Hidden chronic hepatitis C infections remain hard to detect

A public health and primary care birth cohort testing strategy does not detect hidden hepatitis C virus (HCV) infections, according to a new study.

Strategies to detect HCV and hepatitis B virus (HBV) hidden in the general population have been disappointing. “Past drug users or recipients of blood transfusions remain hidden as they may not remember or report these behaviors. Additionally, not all HCV cases are part of a known risk group. To capture all persons who have HCV infection, prospective studies were needed to evaluate the diagnostic yield of HCV testing strategies not based on exposure risk factors,” Jeanne Heil, MSc, of the Public Health Service in Heerlen, The Netherlands, told Medical Economics.

The researchers published their results January 8, 2018 in Annals of Family Medicine.

A prospective cohort study set out to determine the test uptake and positivity rate of a combined public health and primary care birth cohort testing strategy in detecting hidden cases of HCV and HBV. The study included 6,743 adults registered with 11 family practices serving two higher prevalence areas in the Netherlands.

“This best-practice testing strategy was effective in achieving a high test uptake of 51%, and detected HBV cases mainly in non-western migrants. However, it completely failed to detect hidden chronic HCV infections and is not recommended for lower prevalence countries. Most surprising was that no active HCV infections were found,” said Heil.

The researchers expected a higher prevalence based on previous estimations in the hotspots, the overall prevalence of the general population, and based on the estimated hidden population.

This testing strategy could be applied to the United States, she said, which is considered to be a high prevalence country with a HCV prevalence of 2 percent. “Our testing strategy can be applied to detecting HBV and HCV infections, as well as other infectious diseases, in higher prevalence countries. The U.S. Centers for Disease Control recommended one-time HCV testing of adults born from 1945 through 1965. The hotspot-method might possibly be helpful in further targeting this birth cohort,” said Heil.

She noted that testing was offered free of charge in the Netherlands and that a lack of health insurance could be a limiting factor in the United States. Also, the test uptake of a similar testing strategy might be lower in certain groups at risk, for example, intravenous drug users.

Primary care physicians can be enlisted to detect more patients with HCV infection. “Primary care physicians in general should focus their case finding on risk groups. These risk groups include first-generation migrants and refugees from countries where chronic HBV or HCV infections are common, drug users who regularly use or have used needles, men who have sex with men, and healthcare employees,” said Heil.

Additionally, the improved treatment options for chronic HCV infections are a reason for retracing people who have been diagnosed with a chronic infection in the past, but are no longer receiving care, she said.