TOKYO, Jan. 20 (Xinhuanet) -- Japan's Ministry of Health, Labor and Welfare on Tuesday confirmed that a patient contracted the AIDS virus after receiving a transfusion of HIV-tainted blood that had cleared the Japanese Red Cross Society's virus-detection test.

This was Japan's first confirmed HIV infection through a transfusion of donated blood since the Red Cross introduced the current donated-blood testing system in 1999, the ministry said.

A public testing organization has found that the HIV gene sequences detected in the donated blood in question were identical to those in the blood of the patient who received the transfusion, it said.

The blood in question tested HIV-negative in May last year and was used in the transfusion.

But the blood donor tested HIV-positive when he attempted to give blood again in November, and a stored sample of the blood was found infected with the AIDS virus when retested with a more advanced method, according to the ministry. Enditem