The warning came after more than 138,000 flood victims became ill and one of them was found with a leech in his anus.

"Please travel around by boats, if possible. If not, please dress carefully! Wear underpants and long pants. Also cover the lower part of your pants with plastic bags and tie tightly to ensure that no leech can climb in," the ministry's permanent secretary Dr Prat Boonyawongvirot said Sunday.

According to him, a man in Sing Buri was hospitalised after wading through chest-high floodwater. At the hospital, a doctor helped removing a leech from his anus.

"He's now safe. But we would like to warn children not to play in the floodwater," he said. He added that leeches could enter human bodies via nose, mouth, eyes, anus, vagina and urethra.

Aside from leeches, he said germs also dwelt in floodwater and could spread various diseases especially conjunctivitis, skin diseases and athlete's foot disease.

Prat said his ministry's mobile medical units had already treated 138,328 flood victims in flood-hit areas, which included Nonthaburi, Phisanulok, Sukhothai, Phichit, Nakhon Sawan, Angthong and Ayutthaya.

"We have also distributed medicines and garbage bags," he said. Currently, a large number of flood victims could not use toilets and need the garbage bags when nature called.

In Angthong, a hospital director called on people to donate eggs, rice, matches, drinking water, life vests and mosquito repellent cream to flood victims.

Angthong Hospital's director Dr Nirun Jantrakoon said interested donors could call 035615111 round-the-clock. "We have cooked boiled eggs and distributed them to flood victims through our mobile-medical units," he said.

In Chanthaburi, acting provincial public-health chief Dr Chumpol Suwan said the situation was worrying with more than 200,000 local people marooned in their houses amid furious torrents of floodwater.

 "More than 4,450 people have fallen sick," he said.

The Nation