Who to test for HBV and HCV infection – testing approaches

The guidelines recommend offering focused testing to individuals from populations most affected by HBV or HCV infection (i.e. who are either part of a population with higher seroprevalence or who have a history of exposure to or high-risk behaviours for HBV or HCV infection). In settings with a ≥2% or ≥5% seroprevalence of hepatitis B surface antigen (HBsAg) or HCV antibody (anti-HCV) (based on existing published thresholds for intermediate or high seroprevalence, respectively), it is recommended that all adults have routine access to and be offered testing (i.e. a general population testing approach), or use “birth cohort” testing for specific age groups with higher anti-HCV seroprevalence. However, the threshold used by a country will depend on other country considerations and epidemiological context. Overall, these different testing approaches should make use of existing facility-based (such as antenatal clinics, HIV or TB services) or community- based testing opportunities and programmes.

How to test for HBV and HCV infection – serological assays and testing strategies

Overall, the guidelines recommend the use of a single quality-assured serological in vitro diagnostic test (i.e. either a laboratory-based immunoassay [enzyme immunoassay or chemiluminiscence immunoassay] or rapid diagnostic test [RDT]) to detect HBsAg and HCV antibody. RDTs used should meet minimum performance standards, and be delivered at the point of care to improve access and linkage to care and treatment.

Confirming viraemic infection and monitoring for treatment response

Following a reactive HCV antibody serological test result, a quantitative or qualitative RNA NAT is recommended as the preferred testing strategy to diagnose viraemic infection. Detection of core HCV antigen, where the assay has comparable clinical sensitivity to NAT technologies, may be considered as an alternative. The use of HBV DNA NAT following a reactive HBsAg serological test result, is recommended to help further guide who to treat or not treat if there is no evidence of cirrhosis, and to monitor for treatment response, based on existing recommendations from the 2015 WHO HBV management guidelines.

Use of dried blood spot sampling and other strategies to promote testing uptake and linkage to care

The use of capillary whole blood DBS specimens for both serological and NAT technologies for HBV and HCV infection may be considered to facilitate access to testing in certain settings where there are either no facilities or expertise to take venous blood specimens, in persons with poor venous access, or where quality-assured RDTs are not available or their use is not feasible. Programmes should consider only the use of assays that have been validated by their manufacturer for use with DBS specimens. Other recommended interventions to promote uptake of hepatitis testing and linkage to care include peer and lay health worker support in community- based settings, clinician reminders in facilities, and testing as part of integrated services within drug treatment and community-based harm reduction services.

The development of these guidelines was conducted in accordance with procedures established by the WHO Guidelines Review Committee. Clinical recommendations were formulated by a regionally representative and multidisciplinary Guidelines Development Group at a meeting held in September 2015. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to formulate and categorize strength of recommendations (strong or conditional), and was adapted for diagnostic tests. This includes an assessment of the quality of evidence (high, moderate, low or very low), consideration of overall balance of benefits and harms (at individual and population levels), patient/health worker values and preferences, resource use, cost–effectiveness and consideration of feasibility and effectiveness across a variety of resource-limited settings, including where access to laboratory infrastructure and specialized tests is limited. There was a very limited evidence base to guide recommendations on testing approaches (i.e. who to test and service delivery approaches) and an absence of evidence on patient-important outcomes in evaluation of performance of diagnostic tests and testing strategies. The process also identified key gaps in knowledge that will guide the future research agenda. Most of the evidence was based on published studies in adults from Asia, North America and Western Europe; there is a lack of data from sub-Saharan Africa, and in children.

Implementation of these recommendations pose practical challenges to policymakers and implementers in LMICs, particularly in sub-Saharan Africa, where there is currently very limited access to diagnostic tests, antiviral therapies and appropriate laboratory infrastructure. These guidelines also provide the framework for country decision-making and planning for hepatitis laboratory testing programmes to ensure the quality and accuracy of hepatitis testing, as well as approaches to delivery of testing services, including opportunities to integrate hepatitis testing with existing services, where appropriate.

These guidelines and recommendations provide a major opportunity to improve identification and treatment of persons with chronic hepatitis B and C, and achieve the Global Hepatitis Health Sector Strategy (GHSS) on Viral Hepatitis ³ targets, including those on testing (i.e. identify 30% of persons living with HBV and HCV by 2020 and 90% by 2030). This in turn will improve clinical outcomes and save lives, as well as facilitate prevention, reducing hepatitis transmission and new infections.