A man in Northern Vietnam has been confirmed infected with a deadly bird flu virus, a second reported case in two weeks, news media reported.   Vietnam had not seen any human case of bird flu for last 18 months.

The man, whose name was not released and who worked at a poultry slaughterhouse in the capital Hanoi, was hospitalized on May 19, days after he fell sick, a local newspaper called Tien Phone was cited as saying.

The paper said a Vietnamese laboratory conducted tests and found the man who experienced breathing difficulties, a runny nose and a persistent chill, was actually infected with the lethal H5N1 bird flu virus.  

The doctor Nguyen Duc Hien who took care of the patient said the patient is now in a stable condition.   No further information on the man was available from Hien.

Media cited Nguyen Thuy Hanh director of Bach Mai hospital was saying that a few other patients with bird flu-like symptoms received treatment in Hanoi hospital in the past few days, but their test results are expected soon.

The first case in the last two weeks involved a 30-year old man from Vinh Phus province who tested positive for the bird flu on May 20.

The man, who reportedly slaughtered chicken for a friend’s wedding, is reportedly being treated at Hanoi's Bach Mai Hospital.

Vietnam is known for its aggressive measures taken to protect against the spread of the bird flu.   Culling and mass vaccination are two measures the government used to have successfully gotten previous bird flu outbreaks since 2003 under control.

The early outbreaks of H5N1 bird flu are believed to have infected 94 and killed at least 42 people in Vietnam, but no more deaths have been reported since November 2005, media reported.

A recent wave of outbreaks has killed or led to culling of more than 50,000 birds.   Bird flu has reportedly spread rapidly to 14th province in northern Vietnam, according to a government posting, cited by the Associated Press.

H5N1 is highly pathogenic or virulent. But it is largely a disease of birds.   It is not easy for people to get infected and it's particularly hard for the virus to spread from human to human as it's too lethal to spread from one host to another.

According to the World Health Organization, the H5N1 strain has killed at least 187 people worldwide.   Experts and government officials worldwide are worried that persistent outbreaks may create an opportunity for the virus to mutate into a more dangerous strain, leading to world flu pandemic and potentially killing millions of people.