Seven swine flu deaths, including four in Karnataka, were reported on Wednesday, taking India's total toll to 316. Also, 197 new H1N1 cases were reported in the country, taking the total number of people affected with the virus to 10,233.

The highest death toll has been recorded in Maharashtra where 120 people have succumbed to H1N1 virus since the first death was reported in India August 3 in Pune.

According to the World Health Organization (WHO), there were more than 300,000 laboratory-confirmed cases of pandemic influenza H1N1 till September 20. As many as 3,917 people have died globally.

The U.S. Centers for Disease Control and Prevention (CDC) reports that many people who have died of swine flu infections in the United States have also had bacterial infections. A study of 77 patients who died of the new pandemic H1N1 virus showed 29 percent of them had so-called bacterial co-infections. Also, about half of these had Streptococcus pneumoniae, which can be prevented with a vaccine.