By The Nation
Sunday's total is the highest on a single day since the outbreak.
Dr Taweesin Visanuyothin, spokesman for the Public Health Ministry, said on Sunday that the new cases could be divided into three groups.
The first group of 65 are connected to cluster cases -- 21 people had attended a boxing event in a stadium, five had been to entertainment venues, two had attended religious ceremonies and 37 had had close contact with others previously confirmed as infected.
The second group comprises 15 people of whom eight had just travelled back from overseas (six Thais returned from Paoy Paet district in Cambodia, and two were foreign students), while seven had been working near boxing stadiums.
The origin of the virus in the third group of 108 is still being investigated.
Meanwhile, one patient has recovered fully and returned home.
As of March 22, the total number of confirmed cases in the country stands at 599 -- 553 are under treatment, 45 have recovered and been discharged, and there has been one death.