HANOI, June 11 (Reuters) - Vietnam"e;s first human bird flu case in a year and a half left hospital on Monday, doctors said, as the country tries to control numerous outbreaks of the virus in poultry.

The Animal Health Department said four bird flu cases in poultry were found at the weekend in the northern province of Bac Giang and near Haiphong city. Both have been on the government"e;s bird flu watchlist along with 13 other provinces and a city.

A 30-year-old man was admitted to a Hanoi hospital on May 15 after he helped slaughter chickens at a friend"e;s wedding. Vietnamese doctors confirmed he had the H5N1 bird flu virus, the first human case since November 2005.

Doctors at the Bach Mai hospital who treated the man said they increased the dosage of anti-viral drug Tamiflu to 10 days from seven days. They detected the virus in the man"e;s saliva, in his stomach as well as in his excrement.

The patient eventually recovered and was discharged on Monday morning, state-run VnMedia e-newspaper (www.vnmedia.vn) said.

Doctors were still treating a second patient, a slaughterhouse worker from outside Hanoi who became sick late last month. The patient was recovering well, they said.

Bird flu has killed 42 people out of 95 known infections in Vietnam since late 2003. The World Health Organisation (WHO) has not confirmed the two most recent infections in Vietnam.

Globally, the H5N1 virus has killed 189 people out of 310 known cases, according to the WHO. Hundreds of millions of birds have died or been slaughtered, including more than 100,000 in Vietnam"e;s latest outbreaks since early May.