Notes from the Field: Hepatitis A Outbreak Associated with Drug Use and Homelessness - West Virginia, 2018

The Burden of Hepatitis A Outbreaks in the United States: Health Outcomes, Economic Costs, and Management Strategies

BACKGROUND

Hepatitis A (HepA) vaccines are recommended for US adults at risk of HepA. Ongoing United States (US) HepA outbreaks since 2016 have primarily spread person-to-person, especially among at-risk groups. We investigated the health outcomes, economic burden, and outbreak management considerations associated with HepA outbreaks from 2016 onwards.

METHODS

A systematic literature review was conducted to assess HepA outbreak-associated health outcomes, health care resource utilization (HCRU), and economic burden. A targeted literature review evaluated HepA outbreak management considerations.

RESULTS

Across 33 studies reporting on HepA outbreak-associated health outcomes/HCRU, frequently reported HepA-related morbidities included acute liver failure/injury (n = 6 studies of 33 studies) and liver transplantation (n = 5 of 33); reported case fatality rates ranged from 0% to 10.8%. Hospitalization rates reported in studies investigating person-to-person outbreaks ranged from 41.6% to 84.8%. Ten studies reported on outbreak-associated economic burden, with a national study reporting an average cost of over $16 000 per hospitalization. Thirty-four studies reported on outbreak management; challenges included difficulty reaching at-risk groups and vaccination distrust. Successes included targeted interventions and increasing public awareness.

CONCLUSIONS

This review indicates a considerable clinical and economic burden of ongoing US HepA outbreaks. Targeted prevention strategies and increased public awareness and vaccination coverage are needed to reduce HepA burden and prevent future outbreaks.

Vaccination coverage among people who inject drugs: A systematic review

BACKGROUND

People who inject drugs may be at excess risk of acquiring vaccine-preventable diseases and negative associated health outcomes, but experience barriers to vaccination. We aimed to determine vaccination coverage among people who inject drugs globally.

METHODOLOGY

We conducted systematic searches of the peer-reviewed and grey literature, date limited from January 2008 to August 2023, focusing on diseases for which people who inject drugs are at elevated risk for and for which an adult vaccination dose is recommended (COVID-19, hepatitis A, hepatitis B, human papillomavirus, influenza, pneumococcal disease, tetanus). To summarise available data, we conducted a narrative synthesis.

RESULTS

We included 78 studies/reports comprising 117 estimates of vaccination coverage across 36 countries. Most estimates were obtained from high income countries (80%, n=94). We located estimates for hepatitis B vaccination in 33 countries, which included 18 countries with data on serological evidence of vaccine-derived hepatitis B immunity (range: 6-53%) and 22 countries with self-report data for vaccine uptake (<1-96%). Data for other vaccines were scarcer: reported hepatitis A vaccination coverage ranged 3-89% (five countries), COVID-19 ranged 4-84% (five countries), while we located estimates from fewer than five countries for influenza, tetanus, pneumococcal disease, and human papillomavirus.

CONCLUSION

Estimates were sparse but where available indicative of suboptimal vaccination coverage among people who inject drugs. Improving the consistency, timeliness, and geographic coverage of vaccine uptake data among this population is essential to inform efforts to increase uptake.

Determining Herd Immunity Thresholds for Hepatitis A Virus Transmission to Inform Vaccination Strategies Among People Who Inject Drugs in 16 US States

BACKGROUND

Widespread outbreaks of person-to-person transmitted hepatitis A virus (HAV), particularly among people who inject drugs (PWID), continue across the United States and globally. However, the herd immunity threshold and vaccination coverage required to prevent outbreaks are unknown. We used surveillance data and dynamic modeling to estimate herd immunity thresholds among PWID in 16 US states.

METHODS

We used a previously published dynamic model of HAV transmission calibrated to surveillance data from outbreaks involving PWID in 16 states. Using state-level calibrated models, we estimated the basic reproduction number (R0) and herd immunity threshold for PWID in each state. We performed a meta-analysis of herd immunity thresholds to determine the critical vaccination coverage required to prevent most HAV outbreaks among PWID.

