The ministry said many had become ill with water-borne bacterium and parasites.

More than 138,000 flood victims had fallen sick. One was discovered to have been penetrated by a leech.

"Travel around by boat, if possible. If not, dress carefully. Wear underwear and long pants. Also cover the lower part of your pants with plastic bags and tie them tightly to ensure leeches cannot enter," ministry permanent secretary Dr Prat Boonyawongvirot said yesterday.

He explained one Sing Buri man had been hospitalised after wad-ing through chest-high floodwaters. A parasitic leech needed to be removed from his anus.

"He's now safe. But, we would like to warn children not to play in floodwater," he said.

Leeches could enter the human body via any orifice.

The ministry warned flood-waters teemed with bacteria and could spread disease and infection including conjunctivitis, skin disease and fungus.

Prat said ministry mobile medical units had treated 138,328 victims in flood-hit provinces in-cluding Nonthaburi, Phitsanulok, Sukhothai, Phichit, Nakhon Sawan, Angthong and Ayutthaya.

"We have distributed medicine and garbage bags," he said. The bags were used to collect human waste.

Angthong needed donations of food, water and supplies like life vests and mosquito repellent.

Angthong Hospital director Dr Nirun Jantrakoon said it was distributing donated supplies using mobile units. Donations could be arranged by calling (03) 561 5111, 24 hours a day.

Chanthaburi's acting provincial public health chief Dr Chumpol Suwan said the situation was worrying. More than 200,000 people were marooned by fast-flowing floodwaters.

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