Despite a high prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis, follow-up testing rates for these STDs are low among U.S. men who have receptive anal sex, according to a recently published study.
Retesting rates ranged from 42% to 57% at 12 months for uninfected and infected men, respectively, with positivity exceeding 5% for rectal gonorrhea, pharyngeal gonorrhea and rectal chlamydia. The findings highlight the need for interventions to improve adherence to annual retesting in this population, according to Guoyu Tao, PhD, health scientist at the CDC’s STD prevention division, and colleagues.
“Previous studies have found that more than half of all diagnosed [chlamydia] infections were at nonurethral sites in MSM, indicating that many infections would be missed if only urethral screening were performed,” the researchers wrote. “Although CDC recommends rectal [gonorrhea] and [chlamydia] screening of all MSM who report receptive anal sex and previous studies have showed that rectal [gonorrhea] and [chlamydia] were associated with increased risk for HIV seroconversion among MSM, rectal [gonorrhea] and [chlamydia] testing rates have been suboptimal.”
To elucidate testing practices in the private setting, Tao and colleagues obtained gonorrhea and chlamydia nucleic acid amplification test data from a commercial lab servicing all 50 U.S. states and Washington, D.C. They determined the incidence of 12-month follow-up testing and analyzed patient demographics and index test and retest outcomes for any associations with adherence.
The researchers examined gonorrhea and chlamydia results from 81,535 stool specimens collected from 52,063 men between Jan. 1, 2013 to May 31, 2015. The ages of these men ranged from 15 years to 60 years, and the majority had private or commercial insurance.
Upon index testing of a patient’s rectal specimen, 6.1% of men were positive for gonorrhea alone, 8.3% for chlamydia alone and 2.7% for both infections. Men aged 15 years to 24 years were more likely to be positive for rectal gonorrhea or chlamydia, and positivity was more frequent for those who visited public health clinics. Among the subset of men who also had pharyngeal or urine samples collected and tested, 7.4% were positive for pharyngeal gonorrhea, 2.3% for pharyngeal chlamydia, 2.8% for urine gonorrhea and 2.6% for urine chlamydia. Pharyngeal gonorrhea was associated with rectal gonorrhea, as was urine gonorrhea with rectal gonorrhea. Patients who visited infectious disease specialists were more likely to receive pharyngeal or urine testing, and more likely to record positive results.
Of the 26,477 men whose index examination preceded the study’s end date by 12 months, follow-up testing rates did not exceed 23% during any quarter of the study. Men with infection detected during their index examination more often received repeat or follow-up tests than those without index infection (repeat rectal testing, 40% vs. 27.9%; follow-up test, 56.7% vs. 42.4%). Men were also more likely to undergo repeat rectal or follow-up testing if their index test was performed by an infectious disease specialist.
These incidences suggest that gonorrhea and chlamydia are a “substantial public health problem” for MSM reporting receptive anal sex, the researchers wrote. However, suboptimal repeat testing of rectal or other anatomic site samples indicate a key target for upcoming sexual health interventions.
“High rates of positive rectal [gonorrhea] and [chlamydia] specimens and low rates of repeat rectal or follow-up testing suggest that many U.S. providers are not following the CDC guidelines for routine risk assessment and appropriate testing of sexually active MSM,” the researchers wrote. “Interventions are needed to improve the quality of health care services for sexually active MSM.” – by Dave Muoio
Disclosure: Tao reports no relevant financial disclosures. Please see the full study for a complete list of relevant financial disclosures.