The risk from receptive anal sex is five times higher, he said, and circumcision would obviously not protect those men.
A European study estimated the risk of receptive vaginal intercourse to be 0.08%, and insertive vaginal intercourse to be 0.04%.
However, recent studies have raised concerns that a high prevalence of injection risk (including receptive and distributive syringe sharing) persists among new injectors and young IDU [ 6, 7].
Using a high-resolution population map for Namibia, population at risk by receptive and current endemicity by region and population adjusted PfPR2-10 by health district were computed.
A study estimated a per-act risk of receptive oral intercourse with ejaculation at 0.06% with an HIV-positive partner or partner of unknown status, with no increased risk with insertive oral intercourse.
However, convincing data on the relative risks of receptive and insertive UAI have long been available.
Relative to the receptive risks, current risk estimates show that over 85% of the approximately 1.4 million people of northern Namibia have transitioned to endemicity levels that are at least one class lower and PA PfPR2-10 by 2009 were largely <5%.
If the response system is overwhelmed by numerous cases, prioritization of cases for response can be made based on the likelihood of onward transmission, as is exemplified in Swaziland where prioritization is based on local receptivity derived from risk maps the most receptive areas being responded to first.
The data with which the model was developed were collected at a time when vector control and anti-malaria drug use were deployed extensively, especially in Ovambo, Kavango and Caprivi regions and therefore our estimates of receptive risk, while higher than current risk, is not a measure of intrinsic transmission potential in the absence of control.
Sexual role was a more important risk factor with receptive partners having higher odds of being infected with a STI.
