Rectal gonorrhoea (GC) and chlamydia (CT) infections are markers for unprotected receptive anal intercourse and risk for HIV seroconversion among men who have sex with men (MSM) [1–4]. High positivity among asymptomatic MSM screened for rectal GC and CT has been reported in multiple US jurisdictions [5,6], demonstrating a risk for HIV acquisition. Increasing rates of sexually transmitted diseases (STDs) diagnosed among HIV-infected persons have been reported from multiple US jurisdictions [7–9] and suggest ongoing risk behaviour for HIV transmission [10].

Rectal screening for GC and CT is recommended by the Centers for Disease Control and Prevention (CDC) for sexually active MSM [11] and models suggest that it may be cost effective for preventing HIV infection [12]. However, few programmes are carrying out rectal testing, possibly because of the need to perform local validation of the procedure. Comprehensive STD screening, including rectal testing for HIV-infected and noninfected MSM, is a local and national priority, along with intensive behavioural counselling to reduce the likelihood of acquiring or transmitting these infections [11,13–15]. Comprehensive care should also include referral to and retention in clinical services that provide antiretroviral (ARV) treatment among those coinfected with HIV [16–18].

Maricopa County (Phoenix Area) is the fourth most populous county in the USA [19] and is a high-morbidity area for GC, CT and syphilis [20]. Maricopa County reports the highest annual number of new HIV diagnoses in Arizona and these occur disproportionately among MSM and African Americans [21]. Maricopa County has one publicly funded STD clinic providing services to a population of approximately 4 million [22,23]. Rectal testing for GC and CT was implemented at this clinic using nucleic acid amplification testing in October 2011. This test was offered to all men who reported recent receptive anal intercourse (RAI) during intake questioning. We evaluated men undergoing rectal testing at Maricopa County STD clinic for GC and CT, HIV infection and detectable HIV viral loads (VLs) to evaluate HIV acquisition and transmission risk.

Maricopa County began rectal GC and CT testing via clinician-collected rectal swabs on 1 October 2011. This analysis includes all men undergoing rectal testing from the inception of this procedure to 30 September 2013.

In this analysis, nearly one-third of men had rectal GC or CT infection. Most of them (81.7%) were HIV-negative and therefore at very high risk of acquiring HIV infection. In this sample, one-quarter of the men were previously infected with HIV at the time of diagnosis of their rectal GC/CT infection, demonstrating ongoing unprotected receptive anal intercourse (URAI) in this population. Men with rectal GC/CT and HIV coinfection were more often older than 24 years of age and of Hispanic ethnicity. Our data showed that over half of the coinfected men had a detectable VL reported within 1 year of rectal GC and CT testing and their VLs were higher than the VLs of HIV-infected MSM who did not have a rectal GC/CT infection.

These data reflect the findings of other jurisdictions providing rectal GC and CT testing to MSM [5,6]. Our data demonstrate high rectal GC and CT positivity (31.8%), suggesting a greater reservoir of undiagnosed rectal infection among predominantly HIV-negative MSM in Maricopa County. These predominantly HIV-negative MSM with rectal GC and CT are at high risk of acquiring HIV infection [1]. As recommended by CDC [13], risk-reduction counselling to prevent STD and HIV acquisition is incorporated into partner services interviews delivered by disease intervention specialists (DISs) to patients with rectal GC/CT infections in Maricopa County. In addition, community partnerships with local medical care providers have been fostered in preparation for referral of HIV-negative MSM for consideration for HIV pre-exposure prophylaxis (PREP) [24].

We identified HIV transmission risk among the population of HIV-infected MSM who were tested for rectal GC and CT. Most coinfected men in our sample acquired HIV infection prior to their rectal GC/CT diagnosis, demonstrating ongoing unprotected sex. Additionally, our crossmatch of the HIV surveillance and HIV VL data allowed us to describe VL as an additional element of HIV infectivity among this group of MSM undergoing rectal GC and CT testing. A concerning proportion of MSM coinfected with HIV and rectal GC and CT had detectable a VL collected within 1 year of rectal testing and the VLs of coinfected men were higher than those of MSM with HIV alone. These individuals represent community reservoirs of transmissible HIV identified by their history of URAI, rectal GC and CT infections, and high detectable VL. Of the 15 288 prevalent cases of HIV infection in Arizona in 2012, 47% of individuals were retained in care and 36% had a reported undetectable VL [21]. Our data, collected from the same HIV surveillance records, reflect that a considerably lower proportion of HIV-infected patients undergoing rectal testing had undetectable VLs (22.9%) compared with the statewide HIV-infected population, demonstrating opportunities to confirm, establish or re-establish connections to HIV clinical care.

Interpretation of these data should consider the following limitations. First, data on rectal symptoms at the time of testing were not collected, and thus our positivity cannot be compared to values in other jurisdictions where asymptomatic rectal screening was evaluated. Secondly, incomplete laboratory reporting data for VL have been reported in other jurisdictions and probably occurred in this population [25]. We assumed that all MSM undergoing rectal testing had engaged in URAI, including those not diagnosed with rectal infection. Finally, information on sexual practices, including condom use and serosorting was not collected.

To our knowledge, this is the first report of HIV VL among MSM with rectal GC or CT infection. This analysis identified populations at high risk for HIV acquisition and transmission as well as opportunities for expansion of risk-reduction interventions among MSM seeking rectal testing for GC/CT. Opportunities to engage this group of MSM are prioritized as part of HIV prevention efforts in Maricopa County. Contemporary venues and communication sources such as social media and text reminders are under development for use in delivering testing and prevention messages. Additional work is needed to evaluate comprehensive care for HIV-negative MSM that includes risk-reduction counselling, routine STD and HIV screening, and evaluation for PREP.