Detection of hidden hepatitis C virus infection in primary care settings using clinical decision support system: The...

Universal screening for Hepatitis C Virus (HCV) has gained importance following the WHO 2030 objectives. In Spain, with an active infection prevalence of 0.22% at national level (95%CI 0.12%-0.32%), population-wide screening is not currently recommended. Our aim was to evaluate the prevalence of hidden HCV infection in patients who consulted primary care for other reasons and were prescribed any other kinds of blood test.

Our intervention was based on automated software managed at the clinical laboratory level, the pillars of which were: a Laboratory Information System (LIS) holding patients records for the past 15 years, an e-prescribing system, and an algorithm-based clinical decision support system (CDSS). Eligible patients were automatically offered the option of taking an additional test (for HCV) from the same blood draw used for the tests they were being prescribed.

Screening was carried out in 2024 over a six-month period on 7,013 of the 11,490 patients offered screening (61.03%). 55 cases tested positive for HCV (0.78%) and 9 cases tested positive for HCV-RNA (0.13%; 95%CI 0.06%-0.24%), indicating active infection, and were promptly referred for specialist care. The direct cost of detecting one case of active infection was €2,282.47.

We detected hidden HCV infections at a rate compatible with national estimates. Offering the possibility of obtaining an additional test from the same blood draw has removed a psychological and logistical barrier to patient participation. Targeted screening campaigns, managed at the clinical laboratory level with advanced automated systems, can be cost-effective.