SAO PAULO -- Brazilian scientists have identified a new strain of the swine flu virus after examining samples from a patient in Sao Paulo, their institute said on Tuesday.

The variant has been called A/Sao Paulo/1454/H1N1 by the Adolfo Lutz Bacteriological Institute, which compared it with samples of the Influenza A(H1N1) virus from California.

The genetic sequence of the new subtype of the H1N1 virus was isolated by a virology team led by one of its researchers, Terezinha Maria de Paiva, the institute said in a statement.

The mutation comprised of alterations in the Hemagglutinin protein which allows the virus to infect new hosts, it said.

More aggressive

It was not yet known whether the new strain was more aggressive than the A(H1N1) virus which has been declared pandemic by the World Health Organization (WHO).

The genetic makeup of the H1N1 virus and its subvariants are important for scientists.

Pharmaceutical companies are working to mass produce a vaccine against the current A(H1N1) flu.

According to the WHO, 36,000 people in 76 countries have been infected with the H1N1 virus, causing 163 deaths. AFP