With this, the number of infected people has increased to five.

The newly-diagnosed people were apparently staying near the US-based non-resident Nepali couple and their eight-year old son who were diagnosed on Sunday. They came to Nepal via Doha from the US.

The same family’s five-year-old son and their relative’s 17-month-old daughter were tested and it confirmed the AH1N1 virus in the blood samples, according to Dr Senendra Raj Upreti, director of Epidemiology and Disease Control Division under the Ministry of Health.

Dr Upreti said they were tested after symptoms of swine flu were seen.

Treatment has already been started under special attention, he said. Even those who were around the infected people but have not shown any symptoms have been tested.

The test reports were made public on Thursday.

World Health Organisation (WHO) had declared swine flu pandemic on June 11.

The virus has spread to over 113 countries so far. Since it was first detected in Mexico on April 25 this year, over 60,000 people have been infected and 263 have died, according to WHO.

According to Dr Upreti, on 29 April, the government issued an alert to over 40 Rapid Response Teams and stationed a team of health professionals at Tribhuvan International Airport. It has also stepped up vigilance for symptoms of the flu at border points.

The government has also deployed surveillance teams across the country and strengthened hospitals, mainly Tribhuvan Uni-versity Teaching Hospital and Sukraraj Tropical and Infectious Disease Hospital to enable them to provide special treatment.

“AH1N1 virus causes respiratory disease in pigs. It is caused by the type A influenza virus that spreads to humans. But recent outbreaks show genetic assortment mutation especially of bird flu, animal flu and human flu. Hence, it is more dangerous, as it is air-borne and can be transferred from human to human,” said Dr Upreti.