New cases of hepatitis C virus (HCV) infection among HIV-positive gay and bisexual men seen at three clinics in London have declined by nearly 70% since 2015, according to a presentation yesterday at the Conference on Retroviruses and Opportunistic Infections (CROI 2019) in Seattle.
The drop is largely attributable to regular HCV screening and a treatment-as-prevention effect resulting from wider use of direct-acting antiviral (DAA) therapy, said presenter Dr Lucy Garvey of Imperial College Healthcare NHS Trust.
"In order to eliminate hepatitis C as a major public health threat, we need to reduce the number of people who become newly infected or re-infected with the virus," Garvey said. "Our study has shown that greater access to new treatments, closer monitoring and screening can greatly reduce hepatitis C cases, which will lead to better outcomes for the most at-risk patients."
However, another study at the conference sheds doubt on whether it is possible to treat our way out of the HCV epidemic. Dr Daniel Fierer of the Icahn School of Medicine at Mt Sinai in New York City reported that gay and bisexual men who are cured of hepatitis C are becoming re-infected at a rate seven times higher than the primary or initial infection rate. He suggested that prevention is as important as treatment, but acknowledged that we don't really know how to prevent sexual transmission of HCV.
Now that DAAs can cure more than 95% of people with HCV in two or three months, the World Health Organization (WHO) has set a goal of eliminating hepatitis C as a public health threat by 2030; the British HIV Association aims to cure HCV in everyone with HIV and HCV co-infection by 2021. Elimination of 'microepidemics' in defined populations is a good way to start, Garvey said.
One such population is HIV-positive men who have sex with men (MSM), who appear to be mainly acquiring HCV via sexual transmission, as they mostly do not report injection drug use. Sexual transmission of HCV is quite uncommon overall, but it occurs more often among HIV-positive gay and bisexual men.