Staphylococcus aureus carriage and prevalence of skin and soft tissue infections among people who inject drugs: a longitudinal study.

People who inject drugs are frequently colonized with Staphylococcus aureus and have an increased risk for skin and soft tissue infections. This longitudinal study aims to describe S. aureus carriage in this group and the risk for infections during a 1-year follow-up. We included 61 participants from the Malmö Needle Exchange Program. Mapping of S. aureus carriage was conducted by screening cultures every third month and S. aureus growth was semi-quantified. Data regarding infections and living conditions were collected from structured interviews. Statistics included univariate analysis with the Fischer's exact test, univariate logistic regression and multivariate logistic regression. S. aureus carriage was detected in 46-63% of participants, and 75% reported one or more infections during the study period. Self-reported infections were associated with carriage in perineum (OR 5.08 [95% CI 1.45-17.73]), in skin lesions (OR 1.48 [95% CI 1.21-1.81]), and unstable housing situation (OR 12.83 [95% CI 1.56-105.81]). Thus, people who inject drugs are frequent carriers of S. aureus and report a surprisingly high prevalence of skin and soft tissue infections. Homeless people and those with skin carriage seem to be at highest risk. Effective clinical interventions are needed, aiming at preventing infections in this vulnerable group.

Distribution of intranasal naloxone to potential opioid overdose bystanders in Sweden: effects on overdose mortality in a full region-wide study.

OBJECTIVES: Distribution of take-home naloxone is suggested to reduce opioid-related fatalities, but few studies have examined the effects on overdose deaths in the general population of an entire community. This study aimed to assess the effects on overdose deaths of a large-scale take-home naloxone programme starting in June 2018, using an observational design with a historic control period. DESIGN: From the national causes of death register, deaths diagnosed as X42 or Y12 (International Classification of Diseases, 10th revision, ICD-10) were registered as overdoses. Numbers of overdoses were calculated per 100 000 inhabitants in the general population, and controlled for data including only individuals with a prior substance use disorder in national patient registers, to focus on effects within the primary target population of the programme. The full intervention period (2019-2021) was compared with a historic control period (2013-2017). SETTING: Skåne county, Sweden. PARTICIPANTS: General population. INTERVENTIONS: Large-scale take-home naloxone distribution to individuals at risk of overdose. PRIMARY AND SECONDARY OUTCOME MEASURES: Decrease in overdose deaths per 100 000 inhabitants, in total and within the population with substance use disorder diagnosis. RESULTS: Annual average number of overdose deaths decreased significantly from 3.9 to 2.8 per 100 000 inhabitants from the control period to the intervention period (a significant decrease in men, from 6.7 to 4.3, but not in women, from 1.2 to 1.3). Significant changes remained when examining only prior substance use disorder patients, and decreases in overdose deaths could not be attributed to a change in treatment needs for opioid use disorders in healthcare and social services. CONCLUSIONS: The present study, involving 3 years of take-home naloxone distribution, demonstrated a decreased overdose mortality in the population, however, only in men. The findings call for further implementation of naloxone programmes, and for further studies of potential effects and barriers in women. TRIAL REGISTRATION NUMBER: NCT03570099.

Absence of interferon-λ 4 enhances spontaneous clearance of acute hepatitis C virus genotypes 1-3 infection.

OBJECTIVES: Absence of a functional interferon-λ 4 (IFN-λ4) gene (IFNL4) predicts spontaneous resolution of acute hepatitis C virus (HCV) infections in regions with a predominance of genotype 1, whereas variants of the inosine triphosphate pyrophosphatase (ITPase) gene (ITPA) entailing reduced activity associate with increased sustained virologic response rates following some therapeutic regimens. This study aimed at investigating the impact of IFNL4 on acute HCV genotype 2 or 3 infections, and whether ITPase activity influenced outcome. MATERIALS AND METHODS: Two hundred and seven people who injected drugs (PWID) with documented anti-HCV seroconversion, and 57 PWID with reinfection with HCV were analyzed regarding IFNL4 (rs368234815 and rs12979860) and ITPA (rs1127354 and rs7270101), and longitudinally followed regarding HCV RNA. RESULTS: The spontaneous clearance of HCV infection in anti-HCV seronegative PWID was enhanced when IFN-λ4 was absent (44% vs. 20% for IFNL4 TT/TTrs1368234815 and ΔGrs1368234815 respectively, p < .001; OR 3.2) across genotypes 1-3. The proportion lacking IFN-λ4 was further increased following resolution of repeated re-exposure to HCV (74% among re-infected participants who had cleared at least two documented HCV infections). ITPA genetic variants did not independently impact on the outcome, but among males lacking IFN-λ4, reduced ITPase activity markedly augmented the likelihood of resolution (65% vs. 29% for <100% and 100% ITPase activity, p = .006). CONCLUSIONS: Absence of IFN-λ4 entails an enhanced likelihood of spontaneous resolution both following primary acute infection and repeated re-exposure to HCV across genotypes 1-3. Among men lacking IFN-λ4, reduced ITPase activity improved outcome.

High risk of non-alcoholic liver disease mortality in patients with chronic hepatitis C with illicit substance use disorder.

