SEOUL, June 3 -- The number of South Koreans tested positive for the deadly Middle East Respiratory Syndrome (MERS) rose to 30 on Wednesday as five new cases were identified, the health ministry said.

Among the five new cases was one tertiary infection, sending the total number of contagion from the secondary infection to three, according to the Ministry of Health and Welfare.

A 77-year-old woman and three men aged 43, 55 and 58 each were infected from the patient zero for three days from May 15 at the hospital, which the first patient visited secondly.

A majority of secondary infection happened at the second hospital during the three-day period. The first patient visited a total of four hospitals.

The tertiary contagion was a 60-year-old man who shared a room with the 16th infectee for about a week from May 22. The 16th infected man, 40, also transferred the MERS corona virus to two others.

The 16th infectee was initially excluded from the government's isolation list, and was later tested positive for the viral disease after the health authorities conducted a broader range of epidemiological survey.

The MERS is a respiratory illness caused by a new type of corona-virus that is similar to the one causing Severe Acute Respiratory Syndrome (SARS). There is no vaccine or treatment for the disease, with its fatality rate reaching 40.7 percent.

The first case was spotted in Saudi Arabia in 2012. The World Health Organization has reported more than 1,000 cases of MERS globally and more than 400 deaths.