Cotrimoxazole is a broad-spectrum antibiotic comprising two folate pathway inhibitors, trimethoprim and sulfamethoxazole. In sub-Saharan Africa cotrimoxazole treatment reduces death and illness among people with HIV infection by reducing bacterial, fungal and protozoan infections. The World Health Organisation (WHO) now recommends that all children living with HIV infection in regions where the risk of severe bacterial infections and malaria are high take long-term cotrimoxazole as an adjunct treatment to antiretroviral therapy (ART).

We are researching the impact of cotrimoxazole treatment on clinical outcomes and immune function in both HIV-infected and uninfected people with the aim of understanding why it is such an effective drug. In particular, we are interested in why it continues to reduce death and illness among people with HIV infection even when there are very high rates of antibiotic resistance among common infections. Since HIV infection is characterised by abnormally high inflammation and higher inflammation tends to predict worse clinical outcomes, we are exploring whether or not cotrimoxazole affects inflammation. A better understanding of this widely-used drug will help to inform how to use it more effectively to improve health outcomes for all people with HIV infection.

For more information, refer to our recent review of cotrimoxazole usage in developing countries: