By Jack Kim
SEOUL (Reuters) - Two South Korean hospitals are conducting experimental treatment on Middle East Respiratory Syndrome (MERS) patients, injecting them with blood plasma from recovering patients, the health ministry said on Tuesday, as four new cases were reported.
The procedure has been conducted on two consenting MERS patients in addition to existing care, the ministry's head of public health policy, Kwon Jun-wook, told a media briefing.
"There is insufficient clinical basis about the result of plasma treatment among experts in the country," Kwon said, but added: "The ministry has deep confidence in the medical staff on the direction of the treatment."
Plasma treatment was previously used in SARS patients with some positive results in seriously ill patients that led to a decrease in the death rate by up to 23%, Kwon said.
Plasma therapy has not been widely tried for MERS patients, with little clinical study results reported, Eom Joong-sik, professor of infectious diseases at Hallym University's medical college.
Three years after the MERS virus first emerged in humans, there is no cure or vaccine that can protect people from falling sick with it, and little work has been done in develop a vaccine, despite considerable available scientific detail.
South Korea first confirmed MERS on May 20.
Four new cases were reported on Tuesday, bringing the total to 154 in the South Korean outbreak, the largest outside Saudi Arabia. The ministry also said three more patients with MERS had died, taking the South Korean death toll to 19.
The World Health Organization (WHO) has called the South Korean outbreak "large and complex" and all MERS cases have been traced to healthcare facilities.
The health ministry has put more than 5,500 people in quarantine, at home or in health facilities.
MERS is caused by a coronavirus from the same family as the one that triggered China's deadly 2003 outbreak of Severe Acute Respiratory Syndrome (SARS).
The vast majority of MERS infections and deaths have been in Saudi Arabia, where more than 1,000 people have been infected since 2012, and some 454 have died.
The number of new MERS cases in South Korea continued to be sharply lower than last week, when the daily increase reached as high as 23.
The WHO, which conducted a review of South Korea's response last week, said on Saturday the decline suggested control measures were working.
The WHO has scheduled a meeting of its MERS emergency committee later on Tuesday in Geneva to provide technical updates on epidemiology and advice on future actions to be taken in response to the outbreak.