Targeted Next-Generation Sequencing Assay for Direct Detection and Serotyping of Salmonella from Enrichment.

In this study, an automated, targeted next-generation sequencing (tNGS) assay to detect and serotype Salmonella from sample enrichments was evaluated. The assay generates millions of reads to detect multiple Salmonella-specific genes and serotype-specific alleles, detecting all Salmonella spp. tested to date, and serotyping 62 common Salmonella serotypes. Accuracy was tested on 291 pure reference cultures (251 Salmonella, 40 non-Salmonella), 21 artificially contaminated poultry carcass rinse samples, and 363 naturally contaminated poultry environmental samples. Among the 291 pure reference cultures, the automated tNGS assay resulted in 100% detection accuracy, 100% serotyping accuracy for the claimed serotypes, and 0% false positives. The limit of detection was estimated at 5 × 104 CFU/mL by testing enumerated cultures of strains representative of six serotypes. In cocontamination studies with mixtures of two serotypes (Enteritidis, Typhimurium, Kentucky, Infantis, and Newport) at a 1:1 ratio, tNGS detected both serotypes with 100% accuracy. The assay demonstrated 100% accuracy in artificially contaminated poultry carcass rinse sample enrichments. Targeted NGS was highly effective in detecting Salmonella in samples collected from poultry production facilities. Results demonstrated that tNGS could detect Salmonella and provide accurate serotyping information consistent with conventional serology. These findings highlight the reliable and efficient performance of a fully automated tNGS Salmonella assay in detecting and identifying Salmonella strains in complex matrices, reducing the time to results from 4 to 5 days required by the traditional isolation and serotyping to 10-12 h for tNGS after primary enrichment.

Martius flaps for low rectovaginal fistulae: a systematic review and proportional meta-analysis.

BACKGROUND: Rectovaginal fistulae (RVF) are notoriously challenging to treat. Martius flap (MF) is a technique employed to manage RVF, among various others, with none being universally successful. We aimed to assess the outcomes of RVF managed with MF interposition. METHODS: A PRISMA-compliant meta-analysis searching for all studies specifically reporting on the outcomes of MF for RVF was performed. The primary objective was the mean success rate, whilst secondary objectives included complications and recurrence. The MedCalc software (version 20.118) was used to conduct proportional meta-analyses of data. Weighted mean values with 95% CI are presented and stratified according to aetiology where possible. RESULTS: Twelve non-randomized (11 retrospective, 1 prospective) studies, assessing 137 MF were included. The mean age of the study population was 42.4 (±15.7), years. There were 44 primary and 93 recurrent RVF. The weighted mean success rate for MF when performed for primary RVF was 91.4% (95% CI: 79.45-98.46; I2 = 32.1%; P = 0.183) and that for recurrent RVF was 77.5% (95% CI: 62.24-89.67; I2 = 58.1%; P = 0.008). The weighted mean complication rate was 29% (95% CI: 8.98-54.68; I2 = 85.4%; P < 0.0001) and the overall recurrence rate was 12.0% (95% CI: 5.03-21.93; I2 = 52.3%; P = 0.021). When purely radiotherapy-induced RVF were evaluated, the mean overall success rate was 94.6% (95% CI: 83.33-99.75; I2 = 0%; P = 0.350). CONCLUSIONS: MF interposition appears to be more effective for primary than recurrent RVF. However, the poor quality of the data limits definitive conclusions being drawn and demands further assessment with randomized studies.

Electrogram morphology recurrence guided catheter ablation for repeat ablation of persistent atrial fibrillation.

BACKGROUND: There are no standard mapping approaches for patients with persistent atrial fibrillation (PeAF), particularly after failed prior catheter ablation (CA). In this study, we assess the feasibility of using Electrogram Morphology Recurrence (EMR) to guide ablation. METHODS: Ten patients with recurrent PeAF after prior CA underwent detailed mapping of both atria during PeAF using the PentaRay (4 mm interelectrode spacing) and 3D mapping with CARTO. At each site, 15 s recordings were made. Custom software identified each electrogram and cross-correlation was used to identify the most recurrent electrogram morphology from which the % recurrence and cycle length of the most repeatable morphology (CLR) was calculated. Sites of shortest CLR and sites within 5 ms of shortest CLR with recurrence ≥ 80% were used to inform CA strategy. RESULTS: A mean of 342.9 ± 131.9 LA and 328.6 ± 91.5 RA sites were recorded per patient. Nine had PV reconnection. Shortest CLR sites guided ablation in 6/10 patients while 1 patient failed to fulfill shortest CLR criteria, and another 3 did not undergo CA guided by shortest CLR due to operator preference. On 12-month follow-up, all 4 patients without shortest CLR guided CA had recurrent PeAF. Of the 6 patients with shortest CLR guided CA, 5 patients did not have recurrent PeAF (p = 0.048), although 1 had paroxysmal AF and 2 had atypical atrial flutter. CONCLUSION: EMR is a feasible, novel technique to guide CA in patients with PeAF. Further evaluation is needed to provide an electrogram-based method for mapping guided targeted ablation of key areas.

