In a review, London School of Hygiene & Tropical Medicine and University of Bristol researchers found that, worldwide, 2.3 million people with HIV are co-infected with hepatitis C virus (HCV), and more than half of them are intravenous drug users. The study also found that HIV-infected people are substantially more likely to have an HCV infection than those without HIV, emphasizing the need to improve combined HIV/HCV services.
The review, titled “Prevalence and burden of HCV co-infection in people living with HIV: a global systematic review and meta-analysis,” was published in The Lancet Infectious Diseases journal. It was sponsored and commissioned by the World Health Organization (WHO) to update HCV guidelines on the screening of co-infections and initiation of antiretroviral therapy, as well as to advise regional and national policy regarding best approaches to hepatitis C screening and management.
To characterize the epidemiology and burden of HCV co-infection in people with HIV, researchers conducted a systematic review and meta-analysis of studies measuring prevalence of HCV and HIV. A total of 783 studies, published worldwide between Jan. 1, 2002, and Jan. 28, 2015, met the inclusion criteria, resulting in 902 estimates on the prevalence of HIV/HCV co-infection.
Specifically, results revealed that in HIV-infected individuals, co-infection rates were 2.4 percent within the general population, 4.0 percent among pregnant or heterosexually exposed people, 6.4 percent in homosexually active men, and 82.4 percent in people who inject drugs (PWID).
Odds of HCV infection were six times higher in people with HIV than their HIV-negative counterparts. Worldwide, there are approximately 2.28 million HIV/HCV co-infections, of which 1.36 million are in PWID, for an overall co-infection prevalence of 6.2 percent in this group.
“The study shows that not only are people with HIV at much higher risk of HCV infection, groups such as people who inject drugs have extremely high prevalence of HCV infection — over 80 Per cent. There is a need to scale-up routine testing to diagnose HCV infection in HIV programmes worldwide, especially among high-risk groups, as the first step towards accessing the new, highly curative HCV treatments,” Dr. Philippa Easterbrook, with the WHO’s Global Hepatitis Programme, said in a news release.
Dr. Lucy Platt, the study’s lead author and a senior lecturer from the London School of Hygiene & Tropical Medicine, added: “Despite a systematic search of published and unpublished literature, estimates were identified in only 45 per cent of countries and the study quality was variable. Improvement in the surveillance of HCV and HIV is imperative to help define the epidemiology of coinfection and inform appropriate policies for testing, prevention, care and treatment to those in need. This is especially the case in countries with growing populations of PWID and also in sub-Saharan Africa where the burden of coinfection is large due to high burden of HIV.”
The greatest incidence of HIV/HCV co-infection occurs in central Asia and Eastern Europe, the study found, and the sub-Saharan African region accounts for 19 percent (429,600) of all cases.
“This study shows how important injecting drug use is in driving the epidemic of HCV in people with HIV infection, especially in eastern European and central Asian countries. It also shows the need to scale up prevention interventions, such as needle and syringe programmes and opioid substitution therapy, as well as access to HIV and HCV treatment, to reduce morbidity and new infections,” said Professor Peter Vickerman, from the University of Bristol’s School of Social and Community Medicine.
The study highlighted the prevalence of HCV antibodies, a measure of exposure to HCV but not active infection. Assessing the existence of an active virus and necessary treatment requires a costly viral test, and has been measured in only a few studies.