Swine flu, caused by the H1N1 virus, has killed 17 people and infected more than 280 people in Maharashtra since the beginning of the year. Disease experts said the unusually cold winter conditions in the state since January have been a major reason for its spreading.
Seven patients across the state are currently on life support due to respiratory infection.
Of the total deaths this year, 13 (76%) happened over the first week of February; in the same period, 191 infections (68% of the total) were reported — indicating its rapid spread. Seven swine-flu cases were reported in Mumbai since January 1 but there have been no deaths so far.
State surveillance officer Dr P Awate pointed to the cold wave over north and central India making it favourable for the virus to spread. “Most of the deaths are reported from Nagpur, Pune and Nashik and inland areas, which are colder than coastal districts such as Mumbai or Konkan,” he said.
The India Meteorological Department has attributed the climate change to western disturbances combining with upper air cyclonic circulation over north-western regions of the country.
According to several studies, H1N1 virus spreads faster in colder weather conditions because they harden its surface, helping it survive for longer periods. Once the virus settles in the nasal passageways of humans, it adapts to the climate and attacks when the body’s immunity falls (which happens at colder temperatures).
As a result, the number of swine flu cases and deaths have spiked across northern and western states this year. According to data from the health ministry, Rajasthan has reported 3,359 cases and 126 deaths; Gujarat has reported 1,187 cases and 54 deaths; and Punjab, 301 cases and 30 deaths. States such as Jammu and Kashmir, Haryana and Delhi are also reeling under the outbreak of swine flu.
In Maharashtra, Awate said health officials have planned a large-scale vaccination against swine flu, especially to protect vulnerable groups such as children, pregnant women, patients with hypertension, health care workers and senior citizens. “More than 1.25 lakh vaccines will be administered in April and May,” he said.
To avoid delays in diagnosis, disease experts have advised doctors to look out for patients showing atypical symptoms. “If the infection is diagnosed early, it is relatively easier to treat. People must avoid self-medication, as swine flu shares many symptoms with common flu,” said Dr Om Srivastava, Director, infectious diseases department, Jaslok Hospital.
Srivastava said the number of swine flu patients in the state is likely to increase but it would not be anywhere close to the 2009 pandemic, which saw 937 deaths and 9,943 cases. “Climate change may be the contributing factor but certainly not the only cause of the national spread of the virus,” he said.
Srivastava said an antigenic shift (multiple H1N1 virus strains combining to form a new subtype) or antigenic drift (mutation within virus genes) may also be behind the high number of deaths this year. “But detailed studies would be necessary to prove it,” he said.
Primary symptoms of swine flu include fever, lethargy, headache, cough, sore throat and nausea. While most people recover within a week, those with low immunity, and chronic diseases such as asthma, lung diseases, diabetes, cancer, kidney or heart problems, risk serious complications and even death from multi-organ failure.