Comparison of electrogram characteristics in persistent atrial fibrillation.

INTRODUCTION: Multiple analysis techniques evaluate electrograms during atrial fibrillation (AF), but none have been established to guide catheter ablation. This study compares electrogram properties recorded from multiple right (RA) and left atrial (LA) sites. METHODS: Multisite LA/RA mapping (281 ± 176/239 ± 166 sites/patient) was performed in 42 patients (30 males, age 63 ± 9 years) undergoing first (n = 32) or redo-AF ablation (n = 10). All electrogram recordings were visually reviewed and artifactual signals were excluded leaving a total of 21 846 for analysis. Electrogram characteristics evaluated were cycle length (CL), amplitude, Shannon's entropy (ShEn), fractionation interval, dominant frequency, organizational index, and cycle length of most recurrent morphology (CLR ) from morphology recurrence plot analysis. RESULTS: Electrogram characteristics were correlated to each other. All pairwise comparisons were significant (p < .001) except for dominant frequency and CLR (p = .59), and amplitude and dominant frequency (p = .38). Only ShEn and fractionation interval demonstrated a strong negative correlation (r = -.94). All other pairwise comparisons were poor to moderately correlated. The relationships are highly conserved among patients, in the RA versus LA, and in those undergoing initial versus redo ablations. Antiarrhythmic drug therapy did not have a significant effect on electrogram characteristics, except minimum ShEn. Electrogram characteristics associated with ablation outcome were shorter minimum CLR , lower minimum ShEn, and longer mimimum CL. There was minimal overlap between the top 10 sites identified by one electrogram characteristic and the top 10 sites identified by the other 10 characteristics. CONCLUSION: Multiple techniques can be employed for electrogram analysis in AF. In this analysis of eight different electrogram characteristics, seven were poorly to moderately correlated and do not identify similar locations. Only some characteristics were predictive of ablation outcome. Further studies to consider electrogram properties, perhaps in combination, for categorizing and/or mapping AF are warranted.

Document d'orientation sur la distribution et l'utilisation de trousses de naloxone à emporter par les intervenants et intervenantes communautaires en cas de surdose au Canada.

CONTEXTE: La toxicité croissante des opioïdes dans le marché illicite des drogues a fait exploser le nombre de surdoses au Canada et ailleurs dans le monde; le programme de naloxone à emporter (NàE) est une intervention fondée sur des données probantes qui consiste à distribuer des trousses contenant de la naloxone aux membres de la communauté susceptibles d'être témoins d'une surdose. L'objectif du présent document d'orientation est de formuler des recommandations stratégiques à l'intention des programmes fédéraux, provinciaux et territoriaux de NàE, en s'appuyant sur des données probantes issues de la documentation scientifique, de la littérature grise et des communautés, à la lumière de 11 années de distribution de NàE au Canada. MÉTHODES : Le groupe d'élaboration des documents d'orientation sur la naloxone, une équipe multidisciplinaire composée de personnes ayant une expertise et une expérience vécue en matière de toxicomanie, a appliqué l'outil AGREE II (Appraisal of Guidelines for Research & Evaluation) afin d'éclairer l'élaboration du présent document d'orientation. En vue de l'élaboration de nos recommandations, nous avons procédé entre décembre 2021 et septembre 2022 à une revue systématique de tous les types d'ouvrages dans le but de recueillir les données probantes publiées, ainsi que les données probantes et l'expertise issues de la communauté. Nous avons sollicité des commentaires sur nos recommandations préliminaires par le biais d'un comité de révision externe et d'un processus de participation du public. Le projet a été financé par les Instituts de recherche en santé du Canada dans le cadre de l'Initiative canadienne de recherche sur l'abus de substances (ICRAS). Nous avons appliqué les principes du Réseau international en matière de lignes directrices (Guidelines International Network) pour gérer les intérêts concurrents. RECOMMANDATIONS: Les données probantes existantes issues de la documentation sur la NàE étaient de faible qualité. Pour élaborer nos recommandations, nous avons incorporé des données probantes tirées de la documentation scientifique et de la littérature grise, ainsi que l'expertise de la communauté. Nos recommandations portent sur 3 volets : les voies d'administration de la naloxone, le contenu des trousses de NàE et les interventions en cas de situations de surdose. Les trousses distribuées par les programmes de naloxone à emporter doivent offrir le choix entre les préparations intramusculaire et intranasale. Le contenu recommandé de la trousse comprend la naloxone, un dispositif d'administration de la naloxone, un équipement de protection individuelle, des instructions et un étui de transport. Les intervenants et intervenantes communautaires formés à la réponse aux surdoses doivent prioriser la respiration artificielle en cas de dépression respiratoire, et la réanimation cardiorespiratoire (RCR) conventionnelle en cas d'arrêt cardiaque, entre autres interventions. INTERPRÉTATION : Ce projet d'élaboration d'un document d'orientation vise à guider les programmes de NàE au Canada dans un contexte où les données probantes publiées sont rares; les recommandations ont été élaborées en collaboration avec diverses parties prenantes.

