Chinese mainland and Hong Kong Special Administrative Region both reported their second cases of A/H1N1 influenza on Wednesday, bringing China's total confirmed cases to four.

Health authorities of mainland and Hong Kong, as well as other parts of Asia, have been sparing no efforts to prevent further spread of the flu and stepped up medical surveillance of the deadly virus.

China's Ministry of Health confirmed Wednesday a man who returned from Canada last week has tested positive for the A/H1N1 influenza.

The case, the second of its kind on the Chinese mainland, involved a 19-year-old student surnamed Lv who arrived in Beijing from Canada on May 8 and traveled to Jinan, provincial capital of Shandong, three days later.

A statement on the website of China's Health Ministry said Lv was "recovering with a normal body temperature."

The girlfriend of Lv, a 17-year-old girl surnamed Zhang, was quarantined Wednesday. She has shown no symptoms of the virus, according to the health department of Tianjin Municipality.

The development came just two days after a 30-year-old man surnamed Bao was found to have contracted the virus in Chengdu, Sichuan Province. Bao is the first confirmed case of A/H1N1 on the Chinese mainland.

The country's health authorities had begun to trace those in close contact with Lv during his travels.

A Hong Kong man has tested positive for influenza A/H1N1, the second case in Hong Kong, HKSAR's health authorities said Wednesday.

The patient, a 24-year-old local resident, recently traveled to San Francisco in the United States and returned to Hong Kong onboard the Cathy Pacific flight CX879 late Monday, said Thomas Tsang, controller of the Center for Health Protection.

The patient went to see a doctor at a clinic at the airport and was suspected of being infected with influenza A/H1N1. He was then directly taken to the Princess Margaret Hospital from there, Tsang told reporters at a daily briefing.

"The patient had no contact with the local community," he said.

Tsang said the patient developed a fever as early as May 6, followed by a sore throat and coughing on May 8. The fever was mild when he arrived at the airport, which explained his passing the temperature screening without triggering an alarm.

Nevertheless, the patient met three family members upon arriving at the Hong Kong International Airport before going to seek medical help, Tsang said.

The patient was now in stable condition and showed no symptoms of pneumonia.

Tsang said health authorities would have to quarantine the three family members as well as three crew members and six passengers onboard the flight CX879.

The family members of the patient was now in quarantine. Authorities were tracking down the passengers who might have been in contact with the patient.

Hong Kong reported the first confirmed flu case on May 1, which involved a 25-year-old Mexican man. It triggered higher flu alert level in Hong Kong and led to quarantine measures that affected hundreds of passengers, hotel guests, among others. All those put in quarantine, including the patient, have been discharged.

In other parts of Asia, health authorities have also been keeping a close eye on the development of the influenza.

Cambodia is watching closely for unusual outbreak of influenza-like illness and severe pneumonia in the country and have further tightened inspection at international gates after A/H1N1 flu virus reaches Thailand, officials said here on Wednesday.

"We have tightened the inspection on passengers who came from affected countries and the passengers have to pass through thermalscanners for body temperature and fill health declaration procedures," said Ly Sovan, deputy director of anti-communicable department at Health Ministry.

Meanwhile, Cambodian Health Minister Mam Bun Heng on Wednesday inspected the working group of anti-communicable disease influenzaA/H1N1 at the Phnom Penh International Airport and other places.

Ly Sovan said Cambodia was concerned about influenza A/H1N1 after it has spread worldwide, and also tightened inspection on passengers at the international border gates with the neighboring countries after it reached to neighboring Thailand.

Stepping up measures to check H1N1 flu, India has started spraying aircrafts with chemical Virkon to prevent passengers from contracting the disease, the Hindi daily Navbharat Times said on Wednesday.

The precaution is being taken especially at Indira Gandhi International Airport at New Delhi, where all aircrafts that carried suspected H1N1 Influenza cases are being sprayed, said the report.

While health authorities believe the flu would be detected after the passenger has landed, the capsule carrying suspected passenger should also be sprayed so that it would not act as an agent of spread of disease, said the report.

The Virkon works by oxidative destruction of microorganisms providing exceptional performance against a broad spectrum of virus, bacteria and fungi.

(Xinhua News Agency May 14, 2009)