Housing Stability and Hepatitis C Infection for Young Adults Who Inject Drugs: Examining the Relationship of Consistent and Intermittent Housing Status on HCV Infection Risk

Hepatitis C testing and linkage to care in a safety-net hospital emergency department

BACKGROUND AND PURPOSE

In 2020, the CDC expanded hepatitis C (HCV) screening recommendations to include universal screening for persons 18 and older. We implemented universal screening in the emergency department (ED) within a safety-net health system. We aimed to measure HCV prevalence and linkage to care (LTC) outcomes in the ED and compare them to the outpatient clinics within the same health system.

METHODS

Patients aged 18-79 without HCV qualified for screening. We measured prevalence of both anti-HCV+ (exposure) and HCV RNA+ (active infection). Those with active HCV were flagged for LTC and their charts were followed for outcomes. HCV prevalence and LTC in the ED were compared to those in outpatient clinics over the same time.

RESULTS

9511 patients were screened for HCV from 2019 to 2022 in the ED. 6.9 % (659) were anti-HCV+. 54.9 % (320 of 582) of anti-HCV+ individuals or 3.4 % of those screened (320 of 9511) were HCV RNA+. The LTC rate was 24.1 % (77 of 320) and a total of 56 individuals (17.8 % of all HCV RNA+ ED patients, 72.7 % of those linked) initiated treatment. HCV prevalence was higher in the ED compared to the outpatient clinic setting. Demographics and LTC rates also significantly differed between these two cohorts.

CONCLUSIONS

We identified a higher HCV prevalence in the ED relative to the outpatient clinic setting and significant need for improvement in LTC and HCV treatment initiation. Our findings suggest universal screening is an important tool to diagnose HCV infections but may require novel strategies for improved LTC and treatment initiation.

Modeling the impact of the COVID-19 pandemic on achieving HCV elimination amongst young and unstably housed people who inject drugs in San Francisco

BACKGROUND

Young adult (18-30 years) people who inject drugs (PWID) face high hepatitis C virus (HCV) prevalence. In San Francisco, where >60% of PWID lack stable housing, barriers hinder HCV treatment access. We assessed progress towards the World Health Organization's (WHO) HCV elimination goal of an 80% reduction in incidence over 2015-2030, focusing on young (YPWID) and unstably housed PWID in San Francisco.

METHODS

We developed a dynamic HCV transmission model among PWID, parameterized and calibrated using bio-behavioural survey datasets from San Francisco. This included 2018 estimates for the antibody-prevalence among PWID (77%) and care cascade estimates for HCV for YPWID (72% aware of their status and 33% ever initiating treatment). Based on programmatic data, we assumed a 53.8% reduction in testing and 40.7% decrease in treatment from 2020 due to the COVID-19 pandemic, which partially rebounded from April 2021 with testing rates then being 31.1% lower than pre-pandemic rates and treatment numbers being 19.5% lower. We simulated different scenarios of how services changed after the pandemic to project whether elimination goals would be met.

RESULTS

Continuing post-pandemic rates of testing and treatment, the model projects an 83.3% (95% credibility interval [95% CrI]:60.6-96.9%) decrease in incidence among PWID over 2015-2030 to 1.5/100pyrs (95% CrI:0.3-4.4) in 2030. The probability of achieving the elimination goal by 2030 is 62.0%. Among YPWID and unstably housed PWID, the probability of achieving the elimination goal by 2030 is 54.8 and 67.6%, respectively. Importantly, further increasing testing and treatment rates to pre-pandemic levels by 2025 only results in a small increase in the probability (67.5%) of the elimination goal being achieved among all PWID by 2030, while increased coverage of medication for opioid use disorder among YPWID and/or housing interventions results in the probability of achieving elimination increasing to over 75%.

CONCLUSION

The COVID-19 pandemic impeded progress toward achieving HCV elimination. Our findings indicate that existing partial rebounds in HCV testing and treatment may achieve the elimination goal by 2030, with an additional scale-up of interventions aimed at YPWID or unstably housed PWID ensuring San Francisco is likely to achieve elimination by 2030.

