Randomized Trial of a Vaccine Regimen to Prevent Chronic HCV Infection.

BACKGROUND: A safe and effective vaccine to prevent chronic hepatitis C virus (HCV) infection is a critical component of efforts to eliminate the disease. METHODS: In this phase 1-2 randomized, double-blind, placebo-controlled trial, we evaluated a recombinant chimpanzee adenovirus 3 vector priming vaccination followed by a recombinant modified vaccinia Ankara boost; both vaccines encode HCV nonstructural proteins. Adults who were considered to be at risk for HCV infection on the basis of a history of recent injection drug use were randomly assigned (in a 1:1 ratio) to receive vaccine or placebo on days 0 and 56. Vaccine-related serious adverse events, severe local or systemic adverse events, and laboratory adverse events were the primary safety end points. The primary efficacy end point was chronic HCV infection, defined as persistent viremia for 6 months. RESULTS: A total of 548 participants underwent randomization, with 274 assigned to each group. There was no significant difference in the incidence of chronic HCV infection between the groups. In the per-protocol population, chronic HCV infection developed in 14 participants in each group (hazard ratio [vaccine vs. placebo], 1.53; 95% confidence interval [CI], 0.66 to 3.55; vaccine efficacy, -53%; 95% CI, -255 to 34). In the modified intention-to-treat population, chronic HCV infection developed in 19 participants in the vaccine group and 17 in placebo group (hazard ratio, 1.66; 95% CI, 0.79 to 3.50; vaccine efficacy, -66%; 95% CI, -250 to 21). The geometric mean peak HCV RNA level after infection differed between the vaccine group and the placebo group (152.51×103 IU per milliliter and 1804.93×103 IU per milliliter, respectively). T-cell responses to HCV were detected in 78% of the participants in the vaccine group. The percentages of participants with serious adverse events were similar in the two groups. CONCLUSIONS: In this trial, the HCV vaccine regimen did not cause serious adverse events, produced HCV-specific T-cell responses, and lowered the peak HCV RNA level, but it did not prevent chronic HCV infection. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT01436357.).

Estimated Number of People Who Inject Drugs in the United States.

BACKGROUND: Public health data signal increases in the number of people who inject drugs (PWID) in the United States during the past decade. An updated PWID population size estimate is critical for informing interventions and policies aiming to reduce injection-associated infections and overdose, as well as to provide a baseline for assessments of pandemic-related changes in injection drug use. METHODS: We used a modified multiplier approach to estimate the number of adults who injected drugs in the United States in 2018. We deduced the estimated number of nonfatal overdose events among PWID from 2 of our previously published estimates: the number of injection-involved overdose deaths and the meta-analyzed ratio of nonfatal to fatal overdose. The number of nonfatal overdose events was divided by prevalence of nonfatal overdose among current PWID for a population size estimate. RESULTS: There were an estimated 3 694 500 (95% confidence interval [CI], 1 872 700-7 273 300) PWID in the United States in 2018, representing 1.46% (95% CI, .74-2.87) of the adult population. The estimated prevalence of injection drug use was highest among males (2.1%; 95% CI, 1.1-4.2), non-Hispanic Whites (1.8%; 95% CI, .9-3.6), and adults aged 18-39 years (1.8%; 95% CI, .9-3.6). CONCLUSIONS: Using transparent, replicable methods and largely publicly available data, we provide the first update to the number of people who inject drugs in the United States in nearly 10 years. Findings suggest the population size of PWID has substantially grown in the past decade and that prevention services for PWID should be proportionally increased.

Program Adaptations to Provide Harm Reduction Services During the COVID-19 Pandemic: A Qualitative Study of Syringe Services Programs in the U.S.

Syringe services programs (SSPs) are essential to preventing injection drug use-related infections and overdose death among people who use drugs (PWUD). The novel coronavirus (COVID-19) pandemic initially impeded SSPs' operations. To effectively support these programs, information is needed regarding SSPs' experiences adapting their services and the challenges posed by COVID-19. We conducted qualitative interviews with leadership and staff from a sample of 31 U.S. SSPs. Respondents discussed urgent concerns including reduced reach of services, suspended HIV/hepatitis C testing, high COVID-19 risk among PWUD, and negative impacts of isolation on overdose and mental health. They also noted opportunities to improve future services for PWUD, including shifting to evidence-based distribution practices and maintaining regulatory changes that increased access to opioid use disorder medications post-pandemic. Findings can inform efforts to support SSPs in restoring and expanding services, and provide insight into SSPs' role in engaging PWUD during the COVID-19 response and future emergencies.

