Dr Pratch Boonyawongsaviroj, the Public Health Ministry's acting permanent secretary, said 59 patients remained in Nan Hospital, 11 of whom still needed respirators to breathe.

They are among 160 people from Nan's Navai Mai village who were rushed to hospital after eating contaminated bamboo shoots at a merit-making ceremony earlier this month.

No additional patients have turned up in Navai Mai so far.

Last week, 17 villagers in critical condition were transferred to better-equipped Bangkok hospitals, while another nine seriously ill patients were moved to nearby provinces including Chiang Mai, Phitsanulok and Lampang.

Dr Pratch said the condition of the 17 patients in Bangkok remained unchanged. All of them of would require the use of breathing apparatus for at least another few weeks, the doctor said.

Two patients admitted to Nakorn Chiang Mai Hospital had inflamed lungs, said Dr Chaiwat Bamrungkij. "Both patients will need respirators for as long as another two months," he said.

Dr Pisit Sriprasert, head of Nan's Public Health Office, said mobile units would be sent daily to provide medical services for 79 recovered patients who had returned home as well as other people in need of care in Navai Mai village.