Infectious Diseases Among People Experiencing Homelessness: A Systematic Review of the Literature in the United States and Canada, 2003-2022

Homelessness increases the risk of acquiring an infectious disease. We conducted a systematic review of the literature to identify quantitative data related to infectious diseases and homelessness. We searched Google Scholar, PubMed, and SCOPUS for quantitative literature published from January 2003 through December 2022 in English from the United States and Canada. We excluded literature on vaccine-preventable diseases and HIV because these diseases were recently reviewed. Of the 250 articles that met inclusion criteria, more than half were on hepatitis C virus or Mycobacterium tuberculosis. Other articles were on COVID-19, respiratory syncytial virus, Staphylococcus aureus, group A Streptococcus, mpox (formerly monkeypox), 5 sexually transmitted infections, and gastrointestinal or vectorborne pathogens. Most studies showed higher prevalence, incidence, or measures of risk for infectious diseases among people experiencing homelessness as compared with people who are housed or the general population. Although having increased published data that quantify the infectious disease risks of homelessness is encouraging, many pathogens that are known to affect people globally who are not housed have not been evaluated in the United States or Canada. Future studies should focus on additional pathogens and factors leading to a disproportionately high incidence and prevalence of infectious diseases among people experiencing homelessness.

Bridging the gap: Addressing disparities in hepatitis C screening, access to care, and treatment outcomes

Hepatitis C virus (HCV) is a significant public health challenge globally, with substantial morbidity and mortality due to chronic liver disease. Despite the availability of highly effective and well-tolerated direct-acting antiviral therapies, widespread disparities remain in hepatitis C screening, access to treatment, linkage to care, and therapeutic outcomes. This review article synthesizes evidence from various studies to highlight the multifactorial nature of these disparities, which affects ethnic minorities, people with lower socioeconomic status, individuals with substance use disorders, and those within correctional facilities. The review also discusses policy implications and targeted strategies needed to overcome barriers and ensure equitable care for all individuals with HCV. Recommendations for future research to address gaps in knowledge and evaluation of the effectiveness of interventions designed to reduce disparities are provided.

Risk Factors Associated With Unsuccessful Linkage to Outpatient Hepatitis C Care

Background Modern direct-acting antivirals (DAAs) can treat and cure hepatitis C virus (HCV) infection. Treatment of HCV at a population level has the potential to decrease the prevalence of chronic HCV infection and sequela. Unfortunately, many patients fall off the HCV treatment cascade and do not complete HCV treatment. As social determinants of health (SDHs) affect HCV acquisition, we sought to evaluate factors that may limit successful linkage to outpatient HCV care. Methods We conducted a case-control study by matching patients who missed and those who attended their outpatient HCV visits in 2018. We matched cases in a 1:1 ratio using propensity scores. Results Of 1,539 patients, 161 (10.5%) did not attend their HCV clinic appointment. Factors associated with a missed HCV visit on bivariate testing included identifying as Black (p=0.03), housing instability (p<0.001), transportation difficulty (p<0.001), history of medication non-adherence (p<0.001), and undergoing screening during an inpatient admission (p<0.001). Multivariate testing found transportation difficulty (p<0.001) and inpatient admission (p=0.002) to be associated with missing their HCV appointment. Patients who attended their HCV visit were more likely to be alive by the end of 2018 (p=0.07). Conclusion Patients who missed an initial scheduled infectious disease (ID) clinic appointment for HCV treatment had higher rates of housing instability, transportation difficulties, and medication non-adherence. Patients diagnosed with HCV infection should be provided additional support as appropriate to address the social determinants of health that may limit linkage to outpatient HCV care.

An Analysis of Social Determinants of Health and Their Implications for Hepatitis C Virus Treatment in People Who Inject Drugs: The Case of Baltimore

Background

Sixty-eight percent of the nearly 3.5 million people living with hepatitis C virus (HCV) in the United States are people who inject drugs (PWID). Despite effective treatments, uptake remains low in PWID. We examined the social determinants of health (SDoH) that affect the HCV care cascade.

Methods

We conducted a secondary analysis of data from 720 PWID in a cluster-randomized trial. We recruited PWID from 12 drug-affected areas in Baltimore. Inclusion criteria were injection in the prior month or needle sharing in the past 6 months. Intake data consisted of a survey and HCV testing. Focusing on SDoH, we analyzed self-report of (1) awareness of HCV infection (in those with active or previously cured HCV) and (2) prior HCV treatment (in the aware subgroup). We used descriptive statistics and logistic regression for statistical analyses.