RESUMEN: Los programas de servicios de jeringas (reconocido como SSP en inglés) son esenciales para prevenir las infecciones relacionadas con el consumo de drogas inyectables y la muerte por sobredosis entre las personas que consumen drogas (reconocidos como PWUD en ingles). La nueva pandemia del coronavirus (COVID-19) inicialmente impidió las operaciones de los SSP. Para apoyar eficazmente estos programas, se necesita información sobre las experiencias de los SSP que adaptan sus servicios y los desafíos que plantea COVID-19. Realizamos entrevistas cualitativas con el liderazgo y el personal de una muestra de 31 SSPs de EE.UU. Los encuestados discutieron las preocupaciones urgentes, incluyendo la reducción del alcance de los servicios, la suspensión de las pruebas de VIH/hepatitis C, el alto riesgo de COVID-19 entre la PWUD, y los impactos negativos del aislamiento en las sobredosis y la salud mental. También identificaron las oportunidades de mejorar los servicios futuros para las PWUD, incluyendo el cambio a prácticas de distribución basadas en evidencias y el mantenimiento de cambios regulatorios que aumentaran el acceso a medicamentos para el trastorno por consumo de opiáceos después de la pandemia. La información que se encontró en este estudio se puede utilizar junto los esfuerzos para apoyar a los SSP en la restauración y expansión de los servicios, y proporcionar información sobre el papel de los SSP en la participación de PWUD durante la respuesta covid-19 futuras emergencias.

High-Risk Injection-Related Practices Associated with anti-HCV Positivity among Young Adults Seeking Services in Three Small Cities in Wisconsin.

BACKGROUND: Hepatitis C virus (HCV) infection has been increasing among people who inject drugs (PWID), younger than 30 years, and living in rural or suburban areas. We examined injection-related behaviors of young PWID to determine factors associated with HCV infection. METHODS: From September 2013-May 2015, respondent-driven and snowball sampling were used in 3 suburban areas of Wisconsin to recruit PWID 18-29 years who reported injection drug use in the previous 12 months. Participants were tested for HCV antibody (anti-HCV) and reported injection-related behaviors/practices via self-administered computer-based survey. We calculated anti-HCV prevalence and assessed associated factors using multivariable logistic regression. RESULTS: Forty-two percent (117/280) of participants were male, 83% (231/280) were white, and median age was 23 years. Overall HCV prevalence was 33%, but HCV prevalence among males was 39%. Adjusting for age, sex, race/ethnicity, education, relationship status, insurance status and income, anti-HCV positivity was associated with higher injection frequency (> 100 times in the past six months) (aOR = 3.07; 95% Confidence Interval (95% CI): 1.72-5.45), ever shared syringes (aOR = 5.15; 95% CI: 2.52-10.51), past week/last use receptive rinse water sharing (aOR = 1.88; 95% CI: 1.06-3.33), past week/last use receptive filter sharing (aOR = 3.25; 95% CI: 1.61-6.54), reusing syringes (aOR = 1.91, 95% CI: 1.08-3.37), history of overdose (aOR = 8.82; 95% CI: 2.26-3.95), and having ever injected another PWID (aOR = 8.82; 95%CI 3.94-19.76). DISCUSSION: Anti-HCV positivity is associated with high-risk injection practices. Young PWID would benefit from access to evidence-based interventions that reduce their risk of infection, link those infected to HCV treatment, and provide education to reduce further transmission.

The Changing Epidemiology of Hepatitis C Virus Infection in the United States During the Years 2010 to 2018.