Guidance on take-home naloxone distribution and use by community overdose responders in Canada.

BACKGROUND: The increasing toxicity of opioids in the unregulated drug market has led to escalating numbers of overdoses in Canada and worldwide; takehome naloxone (THN) is an evidence-based intervention that distributes kits containing naloxone to people in the community who may witness an overdose. The purpose of this guidance is to provide policy recommendations for territorial, provincial and federal THN programs, using evidence from scientific and grey literature and community evidence that reflects 11 years of THN distribution in Canada. METHODS: The Naloxone Guidance Development Group - a multidisciplinary team including people with lived and living experience and expertise of drug use - used the Appraisal of Guidelines for Research & Evaluation (AGREE II) instrument to inform development of this guidance. We considered published evidence identified through systematic reviews of all literature types, along with community evidence and expertise, to generate recommendations between December 2021 and September 2022. We solicited feedback on preliminary recommendations through an External Review Committee and a public input process. The project was funded by the Canadian Institutes of Health Research through the Canadian Research Initiative in Substance Misuse. We used the Guideline International Network principles for managing competing interests. RECOMMENDATIONS: Existing evidence from the literature on THN was of low quality. We incorporated evidence from scientific and grey literature, and community expertise to develop our recommendations. These were in 3 areas: routes of naloxone administration, THN kit contents and overdose response. Take-home naloxone programs should offer the choice of both intramuscular and intranasal formulations of naloxone in THN kits. Recommended kit contents include naloxone, a naloxone delivery device, personal protective equipment, instructions and a carrying case. Trained community overdose responders should prioritize rescue breathing in the case of respiratory depression, and conventional cardiopulmonary resuscitation in the case of cardiac arrest, among other interventions. INTERPRETATION: This guidance development project provides direction for THN programs in Canada in the context of limited published evidence, with recommendations developed in collaboration with diverse stakeholders.

Incidence and management of gallbladder cancer in cholecystectomy specimens: a 5-year tertiary centre experience.

BACKGROUND: Gallbladder cancer (GBC) is an uncommon, but highly aggressive cancer. Half of these cases are diagnosed pre-operatively, and the remaining cases are discovered incidentally on post-cholecystectomy specimens. There is a significant geographical variability in GBC incidence, with increasing age, female sex, and prolonged duration of cholelithiasis being risk factors for GBC. The primary aim was to define the overall local incidence of GBC incidental GBC and management of these cases. The secondary aim was to determine any pertinent risk factors in our case population. METHODS: A retrospective observational study was performed on all the cholecystectomy specimens at the Gold Coast Hospital and Health Service from 1 January 2016 to 2 December 2021. Data was collected via the electronic medical record. The incidence and management of gallbladder cancers was calculated, and association with body mass index (BMI), smoking status, diabetes, inflammatory bowel disease (IBD) was identified. RESULTS: 3904 cholecystectomy specimens were reviewed. GBC was identified in 0.46% of cholecystectomies. 50% of these cases were found incidentally. Abdominal pain was the most common presenting complaint (94.4%). GBC was associated with increased age and BMI and female sex. There was no association between smoking status, diabetes or IBD with an increased incidence of cancer. Tumour staging guided surgical and/or adjuvant chemotherapy. CONCLUSION: GBC is rare. Patients with symptoms are associated with a poor prognosis. Incidental cancers are common, and negative margin resection based on the T stage of the cancer is the most reliable curative option.