Results

The 342 participants were majority male and Black with a median age of 52 years. Women were more likely to be aware of their status but less likely to be treated. Having a primary care provider and HIV-positive status were associated with increased awareness and treatment. Unhoused people had 51% lower odds of HCV treatment. People who reported that other PWID had shared their HCV status with them had 2.3-fold higher odds of awareness of their own status.

Conclusions

Further study of gender disparities in HCV treatment access is needed. Increased social support was associated with higher odds of HCV treatment, suggesting an area for future interventions. Strategies to identify and address SDoH are needed to end HCV.

Incidence of HIV and hepatitis C virus among people who inject drugs, and associations with age and sex or gender: a global systematic review and meta-analysis

BACKGROUND

Measuring the incidence of HIV and hepatitis C virus (HCV) infection among people who inject drugs (PWID) is key to track progress towards elimination. We aimed to summarise global data on HIV and primary HCV incidence among PWID and associations with age and sex or gender.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies among PWID by searching MEDLINE, Embase, and PsycINFO, capturing studies published between Jan 1, 2000, and Dec 12, 2022, with no language or study design restrictions. We contacted authors of identified studies for unpublished or updated data. We included studies that estimated incidence by longitudinally re-testing people at risk of infection or by using assays for recent infection. We pooled incidence and relative risk (RR; young [generally defined as ≤25 years] vs older PWID; women vs men) estimates using random-effects meta-analysis and assessed risk of bias with a modified Newcastle-Ottawa scale. This study is registered with PROSPERO, CRD42020220884.

FINDINGS

Our updated search identified 9493 publications, of which 211 were eligible for full-text review. An additional 377 full-text records from our existing database and five records identified through cross-referencing were assessed. Including 28 unpublished records, 125 records met the inclusion criteria. We identified 64 estimates of HIV incidence (30 from high-income countries [HICs] and 34 from low-income or middle-income countries [LMICs]) and 66 estimates of HCV incidence (52 from HICs and 14 from LMICs). 41 (64%) of 64 HIV and 42 (64%) of 66 HCV estimates were from single cities rather than being multi-city or nationwide. Estimates were measured over 1987-2021 for HIV and 1992-2021 for HCV. Pooled HIV incidence was 1·7 per 100 person-years (95% CI 1·3-2·3; I2=98·4%) and pooled HCV incidence was 12·1 per 100 person-years (10·0-14·6; I2=97·2%). Young PWID had a greater risk of HIV (RR 1·5, 95% CI 1·2-1·8; I2=66·9%) and HCV (1·5, 1·3-1·8; I2=70·6%) acquisition than older PWID. Women had a greater risk of HIV (RR 1·4, 95% CI 1·1-1·6; I2=55·3%) and HCV (1·2, 1·1-1·3; I2=43·3%) acquisition than men. For both HIV and HCV, the median risk-of-bias score was 6 (IQR 6-7), indicating moderate risk.

INTERPRETATION

Although sparse, available HIV and HCV incidence estimates offer insights into global levels of HIV and HCV transmission among PWID. Intensified efforts are needed to keep track of the HIV and HCV epidemics among PWID and to expand access to age-appropriate and gender-appropriate prevention services that serve young PWID and women who inject drugs.

FUNDING

Canadian Institutes of Health Research, Fonds de recherche du Québec-Santé, Canadian Network on Hepatitis C, UK National Institute for Health and Care Research, and WHO.

The contribution of unstable housing to HIV and hepatitis C virus transmission among people who inject drugs globally, regionally, and at country level: a modelling study

BACKGROUND

A considerable proportion of people who inject drugs are unstably housed. Although unstable housing is associated with HIV and HCV infection among people who inject drugs, its contribution to transmission is unknown. We estimated the global and national proportions of incident HIV and HCV infections among people who inject drugs attributed to housing instability from 2020 to 2029.