Hepatitis C virus (HCV) infection remains an important cause of morbidity and mortality throughout the world, leading to serious health problems among those who are chronically infected. Since 1992, the Centers for Disease Control and Prevention has been collecting data on the incidence of HCV infection in the United States. In 2018, more than 50 000 individuals were estimated to have acute HCV infection.The most recently reported data on the prevalence of infection indicate that approximately 2.4 million people are living with hepatitis C in the United States. Transmission of HCV occurs predominantly through sharing contaminated equipment for injecting drugs.Two major events have had a significant impact on the incidence and prevalence of hepatitis C in the past few decades: the US opioid crisis and the discovery of curative treatments for HCV infection. To better understand the impact of these events, we examine reported trends in the incidence and prevalence of infection.

Access to HIV, Viral Hepatitis, and Substance Use Disorder Treatment/Overdose Prevention Services: A Qualitative Analysis of Syringe Service Programs (SSPs) Serving Rural PWID.

BACKGROUND: Syringe service programs (SSP) increasingly serve rural areas of the United States, yet little is known about access and perceived need for their services. Objectives: This paper presents the HIV and viral hepatitis prevention, testing, and treatment, and, substance use disorder treatment and overdose prevention services offered at three SSPs and which services their clients accessed. Across the three SSPs, 45 clients (people who inject drugs [PWID]), 11 staff, and five stakeholders were interviewed. Results: Most clients (n = 34) reported accessing SSP services weekly and primarily for sterile syringes and injection-related supplies. All clients reported testing for HIV at least once, though concern for acquiring or transmitting HIV was divided between some or no concern. Most clients (n = 43) reported testing for hepatitis C virus (HCV). Concern for acquiring or transmitting HCV was also mixed. Vaccination for hepatitis A and/or B teetered around half (HAV: n = 23) to a third (HBV: n = 15). Most clients (n = 43) knew where to access the overdose countering medication, Narcan. Feelings about substance use treatment options varied, yet most felt not enough were available. Of note, not all assessed services were offered by the sampled SSPs. Conclusions/Importance: The findings help us understand PWIDs' rationale regarding services accessed and preference for particular services. The need for some services was not perceived by those at risk for the illness the services addressed. Discussing risk and providing tailored education is important when providing SSP services to rural residing PWIDs.

Responding to Outbreaks of Human Immunodeficiency Virus Among Persons Who Inject Drugs-United States, 2016-2019: Perspectives on Recent Experience and Lessons Learned.

In 2015, a large human immunodeficiency virus (HIV) outbreak occurred among persons who inject drugs (PWID) in Indiana. During 2016-2019, additional outbreaks among PWID occurred across the United States. Based on information disseminated by responding health departments and Centers for Disease Control and Prevention (CDC) involvement, we offer perspectives about characteristics of and public health responses to 6 such outbreaks. Across outbreaks, injection of opioids (including fentanyl) or methamphetamine predominated; many PWID concurrently used opioids and methamphetamine or cocaine. Commonalities included homelessness or unstable housing, previous incarceration, and hepatitis C virus exposure. All outbreaks occurred in metropolitan areas, including some with substantial harm reduction and medical programs targeted to PWID. Health departments experienced challenges locating case patients and contacts, linking and retaining persons in care, building support to strengthen harm-reduction programs, and leveraging resources. Expanding the concept of vulnerability to HIV outbreaks and other lessons learned can be considered for preventing, detecting, and responding to future outbreaks among PWID.

Quantifying the risk of undetected HIV, hepatitis B virus, or hepatitis C virus infection in Public Health Service increased risk donors.

To reduce the risk of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) transmission through organ transplantation, donors are universally screened for these infections by nucleic acid tests (NAT). Deceased organ donors are classified as "increased risk" if they engaged in specific behaviors during the 12 months before death. We developed a model to estimate the risk of undetected infection for HIV, HBV, and HCV among NAT-negative donors specific to the type and timing of donors' potential risk behavior to guide revisions to the 12-month timeline. Model parameters were estimated, including risk of disease acquisition for increased risk groups, number of virions that multiply to establish infection, virus doubling time, and limit of detection by NAT. Monte Carlo simulation was performed. The risk of undetected infection was <1/1 000 000 for HIV after 14 days, for HBV after 35 days, and for HCV after 7 days from the time of most recent potential exposure to the day of a negative NAT. The period during which reported donor risk behaviors result in an "increased risk" designation can be safely shortened.

