Even though acute hepatitis C virus (HCV) infection may clear up spontaneously, most cases become chronic, resulting in disease manifestations ranging from mild disease to advanced fibrosis, including cirrhosis and hepatocellular carcinoma (1). According to the World Health Organization (WHO), 58 million people worldwide lived with chronic HCV infection in 2016 (2). HCV is a blood-borne virus most frequently transmitted through infected medical supplies and blood products and by the sharing of injection equipment among injected drug users (1). Even though sexual transmission is less common (3, 4), the serological prevalence of HCV infection (i.e., the presence of anti-HCV antibodies) among men who have sex with men (MSM), particularly among those coinfected with the Human Immunodeficiency Virus-1 (HIV-1), is higher than in the general population (4%; range 2.9–13.0%) (5).

Despite the low efficiency of sexual HCV transmission, outbreaks of HCV infection have been reported since 2000, emerging as a real problem among MSM (3, 6, 7). The incidence of HCV infection has increased since 2000, particularly among HIV-1-positive MSM and HIV-1-negative MSM using Pre-Exposure Prophylaxis (PrEP) (3, 8, 9). Furthermore, the use of recreational drugs during sex is common in these populations and frequently associated with sexual risk behaviors (10, 11).

A large proportion of HCV cases remain undetected, especially among individuals outside routine care, precluding access to treatment with direct-acting antiviral agents (DAAs), the cure for HCV (3, 12). Consequently, in addition to prevention and treatment, identifying unknown and untreated HCV cases among the most prevalent populations is fundamental for eliminating HCV infection (2, 4). Different screening strategies targeting at-risk populations have been assessed in different settings, such as primary care, pharmacies, emergency departments, and prisons, to identify unknown HCV infections (13–16). In addition to these small, limited initiatives, a population-based nationwide screening in Egypt tested 79.4% of the population, and in the US, screening is recommended for all adults aged 18–79 years (17, 18).

Studies assessing large-scale, community-based screening programs targeting at-risk communities are limited and necessary to detect HCV-infected individuals. This study aimed to assess the acceptability and feasibility of massive HCV screening among MSM attending MSM events in Sitges (Catalonia, Spain) at point-of-care points (i.e., tents) set up on the street, based on self-testing using saliva quick tests. The secondary objectives were to determine the characteristics of the population included and the prevalence of HCV infection in this population.

This cross-sectional community-based study showed that the point-of-care approach on the street in massive events using quick oral tests allowed us to screen between 36 and 39 individuals per hour and reach many people from a community at risk. The prevalence of HCV antibodies among MSM (0.32%) was very low and even lower among individuals attending opening night parties (0%). Furthermore, our study confirmed that most MSM (67.41%) were at STD risk.

This study assessed a novel HCV screening strategy based on points of care at massive events. We found that the strategy was feasible and well accepted─64.1% acceptability rate in the pilot study─, reaching many individuals, likely due to the approach of offering a quick, non-invasive self-test on the street. A recent systematic review and meta-analysis showed that self-testing using quick tests on saliva samples was well-accepted (23), further supporting its use. Furthermore, the test yielded a negligible number of reading errors. In previous years, 3000–5000 individuals were estimated to attend the three main LGTB+ events in Sitges, and therefore, the number of participants in this study (n = 1249) was significant, considering the context of leisure and party. Thus, this novel strategy based on point-of-care tents on the street enabled data collection from a large sample in a short period, with very similar screening speeds in the pilot and large-screening study. This screening strategy may be implemented in the MSM community and may be a feasible option to screen other high-risk populations for HCV, such as homeless individuals and injected drug users, who are frequently outside routine care, likely due to increased mental health issues (4). Similarly, a recent study using a venue-based sampling strategy showed the feasibility of screening at-risk populations by approaching them at gathering venues (24). The success of setting up point-of-care tents on the street warrants further studies targeting other high-risk populations by setting them up at relevant locations.

The WHO developed a strategy for eliminating viral hepatitis as a public health threat by 2030 (2). Among different actions, this strategy included increasing the rate of detected infected individuals from 20% in 2015 to 30% in 2020 and 90% in 2030 (2). In 2017, Spain was one of the 12 countries on track to meet the WHO goals toward eradicating HCV by 2030 (25), thanks to removing treatment restrictions (26). Nevertheless, the Strategic Plan for Tackling Hepatitis C in the Spanish National Health System included screening of populations at risk (27). Likewise, the Department of Health of Catalonia, in its objectives of the Plan for the Prevention and Control of Hepatitis C in Catalonia, included the detection of unknown infections (28). Thus, screening and detecting HCV-infected individuals is a priority, and strategies reaching at-risk populations, such as the one presented in this study, should be considered. Importantly, this novel strategy carried out by different associations did not require appointments, social workers, or specific health care personnel, and, therefore, it is a cheap strategy that does not represent a burden on the health care system.

