Hepatitis C virus (HCV) is one of the leading causes of viral hepatitis, cirrhosis, and liver cancer worldwide, with an estimated 71 million people living with the virus and nearly 400,000 annual HCV-related deaths.(1) The global HCV burden is disproportionately distributed in low- and middle-income countries,(2) where 80% of the world’s HCV-infected population live and where significant barriers to accessing testing, care and treatment may impede advances in controlling the burden of disease.(3) As of 2019, the World Health Organization (WHO) estimates that globally less than one quarter of all persons with HCV infection had been diagnosed and nearly 40% of diagnosed persons remain untreated.(4)
In 2016, the WHO launched a Global Health Sector Strategy on Viral Hepatitis, with ambitious goals to eliminate HCV as a public health threat by 2030, defined as an 80% reduction in new HCV infections and a 65% reduction in HCV-related mortality by 2030.(5) To achieve these impact targets, modelling indicated that this would require 90% testing coverage of eligible populations, and 80% treatment coverage of those HCV infected. However, global progress toward these goals was already falling short by 2019 with only 21% testing coverage and 62% treatment coverage.(6)
With the availability of highly effective, low-cost generic direct acting antiviral therapy offering cure rates of over 90%,(7, 8) the global HCV response has turned towards expansion of testing and treatment programs. In 2018 the WHO recommended a “treat all” approach for all people aged >12 years infected with HCV regardless of disease stage or population.(9) The 2017 WHO testing guidelines for hepatitis B and C also recommended routine focused HCV testing for most affected populations that include people who inject drugs (PWID) and men who have sex with men (MSM), person in prisons, as well as access to general population screening for those settings and countries with a general population prevalence ≥2%(10, 11) using a single rapid diagnostic test (RDT) or laboratory-based assay. However, access to HCV testing services remains a barrier to achieving HCV elimination goals, particularly among high-risk populations,(3) and nearly 80% of infected individuals worldwide remain undiagnosed.(4, 12)
PWID are among the highest risk groups for HCV worldwide.(13) In Kenya, PWID constitute the highest risk group with a prevalence estimated between 13-40%(14–16) compared with <1 – 4% in the general population.(17, 18) PWID also experience barriers to accessing care that result in low rates of testing, engagement in care, and completion of treatment courses.(19–21) Of Kenya’s estimated 115,000 HCV-infected individuals, fewer than 25% have been diagnosed.(22) Expansion of HCV testing and treatment services that are accessible to vulnerable populations is vital to make progress toward the WHO’s ambitious testing and treatment goals. A recent systematic review showed that full decentralisation and integration of hepatitis C testing and treatment at harm reduction sites – a “one-stop shop” resulted in increased uptake of testing, linkage and treatment among PWID.(23)
Self-testing (ST) is a testing approach in which people, at a time and place of their choosing, can collect their own specimen, perform a rapid test, and then read and interpret the results. While self-testing has been used extensively for pregnancy and certain chronic conditions such as blood glucose monitoring in diabetes for decades, the use has increased in the past decade for infectious diseases such as HIV and malaria. WHO recommends HIVST as safe, accurate and effective at increasing the uptake and frequency of testing among high risk populations such as MSM and female sex workers,(24–27) while achieving comparable positivity and linkage rates to standard HIV testing.(26, 28, 29)
Kenya was an early adopter of HIVST, undertaking studies among healthcare workers as early as 2006 and including HIVST in the national HIV testing guidelines in 2015.(30) As a result, there has been extensive implementation of HIVST and the practice is now widely acceptable in the general population, key populations, and among individuals taking pre-exposure prophylaxis.(31, 32) However, acceptability and other features of HIVST have not been widely studied among PWID in Kenya or in other countries despite their high risk. Self-testing for HCV antibodies is a novel approach, with data limited to a few small pilot studies in the general population using experimental testing products that showed high agreement between results of self-testing and healthcare provider-delivered testing.(33, 34) Acceptability of HCVST was found to be high in one small study of PWID in London, but concerns were highlighted about access to facility based confirmatory viral load testing and care.(35) To better understand usability and acceptability of HCVST among key populations, the WHO has partnered with the Foundation for Innovative New Diagnostics (FIND) to coordinate a series of pilot studies of acceptability and usability of HCVST in different populations in five countries—Egypt (general population in semi-rural community in high burden country),(36) China (MSM), Vietnam (PWID and MSM),(37) Georgia (PWID and MSM) and Kenya (PWID and their partners). Based on preliminary results of these pilots and other data, WHO published HCVST recommendations and guidance in 2021.(38) Here we describe results from the pilot study conducted among PWID living in the coastal region of Kenya.