RESULTS

Estimates of R0 for HAV infection ranged from 2.2 (95% confidence interval [CI], 1.9-2.5) for North Carolina to 5.0 (95% CI, 4.5-5.6) for West Virginia. Corresponding herd immunity thresholds ranged from 55% (95% CI, 47%-61%) for North Carolina to 80% (95% CI, 78%-82%) for West Virginia. Based on the meta-analysis, we estimated a pooled herd immunity threshold of 64% (95% CI, 61%-68%; 90% prediction interval, 52%-76%) among PWID. Using the prediction interval upper bound (76%) and assuming 95% vaccine efficacy, we estimated that vaccination coverage of 80% could prevent most HAV outbreaks.

CONCLUSIONS

Hepatitis A vaccination programs in the United States may need to achieve vaccination coverage of at least 80% among PWID in order to prevent most HAV outbreaks among this population.

Study protocol of a randomized controlled trial comparing two linkage models for HIV prevention and treatment in justice-involved persons

Background

Persons involved in the justice system are at high risk for HIV and drug overdose upon release to the community. This manuscript describes a randomized controlled trial of two evidence-based linkage interventions for provision of HIV prevention and treatment and substance use disorder (SUD) services in four high risk communities to assess which is more effective at addressing these needs upon reentry to the community from the justice system.

Methods

This is a 5-year hybrid type 1 effectiveness-implementation randomized controlled trial that compares two models (Patient Navigation [PN] or Mobile Health Unit [MHU] service delivery) of linking justice-involved individuals to the continuum of community-based HIV and SUD prevention and treatment service cascades of care. A total of 864 justice-involved individuals in four US communities with pre-arrest histories of opioid and/or stimulant use who are living with or at-risk of HIV will be randomized to receive either: (a) PN, wherein patient navigators will link study participants to community-based service providers; or (b) services delivered via an MHU, wherein study participants will be provided integrated HIV prevention/ treatment services and SUD services. The six-month post-release intervention will focus on access to pre-exposure prophylaxis (PrEP) for those without HIV and antiretroviral treatment (ART) for people living with HIV (PLH). Secondary outcomes will examine the continuum of PrEP and HIV care, including: HIV viral load, PrEP/ ART adherence; HIV risk behaviors; HCV testing and linkage to treatment; and sexually transmitted infection incidence and treatment. Additionally, opioid and other substance use disorder diagnoses, prescription, receipt, and retention on medication for opioid use disorder; opioid and stimulant use; and overdose will also be assessed. Primary implementation outcomes include feasibility, acceptability, sustainability, and costs required to implement and sustain the approaches as well as to scale-up in additional communities.

Discussion

Results from this project will help inform future methods of delivery of prevention, testing, and treatment of HIV, HCV, substance use disorders (particularly for opioids and stimulants), and sexually transmitted infections for justice-involved individuals in the community.

Trial registration: Clincialtrials.gov NCT05286879 March 18, 2022.

Leveraging Social and Structural Determinants of Health at the Centers for Disease Control and Prevention: A Systems-Level Opportunity to Improve Public Health

CONTEXT

Social and structural determinants of health (SDOH) have become part of the public health and health care landscape. The need to address SDOH is reinforced by morbidity and mortality trends, including a recent multiyear decrease in life expectancy and persistent health disparities. Leadership on SDOH-related efforts has come from public health, health care, private philanthropy, and nongovernmental entities.

STRATEGY

The Centers for Disease Control and Prevention (CDC) has been addressing SDOH through both disease- or condition-specific programs and crosscutting offices. Guidance from public health partners in the field has led the CDC to consider more strategic approaches to incorporating SDOH into public health activities.

IMPLEMENTATION

The CDC's crosscutting SDOH Workgroup responded to external recommendations to develop a specific vision and plan that aims to integrate SDOH into the agency's infrastructure. The group also sponsors CDC forums for sharing research and trainings on embedding SDOH in programs. The group created a Web site to centralize CDC SDOH research, data sources, practice tools, programs, and policies.

