A woman from Cameroon has been found to be infected with an AIDS-like virus that came from gorillas, French researchers reported Sunday.

The woman, who has no symptoms of HIV infection, is well and was likely infected by another person, not an animal, the researchers said.

Their findings suggest this newly discovered gorilla virus is circulating among people, they reported in the journal Nature Medicine.

We have identified a new human immunodeficiency virus in a Cameroonian woman. It is closely related to gorilla simian immunodeficiency virus and shows no evidence of recombination with other HIV-1 lineages or with chimpanzee SIV, Jean-Christophe Plantier of the Universite de Rouen in France and colleagues wrote.

The 62-year-old woman was diagnosed in 2004, soon after she moved to Paris from Cameroon. Routine genetic sequencing of the virus showed it looked like no other sample of AIDS virus and it was eventually compared to a gorilla simian immunodeficiency virus, itself only discovered in 2006.

AIDS, which has infected an estimated 33 million people globally and has killed another 25 million, has been traced to chimpanzees. Scientists say it likely jumped to people who hunted and butchered the chimps, which are the closest living genetic relatives of humans.

Our findings indicate that gorillas, in addition to chimpanzees, are likely sources of HIV-1, Plantier's team wrote.

The discovery of this novel HIV-1 lineage highlights the continuing need to watch closely for the emergence of new HIV variants, particularly in western central Africa, the origin of all existing HIV-1 groups.

The woman, a widow, herself had no contact with gorillas but said she had several sex partners after her husband died. She remembered having been sick once.

When people become newly infected with HIV, they often have a fever and minor illness at the time but rarely know what it is. They are usually diagnosed later, after the virus has begun damaging the immune system.

There is no cure for HIV but drugs can control it for years.