Prior to this, the virus had hit Nepal in 2009.
Gita Shakya, director of the National Public Health Laboratory in Kathmandu, said people do not have to worry about the disease as it can be cured if detected in preliminary stages.
The reason behind the resurgence of the virus in Nepal was that several districts have been hit recently by viral fever, she said.
At least two dozen people have died due to viral fever in Nepal. "Of the total 24 deaths, some might have been died due to late diagnosis of the swine flu virus," Shakya said.
Sher Bahadur Pun, a doctor at the Infectious Disease Hospital, said some patients have also been diagnosed with both types of influenza A and B of the swine flu virus.
The virus usually attacks children and young people who have low immune capability against minor diseases.
In 2009, over 40 people died due to the outbreak of the virus in the country.