As it gets colder and drier, India may see more H1N1 cases

When dipping temperatures and low rainfall are bad omens for the spread of the influenza, the country received 50 per cent less rainfall this monsoon season
Credit: Getty Images
Credit: Getty Images

India may see an increase in the spread of H1N1 influenza virus in the next few months owing to the prevailing dry and cold conditions.

This winter and lack of rainfall may spread the virus more efficiently. After the southwest monsoon season, the country, as a whole, received 50 per cent less rainfall than normal. The states that are most affected by the virus experienced huge rainfall deficiencies between October 1 and December 19, 2018.

This year, till December 9, the H1N1 virus had killed 969 people across India and the total number of reported cases stood at 13,447. The number of influenza cases and deaths in a few western and southern states are higher than the rest.

The situation is at its worst in Maharashtra, where 2,554 cases and 428 deaths were reported in the period. Just in the week between December 2 and December 9, the state witnessed six deaths due to the virus. Winter is otherwise a bit warmer than usual, but Maharashtra does not even have much moisture because of a rainfall deficiency of 73 per cent between October 1 and December 19.

Towards the northwest, Rajasthan will be dealing with a double whammy in the coming few days. On December 19, the India Meteorological Department (IMD) had declared cold wave conditions with temperatures dipping to 2 degrees Celsius in the state with some places suffering from severe cold waves. Apart from this, Rajasthan has received 93 per cent less rainfall than normal after the end of the southwest monsoon. In the current year, 204 people have died due to H1N1 infection in the state and 2,116 have been admitted in hospitals.

Extremely dry conditions are prevailing in Gujarat as well and the state has seen 98 per cent less rainfall than normal. Also, 2,053 cases of H1N1 influenza have been reported in the state and of those, 88 people have died. Many regions of Gujarat and Rajasthan did not experience much rainfall in August and September either.

In the south, Karnataka and Kerala are the most affected states with 59 and 40 H1N1 virus deaths.  Karnataka has suffered a rainfall deficit of 47 per cent in the past three months, while Kerala has received normal rainfall with a deficit of just 6 per cent.

The spread of H1N1 virus alternates over a period of two years. For example, the number of deaths in the country was very high in 2015 (2,990 deaths) and it then decreased in 2016 (265 deaths) and increased again in 2017 (2,270 deaths).

If this trend were to continue, 2018 should have seen very few cases and deaths but that has not been the case.

“Every alternate year, the virus changes its pattern and comes in a stronger form. The next year, it is in a milder form, but in 2017 and 2018, the virus continued to stay strong and we recorded not only many positive cases, but also deaths in large numbers,” Dr Pradeep Awate, Maharashtra’s head of epidemiology and infectious diseases expert, told the media.

Awate also blamed climate change for the difficulty in controlling the disease. “Due to less rain and more wind, we saw the virus spread quickly. Hence, this year, due to unexpected climate changes, we still kept seeing a rise in positive cases of this virus,” says Awate. Keeping in mind the current conditions, this could rise further.

In fact, long-term climate change might have an impact on the spread of H1N1 virus in a unique way. Winters are bound to be warmer than usual due to global warming like the current season has been predicted to be due to an ongoing El Nino event and continuous warming from green house gas emissions. This will reduce the spread of the virus in these months to some extent. But it will make people more vulnerable to the virus just after the cold season ends. This would require states to be ready to anticipate and tackle the spread of the disease.

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