The Public Health Ministry has opened an emergency operations centre (EOC) and ordered an investigation after more than 100 people across three districts in Phuket fell sick from an unidentified pathogen which left many suffering from severe diarrhoea.
Dr Opas Karnkawinpong, the public health permanent secretary, said health authorities are looking into the cause, which was initially believed to be a virus.
The provincial public health office has been instructed to open the EOC to handle the situation and work closely with provincial authorities as the investigation gets underway.
Dr Opas said that although diarrhoea has a low death rate, sanitation regulations still need to be strictly enforced to ensure it does not become a public health issue following reports of a flood of patients with symptoms on Thursday night.
Dr Kittisak Aksornwong, a health inspector-general, said many were admitted to hospitals in three districts of Muang, Kathu and Thalang although most of those who sought medical treatment only had mild symptoms, including stomach cramps, vomiting and a low-grade fever.
Several schools had also reported cases of students being struck by diarrhoea and ill health, he added.
Samples of water and ice were collected for examination, and health officials were sent to inspect the production and transport of drinking water in tambons Wichit and Chalaong to protect against contamination.
He urged people to consume only freshly cooked food and frequently wash their hands, while those who fall sick are advised to take sick leave where possible in order to curb transmission.