A doctor who treated South Korea's first MERS patient was confirmed to have been infected with the disease Wednesday, sparking fears that it is more contagious than previously thought.
The 50-year-old, whose name was withheld, became the first member of the local medical staff to have caught Middle East respiratory syndrome, according to the Korea Centres for Disease Control and Prevention.
He had treated the 68-year-old patient on May 17, and has been quarantined since Friday after health authorities confirmed the MERS outbreak. He started showing symptoms of fever and diarrhoea around Monday.
A female nurse who also tended to the patient tested negative, as did two other people suspected of infection. As per regulation, people who test positive and negative are quarantined for 14 days ― the incubation period of MERS ― since their last contact with the initial source, in this case the country's first MERS patient.
Later in the day, a suspected case of MERS was reported at a town in North Jeolla Province. A 25-year-old women who recently visited Middle East told authorities that she had mild flu-like symptoms which were similar to the disease. However, the authorities said she was not likely to be infected.
The CDC is currently keeping tabs on 63 people who came in direct contact with MERS patients.
As of Wednesday afternoon, five people have tested positive in just six days since the initial report of the disease. South Korea now has the highest number of MERS patients among non-Middle Eastern nations.
First reported in 2012 in Saudi Arabia, more than 95 per cent of the confirmed cases worldwide have been in the Middle East, where the first Korean MERS patient has visited shortly before being diagnosed. The other four are believed to have been infected after coming in contact with him.
There have been nationwide concerns that the disease may progress to become epidemic, given its rapid rate of infection over the past few days.
Authorities have repeatedly said the possibility of airborne infection is not high, saying that it was a "mere coincidence" that the doctor caught the disease.
"As (the doctor) had not been aware of the disease and did not wear a mask while tending to the patient, it could have been spread by droplet infection," an official from CDC said "There hasn't been a report of the disease spreading by air."
Much of the blame for spread of the disease has fallen on the health authorities, who have been accused of a lackluster initial response.
The fourth patient, who is the daughter of an MERS-infected patient, had reportedly asked to be quarantined after experiencing mild symptoms. But authorities turned her down, saying her symptoms were not strong enough to be considered MERS.
Health Minister Moon Hyung-pyo addressed such criticism in a special report to the parliamentary health and welfare committee and acknowledged that the ministry should have been better prepared.
"We will set up around-the-clock monitoring. If a person who has been in contact with a patient starts showing symptoms, we will immediately quarantine and examine that person," he said.
A CDC official said the organisation has altered the standards for quarantine of potential MERS patients, so that one can be isolated upon request even if he or she does not show strong symptoms.
To date, 1,142 people from 23 countries across the country have been infected by MERS, of which 465 died.