WHO reaffirms: it's not dirty needles, it's unsafe sex. (Environmental Intelligence).

A politically volatile finding about how HIV is transmitted in sub-Saharan Africa has been refuted by an expert group convened by the World Health Organization (WHO) and UNAIDS.

The controversy erupted in recent months with the publication of a series of articles in the International Journal of STD and AIDS, which purportedly linked the majority of infections to unsanitary medical practices, including the reuse of needles, contaminated blood transfusions, and the use of improperly cleaned surgical tools. The articles, by a group of researchers headed by David Gisselquist (an independent consultant with a Ph.D. in economics), contend that only about a third of all HIV infections in sub-Saharan Africa are due to heterosexual transmission. Those conclusions flatly contradict the findings of WHO/UNAIDS, which attribute 90 percent of African infections to unsafe sex. Gisselquist's team suggests that Western preconceptions about Africans' sexual promiscuity and the fear of generating public distrust in health care have prevented the evidence of medical exposure to HIV from being fully examined until now.

In response, WHO/UNAIDS convened an expert panel to review the evidence to date, including the work by Gisselquist. The panel found significant flaws in the Gisselquist claims, and reaffirmed that unsafe sex is the predominant mode of HIV transmission in the region, with injections accounting for approximately 2.5 percent of infections. The WHO/UNAIDS position was echoed by U.S. Deputy Secretary of Health and Human Services (HHS) Claude Allen, who stated at a Senate hearing in March, "We [HHS] would be prepared to defend the 90 percent figure [for sexual transmission]."

Making injections safer should remain a global health priority (of the estimated 16.7 billion injections given annually worldwide, about 40 percent are with unsterilized needles), said the WHO/UNAIDS group, but clean injections alone will not curb HIV infections. Comparing HIV with the hepatitis C virus (HCV) which is easily spread through needles and blood but not sex, the review group found little correlation between the two. In fact, countries with advanced safe-injection programs, such as Zimbabwe and South Africa, have extremely high rates of HIV while having low rates of HCV. The review also noted that HIV prevalence among children under five--a group that is routinely vaccinated--is primarily due to mother-to-child transmission, which would not be likely if the vaccination needles were frequently HIV-contaminated. Vaccinated infants of HIV-negative mothers have very low rates of infection.

The review group also criticized the Gisselquist team's use of self-reported sexual behavior data. According to WHO/UNAIDS, people often underreport their sexual activity. It was noted, for example, that in a study of 980 women, 23 HIV-positive women reported never having had sex--but so did 15 pregnant women.

The WHO/UNAIDS review also states that the 2.3 percent transmission efficiency (the probability of an individual becoming infected from a contaminated needle) used by Gisselquist is too high. WHO assumes HIV transmission efficiency from needles to be 0.3 percent, and uses a higher value of 1.3 percent when modeling HIV transmission in order to arrive at estimates that it believes are "generously high." The bottom line, says the expert review group, is that the highest risk remains with unsafe sex.