DDC director-general Dr Opas Karnkawinpong said the Bamrasnaradura Infectious Diseases Institute informed the department on Saturday that the woman had tested positive for the disease.
The patient had reportedly had intercourse with a foreigner but had not travelled abroad recently.
Opas said the patient developed a low fever on August 20 and found blisters near her anus the following day. On August 22, more blisters appeared in other parts of her body, prompting her to seek treatment at the institute in Nonthaburi province.
Doctors conducted real-time polymerase chain reaction (RT-PCR) tests and confirmed her infection on Friday.
So far, three people have come in close contact with the woman and are being closely monitored. Since they last came in contact with her on August 21, they will be monitored until September 11.
“Avoid touching the bodily fluids of anyone who has a fever, rash or blisters, and avoid having sexual intercourse with untested persons. Always wear a facemask in public, wash your hands regularly with soap and water or alcohol sanitiser,” Opas said.
“If you find blisters, rashes or pustules on your body along with symptoms like fever, headache, muscle ache and swollen lymph nodes, get tested immediately or call the 1422 DDC hotline.”
As of Saturday, 48,331 monkeypox cases have been identified worldwide with 15 deaths. The five countries with the most cases are the US, Spain, Brazil, France and Germany.
Thailand has seen seven cases since the first case was identified in July. Three of the patients were foreign arrivals and the other four locals who had come in contact with foreigners. Four of the seven patients have recovered, while three are still in hospital.