Transmission of Human Herpesvirus 8 by Sexual Activity Among Adults in Lagos, Nigeria
February 6, 2003
Findings about the modes of transmission of human herpesvirus 8 (HHV-8) are inconsistent. Researchers have found that European and American homosexual men have high antibody prevalence, and that seropositivity correlates with the number of homosexual partners and STDs. Other studies have suggested the infection could be transmitted through heterosexual contact. The high prevalence of HHV-8 among children in sub-Saharan Africa, Italy and among Brazilian Amerindians suggests that the virus can be spread non-sexually to children. The current study tested blood samples from a survey of adults in Lagos, Nigeria, to correlate HHV-8 antibody with sexual activity -- as manifest by groups with different sexual behavior -- and by laboratory evidence of individual STDs.Adapted from:
The researchers analyzed samples from 2,002 individuals, 766 subjects in the referent population (healthy individuals at relatively low HIV risk), 373 STD patients, and 863 commercial sex workers (CSW). They found that HIV prevalence was higher in the STD and CSW groups (15.6 percent and 11.3 percent, respectively) than among the referent population (5.0 percent). HIV prevalence varied by sex and subject category. The authors found an increased risk of HHV-8 seropositivity among men and women with markers of risky sexual activity. They theorized that the results "are probably related to heterosexual activity."
CSW and STD patients had higher HHV-8 prevalences than the referent population. Within specific populations, the report noted, those with at least one STD were more likely to be HHV-8 seropositive than those without STDs. "We interpret our findings," Eltom and colleagues wrote, "as suggesting that STD are a marker of sexual promiscuity rather than that STD are a specific co-factor. Taken together, our findings of HHV-8 associations with subject category and with STD suggest that the sexual spread of HHV-8 occurs in this population."
Men were nearly twice as likely as women to have HHV-8, and the authors found that men in the referent population were 1.5 times more likely to show laboratory evidence of an STD, "which is consistent with men having more promiscuous sexual behavior," they wrote. "Therefore, the higher HHV-8 prevalence in men and in CSW is thus compatible with HHV-8 transmission in adults by sexual routes. However," they cautioned, "we cannot exclude the possibility that sexually transmitted diseases act by increasing the likelihood of infection, either because partners with STD are more infectious or because subjects with STD are more susceptible."
The investigators speculate that non-sexual routes of the spread of HHV-8 among children might include saliva exposure, although they discount that as a likely mechanism among adults. They note that African adults do not commonly practice kissing.
The authors concluded that they were "confident that the association between HHV-8 seropositivity and having multiple sexual partners, as measured by being in a group with multiple sexual partners or by having laboratory evidence of STD is valid. These findings, therefore, support sexual transmission as one route of HHV-8 infection in African adults."
12.06.02; Vol. 16: P. 2473-2478; Mohamed A. Eltom; Sam M. Mbulaiteye; Abinbola J. Dada; Denise Whitby; Robert J. Biggar