PROGRESS

The CDC has shown strong leadership in prioritizing SDOH in recent years. Individual programs and crosscutting offices have developed various models aimed at ensuring that public health research and practice address SDOH.

DISCUSSION

Building sustainable SDOH infrastructures in public health institutions that reach across multiple health topics and non-health organizations could increase chances of meeting public health morbidity and mortality reduction goals, including decreasing health disparities. Although public health priorities and socioeconomic trends will change over time, experience suggests that social and structural factors will continue to influence the public's health. The CDC and state, tribal, local, and territorial public health institutions have played important leadership roles in the system of community and service organizations that interface with communities they mutually serve to address SDOH. Continued capacity-building could help grow and sustain an SDOH infrastructure that advances this work.

Heterogeneity in Jail Nursing Medical Intake Forms: A Content Analysis

Despite high prevalence of infectious diseases and substance use disorders in jails, there are limited guidelines for the nursing intake process in this setting. We performed a content analysis of nursing intake forms used at each of the 14 Massachusetts county jails, focusing on infectious disease and substance use disorder. Only 85% of jails offered HIV testing during nursing intake and 50% of jails offered hepatitis C testing. Preventive interventions such as vaccines or pre-exposure prophylaxis therapy were infrequently offered during nursing intake. Screening for substance use disorder was present on the majority of intake forms, but only 23% of intake forms inquired about ongoing medication-assisted treatment for opioid use disorder. The results reflect heterogeneity in nursing intake forms, highlighting missed opportunities for public health interventions.

Vaccine-preventable diseases other than tuberculosis, and homelessness: A scoping review of the published literature, 1980 to 2020

BACKGROUND

Homelessness may result in the breakdown of regular health services, including routine vaccination programmes. A scoping review was conducted to describe vaccine-preventable diseases (VPD) other than tuberculosis in people experiencing homelessness (PEH).

METHODS

We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). We searched peer-reviewed literature published in English, French, Spanish or Portuguese reporting the outbreak of VPD or VPD prevalence in both infant and adult homeless populations published between 1980 and 2020, using PubMed/Medline, SciELO, Google Scholar, and Web of Science databases. Relevant information from the studies was charted in Microsoft Excel and results were summarised using a descriptive analytical method.

RESULTS

Eighty-one articles were included. A high prevalence of past hepatitis B virus (HBV) and hepatitis A virus (HAV) infections were observed through serosurveys, mostly in high income countries or high-middle income countries (USA, Canada, France, Iran or Brazil). Ten outbreaks of HAV infection were also reported, with lethality rates ranging from 0 to 4.8%. The studies identified numerous risk factors positively associated with HBV infection, including older age, homosexual or bisexual practice, injected drug use (IDU), and, with HAV infection including IDU, having sexual partner(s) with a history of unspecified hepatitis, insertive anal penetration, or originating from a country with a high prevalence of anti-HAV antibody. Eleven outbreaks of pneumococcal infection affecting PEH were reported in Canada and USA, with lethality rates from 0 to 15.6%. Six diphtheria outbreaks were reported. Vaccination status was rarely documented in these studies.

CONCLUSIONS

The literature suggests that homeless populations generally experience a high VPD burden suggesting the need for a national vaccination programme and planning for delivering vaccines in this population.

