New Delhi, May 5 (Inditop) India continues to be free from swine flu infection with three of the five people suspected to have influenza A (H1N1) testing negative for the disease, officials said Tuesday.

“The clinical samples of three passengers who were under observation in a government hospital in Delhi have been found to be negative for influenza A(H1N1). We have received samples of two passengers who reported flu symptoms in Kochi and results are expected by Wednesday,” an official at the National Institute of Communicable Diseases (NICD) told IANS.

A health ministry official said the three people who were quarantined in Delhi – two of whom came from the US and one from Canada – were discharged Tuesday after they tested negative for swine flu.

The two in Kochi had come from Dubai after visiting the US and Britain.

India has intensified measures to tackle swine flu by beefing surveillance at border road posts besides airports and ports.

The 21 airports in the country where screening is being done are Ahmedabad, Amritsar, Bangalore, Calicut, Chennai, Cochin, Coimbatore, New Delhi, Varanasi, Goa, Hyderabad, Jaipur, Kolkata, Lucknow, Mangalore, Mumbai, Nagpur, Pune, Srinagar, Tiruchirapalli and Tiruvananthapuram.

According to the World Health Organisation (WHO), 21 countries have officially reported 1,124 cases of influenza A (H1N1) infection.

Mexico has reported 590 laboratory confirmed human cases of infection, including 25 deaths. The US has reported 286 laboratory confirmed human cases, including one death.