Hepatitis C Antibody Testing of MSM at STI Clinic Yields More Cases Faster

Routine hepatitis C (HCV) antibody testing of men who have sex with men (MSM) at an Amsterdam sexually transmitted infection (STI) clinic yielded additional and earlier HCV diagnoses in HIV-positive men attending an HIV clinic. More than half of men tested for HCV at both their HIV clinic and the STI clinic had their first positive test at the STI clinic, according to the study.

Outbreaks of HCV infection are reported in networks of HIV-positive MSM in Europe, Australia and the United States. HIV/HCV coinfection is linked to faster progression of both HCV and HIV disease. Since 2007, these conditions led an Amsterdam STI clinic to conduct routine HCV antibody screening in HIV-positive MSM or MSM with unknown HIV status. An Amsterdam team conducted this analysis to examine HCV diagnosis trends in HIV-positive or HIV-status-unknown men after routine screening began.

The analysis included all HIV-positive or status-unknown MSM who visited the STI clinic from November 2007 through December 2010. The researchers contacted Amsterdam HIV clinics to gather data, including HCV testing data, on men who tested positive for HCV on their first visit to the STI clinic (prevalent HCV) or on a subsequent visit after testing negative (incident HCV). They compared HCV diagnosis date at the STI clinic with HCV diagnosis date at the HIV clinic, excluding men diagnosed with HCV at the HIV clinic before the STI clinic began routine HCV testing in November 2007.

During the study period, 1742 HIV-positive men at 5032 STI clinic visits and 446 HIV status-unknown men at 579 visits had HCV antibody testing. Among HIV-positive MSM, median age stood at 41 years; 64% were born in the Netherlands; 61% had condomless anal intercourse in the past six months; and 42% had an STI diagnosed. Among HIV status-unknown men, median age was 41 years; 72% were born in the Netherlands; 40% had condomless anal intercourse in the past six months; and 26% had an STI diagnosed. Less than 1% of the HIV-positive men and none of the status-unknown men reported injecting drugs.

On the first HCV antibody test at the STI clinic, HCV prevalence stood at 6.4% in HIV-positive men (112 of 1742) and 0.7% in status-unknown men (3 of 446). In 3259 follow-up visits by 856 HIV-positive MSM, 32 with an initially negative or indeterminate HCV test became positive to yield an HCV incidence of 2.35 per 100 person-years. Among 34 HIV-positive men whose sex partners told them they had HCV, 4 (11.8%) had an HCV-positive test. No initially HCV-negative man with unknown HIV status became positive during follow-up.

The researchers gathered HCV testing data from the HIV clinics of 85 HIV-positive men who had a positive HCV antibody test at the STI clinic. Among 54 men who did not have a positive HCV antibody test before STI clinic testing and who had HIV clinic testing data available, 28 men (52%) first tested HCV positive at the STI clinic. From clinical data on 21 men, the researchers calculated that the STI clinic diagnosed HCV infection a median of 31 days (interquartile range 12 to 49) before HCV diagnosis at the HIV clinic. The investigators determined that three men who tested positive in the STI clinic probably would not have had an HCV test at their next HIV clinic visit.

The Amsterdam team concludes that HCV prevalence and incidence are high in HIV-positive men seeking care at an STI clinic, and that a high proportion of men with HCV-positive partners themselves test positive for HCV. They found that starting routine HCV testing for HIV-positive MSM at the STI clinic "resulted in additional and earlier HCV detection." The authors propose that, "from a public health perspective, HCV screening at an STI clinic might limit further spread in the [HIV MSM] community."