BEIJING, July 25 (Xinhuanet) -- Chinese Ministry of Health and Ministry of Agriculture are closely monitoring the swine virus infection that took place in southwest China's Sichuan Province.

The ministries have reported the infection to the World Health Organization, the UN Food and Agricultural Organization and health authorities of Hong Kong, Macao and Taiwan, said the Health Ministry Monday.

Preliminary probe shows the unknown disease in Sichuan was caused by a kind of a swine virus known as streptococosis II.

The province has reported 80 cases of the infection as of Monday, including 67 confirmed cases and 13 suspected cases. Nineteen people have been reported dead and 17 people are in critical condition. Four have been discharged from hospital, according to the Ministry of Health.

The patients came from 75 villages in 40 townships in cities and counties including Ziyang City, Jianyang City, Lezhi County and Zizhong County in Neijiang City.

All the patients had direct contact with ill or dead pigs before showing symptoms, said experts.

The patients first reported symptoms of fever, weakness and sickness, and then got symptoms of endemic bleeding and shock. Their number of the white blood cells has also been soaring along with the progression of the disease.

Judging from the symptoms and tests of the dead pigs, experts reached the preliminary conclusion that the disease was caused by swine streptococosis II.

With the enlarged searching, the number of the affected people has been increasing, but the cases were dispersed in different areas with no obvious signs of epidemic relationships. No evidence has been found that the disease can spread among human beings, said the ministry.

Swine streptococosis was first spotted in the 1950s and has been reported in many countries including France, Denmark, the United States and Canada.