Hep C Spikes in San Diego

The findings of a new study — presented at last week’s 2017 AASLD Liver Meeting in Washington, D.C. — show that incidence of the Hepatitis C virus (HCV) is increasing among gay and bisexual men living with HIV in the San Diego area.  This is the largest analysis of its kind done in the United States to date, according to the official report from NAM aidsmap.

Beginning in the early 2000s researchers in the UK and elsewhere in Europe began to report “clusters” of apparently sexually transmitted acute HCV infection among HIV-positive men who have sex with men (MSM). Similar outbreaks have since been seen in Australia and the US.

The small number of men who reported injecting drug use had a higher likelihood of being newly infected with hepatitis C virus (HCV), but so did the much larger proportion who reported non-injection methamphetamine use. Acute HCV was predominantly seen among HIV-positive MSM — however, a small number of cases were reported among HIV-negative gay men as well.

Among the men who did not inject drugs, several other risk factors were implicated in sexual transmission of HCV, including barrier free anal sex, fisting, use of sex toys, other sexually transmitted infections, and non-injection drug use — though these factors have not been consistent across studies. Traditionally it has been assumed by most experts that HCV is transmitted through sexual activity that involves blood, but the virus has also been detected in semen, rectal secretions, and feces.

This latest research began after San Diego's largest HIV clinic, the UCSD Owen Clinic, saw a spike in HCV rates among HIV-positive gay male patients. Antoine Chaillon of the University of California at San Diego and colleagues did a retrospective pooled analysis of HCV incidence among HIV-positive MSM attending the Owen Clinic and the San Diego Veterans Affairs (VA) Hospital between 2000 and 2015. Together these facilities see about one-third of the estimated 3400 HIV-positive MSM in the city.

The analysis included 2768 MSM (2396 at the Owen Clinic, 373 at the SDVA) who were initially HCV negative and had at least one subsequent test during a median of about 4 years of follow-up. A total of 149 infections occurred among Owen Clinic clients and 23 among the VA patients. There were no notable differences in infection rates according to age or race/ethnicity.

The incidence of HCV transmission was three times higher among men who reported only meth use, but not injecting drug use, compared to those with no history of either. Incidence was about 5 times higher among men who reported only injecting drug use and more than 4 times higher among men who reported both drug injection and meth use, compared to those who said they did neither.

The researchers concluded that “these congruent results from the two largest HIV clinics in San Diego reinforce our findings that HCV incidence is high and increasing among HIV-positive MSM in San Diego,” and are similar to findings in major European cities.

Researchers emphasized the need for regular HCV testing for gay and bi men, rapid diagnosis and treatment to prevent transmission, strategies to prevent reinfection, and interventions around substance use and chemsex.