Health officials are monitoring the condition of 12 people who were in close contact with a traveller diagnosed with monkeypox who transited through Thailand for two hours while en route to Australia.
Chakrarat Pittayawonganon, director of epidemiology at the Department of Disease Control, said yesterday the 12 people were passengers and flight attendants on the same flight as the confirmed case.
They have been asymptomatic over the past seven days and would be monitored for 21 days in total, the disease's incubation period.
Dr Chakrarat said the confirmed case travelled from Europe and spent two hours in transit.
Those who were in close contact with the case were not at high risk because the infected passenger was asymptomatic during the transit period.
The confirmed case developed symptoms in Australia, where the diagnosis was made.
"So far there has not been a confirmed case in Thailand," Dr Chakrarat said.
There have been 406 confirmed monkeypox cases and 88 suspected cases recorded in 32 countries as of Sunday, according to Dr Chakrarat.
These include 139 cases in Spain, 101 in Britain, 74 in Portugal, 63 in Canada, 22 in Germany and 13 in the United States.
The disease is endemic to Central Africa.
Dr Chakrarat said that monkeypox was not a dangerous communicable disease and was rated as a communicable disease justifying surveillance, like malaria and dengue haemorrhagic fever.
Symptoms include fever, sore throat, headache, body ache, backache, swollen lymph nodes, a rash, blisters and scabs.
Health officials were looking for arrivals with such symptoms and those who came from countries where there were cases, including African countries, Spain, Canada, Germany, Portugal, Britain and the US.
Officials were also looking for people who may have been in close contact with wild animals and monkeys imported from Africa.
The World Health Organization (WHO) said in its latest update, issued on Sunday, that: "One case of monkeypox in a non-endemic country is considered an outbreak. The sudden appearance of monkeypox simultaneously in several non-endemic countries suggests that there may have been undetected transmission for some time as well as recent amplifying events."