In 2022, it was estimated that 50 million people were chronically infected with hepatitis C virus (HCV), with an average of just over a million new infections occurring annually.¹ As a result, approximately 242 000 people succumbed to the infection, especially those with long-term complications.¹ A subset of infected individuals (15% – 25%) will spontaneously clear the virus, while 75% – 85% will progress to chronic infection with an increased risk of developing chronic liver cirrhosis and hepatocellular carcinoma.² Acute hepatitis C infection is predominantly asymptomatic, with 20% of cases presenting with mild symptoms such as fatigue, nausea, vomiting, diarrhoea and dark urine.^2,3 Consequently, to accurately confirm the diagnosis of HCV infection laboratory-based testing comprised of both serological and molecular techniques is necessary.³ In the era of curable treatment for HCV, early and accurate HCV diagnosis is key to meeting the World Health Organization (WHO) elimination goals for 2030, which aim for the reduction of new HCV infections by 90% and mortality by 65%.^1,3 Post-HCV infection, HCV ribonucleic acid (RNA) is usually detectable in serum after one to three weeks. Detectable HCV RNA in an individual’s sera beyond 6 months indicates a persistent chronic infection.⁴ Curative therapy had been available for HCV and can achieve sustained virological response (SVR) in 30% – 50% of patients; however, many individuals experienced significant adverse effects.⁵ In 2022, direct acting antivirals (DAA) therapy was approved for use in South Africa, following a lengthy clinical observation for effectiveness and tolerance, marking a major milestone in HCV treatment and management.^6,7 However, access to DAAs has remained limited because of high costs and limited diagnostic infrastructure.^6,7 The DAAs aim to clear the virus and lessen the chance of severe disease progression. Successful treatment is measured by a SVR with undetectable HCV RNA 12 weeks after treatment is stopped.⁸ The effectiveness of DAA therapy is further enhanced by the use of pan-genotypic agents.^6,9 South African seroprevalence data show that anti-HCV is approximately 1% or less in the general population and varied among high-risk groups.^6,7,10 The accuracy and validity of overall HCV prevalence may be compromised because of poor follow-up and linkage to care.⁸

The HCV testing algorithm used in South African laboratories involves two tests: an initial serological test to detect anti- HCV antibodies and if positive, followed by a confirmatory test to detect the presence of HCV viral RNA.⁸ A significant drawback with the previous diagnostic algorithm was the need for additional hospital visits weeks later, where a second sample was extracted for HCV quantitative RNA PCR to confirm and describe viral load (VL). The testing required screening and confirmatory samples from more than one hospital visit, consequently, patients were left with an inconclusive diagnosis for weeks.⁸ Recently, a laboratory-based HCV reflex testing protocol was developed by the Department of Health to counteract inconclusive results and loss of follow-up.⁸ Laboratory-based HCV reflex testing refers to a testing algorithm in which patients have only a single clinical encounter and one blood draw or specimen for an initial laboratory-based HCV antibody test, which is then sent to the laboratory.¹¹ If the sample for HCV antibody testing is positive, then the same sample is automatically used for a prompt ‘reflex’ laboratory-based HCV RNA test.^8,11,12 The result returned to the patient or medical practitioner is for both the HCV antibody and HCV RNA results. Therefore, no further visit or specimen collection is required.^8,12

