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Updated: Apr 23, 2026

Amplifying and Quantifying HIV-1 RNA in HIV Infected Individuals with Viral Loads Below the Limit of Detection by Standard Clinical Assays
Published on: September 26, 2011
HIV status and viral loads among men testing positive for rectal gonorrhoea and chlamydia, Maricopa County, Arizona,
M M Taylor1, D R Newman, J Gonzalez
1Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA; Maricopa County Department of Public Health, Phoenix, AZ, USA; STD Program, Arizona Department of Health Services, Phoenix, AZ, USA.
Objectives:
Men diagnosed with rectal gonorrhoea (GC) and chlamydia (CT) have engaged in unprotected receptive anal intercourse. We reviewed the HIV positivity and HIV viral loads (VLs) of men who had rectal GC and CT testing to evaluate potential HIV acquisition and transmission risk.
Methods:
Rectal GC and CT testing data for men attending the Maricopa County STD clinic during the period from 1 October 2011 to 30 September 2013 were cross-matched with HIV surveillance data to identify men with HIV coinfection. We examined HIV status, HIV diagnosis date, and the values of VL collected nearest to the date of reported rectal infection.
Results:
During the 2-year time period, 1591 men were tested for rectal GC and CT. Of the men tested, 506 (31.8%) were positive for GC (13.2%), CT (12.2%) or both (6.4%); 119 (23.5%) of those with rectal GC or CT were coinfected with HIV. Among the 275 men with HIV at the time of rectal testing, 54 (19.6%) had no reported VL; 63 (22.9%) had an undetectable VL (< 20 HIV-1 RNA copies/mL) and 158 (57.4%) had a detectable VL collected within 1 year of rectal diagnosis. Mean VL was higher among HIV and rectal GC/CT coinfected cases compared with men with HIV alone (174 316 vs. 57 717 copies/mL, respectively; P = 0.04).
Conclusions:
Approximately one-third of men undergoing rectal testing were positive for GC or CT and one-quarter of men with rectal GC or CT also had HIV infection. Of the HIV-infected men tested for rectal GC or CT, more than half had a detectable VL collected near the time of rectal testing, demonstrating a risk for transmitting HIV.
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