An estimated 354 million people live with hepatitis B (HBV) or hepatitis C virus (HCV) worldwide, and among them more than one million die yearly from complications such as hepatocellular carcinoma or cirrhosis (1). The majority of this burden is borne by people in Africa and Asia. In the Americas, the number of people chronically infected with HBV and HCV were estimated at 14 million (2). The number of deaths related to HBV and HCV in 2019 for the region were estimated at 15,000 and 31,000, respectively (1).

As these chronic viral infections progress asymptomatically over the years until serious liver damage is established, most people chronically infected with HBV or HCV remain undiagnosed unless there is a screening program for these infections targeting asymptomatic people. In fact, The World Health Organization (WHO) estimates that only 10% of people living with HBV and 21% of those living with HCV have been diagnosed (1). The WHO presently aims to achieve the worldwide elimination of hepatitis B and C as public health threat by 2030 (3).

Haiti is a small country of 11 million people located in the Caribbean, where little attention has been paid to viral hepatitis. The country was the last in the Americas to introduce hepatitis B vaccines into the routine infant immunization program in 2012 using pentavalent vaccines scheduled at 6, 10, and 14 weeks of life (4). In 2020, 8 years after the introduction of the hepatitis B vaccines, coverage of three-dose pentavalent vaccines still remained low at 51% among 1-year-old children according to the WHO/UNICEF data (5). Moreover, the birth dose vaccination is not yet introduced into the national immunization program and pregnant women are not systematically screened for HBV to prevent mother-to-child transmission (MTCT) despite the WHO's recommendations (6). There is no national program targeting chronic viral hepatitis in Haiti.

To date, there is no systematic review specific to Haiti to estimate the prevalence of chronic viral hepatitis in this country. Regarding the prevalence of HBsAg, studies on a global or regional scale have provided country-specific estimates including that of Haiti, but with marked variations between studies. In a systematic review and meta-analysis by Schweitzer et al. (7) published in 2015, an estimated 13.6% (95% CI: 9.0–19.9) of Haitians were positive for HBsAg. Kowdley et al. also conducted a systematic review and meta-analysis, and reported a pooled prevalence of 4.8% (95% CI: 3.9–5.7) in their first publication in 2011 and 4.6% (95% CI: 3.2–6.0) in their updated publication in 2021 (8, 9). On the basis of a combination of literature review and expert opinions, the Polaris Observatory Collaborators estimated that the prevalence of HBsAg in Haiti in 2016 was 2.9% (95% CI: 2.7–4.1) (10). Most recently, the Global Burden of Disease (GBD) study reported a decrease in prevalence of HBV from 1.9% (95% CI: 1.5–2.2) in 1990 to 1.6% (95% CI: 1.3–1.9) in 2019, using a combination of systematic review and mathematical modeling (11). Interpretation of these heterogeneous estimates is complicated. Moreover, besides the articles by Kowdley et al., these estimations were based on a small number of studies (two for Schweitzer et al., four for Polaris, and one for GBD). Regarding HCV and hepatitis D virus (HDV), none of the previous systematic reviews estimating the global prevalence of these infections included a study from Haiti (12–15).

We, therefore, conducted a systematic review and meta-analysis specific to Haiti for the prevalence of HBV, HCV, and HDV among three groups: (i) children, (ii) the general adult population, and (iii) the high-risk adult population. The data generated by this work can serve as baseline data before any public health interventions targeting these infections are implemented in this country.

A total of 453 articles were identified after the removal of duplicates. Following the independent screening by two reviewers, 42 full-text articles were assessed for eligibility, and 21 met the eligibility criteria. In addition, four more eligible articles were manually identified from the references of the included studies and other review articles. Finally, 25 studies were included in the meta-analysis for the following hepatitis markers: HBsAg only (16 studies), anti-HCV antibody only (three studies), and both HBsAg and anti-HCV antibody (6 studies). There was no study assessing HDV prevalence among Haitian (Figure 1).

Of the 22 studies reporting the prevalence of HBsAg, six were classified as having a low risk of bias, seven as a moderate, and nine as a high risk. Of the nine studies reporting the prevalence of anti-HCV antibody, two were classified as a low risk of bias, six as moderate, and one as high. There was a wide variation in the recruitment sites. For HBsAg, seven studies recruited participants in hospitals, seven during antenatal or perinatal care, two from blood bank, and six in community survey. For anti-HCV antibody, four studies recruited in hospital, two during antenatal care, two from blood bank, and three in community survey.

Through a systematic review and meta-analysis, the pooled prevalence of HBsAg was 3.5% (95% CI: 2.8–4.4) and that of anti-HCV was 0.9% (95% CI: 0.6–1.4) among the general adult population from Haiti. In this population, the prevalence of HBsAg might have decreased from 4.8% (before 2000) to 3.1% (after 2000), whilst such decrease was not observed for the prevalence of anti-HCV antibody. The prevalence of HBsAg did not considerably vary between people living in Haiti and those who migrated to other countries; a similar pattern was observed for anti-HCV. There was no study reporting the prevalence of HDV in Haitian.

