“I believe that whenever there is a drop in temperature, cases of influenza increase. This year there was intermittent rain and temperature kept fluctuating from high to low due to which cases were increased. However most of the cases were detected at a time of testing but in reality the numbers are more,” he said.
High Positivity Rate in H3N2 Tests, Slow Recovery for Patients
Dr Gautam Bhansali, physician of Bombay Hospital, said that cases of upper respiratory tract infection are still being reported. Out of all the H3N2 tests conducted so far, 60 percent have been found positive. This is a viral disease and most of them do not get themselves tested.
“Most of the patients had low immunity which was favourable for influenza strain to attack them. Moreover it is like a viral disease or fever which spreads faster, but patients are also taking atleast two to three weeks to get recovered,” he said.