Brown University researchers have refuted claims of promiscuity and overlapping multiple sexual partners driving the HIV epidemic. Their study results suggest that there is not much scientific evidence to support the idea.

Thus, they have said that more research is needed to prove that the sexual practice of concurrency has accelerated the spread of HIV in Africa.

"People have just accepted at face value that this is the main thing that's driving the epidemic. But the evidence that concurrency is a major factor is very weak," said epidemiologist Mark Lurie, assistant professor community health and medicine.

In their argument, Lurie and co-author Samantha Rosenthal have said that there is no conclusive evidence that overlapping multiple sexual partners increases the size of an HIV epidemic, accelerates the speed at which the virus is transmitted or makes HIV more persistent in a given population.

They drew their conclusion by looking at previous studies that examined concurrency in any way.

And this, they say, is because HIV epidemics can't be explained by a single variable-a number of factors are more likely, with some factors more important in some geographic areas than others.

"The studies you need to prove causality don't exist. None of those studies have been done," said Lurie.

While the researchers don't dispute the notion that concurrent sexual relationships could "theoretically" play a major role driving HIV transmission through networks of people, but to prove this true, a number of research initiative are needed, they said.