Google celebrated the 100th birthday of American researcher and virologist Jonas Salk, who invented the Polio vaccine, by featuring a doodle of the scientist on its home page on Tuesday.
Polio is a virus induced highly infectious disease that invades the nervous system and causes total paralysis. The virus is mostly transmitted through oral/fecal route or sometimes through contaminated water and food and multiplies in the intestine.
Polio generally affects children below five years of age and among those paralyzed it is fatal for 5% to 10%.
India's fight against polio
India has made good use of Salk's vaccine and done remarkably well in eradicating polio. The last official case reported in India was in 2011.
The following visualisation shows the number of polio cases reported in India from 1998 to 2014.
As can be seen in the graph, no polio cases were reported in the last three years.
To achieve this 'zero reported case' mark, India went into a rapid vaccination mode from 1995 to 2013 and vaccinated a total of 1,138 crore children in that period. Here is a detailed state-wise report for the same time period.
But the journey leading to complete eradication was long and tough. Before the launch of the Global Polio Eradication Initiative, polio crippled an estimated 200,000 children in India each year. As seen in previous graphs this number was brought down to 741 in 2009 and by 2012 it was zero and remains so until now.
The journey for polio free India started in 1994 through a polio pilot programme which was conducted in Delhi. Each year new programmes were introduced and finally the year 2012 was declared as a polio-free year and India was no longer considered as a polio endemic country.Here is a detailed time-line of India's fight against polio through the years.
Globally a few countries like Nigeria, Pakistan, and Afghanistan are still polio endemic.
Especially, Pakistan has reached 210 cases in 2014. According to polio eradication initiative website, this is the highest number of cases on record by October in any year, and accounts for more than 85% of all cases worldwide.
The following visualization shows the number of polio cases reported in 2014 in some of the countries where polio is prevelant at present.
Rukhsar (in above photo), from Panchla Block, Howrah, West Bengal, was paralyzed by polio on 13 January 2011. She is the last known polio victim in India.
Will she be the last one?
Story ideation, research and data collection : Sourjya Bhowmick (@sourjyabhowmick)
Story written, visualization, data collection : Vignesh Radhakrishnan (@vinuthewriter)
Data sources :
Data for timeline - Ministry of Health and Family Welfare booklet
Polio data - Parliamentary Q and A