METHODS

In this modelling study, we developed country-level models of unstable housing and HIV and HCV transmission among people who inject drugs in 58 countries globally, calibrated to country-specific data on the prevalences of HIV and HCV and unstable housing. Based on a recently published systematic review, unstably housed people who inject drugs were assumed to have a 39% (95% CI 6-84) increased risk of HIV transmission and a 64% (95% CI 43-89%) increased risk of HCV transmission. We used pooled country-level estimates from systematic reviews on HCV and HIV prevalence in people who inject drugs. Our models estimated the transmission population attributable fraction (tPAF) of unstable housing to HIV and HCV transmission among people who inject drugs, defined as the percentage of infections prevented from 2020 to 2029 if the additional risk due to unstable housing was removed.

FINDINGS

Our models were produced for 58 countries with sufficient data (accounting for >66% of the global people who inject drugs population). Globally, we project unstable housing contributes 7·9% (95% credibility interval [CrI] 2·3-15·7) of new HIV infections and 11·2% (7·7-15·5) of new HCV infections among people who inject drugs from 2020 to 2029. Country-level tPAFs were strongly associated with the prevalence of unstable housing. tPAFs were greater in high-income countries (HIV 17·2% [95% CrI 5·1-30·0]; HCV 19·4% [95% CrI 13·8-26·0]) than in low-income or middle-income countries (HIV 6·6% [95% CrI 1·8-13·1]; HCV 8·3% [95% CrI 5·5-11·7]). tPAFs for HIV and HCV were highest in Afghanistan, Czech Republic, India, USA, England, and Wales where unstable housing contributed more than 20% of new HIV and HCV infections.

INTERPRETATION

Unstable housing is an important modifiable risk factor for HIV and HCV transmission among people who inject drugs in many countries. The study emphasises the importance of implementing initiatives to mitigate these risks and reduce housing instability.

FUNDING

National Institute for Health Research and National Institute of Allergy and Infectious Diseases and National Institute for Drug Abuse.

The hepatitis C epidemic in Canada: An overview of recent trends in surveillance, injection drug use, harm reduction and treatment

Hepatitis C continues to be a significant public health concern in Canada, with the hepatitis C virus (HCV) responsible for more life-years lost than all other infectious diseases in Canada. An increase in reported hepatitis C infections was observed between 2014 and 2018. Here, we present changing epidemiological trends and discuss risk factors for hepatitis C acquisition in Canada that may have contributed to this increase in reported hepatitis C infections, focusing on injection drug use. We describe a decrease in the use of borrowed needles or syringes coupled with an increase in using other used injection drug use equipment. Also, an increased prevalence of injection drug use and use of prescription opioid and methamphetamine injection by people who inject drugs (PWID) may be increasing the risk of HCV acquisition. At the same time, while harm reduction coverage appears to have increased in Canada in recent years, gaps in access and coverage remain. We also consider how direct-acting antiviral (DAA) eligibility expansion may have affected hepatitis C rates from 2014 to 2018. Finally, we present new surveillance trends observed in 2019 and discuss how the coronavirus disease 2019 (COVID-19) pandemic may affect hepatitis C case counts from 2020 onwards. Continual efforts to i) enhance hepatitis C surveillance and ii) strengthen the reach, effectiveness, and adoption of hepatitis C prevention and treatment services across Canada are vital to reducing HCV transmission among PWID and achieving Canada's HCV elimination targets by 2030.

Detection of active hepatitis C in a single visit and linkage to care among marginalized people using a mobile unit in Madrid, Spain

BACKGROUND

The burden of hepatitis C virus (HCV) infection among marginalized people in Spain is high, despite the fact that HCV prevalence has decreased in recent years. We aimed to assess the effectiveness of a simplified point-of-care (PoC) model for screening for active HCV infection via a mobile unit and subsequent linkage to care with the assistance of navigators.

METHODS

We carried out a prospective study on 2001 participants from Madrid, Spain. A nurse and a navigator/educator screened for hepatitis C in a mobile unit, using the OraQuick HCV Rapid Antibody Test and Xpert HCV VL Fingerstick assay. Participants with active HCV were referred to the hospital the same day with a navigator for evaluation and treatment of HCV.