The prevalence of HCV antibodies among the 1466 individuals screened was lower than reported in other settings. The general prevalence of HCV varies among countries (29) and among MSM, the reported prevalences also differ. Previous studies reported a prevalence of 0.3–1.5% among HIV-negative MSM in different countries in Europe, Asia, and the Americas (3, 30). Recent systematic reviews and meta-analyses estimated pooled prevalences of 3.4 (95% CI: 2.8–−4.0) (31) and 5.9% (95% CI: 5.1–6.8) (29) regardless of HIV status. The estimated pooled prevalence in Spain was 6.3% (95% CI: 3.7–9.4) (29). The few studies assessing the seroprevalence of HCV in MSM in Catalonia estimated prevalences of 0.75% (95% CI: 0.1–1.6%) (32), 2.0% (95% CI: 0.7–4.8) (33) and, more recently, 0.52% (95% CI: 0.33–0.82) (34), in line with our study. In this regard, the MSM included in the large screening study were from 65 different nationalities and may not necessarily reflect the prevalence in Spain. Nevertheless, the low prevalence found in this study among MSM, similar to that in the no-MSM community, may be explained by the awareness of STDs and the importance of healthcare, with frequent blood tests, in this community.

In addition, the recruitment strategy and populations analyzed may further explain differences in the seroprevalences reported in our setting. In this regard, HCV prevalence is higher in MSM who inject drugs and those who are HIV-positive (29, 31). Although most of the previous studies were conducted in community care centers and STD clinics, the reasons for consultation may differ, and the MSM populations screened may have different characteristics regarding the prevalence of HIV infection, use of injected drugs, and other factors influencing HCV transmission (32–34). Our study included all adults attending popular events in the MSM community and, in the pilot study, adult men and women attending opening night parties, regardless of HIV status and injected drug use, capturing general prevalences irrespective of other factors. Despite reporting exposure to STD and sexual risk behaviors, the HCV seroprevalence in MSM participating in the screening was low. Recent studies have reported that the incidence of HCV infection among MSM using PrEP is increasing, suggesting an association between PrEP use and sexual risk behaviors in MSM (3). Furthermore, the sexualized use of drugs (Chem sex) is associated with risk behaviors (35, 36), in addition to the intrinsic risk of sharing injecting equipment. Moreover, a trend towars sexual risk behaviors among MSM in high-income countries has been reported (37). These observations indicate that MSM are at high risk for HCV transmission, and therefore, screenings in this community should still be a priority.

The results from this study should be interpreted in the context of limitations associated with the screening method. Regarding the HCV RNA negativity in all four HCV AB positive individuals, which gave us a positive predictive value of 0, this may be related to the considerably low prevalence of the infection in the study population; however, we cannot exclude the possibility of a false negative result for the HCV RNA test. On the other hand, although the quick oral test enabled the identification of anti-HCV antibodies outside the clinic, seroconversion may take a long time, precluding the detection of acute infection (38) which could result in a false-negative outcome in some of the study participants. Although we were able to collect information regarding the sexual behaviors of the screened population, we did not collect data regarding HIV infection, PreP use, or injected drug use, among other factors related to HCV transmission, precluding subgroup analyses. However, the association between these factors and HCV transmission has been reported, and the general goal of our study was to provide evidence of the feasibility of a novel point-of-care self-testing strategy on the street to reach populations at risk. Given the nature and purpose of this study, data was collected on paper, limiting the number of variables collected and their quality. Moreover, no selection strategy was implemented other than setting the point of care during MSM events, so we cannot ensure that our sample is representative of the study population. Finally, while our study focused on demonstrating the feasibility of screening, we must acknowledge that the detection yield was notably low, as no participants with active infection were identified. This outcome may be attributed to a selection bias, including the participation of individuals who had previously undergone hepatitis C testing or those who were at a low risk for this infection. Additionally, it could reflect a genuine decrease in the prevalence of hepatitis C in this population due to current antiviral treatments, or it may result from false negative findings, as previously discussed. Nevertheless, the primary message we aim to convey in this study is that this approach represents a highly cost-effective strategy in terms of economic resources and time. We believe it would be worthwhile to apply this screening model in populations with a higher prevalence of hepatitis C and limited access to healthcare services.

A point-of-care strategy on the street using quick oral anti-HCV antibodies self-testing at massive MSM events is feasible, well-accepted, quick, and cheap, facilitating the screening of many individuals of communities at risk in a short period. This strategy may be useful to perform massive screening at the community and reach other populations at risk of HCV infection.