Thailand has stepped up bird flu surveillance in seven provinces for the hot, monsoon season when the virus could re-emerge, a senior government official said on Saturday.

"July is a risky month. Over the past two years the outbreak started this month," Yukol Limlaemthong, head of the Livestock Department, told Reuters.

He said four northern provinces -- Uttaradit, Sukhothai, Phitsanulok and Pichit -- would be closely monitored for outbreaks of the H5N1 virus, which has killed 14 Thais since it emerged in late 2003.

"They are risky areas because of flooding and the rainy season. This situation is good for the virus to grow. We have not found the virus, but we want people to be alert," Yukol said.

Three provinces where outbreaks have occured in the past two years -- Suphan Buri and Kanchanaburi in the west and Nakhon Pathom near the capital, Bangkok -- were also on the watch list.

Thailand was slow to respond to the disease when it began ravaging poultry flocks in late 2003, but it now has one of the strongest surveillance systems in the region.

Thailand has not had a human death since December 2005 and no new outbreaks among poultry for about 8 months.

However, a recent incident where Thai villagers ignored government warnings and handled and ate chickens that died mysteriously has raised fears that public vigilance against the disease is waning.

The global human death toll now stands at 132 after Indonesian officials said on Friday a three-year-old girl who died this month had tested positive for the virus.

Experts fear the avian influenza virus could spark a human pandemic if it mutates into a form that can pass easily among people.