The three patients hospitalized with the infectious disease are all men, and their ages range from 21 to 40 years, DDC director-general Dr Tharet Krutnairawiwong told a press conference.
Two of the men were close friends, Tharet said. He said one of the three patients is a foreigner.
All three patients had mild cases and are recovering at Bamrasnaradura Infectious Diseases Institute.
After three weeks – when they are no longer contagious – they will be discharged from the hospital, Tharet said.
Since Thailand classified monkey pox as a serious communicable disease requiring close surveillance on May 25 last year, a total of 18 cases have been detected in Thailand, including the three new cases.
The first case was detected on July 21 last year.
Investigations of the three new cases convinced health officials that the men were admitted to hospital before they were able to spread the virus, Tharet said.
The virus is spread through contact with an infectious blister or through sex with infected people.
The DDC will continue closely monitoring for the disease as an average of one to three cases are detected monthly, said its deputy director-general, Dr Sophon Iamsirithaworn.
Avoid close contact with people who have blisters and refrain from having sex with strangers, he advised.