(Adds details from Singapore, Japan, Bangladesh, Malaysia)
April 26 (Reuters) - Asia, a continent that has battled deadly viruses such as the H5N1 bird flu and SARS in recent years, began taking steps over the weekend to ward off a new flu virus.
The swine flu virus has killed up to 81 people in Mexico and infected 11 others in the United States. More than 1,300 are believed to be infected in Mexico.
Following are some details of how Asian countries are responding to the crisis and how markets are expected to react:
Analysts did not think the epidemic would have a dramatic impact on markets on Monday morning, but warned that if the epidemic worsens that could change.
"It's still too early to say how far and wide this may spread but investors will be cautious," said Ben Kwong, chief operating officer with KGI Asia.
Patrick Shum, strategist at Karl Thomson Securities, agreed that investors would be keeping a close eye on developments in the coming days.
"There won't be an immediate significant impact on the market but if it is anything like SARS, especially coming at a time when most global economies are in a recession, then markets will take a hit," he said.
China's quarantine authority issued an emergency notice on Saturday night requiring people to report flu-like symptoms at ports of entry when coming from swine flu-affected places. The ministries of health and agriculture say they are closely monitoring the situation.
Singapore's ministry of health says it is monitoring the situation closely and has urged medical staff to be on the alert for any suspected human cases.
It advised the public to seek immediate medical attention if they develop symptoms of swine flu within seven days of travel to California, Texas or Mexico. It urged them to maintain good hygiene and wash hands frequently, especially after contact with respiratory secretions. Those who are sick with respiratory illnesses should avoid crowded areas and wear masks.
Health Minister Khaw Boon Wan urged citizens to limit their travel to affected areas such as Mexico and the United States, state-run FM 938 radio reported on Sunday.
"Another worrisome sign is that many of the patients have not come in contact with any farms or pigs before. So that means the human-to-human transmission is quite efficient. And of course, it has now crossed borders into the southern part of the U.S.," Khaw said.
Vietnam has launched its disease surveillance system to detect suspected cases and was seeking more information from the World Health Organisation on the disease and ways of prevention.
Nguyen Huy Nga, head of the health ministry's Preventive Medicine Department, was quoted by the state-run Tuoi Tre (Youth) newspaper on Sunday as saying the country needed to watch developments closely as the virus may be spreading in U.S. states where many people of Vietnamese origin live.
The government has stepped up quarantine and safety checks on travellers arriving from the United States and Mexico, as well as pork imports from those countries.
An emergency quarantine system is in place, with simple tests conducted on people arriving with flu symptoms at airports.
Hong Kong has stepped up surveillance at border control points and travellers found with swine flu symptoms will be taken to hospitals for further checks.
Samples taken from people with flu-like symptoms and who had travelled in the affected places within seven days before the onset of symptoms will be tested in laboratories.
Japan's Narita airport, east of Tokyo, ramped up temperature checks for travellers from Mexico using thermographic imaging equipment, which was previously in place at the airport.
Japan's foreign ministry issued an advisory asking those who were going to Mexico to consider if such trips were necessary.
According to Japan's Kyodo news agency, Prime Minister Taro Aso has ordered the cabinet's crisis management officer to come up with measures to block swine flu from entering Japan, closely cooperate with other countries and provide information to the public. The cabinet will meet on on Monday to discuss the issue.
Kyodo said Japan's farm ministry had instructed animal quarantine officers to examine imported live pigs to make sure they were not infected.
The ministry did not ask for checks on imported pork as it says cooking kills the virus. It regarded the possibility of the virus turning up in pork to be low, Kyodo reported.
Agriculture Secretary Arthur Yap ordered more monitoring of ports of entry to stop the entry of pigs or pork from Mexico and the United States.
Yap said there was no outbreak of swine flu in the Philippines but ordered government agencies to encourage regular vaccination of hogs.
Malaysia's health ministry has begun screening passengers travelling to and from Mexico at all border points.
The veterinary department will meet the Pig Farmers Association on Monday and brief the health minister on the matter, the Veterinary Services Department's Director General, Abd Aziz Jamaluddin, told Reuters by phone on Sunday.
Sheikh Altaf Ali, secretary of the ministry of health and family planning, said the government was aware of the flu outbreak and was monitoring it. (Reporting by Asian bureaux; Writing by Tan Ee Lyn in Hong Kong; Editing by Alex Richardson and Dean Yates)