India Outbreak: over 1,300 fatalities from H1N1 swine flu
With states witnessing an unprecedented number of Influenza A H1N1 cases and over 1,300 deaths so far this year, India seems to be in the grip of a major flu outbreak. This current H1N1 strain is popularly referred to as swine flu in India because the initial transmission of the virus happened through infected pigs in 2009 - 2010 when the virus spread from central Mexico to 74 other countries (including India) killing up to an estimated 575,400 people, according to the US Centers for Disease Control and Prevention.
A blast from the not-so-distant past
Swine flu deaths in India from 2009 to 2015
As reported by The Wire:
India first detected a case of the new pandemic H1N1 strain in May 2009 in Hyderabad, after which morbidity climbed quickly. Until then, the circulating flu strains in India included H3N2, a remnant of the 1968 Hong Kong pandemic, and H1N1 from the 1977 Russian flu. The latter was genetically different from the one that hit humans in 2009. “None of the Indians had any immunity against it. So the inevitable thing that had to happen was that a large number of people fell sick,” says Jayaprakash Muliyil, an epidemiologist from CMC, explaining the first wave of the pandemic in India.
According to Health Ministry data, a total of 25,864 cases have been reported across the country since January 2017, raising a serious health concern across states even as experts attributed a “change in the virus’s strain” to be behind the increasing incidence and deaths this year.
Change in virus?
Antigenic shift vs. antigenic drift
The National Centre for Disease Control and All India Institutes of Medical Sciences in Delhi and Pune's National Institute of Virology have found that the H1N1 strain in circulation this year is different from that in previous years. Health officials have stated that this year’s outbreak could be due to changes in the H1N1 virus. The institute said that India has started witnessing the spread of the Michigan strain of the H1N1 virus this year. Earlier, India had recorded cases only of the California strain.
Genetic changes in influenza viruses occur in two ways. More often, the influenza virus undergoes small genetic changes that create viruses that are only slightly different from the original virus. A person who has been exposed to the original virus may have developed immunity to it, but will not be immune to this newer version created through antigenic drift. Sometimes, there is a significant mutation (two or more different influenza viruses, combine) that creates a new strain of virus. The phenomenon is called antigenic shift and can cause dangerous outbreaks like the H1N1 pandemic of 2009.
Delay in treatment
Doctors treating H1N1 patients said that most patients get to hospital days after the onset of symptoms. Oseltamivir, the antiviral drug effective against the H1N1 virus, works best when administered within 48 hours of the patient complaining of symptoms. Those suffering from H1N1 complain of fever, sore throat, a running nose and body pain, among other symptoms.
States reporting the most cases include Maharashtra (4,456), Gujarat (4,741), Tamil Nadu (3,045) and Karnataka (3,012). Maharashtra remains the worst affected with a death toll of 488, followed by Gujarat, which has recorded 354 fatalities. Maharashtra and Gujarat have accounted for ~65% of the deaths so far. Gujarat is reeling from one of the worst outbreaks of the flu recording 4,741 cases, with a mortality rate of 7.23%. Maharashtra has contributed to more than 45% of all H1N1 casualties and one-fourth of the confirmed cases since January this year. Tamil Nadu recorded over 3,000 H1N1 cases and 15 deaths since January.
Prevention is better than cure
Flu Prevention Tips
Standard measures to control the spread of infection include good health habits such as covering your coughs and washing your hands often. Early diagnosis and early treatment of the disease is also important, especially during the outbreak season. However, both the World Health Organization and the India’s Ministry of Health and Family Welfare recommend vaccination as the most effective tool against H1N1 virus infections.
The peak season for influenza in India is during the monsoon; so vaccine should be given before the monsoon and the second peak is seen in winter in northern states from November to February. In areas with peak in winter, the vaccine should be given from September to October and for rest of the country where monsoon is the peak season for influenza, the vaccine should be given from April to May.
Vaccine uptake in India is dismal even among the high risk population including healthcare workers and patients with chronic medical conditions (like heart disease, diabetes, chronic obstructive pulmonary disease) and pregnant women. Healthcare workers in particular are a special case because they not only come in contact with patients, posing a risk to them, but they may also spread infections to the high-risk patients whom they treat.
Across the country 25,864 cases of H1N1 infection have been recorded.
Most epidemiologists in India agree that it is time for the government to financially support an immunisation policy for high-risk people. H1N1 has killed over 1,300 people till May. The figure is four times more than deaths recorded last year. Virologist, pediatrician, microbiologist, and public health expert Dr T. Jacob John told The Wire, “Given the burden, we deserve a national immunisation policy.”