Study Challenges WHO Recommendation to Increase HCV Screening in HIV-Infected Populations
In a recent study of 1,812 human immunodeficiency virus (HIV)-infected individuals in sub-Saharan Africa, researchers found that none of these individuals had confirmed hepatitis C virus replication.
In a recent study of 1,812 human immunodeficiency virus (HIV)-infected individuals in sub-Saharan Africa (SSA), researchers found that none of these individuals had confirmed hepatitis C virus (HCV) replication.
Gilles Wandeler, MD, MSc, from the University of Bern, Switzerland, and colleagues published the results of their study in Open Forum Infectious Diseases.
“Among individuals infected with HIV in 2 southern African cohorts, HCV seroprevalence ranged from 0.1% to 2.5% depending on the antibody test used,” the authors write. ”However, no active HCV infections were observed, despite the presence of traditional risk factors for percutaneous transmission of blood-borne infections in a majority of patients.”
HCV is often prevalent among HIV-infected populations and has become a significant threat to the survival of HIV-infected patients. In an attempt to reduce HCV-induced morbidity and mortality, the World Health Organization (WHO) therefore recommends a risk-based screening approach that includes screening of HIV-infected populations.
Diagnostic tests for HCV include serologic assays and molecular virologic assays. Although the presence of anti-HCV antibodies in the blood indicates that an individual has been infected with HCV, it does not imply a current infection. However, the presence of HCV RNA indicates active, ongoing viral replication and therefore active infection.
Coinfection with HIV and HCV is particularly common in SSA. However, although studies have shown that the prevalence of anti-HCV antibody-positivity ranges from 4% to 7%, the prevalence of replicating (ribonucleic acid [RNA]-positive) HCV infections ranges from less than 1% to more than 10%, depending on the region.
In SSA, the false-positive rate of HCV serological tests is also high. As a consequence, screening of all HIV-infected populations in this region may not be cost-effective. More information on the prevalence of replicating HCV infections in SSA is therefore needed.
With this in mind, the researchers conducted a study in clinics in Zambia and Mozambique between May 2013 and November 2014. They screened 1,812 (Mozambique, n = 1,057; Zambia, n = 755) antiretroviral therapy (ART)-naive HIV-infected patients for the presence of anti-HCV antibodies: all patients were screened using the oral Oraquick point-of-care test which is known to have good diagnostic accuracy; in addition, 118 patients were randomly selected to undergo a second serologic screening test using an enzyme-linked immunosorbent assay (ELISA). Next, all patients with a positive antibody test result underwent HCV RNA testing.
The median age of all participants was 32 years and 65.5% were female.
Using the anti-HCV Oraquick test, only 1 patient in Zambia had a positive result, resulting in a seroprevalence of 0.13%. However, this patient had a negative HCV RNA confirmation test.
Of the 118 patients who also underwent the ELISA-based screening test, 3 were positive for anti-HCV antibodies. Two of these 3 patients had a negative HCV viral load; the third had an HCV viral load of 50 IU/mL in a first sample, but a negative result in a second sample.
In the patients who were tested with both serologic screening assays, the overall anti-HCV antibody seroprevalence was 2.5%.
According to the authors, “[t]hese data underscore the importance of confirming active HCV infection and challenge the recommendation to scale up HCV screening for all individuals infected with HIV in the region.”
They emphasize that, because these results demonstrate the limitations of anti-HCV assays, HCV RNA testing should be used to confirm HCV prevalence.
“Resources to screen for and treat HCV are limited in most SSA settings; therefore, national governments should assess local epidemiological data before implementing HCV testing in all individuals infected with HIV,” the authors conclude.
Dr. Parry graduated from the University of Liverpool, England in 1997 and is a board-certified veterinary pathologist. After 13 years working in academia, she founded Midwest Veterinary Pathology, LLC where she now works as a private consultant. She is passionate about veterinary education and serves on the Indiana Veterinary Medical Association’s Continuing Education Committee. She regularly writes continuing education articles for veterinary organizations and journals, and has also served on the American College of Veterinary Pathologists’ Examination Committee and Education Committee.