By Panarat Thepgumpanat and Orathai Sriring
BANGKOK (Reuters) - Thailand reported its first domestic coronavirus transmission in more than 100 days on Thursday, after a man recently jailed and with no overseas travel history tested positive in a Bangkok prison during a routine check for new inmates.
Authorities moved quickly to locate and isolate people in contact with the 37-year-old and trace his movements over the past two weeks, including three places where he had worked, the jail and the court at which he had appeared.
"We may go further back but we will examine this first," said Walailak Chaifu, Director of the country's Bureau of Epidemiology.
The new case will be a setback for Thailand, which has been credited with keeping the highly contagious virus under control, while maintaining months of immigration curbs that have devastated its tourism-reliant economy. It has removed most of its internal coronavirus restrictions.
The inmate, a former nightclub DJ, tested positive on Wednesday and had not travelled abroad or been in close contact with a known case, the corrections department said.
All of Thailand's cases since late May - typically less than a handful each day - have been found in state quarantine among people returning from overseas. It has reported just 3,427 cases and 58 deaths in total.
Thailand is the second country in Southeast Asia to see community transmission resume following a lengthy containment period, after the virus resurfaced in Vietnam in late July, also after a 100-day absence.
Methipoj Chakametikul, head of Bangkok's disease control division, said five "high risk individuals" had been identified at the inmate's home plus two others who had left Bangkok.
"We ordered the closure of his work places for three days for cleaning and are investigating his close co-workers," Methipoj said.
Officials sought to downplay the prospect of a second wave of cases and said more laboratory results were needed to be certain that the infection was recent.
"We've identified an infection, but in terms of an outbreak, we are investigating," said Suwanchai Wattanayingcharoen, director-general of the Department of Disease Control.
"If we all help each other, then it will not lead to an outbreak."
(Additional reporting by Chayut Setboonsarng; Editing by Martin Petty)