Best Practice Testing Failed to ID Hidden HCV Infections

Veronica Hackethal, MD

January 08, 2018

A best practices strategy to improve detection of hepatitis B (HBV) and HCV virus infections had high uptake but failed to find undiagnosed HCV infections, a study found.

The study, published online January 8 in the Annals of Family Medicine, is the first conducted in Europe to use a strategy that combines public health and primary care in birth cohort testing of hotspots with high HCV prevalence.

"Because no active HCV infections were found in the identified hotspots, it is likely that the strategy taken would not be effective in other areas of the Netherlands and other low-prevalence countries," Jeanne Heil, MSc, from the Public Health Service, South Limburg, Heerlen, the Netherlands, and colleagues write.

HCV and HBV infections are usually asymptomatic, which is why many people go undiagnosed until later in the infection, when liver damage can occur. In recent years, more effective treatments for HCV have been developed; however, better strategies for earlier identification of infections are needed so that people can take advantage of these improved therapies.

Current recommendations advise universal testing for high-risk individuals, such as injection drug users, people with HIV, people who have received infected blood products, or those with a history of exposure or past risky behavior. However, some people do not remember or do not report such risks and go untested.

Testing the general population may improve detection of hidden infections. One such strategy is birth cohort screening, which is currently recommended in the United States, where the HCV prevalence is 2%. That raises the question of whether this strategy works in countries with lower prevalence, such as the Netherlands, which has a prevalence of 0.1 to 0.4% nationwide.

The researchers conducted a prospective cohort study that included 6743 individuals aged 40 to 70 years. Participants received care at 11 family practice clinics in two areas that are hotspots of HCV in the southern Netherlands. In these areas, HCV prevalence is 1%, and 66% of HCV infections are estimated to be undiagnosed.

Family physicians personally invited patients to participate in testing, which was also advertised in waiting rooms and local newspapers. In addition, the regional public health service distributed letters and reminders about testing and organized testing at two community centers. Testing was free of charge and also took place in family practice clinics, at home, or at the hospital. Those who did not get tested received a reminder letter within 1 week. Participants were initially screened with anti-HCV and antihepatitis B core tests. Positive results were confirmed with additional testing.

Those tested and those who declined testing received a questionnaire asking about sociodemographic information, HCV exposure risk factors (with the exception of sexual exposure risk), and reasons for participating.

The strategy had high test uptake of 50.9% (n = 3434 patients), but did not detect any active or chronic HCV infections (0.00%; 95% confidence interval [CI], 0.00% - 0.11%).

Positive test rates for anti-HCV, indicating past infection, were 0.20% (95% CI, 0.08% - 0.42%; n = 7). Rates for antihepatitis B core, indicating past HBV infection, were 4.14% (95% CI, 3.49% - 4.86%; n = 142). And rates for hepatitis B surface antigen, indicating active HBV infection, were 0.26% (95% CI, 0.12% - 0.50%; n = 9).

Of those with active HBV infection, follow-up testing at 6 months showed that seven were undiagnosed, and six were chronic. The public health service traced 13 close contacts and vaccinated nine for HBV.

To detect one positive case of past HCV infection, 491 people would need screening. To detect one positive case of past HBV infection, 24 people would need screening. And to detect one positive case of active HBV infection, 382 people would need screening.

The authors mention several limitations, including the possibility of selection bias, particularly if those with HCV had low health literacy and chose not to participate. The study lacked information on many people who declined testing because 23% of these individuals did not respond to the questionnaire. That raises the possibility that results may not generalize to the larger Dutch population.

The study was supported by the National Institute for Public Health and the Environment and AbbVie Inc. The authors have disclosed no relevant financial relationships.

Ann Fam Med. Published online January 8, 2018.

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