Bacterial and Fungal Infections in Persons Who Inject Drugs - Western New York, 2017.

During 2014-2017, CDC Emerging Infections Program surveillance data reported that the occurrence of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections associated with injection drug use doubled among persons aged 18-49 years residing in Monroe County in western New York.* Unpublished surveillance data also indicate that an increasing proportion of all Candida spp. bloodstream infections in Monroe County and invasive group A Streptococcus (GAS) infections in 15 New York counties are also occurring among persons who inject drugs. In addition, across six surveillance sites nationwide, the proportion of invasive MRSA infections that occurred in persons who inject drugs increased from 4.1% of invasive MRSA cases in 2011 to 9.2% in 2016 (1). To better understand the types and frequency of these infections and identify prevention opportunities, CDC and public health partners conducted a rapid assessment of bacterial and fungal infections among persons who inject drugs in western New York. The goals were to assess which bacterial and fungal pathogens most often cause infections in persons who inject drugs, what proportion of persons who inject use opioids, and of these, how many were offered medication-assisted treatment for opioid use disorder. Medication-assisted treatment, which includes use of medications such as buprenorphine, methadone, and naltrexone, reduces cravings and has been reported to lower the risk for overdose death and all-cause mortality in persons who use opioids (2,3). In this assessment, nearly all persons with infections who injected drugs used opioids (97%), but half of inpatients (22 of 44) and 12 of 13 patients seen only in the emergency department (ED) were not offered medication-assisted treatment. The most commonly identified pathogen was S. aureus (80%), which is frequently found on skin. Health care visits for bacterial and fungal infections associated with injection opioid use are an opportunity to treat the underlying opioid use disorder with medication-assisted treatment. Routine care for patients who continue to inject should include advice on hand hygiene and not injecting into skin that has not been cleaned or to use any equipment contaminated by reuse, saliva, soil, or water (4,5).

Increases in Acute Hepatitis C Virus Infection Related to a Growing Opioid Epidemic and Associated Injection Drug Use, United States, 2004 to 2014.

OBJECTIVES: To compare US trends in rates of injection drug use (IDU), specifically opioid injection, with national trends in the incidence of acute HCV infection to assess whether these events correlated over time. METHODS: We calculated the annual incidence rate and demographic and risk characteristics of reported cases of acute HCV infection using surveillance data from 2004 to 2014 and the annual percentage of admissions to substance use disorder treatment facilities reporting IDU for the same time period by type of drug injected and demographic characteristics. We then tested for trends. RESULTS: The annual incidence rate of acute HCV infection increased more than 2-fold (from 0.3 to 0.7 cases/100 000) from 2004 to 2014, with significant increases among select demographic subgroups. Admissions for substance use disorder attributed to injection of heroin and prescription opioid analgesics increased significantly, with an almost 4-fold increase in prescription opioid analgesic injection. Significant increases in opioid injection mirrored those for reported cases of acute HCV infection among demographic subgroups. CONCLUSIONS: These findings strongly suggest that the national increase in acute HCV infection is related to the country's opioid epidemic and associated increases in IDU.

Access to Syringe Services Programs - Kentucky, North Carolina, and West Virginia, 2013-2017.

The Appalachian region of the United States is experiencing a large increase in hepatitis C virus (HCV) infections related to injection drug use (IDU) (1). Syringe services programs (SSPs) providing sufficient access to safe injection equipment can reduce hepatitis C transmission by 56%; combined SSPs and medication-assisted treatment can reduce transmission by 74% (2). However, access to SSPs has been limited in the United States, especially in rural areas and southern and midwestern states (3). This report describes the expansion of SSPs in Kentucky, North Carolina, and West Virginia during 2013-August 1, 2017. State-level data on the number of SSPs, client visits, and services offered were collected by each state through surveys of SSPs and aggregated in a standard format for this report. In 2013, one SSP operated in a free clinic in West Virginia, and SSPs were illegal in Kentucky and North Carolina; by August 2017, SSPs had been legalized in Kentucky and North Carolina, and 53 SSPs operated in the three states. In many cases, SSPs provide integrated services to address hepatitis and human immunodeficiency virus (HIV) infection, overdose, addiction, unintended pregnancy, neonatal abstinence syndrome, and other complications of IDU. Prioritizing development of SSPs with sufficient capacity, particularly in states with counties vulnerable to epidemics of hepatitis and HIV infection related to IDU, can expand access to care for populations at risk.