RESULTS

Overall, 1621 (81%) participants had not been exposed to HCV, 380 (18.9%) were positive for HCV antibodies, and 136 (6.8%) had active hepatitis C. Among the latter, 134 (98.5%) received the HCV screening results, 133 (97.8%) had an appointment at the hospital, 126 (92.8%) were seen by a physician once they were at the hospital, and 105 (77.2%) started HCV treatment. Being over 50 years old and a person who uses drugs, particularly people who inject drugs (PWID), was directly associated with active hepatitis C (p<0.05). PWID were the only patients with HCV reinfection (4.3% in people without recent injecting drug use and 5.9% in people with recent injecting drug use). Among PWID, no income and daily alcohol intake were also directly associated with active hepatitis C. People with recent injecting drug use showed the lowest rates of attendance at the hospital (91.8%) and starting HCV treatment (70.4%).

CONCLUSION

HCV screening using a two-step PoC-based strategy and its linkage to care was extremely efficient for identifying and treating marginalized people with active hepatitis C, thanks to the use of a mobile unit with personnel and technical equipment, an interdisciplinary team, and collaboration between institutions.

Disparities in risk perception and low harm reduction services awareness, access, and utilization among young people with newly reported hepatitis C infections in California, 2018

Background

Newly reported hepatitis C virus (HCV) infections in California increased 50% among people 15–29 years of age between 2014 and 2016. National estimates suggest this increase was due to the opioid epidemic and associated increases in injection drug use. However, most of California’s 61 local health jurisdictions (LHJs) do not routinely investigate newly reported HCV infections, so these individuals’ risk factors for infection are not well understood. We sought to describe the demographics, risk behaviors, and utilization of harm reduction services in California’s fastest-rising age group of people with newly reported hepatitis C infections to support targeted HCV prevention and treatment strategies.

Methods

California Department of Public Health invited LHJs to participate in enhanced surveillance if they met criteria indicating heightened population risk for HCV infection among people ages 15–29. From June–December 2018, eight LHJs contacted newly reported HCV cases by phone using a structured questionnaire.

Results

Among 472 total HCV cases who met the inclusion criteria, 114 (24%) completed an interview. Twenty-seven percent of respondents (n = 31) had ever been incarcerated, of whom 29% received a tattoo/piercing and 39% injected drugs while incarcerated. Among people who injected drugs (PWID)—36% (n = 41) of all respondents—68% shared injection equipment and many lacked access to harm reduction services: 37% knew of or ever used a needle exchange and 44% ever needed naloxone during an overdose but did not have it. Heroin was the most frequently reported injected drug (n = 30), followed by methamphetamine (n = 18). Pre-diagnosis HCV risk perception varied significantly by PWID status and race/ethnicity: 76% of PWID vs. 8% of non-PWID (p < 0.001), and 44% of non-Hispanic White respondents vs. 22% of people of color (POC) respondents (p = 0.011), reported thinking they were at risk for HCV before diagnosis. Eighty-nine percent of all respondents reported having health insurance, although only two had taken HCV antiviral medications.

Conclusions

Among young people with HCV, we found limited pre-diagnosis HCV risk perception and access to harm reduction services, with racial/ethnic disparities. Interventions to increase harm reduction services awareness, access, and utilization among young PWID, especially young PWID of color, may be warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11492-3.

Homelessness, unstable housing, and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I2 statistic and p value for heterogeneity.

FINDINGS

We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23-1·95; p=0·0002]; I2= 62·7%; n=17) and HCV (1·65 [1·44-1·90; p<0·0001]; I2= 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06-1·84; p=0·019]; I2= 65·5%; n=9; and for HCV: 1·64 [1·43-1·89; p<0·0001]; I2= 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13-2·95; p=0·014]; n=5) was higher than for homelessness (1·44 [1·13-1·83; p=0·0036]; n=12), whereas no difference was seen between these outcomes for risk of HCV acquisition (1·72 [1·48-1·99; p<0·0001] for unstable housing, 1·66 [1·37-2·00; p<0·0001] for homelessness).

INTERPRETATION

Homelessness and unstable housing are associated with increased risk of HIV and HCV acquisition among PWID. Our findings support the development of interventions that simultaneously address homelessness and unstable housing and HIV and HCV transmission in this population.

FUNDING

National Institute for Health Research, National Institute on Drug Abuse, National Institute of Allergy and Infectious Diseases, and Commonwealth Scholarship Commission.