The government is keeping a close watch on three members of a family reportedly suffering from idiopathic pulmonary fibrosis.

The disease is thought to be similar to the mysterious virus which recently killed three pregnant women.

According to the Korea Centers for Disease Control and Prevention, an agency under the Ministry of Health and Welfare, a 32-year-old woman and her 6-year-old daughter, both unidentified, were admitted to a general hospital in Seoul with the disease.

The illness hardens tissue, impairing lung function. Another girl, aged 1, has been admitted to a hospital in Busan with the same symptoms ― constant coughing and breathing problems.

While the mother and the older child have been put on the waiting list for a lung transplant, the 1-year-old is too young to receive the surgery, the KCDC said.

All eyes are on whether their disease is related to the pulmonary disease that killed three of seven pregnant women who were hospitalized with it since April. If so, it will be the first case reported since May and will concern the government, which has flatly denied the possibility of a massive outbreak.

The authorities said the recent case differs from the previous disease in its pattern of development.

“Since the two children are too small to have a biopsy using a pulmonary endoscope, it is hard to get exact information. But it seems that the pattern of developing the idiopathic pulmonary fibrosis is not similar to that of the other patients reported to have similar symptoms,” a ministry official said.

“Doctors said the mother-daughter case seems to be a simple developed form of pneumonia,” Yang Byung-gook, a KCDC official, said.

Experts have detected adenovirus in one of the seven patients diagnosed with the earlier disease, but have yet to identify it or the route of infection. The government has denied that the disease is infectious since no additional patient has been reported since mid-May.

By Bae Ji-sook (baejisook@heraldcorp.com)