Invasive Methicillin-Resistant Staphylococcus aureus Infections Among Persons Who Inject Drugs - Six Sites, 2005-2016.

In the United States, age-adjusted opioid overdose death rates increased by >200% during 1999-2015, and heroin overdose death rates increased nearly 300% during 2011-2015 (1). During 2011-2013, the rate of heroin use within the past year among U.S. residents aged ≥12 years increased 62.5% overall and 114.3% among non-Hispanic whites, compared with 2002-2004 (2). Increases in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections related to increases in injection drug use have been recently highlighted (3,4); likewise, invasive bacterial infections, including endocarditis, osteomyelitis, and skin and soft tissue infections, have increased in areas where the opioid epidemic is expanding (5-7). To assess the effects of the opioid epidemic on invasive methicillin-resistant Staphylococcus aureus (MRSA) infections during 2005-2016, surveillance data from CDC's Emerging Infections Program (EIP) were analyzed (8). Persons who inject drugs were estimated to be 16.3 times more likely to develop invasive MRSA infections than others. The proportion of invasive MRSA cases that occurred among persons who inject drugs increased from 4.1% in 2011 to 9.2% in 2016. Infection types were frequently those associated with nonsterile injection drug use. Continued increases in nonsterile injection drug use are likely to result in increases in invasive MRSA infections, underscoring the importance of public health measures to curb the opioid epidemic.

Using Population Based Hospitalization Data to Monitor Increases in Conditions Causing Morbidity Among Persons Who Inject Drugs.

Epidemics of opioid use and injection drug use (IDU) are associated with an increase in HIV and viral hepatitis infections and overdose deaths in the United States. Persons who inject drugs (PWID) are also at risk for serious infections caused by skin organisms introduced via IDU. We examined National Inpatient Sample hospital discharge data to determine trends in three serious infectious disease-associated conditions that primarily affect PWID in addition to HIV and viral hepatitis: infective endocarditis (IE), central nervous system (CNS) abscesses, and osteomyelitis. We found an increase in the number of primary hospitalization discharge diagnoses for IE among persons aged ≤39 years from 2009 to 2013. Hospitalization rates for these diagnoses also increased over this study period for person with secondary diagnoses of hepatitis B, C, or D viruses and substance-related disorders for IE, CNS abscess and osteomyelitis. Policies that improve access to sterile injection equipment, improve education regarding IDU, and treatment for substance use disorder may help to reduce the impact of serious and often fatal infectious diseases among PWID.

Clinicians' Views of Hepatitis C Virus Treatment Candidacy With Direct-Acting Antiviral Regimens for People Who Inject Drugs.

BACKGROUND: Direct-acting antivirals (DAAs) are curative in most persons with chronic hepatitis C virus (HCV) infection. However, high cost and concerns about adherence and reinfection may present continued barriers to treatment, particularly for people who inject drugs (PWID). OBJECTIVE: To understand changes in assessments of treatment candidacy, given advances in treatment. METHODS: Clinicians attending the Liver Meeting® in 2014 who reported prescribing HCV treatment in the past three years were invited to complete a survey regarding HCV treatment decisions. Participants assessed their likelihood to treat HCV in PWID in association with time of abstinence from injection drug use and what impacts their decision to provide treatment using interferon and DAAs. RESULTS: 108 clinicians completed the survey; 10% were willing to treat an active PWID (last injection within 30 days) using interferon-containing regimens, and 15% with all-oral regimens. For each increasing time interval of injection abstinence, there was an increase in the odds of a clinician reporting willingness to treat with DAAs (Odds Ratio (OR) 2.57, 95% CI 2.18, 3.03) and with interferon-based treatment (OR 2.22 (95% CI 1.90, 2.61), Reinfection and medication cost were cited as most important concerns when determining candidacy. CONCLUSIONS: A cure is now the norm in HCV treatment, and there is an increasing need to address the barriers to treating PWID, the population with the highest burden of infection. Understanding treatment candidacy assessments is essential to improving uptake. This study provides insight into how clinicians view treatment candidacy in this era of DAAs and can help identify supportive treatment environments and concurrent programs.

