Study Shows Link Between Asymptomatic Rectal Bacterial Pathogens and HIV incidence

The presence of rectal bacterial sexually transmitted infection (bSTI) was predictive of HIV seroconversion, according to study results reported in the journal Open Forum Infectious Disease earlier this month.The study authors argued that their findings argue for screening young adults who are gay, bisexual or transgender for bSTI, specifically infection with Neisseria gonorrhoeae, the bacteria that cause gonorrhea.

The study was conducted using data collected in the RADAR study, a longitudinal study of 1,243 young adult sexual and gender minorities in the Chicago. At the time of enrollment, the study participants were ages 16 to 20, assigned male at birth, had a sexual encounter with a man in the previous year and identified as gay, bisexual or transgender.

Lead author Ross A. Baiers, M.P.H., of the Institute for Sexual and Gender Minority Health and Wellbeing at Northwestern’s Feinberg School of Medicine, and his colleagues, compared the HIV seroconversion rate among the study participants who tested positive for Mycoplasma genitalium, Neisseria gonorrhoeae and Chlamydia trachomatis with the rate among those who didn’t. They found that the study participants who tested positive for

Neisseria gonorrhoeae were five times like to become infected with HIV than others in the study. The association between positive tests for Mycoplasma genitalium and Chlamydia trachomatis and HIV seroconversion was not statistically significant. Overall, they found that 55.6% of those who became infected with HIV had tested positive for a rectal sexually transmitted disease at their prior visit.

Of all the people who were HIV negative at the beginning of the study, 2.8% seroconverted for HIV.

Among those who tested positive for Mycoplasma genitalium, Neisseria gonorrhoeae and Chlamydia trachomatis, 1.9%, 4.6% and 2.0% converted to HIV at a subsequent visit. Among those with negative tests for Mycoplasma genitalium, Neisseria gonorrhoeae and Chlamydia trachomatis, 0.7%, 0.8% and 0.9% converted to HIV.

The total number of condomless anal sex partners was also associated with HIV infection.

Only a small percentage (6.3%) of those who tested positive for one rectal bSTI reported having symptoms, which included discharge from the rectum, rectal pain or rectal itching.

“Given the low rate of symptoms in individuals with rectal bSTI detection, paired with the high predictiveness of HIV seroconversion after rectal NG [Neisseria gonorrhoeae] detection, our findings support the CDC’s current recommendation to conduct asymptomatic testing every 3-6 months in at risk populations as it increases the likelihood of adequately targeting HIV prevention services to those with the highest likelihood of seroconversion,” write Baiers and his colleagues. They noted that the average lifetime cost of managing an HIV infection is in excess of $1 million so asymptomatic testing, if it were to lead to fewer cases of HIV, could save money.

They also suggested that future research might determine whether doxycycline postexposure prophylaxis as a bSTI strategy might have also reduce HIV transmission.