Demonstration of a population-based HCV serosurvey in Ho Chi Minh City, Viet Nam: Establishing baseline prevalence of and continuum of care for HCV micro-elimination by 2030

Pilot model of hepatitis C virus micro-elimination in high-risk populations in Hong Kong: Barriers and facilitators

BACKGROUND

Although the general seroprevalence of hepatitis C virus (HCV) infection in Hong Kong is <0.5 %, Hong Kong is still striving for HCV elimination owing to barriers in care cascade encompassing linkage-to-care (LTC), treatment initiation and adherence. We aimed to evaluate the feasibility of a pilot model of micro-elimination to strengthen the HCV care cascade for high-risk groups in Hong Kong.

METHODS

We initiated the pilot Conquering Hepatitis vIa Micro-Elimination (CHIME) program which adopts an integrated care approach involving outreach visits to halfway house or drug rehabilitation centers run by non-governmental organizations. Participants with history of injection drug use (PWID), recreational drug use, or imprisonment were included. We performed point-of-care test for anti-HCV with reflex HCV RNA testing. LTC with government-subsidized direct acting antiviral was provided to viremic participants. We compared the impact on the care cascade with a cohort of HCV patients (17.8 % PWID) under usual care.

RESULTS

396 participants (62.9 % PWID) were screened and 187 (47.2 %) were viremic, of which 29.8 % had cirrhosis. Proportion with LTC, treatment initiation and adherence were 76.5 % and 63.7 %, 90.9 % and 85.8 %, and 90.0 % and 92.2 %, for the CHIME program and usual care, respectively. The CHIME program was significantly associated with higher odds of LTC (OR 1.797, 95 % CI 1.221-2.644). Non-engagement in care (affecting 37.9 % participants with HCV viremia) was associated with unemployment (OR 2.165, 95 % CI 1.118-4.190).

CONCLUSION

The pilot CHIME program demonstrated feasibility of an integrated approach to consolidate the HCV care cascade in high-risk populations in Hong Kong.

Low HBV knowledge is associated with low HBV vaccination uptake in general adult population despite incentivization of HBV vaccination

BACKGROUND

Hepatitis B virus (HBV) vaccination in Vietnamese adults remains low and unequally distributed. We conducted a study on HBV-naïve adults living in Ho Chi Minh City, Viet Nam, to determine barriers associated with HBV vaccination uptake after removing the financial barrier by providing free coupons for HBV vaccination.

METHODS

After being screened for HBsAg, anti-HBs, and anti-HBc, 284 HBV-naïve study participants aged 18 and over (i.e., negative for HBsAg, anti-HBs, and anti-HBc total) were provided free 3-dose HBV vaccine coupons. Next, study participants' receipt of 1st, 2nd, and 3rd doses of HBV vaccine was documented at a pre-specified study healthcare facility, where HBV vaccines were distributed at no cost to the participants. Upon study entry, participants answered questionnaires on sociodemographics, knowledge of HBV and HBV vaccination, and related social and behavioral factors. The proportions of three doses of HBV vaccine uptake and their confidence intervals were analyzed. Associations of HBV vaccine initiation with exposures at study entry were evaluated using modified Poisson regression.

RESULTS

98.9% (281 of 284) of study participants had complete data and were included in the analysis. The proportion of participants obtaining the 1st, 2nd, and 3rd doses of HBV vaccine was 11.7% (95% Confidence Interval [95% CI] 8.0-15.5%), 10.7% (95%CI 7.1-14.3%), and 8.9% (95%CI 5.6-12.2%), respectively. On the other hand, participants were more likely to initiate the 1st dose if they had adequate knowledge of transmission (adjusted relative risk [aRR] = 2.58, 95% CI 1.12-5.92), adequate knowledge of severity (aRR = 6.75, 95%CI 3.38-13.48), and annual health-checking seeking behavior (aRR = 2.04, 95%CI 1.07-3.87).

CONCLUSION

We documented a low HBV vaccination uptake despite incentivization. However, increased vaccine initiation was associated with better HBV knowledge and annual health check-up adherence. When considering expanding HBV vaccination to the general adult population, we should appreciate that HBV knowledge is an independent predictor of vaccine uptake.

Significant gaps in hepatitis B vaccination in adults in Viet Nam: Important targets toward hepatitis B elimination by 2030

BACKGROUND

Gaps in adult hepatitis B vaccination were undefined in Vietnam, a lower-middle-income country. To address these gaps, this study defined hepatitis B vaccine coverage in adults and its associated factors in Ho Chi Minh City (HCMC), Viet Nam. We also proposed interventional strategies, prioritizing gap identification to facilitate hepatitis B elimination by 2030 and beyond.

METHOD

During 2019-2020, a multi-stage cluster serosurvey with probability proportional to size was conducted to representatively invite 20,000 adults (18 years or older) throughout HCMC for hepatitis B screening (HBsAg, anti-HBs, and anti-HBc). Serologic results defined two dependent variables: vaccine-induced immunity (i.e., isolated anti-HBs) and susceptibility (i.e., HBV naive). Associations of dependent variables with surveyed demographics, socioeconomic statuses, behaviors, and medical history at risk for hepatitis B were evaluated using weighted Poisson regression.

RESULTS

The prevalence was 18.5% (95%CI, 17.3-20.0%) for vaccine-induced immunity and 37.7% (35.6-39.8%) for susceptibility. Even though analyses in the general population revealed a falling trend in vaccine-induced immunity prevalence from younger to older age groups, sensitivity analyses in the non-infected population (i.e., those who were both negative for HBsAg and anti-HBc) showed that younger age groups, especially those aged 30 to 50 years, had the lowest prevalence. Social inequalities existed in different ethnicities, residence areas, education levels, house ownership, and health insurance statuses. There was no significant association between vaccine-induced immunity or susceptibility and risky behaviors and medical histories.

CONCLUSION

This study depicts a significant unmet need for hepatitis B vaccination in the general adult population in HCMC, Viet Nam. Indeed, the lack of vaccination was unevenly distributed regarding age groups, geographical areas, and socioeconomic statuses, which reveals profound social disparities. Therefore, to achieve hepatitis B elimination goals, besides the current recommendations for infants and risk-based strategies, hepatitis B vaccination should be recommended for the broader population.