Appreciating Reasons for Nonadherence in Women.

Women aged 15-24 years have an HIV infection rate twice that of men the same age. In this study we examined reasons why HIV-infected women taking antiretroviral therapy (ART) report missing HIV medications. Women (N = 206) on ART were 2.2 times more likely to endorse reasons pertaining to forgetfulness versus reasons pertaining to problems taking pills (OR = 2.2, 95% CI = 1.63, 2.94, p <.001). There was a difference between the adherent and nonadherent groups in types of reasons overall (p <.001, 95% CI = -3.82, -2.03). Using a patient-centered approach to understand type of nonadherence (intentional vs. unintentional) may support development of novel interventions.

Preference, acceptability and implications of the rapid hepatitis C screening test among high-risk young people who inject drugs.

BACKGROUND: People who inject drugs (PWID) are at highest risk for hepatitis C virus (HCV) infection, yet many remain unaware of their infection status. New anti-HCV rapid testing has high potential to impact this. METHODS: Young adult (<30 years) active PWID were offered either the rapid OraQuick® or standard anti-HCV test involving phlebotomy, then asked to complete a short questionnaire about testing perceptions and preferences. Sample characteristics, service utilization, and injection risk exposures are assessed with the HCV testing choice as the outcome, testing preferences, and reasons for preference. RESULTS: Of 129 participants: 82.9% (n = 107) chose the rapid test. There were no significant differences between those who chose rapid vs. standard testing. A majority (60.2%) chose the rapid test for quick results; most (60.9%) felt the rapid test was accurate, and less painful (53.3%) than the tests involving venipuncture. CONCLUSIONS: OraQuick® anti-HCV rapid test was widely accepted among young PWID. Our results substantiate the valuable potential of anti-HCV rapid testing for HCV screening in this high risk population.

Changes in Illicit Drug Use Among High School Students in Southeastern U.S. States-2009 to 2019.

To determine if decreasing lifetime use of methamphetamines, cocaine, ecstasy, and inhalants among high school students occurring from 2009 to 2019 in the U.S. also occurred in five southeastern states, Youth Risk Behavior Survey data representative of high school students in grades 9-12 in 2009 and 2019 were analyzed. In a classroom setting, lifetime use of methamphetamines, cocaine, ecstasy, and inhalants were self-reported. Students nationwide (n = 30,087) were compared to students in Alabama, Georgia, Louisiana, Mississippi, and South Carolina (n = 18,237). Lifetime methamphetamine use significantly increased from 4.8% in 2009 to 6.2% in 2019 in the southeast but decreased from 4.1 to 2.2% nationwide. Use of cocaine, ecstasy, and inhalants remained stable in the southeast while decreasing significantly nationwide from 2009 to 2019. During a period when use of methamphetamines, cocaine, ecstasy, and inhalants among high school students in the U.S. decreased, use in southeastern states did not change. Culturally specific programs and interventions may be needed to prevent illicit drug use in communities of southeastern states where youth remain at risk.

Naloxone Use During Pregnancy-Data from 26 US Jurisdictions, 2019-2020.

OBJECTIVES: We aimed to determine the prevalence of self-reported naloxone use during pregnancy among people in the United States with a recent live birth. A secondary objective was to characterize people at increased risk of overdose who did and did not use naloxone. METHODS: We analyzed data from the Pregnancy Risk Assessment Monitoring System from 26 US jurisdictions that conducted an opioid supplement survey from 2019 to 2020. Respondents with increased risk of experiencing an opioid overdose were identified based on self-reported use of illicit amphetamines, heroin, cocaine, or receiving medication for opioid use disorder (MOUD) during pregnancy. Weighted prevalence estimates and 95% confidence intervals were calculated for reported naloxone use at any point during pregnancy among people with an increased risk of overdose. RESULTS: Naloxone use during pregnancy was reported by <1% of the overall study population (unweighted N = 88/34,528). Prevalence of naloxone use was 5.0% (95% CI: 0.0-10.6) among respondents who reported illicit amphetamine use, 15.2% (1.8-28.6) among those who reported heroin use, and 17.6% (0.0-38.1) among those who reported cocaine use. Naloxone use was 14.5% (8.4-20.6) among those who reported taking MOUD. Among people with increased risk of overdose, no significant differences in naloxone use were observed by age, race/ethnicity, education level, residential metropolitan status, or insurance status. CONCLUSIONS: Prevalence of naloxone use among people with an increased risk of overdose during pregnancy ranged from 5.0% to 17.6%. Access to naloxone, overdose prevention education, and treatment for substance use disorders may help reduce morbidity and mortality.

