The Public Health Ministry has issued alerts instructing all international airports to step up their screening of arrivals, especially from 17 countries where monkeypox cases have now been confirmed, according to its deputy minister, Sathit Pitutecha.
"Each airport has a disease control unit and officials will intensify measures against monkeypox by being more vigilant," he said.
Skin disease and sexually transmitted disease clinics will be asked to watch out for monkeypox as Mr Sathit urged the public to keep abreast of the situation from the Department of Disease Control (DDC).
Dr Chakkarat Pitayawonganon, director of the DDC's epidemiology division, said travellers from the UK, Spain and Portugal are being closely monitored for monkeypox.
He said travellers from these countries who have visible symptoms such as rashes will be asked to take a test, adding that no tests have been conducted so far.
The ministry has not declared monkeypox a dangerous communicable disease yet and no domestic cases have been reported. However, it will meet to assess the risk of infection, he said, adding the ministry has not considered a vaccination programme.
Dr Supakij Sirilak, director-general of the Department of Medical Sciences, said smallpox vaccines are known to be 85% effective against monkeypox and the department is well-equipped to test and approve such vaccines if needed.
As smallpox was eradicated in 1980, vaccination against the disease has not taken place for 40 years. However, vaccines have been developed against the virus out of concern it could be used as a bio-weapon.
He said three drugs -- tecovirimat, cidofovir and brincidofovir -- which were developed to treat smallpox are still being analysed for their effectiveness.
The World Health Organization (WHO) held an emergency meeting on Friday to discuss the outbreak after more than 100 cases were detected in Europe.
Monkeypox causes symptoms which are similar to smallpox although they are often less severe and it is not as contagious.
Thassayu Dechachote, chief of disease control at Phuket airport, said the airport is stepping up surveillance against monkeypox as 130 passengers have come from at-risk countries recently. But no cases have been found so far.