Hepatitis A virus survival on drug paraphernalia

The ongoing hepatitis A outbreaks in multiple states in the United States have concerned public health authorities since March 2017. The outbreaks have spread throughout 30 states and include primarily persons who use drugs, including persons who inject drugs (PWID) and persons experiencing homelessness. Contaminated drug injection paraphernalia and sharing of these items could potentially aid in transmission of hepatitis A virus (HAV) among these populations. We examined HAV survival on drug paraphernalia frequently shared among PWIDs. The effect of low pH on HAV survival using citric acid, which is frequently used by PWIDs during dose preparation, was investigated. We compared the plaque assay results with those concurrently obtained by qRT-PCR to establish whether HAV RNA levels could be used as surrogates for plaque assay results. HAV suspended in minimal essential media at room temperature infected FRhK4 cells for more than 17 weeks. HAV remained viable in syringes/needles for up to 10 weeks depending on the gauge of the needles and the syringe dead volumes, and on cookers, tourniquets and cotton balls/filter surfaces for up to 4 weeks. HAV retained its infectivity for more than 10 weeks at pH as low as 2. In conclusion, our findings show that HAV survives and remains infective in or on injection drug use equipment for 1 to 10 weeks depending on the type of paraphernalia examined and environmental conditions. These findings suggest that contaminated drug paraphernalia can potentially facilitate the transmission of HAV within populations who share these items.

Hepatitis A vaccination

Hepatitis A is an important public health issue worldwide. Hepatitis A vaccine (HepA) was first licensed in 1992. Both inactivated HepA (HepA-I) and live attenuated HepA (HepA-L) are highly immunogenic and well tolerated, and immune protection postvaccination can persist for at least 20 y. HepA is effective for both preexposure and postexposure prophylaxis, especially among children and young adults. The strategy of HepA vaccination varies in different countries and mainly includes vaccination among high-risk populations, regional childhood vaccination and universal childhood vaccination. The incidence of hepatitis A has decreased greatly in many countries in the last 30 y, but hepatitis A outbreaks frequently occur among high-risk populations and those who have not been covered by universal child vaccination programs in recent years. Disease surveillance and serosurveys are suggested to clarify the shift in the epidemiology of hepatitis A. The long-term persistence of immune protection after one dose of HepA should be further studied, as well as the cost-effective evaluation of different strategies of HepA vaccination. Based on this evidence, the recommendation on HepA vaccination should be put forward scientifically and updated in a timely and well-implemented manner.

Disparities in hepatitis A virus (HAV) vaccination coverage among adult travelers to intermediate or high-risk countries: The role of birthplace and race/ethnicity

BACKGROUND

While the hepatitis A virus (HAV) vaccine is recommended for United States (US) travelers to endemic regions, vaccination rates are lower among non-US-born adults and some racial minority groups.

PURPOSE

We aimed to examine the relationship between birthplace, race and their interaction as predictors of self-reported HAV vaccination among adult travelers to high-risk countries (HRCs) through analysis of the National Health Interview Survey (NHIS), 2012-2015.

METHODS

The study included 36,872 US adult participants in the 2012-2015 NHIS who traveled to countries where HAV is endemic. The main outcome was self-reported HAV vaccination (≥2 doses). Complex survey methods were applied to all models to provide statistical estimates that were representative of US adults. Multivariable logistic regression models adjusting for demographic, socioeconomic, medical, and access-to-care characteristics were fitted to examine the association between birthplace, race, race-by-birthplace (for interaction) and vaccination status.

RESULTS

For adult travelers to HRCs, the adjusted odds ratio (AOR) of HAV vaccination was lower for non-US-born compared to US-born adults, AOR 0.86 (95% CI; 0.76, 0.98). For Hispanics, the AOR of HAV vaccination was 0.80 (95% CI; 0.70, 0.91) as compared to non-Hispanic-Whites. Furthermore, a significant qualitative interaction between birthplace and race was found (P-value 0.0005). Among non-Hispanic Blacks, the adjusted odds of HAV vaccination for non-US-born adults were 1.35 (95% CI; 1.06, 1.72) times the odds for US-born adults. In contrast, the AORs of HAV vaccination of non-US-born versus US-born adults were 36% (95% CI; 17%, 51%) and 30% (95% CI; 12%, 44%), lower for Asians and Hispanics, respectively.

CONCLUSIONS

The association between birthplace and HAV vaccination status differs by race among travelers to HRCs, with US-born non-Hispanic Black and non-US-born Asian and Hispanic adults having lower odds of vaccination. Health care resources should be focused on these target populations to improve travel vaccination compliance.