Ketan Ranga uncovers the dark, fascinating story of a boy who got swine flu during a US trip and brought it upon hundreds of others through chance encounters

This is the incredible story of how one boy unwittingly transmitted the swine flu virus to almost 409 people in Pune. The journey began on board a Chicago-Delhi flight on July 4.

But first, an introduction of the boy, who was so to speak, bitten by the bug towards the end of his stay in the US.
Santosh Sonavane (16, name changed) was among 40 other students selected by the American Field Services as part of a student exchange programme to  the USA.

Of the 40, seven students were from Pune, one from Dhule and one from Nashik. They spent 11 months in the US, beginning in August 2008, in different states and stayed with host families.

During their stay, they completed the equivalent of Std XI. "I stayed in Indiana with a wonderful family," reminisces Santosh.

Finally, as all good things do, their stay in the US came to an end and on June 30, 2009, they went to Washington DC for a three-day orientation course.

On July 4
Santosh and the 40 students took a Delhi flight from Chicago. On board the flight, Santosh realises he has a sore throat, but no fever.
All the 40 students spend three days in Delhi and on July 7, four students from Pune and Santosh take a SpiceJet flight for Pune.
"On the flight, I felt really ill. I was feverish, had a cough, my throat was hurting and I felt vaguely restless," said Santosh.

On July 7
In the evening, in the Sonavane home, his mother calls for an impromptu celebratory gathering. Present are his uncle, aunt, school-going cousin and his mother.

July 8
Santosh's fever persists and so do the other symptoms. His mother takes him to the doctor and then to the Naidu Hospital. His throat swab is taken and on July 9, he tests positive for H1N1 and is admitted to Naidu Hospital.
Immediately, his mother, aunt, uncle and cousin, all present at his homecoming party, are tested and the reports are awaited, though they do not have flu symptoms.
All the four students, who were along with Sonavane are also tested and found to be H1N1 positive. However, none of their relatives are affected by the flu.

July 11
Santosh's cousin, Anil Savle (name changed) goes to school. He attends one of the five branches Abhinav School has in the city.

July 12
The throat swab reports of the Sonavane family arrive from the National Institute of Virology and all four test positive. In the single day that Savle goes to school, three students are infected, which unfortunately is known much later.

July 13
The next day, unaware of the virus they are carrying, the three students attend a programme organised in the lead up to the total solar eclipse on July 22.
Many students from Abhinav school and other schools comprise the 1,000-odd people present in the packed auditorium. It is here that more than 50 people of the 130 tested are confirmed positive for the flu.
The dates are hazy from here, but the same three students also infected 21 students, directly and indirectly in the Abhinav School they attended and its four other branches.
The 50-odd people who were infected at the auditorium contributed in a major part to the spread of the virus to 109 students in 19 schools in Pune.
In fact, say experts, most of the 409 swine flu cases in Pune trace their roots to Santosh.
Doctors say the virus, known to be extremely contagious, spread from person to person at school canteens, classrooms, during run-ins at recess, impromptu get togethers, while travelling to school or back home.
The adults got it at cinema halls, malls. And that, is the way, the cookie crumbles.