Hepatitis C virus (HCV) is the most common blood-borne infection in the United States and presents a substantial health care burden. There is no vaccine to prevent the infection and over half of people who acquire HCV go on to develop chronic illness. However, directing acting antiviral treatments can result in virologic cure in most patients.
A recent US Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report
(MMWR) contained augmented recommendations for HCV screening from the Division of Viral Hepatitis. The 2 new recommendations call for HCV screening at least once for all adults aged 18 years or older and for women during each pregnancy.
An exception to these recommendations is made in settings where the prevalence of HCV infection is <.1%, as risk is not considered substantial enough to warrant universal screening.
Consistent with prior guidelines, all people with individual risk factors should receive periodic HCV testing regardless of age and even in the context of a setting with <0.1% prevalence. In addition, any person who requests HCV testing should be permitted to receive the test.
The recommendation for screening during pregnancy comes as the general rise in HCV infections among younger people has created new opportunities for vertical transmission.
“As new HCV infections have increased among reproductive aged adults, rates of HCV infection nearly doubled during 2009–2014 among women with live births,” the authors wrote.
Only about 20% of infants with vertically-acquired HCV clear the infection, leading 50% to develop asymptomatic infection and 30% to develop chronic active infection.
The new recommendations were developed based on extensive review of the literature on HCV. There were 2 research questions which guided this review:
- Does universal screening for HCV among pregnant women, compared with risk-based screening, reduce morbidity and mortality among mothers and their children?
- Does universal screening for HCV among adults aged ≥18 years, compared with risk-based screening, reduce morbidity and mortality?
For the universal adult screening review, the initial literature search yielded 4867 studies. After exclusion criteria was applied, 668 full texts were analyzed. Among them, 368 articles had relevant data available.
The initial literature search yielded 1500 studies, with 86 ultimately available for review after abstract screening.
While studies examining risks of HCV screening were examined, the Division of Viral Hepatitis concluded that identified or potential harms did not outweigh the benefits of screening given the high prevalence identified across studies.
Studies concerning cost-effectiveness of testing appeared to suggest the benefits of the practice. For example, a study on the potential benefit of universal screening identified an incremental cost-effectiveness ratio of $11,378 per quality-adjusted life year gained when compared with limited 1945–1965 birth cohort screening.
While the threshold for prevalence of <.1% was determined in part by cost effectiveness considerations, no state in the US has an HCV prevalence in adults below .1% according to National Health and Nutrition Examination Survey data.
The report also reiterates risk factors for HCV infection. Intravenous drug use is the most frequent means of HCV transmission in the US, but surgeries where proper disinfection is not performed and sexual behaviors such as anal sex without a condom are also risk factors for transmission.
Other exposures can come from sharing personal items which have been contaminated with blood such as razors, “stick and poke” tattooing, and needle injuries among health care workers.
The authors also identified avenues for future research and intervention, including in the subpopulation of pregnant women.
“Additional data on the safety of direct acting antiviral use during pregnancy are needed to inform treatment during pregnancy, which might reduce the risk for perinatal transmission. Finally, for expanded screening to be effective in reducing the morbidity and mortality of hepatitis C in the United States, models to address barriers related to access to direct acting antiviral treatment are needed,” the authors wrote.
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