Hepatitis C virus infection and co-infection with HIV among persons who inject drugs in 10 U.S. cities-National HIV Behavioral Surveillance, 2018.

BACKGROUND: Characterizing acute and chronic hepatitis C virus (HCV) infection and HIV/HCV co-infection among persons who inject drugs (PWID) can inform elimination efforts. METHODS: During 2018 National HIV Behavioral Surveillance in 10 U.S. metropolitan statistical areas (MSAs), PWID were recruited using respondent-driven sampling and offered a survey, HIV testing, and HCV antibody and RNA testing. We examined prevalence and associated characteristics of HCV infection and HIV/HCV co-infection. Associations were assessed using log-linked Poisson regression models with robust standard errors accounting for clustering by recruitment chain and adjusting for MSA and network size. RESULTS: Overall, 44.2% had current HCV infection (RNA detected), with 3.9% classified as acute infection (HCV antibody non-reactive/RNA detected) and 40.3% as chronic (HCV antibody reactive/RNA detected). Four percent had HIV/HCV co-infection. Current HCV infection was significantly higher among PWID who were male, White, injected >1 time/day, shared syringes in past year, and shared injection equipment in past year. PWID who were transgender, injecting >5 years, and most often injected speedball (heroin and cocaine together) or stimulants alone were more likely to have HIV/HCV co-infection. Among PWID who never previously had HCV infection, 9.9% had acute HCV infection. Among PWID who started injecting ≤5 years ago, 41.5% had already acquired HCV infection. CONCLUSIONS: Acute and chronic HCV infections were substantial among a sample of PWID in 10 U.S. MSAs. Accessibility to HCV RNA testing, promoting safer practices, and intervening early with harm reduction programs for recent injection initiates will be critical to disease elimination efforts for PWID.

Frequent longitudinal sampling of hepatitis C virus infection in injection drug users reveals intermittently detectable viremia and reinfection.

BACKGROUND: Detection of hepatitis C virus (HCV) reinfection and intercalation (ie, intermittent recurrent bouts of viremia with homologous virus interspersed with aviremic periods) requires extensive and frequent evaluation and viral sequencing. METHODS: HCV infection outcomes were studied prospectively in active injection drug users with recurrent HCV RNA-positive tests after serial negative results. HCV viremia and viral sequences (Core/E1) were assessed from monthly blood samples. RESULTS: Viral clearance, reinfection, and intercalating infection were all detected. Among 44 participants with apparently resolved HCV (26 incident HCV clearers and 18 enrolled with already resolved infection), 36 (82%) remained persistently HCV RNA negative, but 8 demonstrated intermittent recurrent viremia. Four of these (50%) had confirmed reinfection with a heterologous virus; 3 demonstrated viral intercalation, and 1 was not classifiable as either. Estimated incidence of first reinfection was 5.4 per 100 person-years (95% confidence interval, 2.0-14.5). Six (75%) participants, including 3 of 4 with reinfection, demonstrated sustained viral clearance for a median of 26 months since last HCV RNA test. CONCLUSIONS: These results show that frequent monitoring and viral sequencing are required to correctly assess HCV outcomes and estimate incidence of reinfection (which was previously overestimated). Sustained clearance may take many months and occur after episodes of reinfection and viral intercalation. Three of 4 subjects who had confirmed reinfection showed evidence of long-term clearance. Viral intercalation occurs with significant frequency. Further studies of these events, especially immunological, are needed to inform HCV clinical care and vaccine development.