The spread of HIV can be reduced by changing the behaviour of infected people, a study has found.

The five-year study was conducted by two University of KwaZulu-Natal (UKZN) scientists and involved almost 2000 participants.

It found that initially, 55 percent of the sexually active people in the group practised unprotected sex.

The study used the information, motivation and behaviour skills (IMB) approach to behaviour change, developed by professors at the University of Connecticut, in the United States.

It found at the end of the five-year period that there was an 88 percent reduction in unprotected sex between the HIV-infected participants and their partners.

One of the University of Connecticut professors, Jeffrey Fisher, said in a statement too many HIV prevention programmes depended on providing patients with information only.

"This significant reduction in risky sexual behaviour... demonstrates that providing a tailored, rigorously evaluated intervention based on a combination of information, motivation and skills can be a useful addition to the HIV prevention strategy in South Africa."

UKZN professor Sandy Pillay said HIV prevention needed to be promoted among those diagnosed as positive.

"This study provides an evidence-based approach which could be used for this important link in HIV prevention," Pillay said.

"After all, HIV spread is totally dependent on behaviour and effecting behaviour change has to be the foundation of any HIV prevention strategy."

The study was funded by the National Institute of Mental Health of the United States, in collaboration with the University of Connecticut and the KwaZulu-Natal health department.