Previously in South African practice, the diagnosis of HCV required at least two visits to screen and diagnose HCV infection; as a result, a proportion of patients will be lost to follow-up and they could not be linked to care.^8,14 Improving access to rapid, simple and affordable HCV diagnostics is critical to advancing global HCV elimination efforts. In 2019, a laboratory-based HCV reflex testing algorithm was introduced to address issues related to inconclusive results and patient loss to follow-up.⁸ This study included 212 670 patients tested for HCV antibodies over 5 years in the public sector, making this one of the largest HCV descriptive studies focusing on a general South African population. Of the 212 670 patients serologically tested for HCV antibodies, 204 046 (95.9%) tested negative, while 8575 (4.04%) tested seropositive. In this study, we are reporting 4.04% seroprevalence from a general South African cohort. Furthermore, the seroprevalence observed in our study is considerably higher than previous estimates of less than 1% for South Africa’s general population and higher than the 2.64% reported for the general population in sub-Saharan Africa.^{6,7,11,12,13,14} Research describing HCV seroprevalence in South Africa has largely been directed to the high-risk populations, including people who inject drugs (PWID), men who have sex with men (MSM), HCV and HIV concurrently infected patients, the homeless, and the incarcerated because of their high HCV prevalence rates.^11,12,13,14 The accurate seroprevalence data in a broader population is necessary for South Africa to track progress and refine elimination strategies towards the WHO’s target of eliminating HCV as a public health threat by 2030.¹ Our findings, drawn from a large public sector cohort tested over five years, suggest a potentially broader transmission of HCV within the general population. This highlights the urgent need for ongoing reassessment and updated prevalence studies to inform national elimination efforts. The HCV RNA testing was performed for only 25% of seropositive patients, among whom more than half had detectable HCV RNA copies ranging between < 15 IU/mL and < 10 000 000 IU/mL. Our findings are consistent with other studies conducted in South Africa and across sub-Saharan Africa, which also report that over half of HCV-seropositive individuals were viraemic.^12,14,15 However, what is particularly concerning is that in our study, a staggering 75% of seropositive patients did not have a linked HCV RNA result. This finding substantiates our hypotheses that the HCV diagnostic algorithm recommended by the WHO and by the South African Hepatitis National Guidelines are not adhered to in clinical practice. Failure to confirm active HCV infection delays crucial interventions, such as timely initiation of treatment in the DAA era, thereby prolonging disease progression and increasing the risk of complications.^6,16

Furthermore, undiagnosed individuals with detectable HCV RNA may continue to transmit the virus especially among high-risk groups and at a population-based level.¹⁶ This ongoing transmission could sustain high rates of infection, undermining efforts to achieve the WHO’s target of a 90% reduction in new HCV infections by 2030. A significantly higher proportion of males (74.8%) were found to be seropositive than females (23.6%), and younger across all 5 years.

These results correlate with several studies conducted on HCV prevalence.^5,17 Since the early 2000s, sexual transmission has been recognised as an emerging risk factor for HCV infection, particularly among HIV-positive MSM.¹⁸ The risk is further compounded by concomitant injecting drug use in this population.¹⁹ We observed a similar distribution across all age groups, with the majority of cases occurring among young adults, with a median age of 28 years (interquartile range [IQR]: 25–31), representing the highest number of HCV-seropositive results. This observation is widely reported in the literature and is often attributed to the higher representation of males in high-risk groups such as PWID, MSM and incarcerated individuals.^5,20 Other studies have also reported a notable rise in HCV cases among individuals aged 20–29 years, which were primarily linked to injection drug use and high-risk behaviour.^11,12,13,14 Also, higher prevalence among young adults emphasises the role of intravenous drug use in the transmission of HCV infection.The risk of transmission of HCV among young children born to HCV-infected mothers is approximately 5%. This risk increases to approximately 10% in mothers co-infected with HIV or with HCV viral loads ≥ 10⁶ IU/mL.^21,22 Of the 8575 HCV-seropositive patients, 722 (8.4%) were children younger than 12 years of age, with a median age of 0 years. A reported 25% to 40% of children with perinatally acquired HCV infection may spontaneously clear the virus, usually between the ages of 2 years and 5 years,^23,24 which may explain the observed decline of HCV infection in the 13–19 year age group, where the median age was 18 years and prevalence was 1.2%. In this study period, hospital admissions were overall significantly higher compared to outpatients (p < 0.002), although this occurrence may not be directly linked to HCV infection. Over the years, observational studies conducted in high-income countries have shown that among HCV infected individuals, hospitalisation related to HCV infection was gradually increasing. However, since the introduction of DAAs, hospitalisation rates have markedly declined, thereby reducing the overall healthcare burden.^25,26 In contrast, our findings demonstrate that this trend has not yet been observed in the South African context.

This study highlights a gap in the current HCV diagnostic algorithm in South Africa. Even with reflex testing having been implemented in South Africa, there are still gaps in patients’ linkage after a positive HCV antibody result. Therefore, if follow-up systems are not strengthened, the benefits of reflex testing are not fully exploited. With a seroprevalence of 4.04% among the general population, our findings underscore the need to frequently update seroprevalence data to inform elimination strategies. Our findings also suggest an ongoing transmission in the general South African population. The lack of follow-up HCV RNA testing highlights a setback in implementing recommended diagnostic algorithms and patients’ linkage to care.