Aims: Hepatitis C virus (HCV) is a slowly progressive disease, often transmitted among people who inject drugs (PWID). Mortality in PWID is high, with an overrepresentation of drug-related causes. This study investigated the risk of death in patients with chronic hepatitis C virus (HCV) infection with or without illicit substance use disorder (ISUD).Methods: Patients with HCV were identified using the Swedish National Patient Registry according to the International Classification of Diseases-10 (ICD-10) code B18.2, with ≤5 matched comparators from the general population. Patients with ≥2 physician visits with ICD-10 codes F11, F12, F14, F15, F16, or F19 were considered to have ISUD. The underlying cause of death was analyzed for alcoholic liver disease, non-alcoholic liver disease, liver cancer, drug-related and external causes, non-liver cancers, or other causes. Mortality risks were assessed using the standardized mortality ratio (SMR) with 95% CIs and Cox regression analyses for cause-specific hazard ratios.Results: In total, 38,186 patients with HCV were included, with 31% meeting the ISUD definition. Non-alcoholic liver disease SMRs in patients with and without ISUD were 123.2 (95% CI, 103.7-145.2) and 69.4 (95% CI, 63.8-75.3), respectively. The significant independent factors associated with non-alcoholic liver disease mortality were older age, being unmarried, male sex, and having ISUD.Conclusions: The relative risks for non-alcoholic liver disease mortality were elevated for patients with ISUD. Having ISUD was a significant independent factor for non-alcoholic liver disease. Thus, patients with HCV with ISUD should be given HCV treatment to reduce the risk for liver disease.

Death from liver disease in a cohort of injecting opioid users in a Swedish city in relation to registration for opioid substitution therapy.

INTRODUCTION AND AIMS: Injecting opioid users are at elevated risk of death. Although liver disease (especially hepatitis C) is common, its impact on mortality is low in active injectors. Because opioid substitution therapy (OST) reduces the risk of death from directly drug related causes, we hypothesised that the proportion of liver-related deaths would increase in subjects receiving OST. We investigated liver-related mortality in a cohort of injecting opioid users attending a needle exchange program (NEP) in a Swedish city in relation to OST exposure. DESIGN AND METHODS: Participants enrolled in the NEP between 1987 and 2011 with available national identity numbers, and registered use of opioids, were included. Linkage based on national identity numbers was performed with national registers for death, emigration and prescription of OST. Participants were categorised as non-OST recipients until the registered date of first OST prescription, and hence as OST recipients. Hazard ratios were calculated by Cox regression for overall and liver-related mortality in relation to OST, with OST as a time-dependent variable. RESULTS: Among 4494 NEP participants, 1488 opioid users were identified; 711/1488 had been prescribed OST. During a follow-up period of 15 546 person-years 368 deaths occurred. Sixteen deaths were caused by liver disease; 10 of these occurred in OST recipients. The risk of liver-related death was significantly increased in OST receiving participants (hazard ratio 3.08, 95% confidence interval [1.09, 8.68], P = 0.03). CONCLUSIONS: Liver related mortality among opioid users was significantly elevated in OST recipients, showing the long-term importance of chronic liver disease in this population. [Jerkeman A, Håkansson A, Rylance R, Wagner P, Alanko Blomé M, Björkman P. Death from liver disease in a cohort of injecting opioid users in a Swedish city in relation to registration for opioid substitution therapy. Drug Alcohol Rev 2017;36:424-431].

Hepatitis C viremia patterns in incident hepatitis C infection and one year later in 150 prospectively tested persons who inject drugs.

OBJECTIVES: To assess HCV viremia levels just before, during and one year after anti-HCV seroconversion in people who inject drugs (PWID). METHODS: PWID enrolling into a needle exchange program in Malmö, Sweden, 1997-2005 constituted the source population. Sera were obtained at enrolment and at approximately 3-4 monthly intervals afterwards, and were initially tested for anti-HIV, HBsAg/anti-HBc and anti-HCV and thereafter for markers previously negative. Seroconversion to anti-HCV had occurred during the study period in 186 out of 332 seronegative subjects. In these anti-HCV seroconverters, quantitative HCV RNA PCR was retrospectively performed on frozen sera to determine viremia levels in the last anti-HCV negative, the first anti-HCV positive and in one year follow-up samples. RESULTS: Among 150 subjects seroconverting to anti-HCV with samples available from all three defined time-points, eight different patterns of viremia were observed. Spontaneous clearance at one year was noted in 48 cases (32%) and was associated with female gender (p = 0.03, CI 0.17-1.00). In 13 cases HCV-RNA was not detected in any study sample. Among 61 subjects with pre-seroconversion viremia, viral load was significantly higher in the pre-seroconversion samples compared to subsequent samples. For the whole group, viral load declined to undetectable levels at seroconversion in 28% of cases (but with recurrent viremia in 15%). CONCLUSIONS: Different patterns of HCV RNA kinetics were observed among PWID with documented seroconversion to anti-HCV. The frequently observed absence of detectable HCV RNA in the first anti-HCV positive sample (irrespective of subsequent viremia) demonstrates the importance of repeated sampling and RNA testing for determination of the outcome of acute infection.