HONG KONG - A local microbiologist said on Monday that the number of Middle East Respiratory Syndrome (MERS) cases in South Korea is expected to climb and the key is to track down the source of infection.

Ho Pak Leung, a microbiologist at the University of Hong Kong, said on a local radio program that protective measures has been neglected in hospitals in South Korea over the past two weeks, resulting in the rise in number of MERS cases.

Ho expected the number of infection to grow and sporadic cases be found in hospitals in South Korea, adding that tracing the source of infection would be most crucial at the moment.

In Hong Kong, two suspected patients of MERS, who had recently traveled to South Korea, are under isolation, the region's Center for Health Protection announced on Sunday, saying both are in stable condition.

The two cases involve a 21-year-old woman and a 66-year-old man, who attended a hospital on June 3 and an out-patient clinic on June 2 respectively in South Korea.

To date, 86 MERS cases have been reported by South Korea, according to the center, adding it would maintain close communication with the World Health Organization and South Korean health authorities.