Infections with HIV-1 group O are found in 1 to 3 % of persons living with HIV in Cameroon. The natural history and treatment response is not well understood. The natural resistance to non nucleoside reverse transcriptase inhibitors and their possible low sensitivity to protease inhibitors complicate the choice of an adequate treatment options.

This observational study is aimed at evaluating the antiretroviral treatment response of HIV-1 group O infected patients in comparison with HIV-1 group M infected patients. The proposed standardized follow-up will facilitate a better understanding of the natural history and treatment specificities to improve the patients management.

This is a non randomized study, open label, with standardized follow-up. A total of 171 patients

Inclusion Criteria:

• HIV-1 group O or group M infection
• No history of antiretroviral treatment (except for PMTCT)
• Criteria for treatment initiation according to the Cameroons national guidelines

Exclusion Criteria:

• Ongoing traditional treatment which could interfere with hepatic function
• Ongoing treatment with rifabutin, rifampicin or rifampin
• Acute hepatitis B infection
• Pregnancy or lactating mother
• HIV-1 group O and group M co-infection

HIV-1 infected patients coming for medical care in four treatment centers in Yaounde.