The Centre for Covid-19 Situation Administration (CCSA) has expanded the definition of "Patient under Investigation" (PUI) in a bid to intensify the identification of potential carriers of the novel coronavirus.
PUI is a blanket term for suspected carriers. If someone is considered a PUI, he or she must be tested. Criteria were established by the Disease Control and Medical Services Department.
Before the expansion of the definition, a person was considered a suspected carrier if he or she fell into the following categories: A person with a body temperature exceeding 37.3 degrees Celsius; a person with a lung infection; health personnel who have developed flu-like symptoms; and a group of at least five people suffering respiratory infections in the same community.
Now the PUI includes a person unable to smell and those who have visited risky areas or have certain jobs, according to the administration.
It said risky areas refer to places visited by known carriers, including districts and provinces considered as disease hotbeds.
Markets, shopping malls, medical service venues and public transport are also on the list.
As for the jobs, the CCSA said it referred to people who come in contact with tourists and large numbers of people.
Taweesilp Visanuyothin, spokesman for the CCSA, on Wednesday said the definition was expanded on May 1. "[PUIs] can go to a hospital when they have these [symptoms] or even if mild symptoms are showing," Dr Taweesilp. "This is because some infected people are [asymptomatic]."
He said those who need Covid-19 testing can be tested without paying medical bills.
The CCSA on Wednesday reported only one new Covid-19 case, bringing the total number of cases to 2,989.
The new patient is a 27-year-old Thai woman who returned from Russia on Sunday. She was first quarantined at a hotel in Samut Prakan but was later admitted to a hospital after developing a fever.
People who were aboard the flight of 70 passengers have been kept under state quarantine to monitor their conditions, Dr Taweesilp said.
There was only one death on Wednesday, taking the toll to 55.
He was an Australian national working as a hotel manager in the southern province of Phangnga. The 69-year-old was known to have suffered from asthma.
So far 2,761 patients have recovered and been discharged from hospitals, Dr Taweesilp added.