Saturday, April 23, 2011

"The Million Death Study" Published - Snakebite in India

Confusion over the number of people who die in India annully from snakebites is an on-going problem. In 1880, Joseph Fayrer suggested 19,060 Indians died from snake envenomation. His comment instituted a campaign of snake extermination , with 467,744 snakes killed for bounty. Fayrer reported a minimal decrease in deaths - 18,610 people died. However, by 1889, the snake bite deaths increased to 22,480 at a time when the population was 250 million. Swaroop and Grab (1954) assembled the World Health Organization's (WHO) first global snake bite estimates but they lacked reliable data from India, reporting 20,000 deaths. This number may have been based upon Fayrer's 1889 number. Sawai and Homma (1972) attempted to estimate the number by visiting Indian hospitals accompanied by extrapolation and estimated 10,000 deaths per year suggesting 90 per cent of the victims did not seek hospital treatment. Chippaux (1998) estimated snake envenomation killed between 9,900 and 21,600 per year when the population was nearing one billion. A 2005 WHO study estimated 50,000 snakebite deaths in India, but a 2008 follow-up,estimated 11,000 deaths; and a second 2008 report done by the Indian government estimated only 1,400 mortalities, possibly because 6 of the xx Indian states failed to respnd to the study. Snakebite in India does not have to be reported to the Ministry of Health, and traditional folk treatments are still relied upon in many regions. On April 12, 2011 a new study, with the nickname "The Million Death Study" was published in PLoS Neglected Tropical Diseases (Mohapatra et al. 2011 -see below)

The study examined 123,000 deaths from 6,671 randomly selected areas between 2001and 2003. Full-time, non-medical field workers interviewed living respondents about all deaths. The underlying causes were independently coded by two of 130 trained physicians. The authors' summary follows:

Earlier hospital based reports estimate about 1,300 to 50,000 annual deaths from snakebites per year in India. Here, we present the first ever direct estimates from a national mortality survey of 1.1 million homes in 2001–03. Full-time, non-medical field workers interviewed living respondents about all deaths. The underlying causes were independently coded by two of 130 trained physicians. The study found 562 deaths (0.47% of total deaths) were assigned to snakebites, mostly in rural areas, and more commonly among males than females and peaking at ages 15–29. Snakebites also occurred more often during the rainy monsoon season. This proportion represents about 45,900 annual snakebite deaths nationally (99% CI 40,900 to 50,900) or an annual age-standardised rate of 4.1/100,000 (99% CI 3.6–4.5), with higher rates in rural areas (5.4) and with the highest rate in the state of Andhra Pradesh (6.2). Annual snakebite deaths were greatest in the states of Uttar Pradesh (8,700), Andhra Pradesh (5,200), and Bihar (4,500). Thus, snakebite remains an underestimated cause of accidental death in modern India, causing about one death for every two HIV-related deaths. Because a large proportion of global totals of snakebites arise from India, global snakebite totals might also be underestimated. Effective interventions involving education and antivenom provision would reduce snakebite deaths in India.
It seems unlikely that this study will end the on-going controversy over the number of snakebites and deaths from snake venom in India. However, it is an intriguing piece of work and if you are interested in the problem it is worth the time to ready the author's ideas. 

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