NATAP: Oral Sex & HIV Transmission Risk

[Guest guest]

NATAP - www.natap.org

More on Oral Sex and HIV Transmission Risk

AIDSClinical Care, December 2003

By G. Nagy, MD

Detailed interviews of a cohort of gay men with acute infection provide

further evidence that oral sex can be a route of HIV transmission and suggest

that

penile piercings may increase this risk.

Although the risk for HIV transmission through oral sex is difficult to

quantify (in large part because the mode of transmission in any given case can

be

difficult to establish), published studies suggest that the risk associated

with fellatio is low, but not zero (see AIDS 1998;12:2095-105; 7th Conference on

Retroviruses and Opportunistic Infections, Abstract 473; and AIDS

2000;16:2350-2352). Investigators in Sydney conducted detailed interviews with

75 acutely

infected gay men between 1993 and 1999 to assess all risk behavior in the 6

months preceding seroconversion and to determine the likely mode of

transmission.

The researchers established the most likely mode of transmission by sorting

exposures according to a risk hierarchy: high risk (sharing needles for

intravenous drug use, unprotected receptive and insertive anal intercourse),

medium-to-low risk (condom-protected receptive and insertive anal intercourse,

blood

or semen contact with an open wound, oral sex, and penile-anal external contact

without insertion), and no risk (visits to dentists, blood donation in

Australia, stepping on a discarded syringe, sex with a verified HIV-negative

partner, and mosquito bites). Each exposure was also adjusted for the likelihood

that

the partner was infected, the partner's likely viral load, the timing of the

contact relative to seroconversion illness, the presence of skin lesions or

breakdown in either partner, duration of the exposure, and occurrence of

ejaculation.

HIV transmission was thought to have occurred from high-risk behaviors in 60

men and from low-to-medium risk behaviors in 15 men. Eleven of the men with

only low-to-medium risk behaviors reported condom-protected anal intercourse,

and several noted that they assumed this practice was completely safe. In 5

cases, the likely source of transmission was concluded to be oral sexual

contact.

Three of these 5 men, all of whom had also engaged in protected anal sex, had

penile piercings (none of which had been performed recently), and the oral sex

involved

insertive fellatio. In the fourth case, the infected individual reported no

anal intercourse, but receptive oral sex with ejaculation in the setting of

gingivitis and open wounds in the mouth from dental treatment. In the fifth

case,

the infected individual reported a single instance of condom-protected

receptive anal intercourse with a man who was having anal sex for the first

time,

and a recent history of multiple oral sexual contacts with casual partners.

This is a retrospective, small case series that cannot definitively establish

either a route of transmission or the likelihood of transmission per oral

sexual act. Questionnaires and interviews are flawed in that recall of past

exposures may be inaccurate. However, the methodology employed in this case

series

was thorough and, in some instances, uncovered risk behaviors that were not

initially reported. The link between possible breaches in skin integrity from

piercings and the transmission of HIV needs to be further investigated.

Dr. Nagy is Assistant Professor of Medicine at Mount Sinai School of Medicine

in New York.

Richters J et al. HIV transmission among gay men through oral sex and other

uncommon routes: Case series of HIV seroconverters, Sydney. AIDS 2003 Oct 17;

17:2269-71.

REVIEW OF ORIGINAL ARTICLE

This published article was reviewed upon publication in Octiber by NATAP but

is worth repeating discussion.

HIV transmission among gay men through oral sex and other uncommon routes:

case series of HIV seroconverters, Sydney

http://www.natap.org/2003/oct/100903_5.htm