To date, multiple studies reported a country-specific estimates for HBsAg in Haiti with marked variations. The highest estimate was provided by Schweitzer et al. (7) (13.6%, 95% CI: 9.0–19.9). That systematic review and meta-analysis only included two studies with a total of 155 participants (27, 29); importantly, they used the prevalence of HBsAg in people positive for hepatitis B core antibody (anti-HBc) that had been reported in one of the two included studies (29). It is obvious that those who have been exposed to HBV (i.e., anti-HBc positive) should have higher prevalence of HBsAg than the general population, thus leading to an overestimation of the HBV burden. The pooled prevalence of HBsAg among the general adult population in our meta-analysis (3.5%, 95% CI: 2.8–4.4) fell into the range of the previous estimate reported by the Polaris Observatory Collaborators (2.9%, 95% CI: 2.7–4.1) (10). Their hybrid method combining literature review, international expert interviews, meta-analysis, and modeling, yielded a pertinent estimate because it was based on large data on blood donors and pregnant women, all included as well in this review.

The prevalence observed in our systematic review was lower than the estimates in many of Asian or African countries, where about 6% of the population carry HBsAg (47–51), but much higher than the Americas' average (0.7%, 95% CI: 0.4–1.6) (2). Assuming that 3.5% of 7.8 million adults in Haiti are chronically infected with HBV, about 273,000 people would need follow-up and care for their chronic HBV infection (52). Our findings also suggest that HBV prevalence might be higher among high-risk groups, including patients with tuberculosis or those living with HIV.

As expected, the HBsAg prevalence in pregnant women (3.8%) was similar to the prevalence in the general adult population. Although the rate of HBeAg carriage in HBsAg-positive mothers was not high, a significant proportion presented a high viral load (20.7% had a viral load ≥200,000 IU/ml). This being a strong marker for MTCT (53), it is important to consider systematic measures for prevention of MTCT of HBV in Haiti.

We found a decreasing trend of HBsAg in the general adult population by comparing the pooled estimates before and after the year 2000. This decreasing trend might be underestimated by the use of non-sensitive assay before 2000; indeed, all the pre-2000 studies but one used radioimmunoassay to detect HBsAg, which has much lower analytical sensitivity than chemiluminescence or enzyme immunoassay that were used in studies conducted after 2000. This indicates that the true prevalence of HBsAg before 2000 could have been even higher than what we observed, further confirming the decreasing trend in HBsAg prevalence over time. This spontaneous decrease in HBsAg prevalence in adults, in the absence of a large impact from a recently introduced hepatitis B immunization program, could be explained by changes in demographic factors, such as decrease in sibship size or increase in maternal age at first childbirth in Haiti (54). Delaying the age of marriage and childbearing may result in a decrease in HBsAg prevalence because older mothers, if chronically infected with HBV, have a higher chance of having lost HBeAg and remaining in low viral load with a decrease in risk of transmitting HBV to their babies (55–57). Moreover, the reduction in sibship size may contribute to the reduction in horizontal transmission that mainly occurs between siblings within a household (58, 59). This aligns with the lower prevalence seen among children after 2000.

All but one study constantly showed that the prevalence of anti-HCV was below 1%, which is close to the average for the Americas (0.7%, 95% CI: 06–0.8). There was no significant variation of the anti-HCV prevalence between studies conducted before 2000 (0.6%, 95% CI: 0.3–1.5) and after 2000 (1.0%, 95% CI: 0.6–1.6). No considerable variation in anti-HCV prevalence was observed by place of residence (0.9%, 95% CI: 0.5–1.5 in Haiti and 1.0%, 95% CI: 0.7–1.4 abroad). Assuming a prevalence of anti-HCV at 0.9% among adults and a proportion of 75% of anti-HCV positive to carry HCV RNA (60), there could be about 50,000 people in Haiti that are chronically infected with HCV and would benefit from curative treatment with directly acting antiviral (DAA). Most Haitians pay for medical fee out of pocket; therefore, it will help if DAAs are financed like antiretroviral drugs for HIV.

This review had a few constrains. First, in two studies reporting on HBsAg, we could not separate adult from children population (27, 28), one of them also including pregnant women (27). Similarly, for one study reporting anti-HCV antibody, adults and children were considered together (44). Those three studies were analyzed as adult population. Second, the study by Jean-Baptiste et al. and the Pan American Health Organization evaluating blood donors did not distinguish first time donors from repeat blood donors (34, 38); including regular blood donors in this group could cause an underestimation of the prevalence. Finally, we did not have enough studies to estimate prevalence of anti-HCV antibody for pregnant women, for PLHIV or to estimate the prevalence of HBsAg in children born after 2012.

In conclusion, this systematic review pooled prevalence for HBsAg and anti-HCV antibody among Haitian people. High prevalence of HBsAg in this population requires an urgent intervention such as increase in coverage of infant hepatitis B immunization, integration of birth dose vaccines, and prevention of mother-to-child transmission of HBV by antenatal screening and provision of peripartum antiviral prophylaxis. The prevalence of anti-HCV antibody was not as high as HBsAg, but still requires an immediate intervention as thousands of people could avoid having liver-related morbimortality in Haiti. This systematic review also identified an important knowledge gap; the prevalence of HDV needs to be evaluated in Haiti.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding authors.

JV and YS developed the study protocol and wrote the manuscript. JV performed the search and data analysis. JV and CN screened the articles and extracted the data. SW provided data. YM provided statistical support. All authors reviewed and agreed with the final version of the manuscript.