Thailand's public health ministry has listed 14 provinces as at risk from reappearance of the H5N1 birdflu virus.

"The cool weather provides a good environment for it," said deputy permanent secretary Dr Paijit Warachit.

He named Bangkok, Nonthaburi, Pathum Thani, Ayutthaya, Lop Buri, Chai Nat, Prachin Buri, Nakhon Nayok, Suphan Buri, Kanchanaburi, Nakhon Ratchasima, Chaiyaphum, Khon Kaen and Nong Bua Lamphu as provinces prone to birdflu risk.

Paijit said he has instructed health officers known as "Mr Bird Flu" across the country to monitor for avian flu and infection in humans, especially in provinces where the virus appeared frequently.

He said the ministry was bringing in stricter controls, even though H5N1 infection in humans had not been reported for three years.

Measures include rapid detection and reporting of infection, rapid primary spreading control, sampling, containment training, laboratory preparation and information on prevention.

He said national strategy covered poultry farming, surveillance, prevention of human and animal infection and pandemic preparedness.

The World Health Organisation says 61 countries are infected. Thailand has seen 25 human cases, of whom 17 have died.