Membrane Potential-Dependent Uptake of Cationic Oligoimidazolium Mediates Bacterial DNA Damage and Death.

The treatment of bacterial infections is becoming increasingly challenging with the emergence of antimicrobial resistance. Thus, the development of antimicrobials with novel mechanisms of action is much needed. Previously, we designed several cationic main-chain imidazolium compounds and identified the polyimidazolium PIM1 as a potent antibacterial against a wide panel of multidrug-resistant nosocomial pathogens, and it had relatively low toxicity against mammalian epithelial cells. However, little is known about the mechanism of action of PIM1. Using an oligomeric version of PIM1 with precisely six repeating units (OIM1-6) to control for consistency, we showed that OIM1-6 relies on an intact membrane potential for entry into the bacterial cytoplasm, as resistant mutants to OIM1-6 have mutations in their electron transport chains. These mutants demonstrate reduced uptake of the compound, which can be circumvented through the addition of a sub-MIC dose of colistin. Once taken up intracellularly, OIM1-6 exerts double-stranded DNA breaks. Its potency and ability to kill represents a promising class of drugs that can be combined with membrane-penetrating drugs to potentiate activity and hedge against the rise of resistant mutants. In summary, we discovered that cationic antimicrobial OIM1-6 exhibits an antimicrobial property that is dissimilar to the conventional cationic antimicrobial compounds. Its killing mechanism does not involve membrane disruption but instead depends on the membrane potential for uptake into bacterial cells so that it can exert its antibacterial effect intracellularly.

First case of nickel-metal hydride battery ingestion in child.

We describe a case of a 12-year-old female with a past history of autism spectrum disorder who presented to the emergency department of a rural hospital in Australia after ingesting two nickel-metal hydride (NiMH) batteries at home. Hitherto, no literature has described any gastrointestinal complications related to NiMH battery ingestion. This paper aims to provide insight into the management of NiMH battery ingestion and to increase the awareness of the need for prompt management to prevent further damage to the gastrointestinal tract.

Point-of-care ultrasound-assisted diagnosis of gastric vessel rupture in a young man presenting with chest pain: A cautionary tale.

We report a young male patient who presented with chest and shoulder tip pain with spontaneous intraperitoneal haemorrhage (haemoperitoneum) due to gastric vessel rupture. Point-of-care ultrasound detected abdominal free fluid, which led to a CT scan of the abdomen and reached the diagnosis. Intra-abdominal bleeding can present as referred chest or shoulder tip pain, as more commonly seen in females with pelvic pathologies. Point-of-care ultrasound may add diagnostic value with the detection of a haemoperitoneum in this context.

Time to acute general surgical review: a retrospective study in a tertiary referral centre.

BACKGROUND: The Acute Surgical Unit (ASU) is a busy service receiving Emergency Department (ED) referrals for adult and paediatric general surgery care alongside trauma. The ASU model deviates from the traditional on-call model and has been shown to improve efficiency and patient outcomes. The primary aim was to evaluate time to surgical review ED presentation and general surgical referral. Secondary aims were to assess referral numbers, pathology and demographics at our institution. METHODS: A retrospective observational analysis was conducted on all referral times from the ED to the ASU between 1 April and 30 September 2022. Patient demographics, triage and referral times, and diagnoses were collected from the electronic medical record. Time between referral, review and surgical admission were calculated. RESULTS: A total of 2044 referrals were collected during the study period, and 1951 (95.45%) were included for analysis. Average time from ED presentation to surgical referral was 4 hours and 54 min with average time to surgical review from referral taking 40 min. On average, total time from ED presentation to surgical admission was 5 h and 34 min. Trauma Responds took 6 min to review. Colorectal pathology was the most commonly referred disease type. CONCLUSION: The ASU model is efficient and effective within our health service. Overall delays in surgical care may be external to the general surgery unit, or before the patient is made known to the surgical team. Analysis of time to surgical review is a key statistic in the delivery of acute surgical care.

Genomic Characterization of a Relative of Mumps Virus in Lesser Dawn Bats of Southeast Asia.

The importance of genomic surveillance on emerging diseases continues to be highlighted with the ongoing SARS-CoV-2 pandemic. Here, we present an analysis of a new bat-borne mumps virus (MuV) in a captive colony of lesser dawn bats (Eonycteris spelaea). This report describes an investigation of MuV-specific data originally collected as part of a longitudinal virome study of apparently healthy, captive lesser dawn bats in Southeast Asia (BioProject ID PRJNA561193) which was the first report of a MuV-like virus, named dawn bat paramyxovirus (DbPV), in bats outside of Africa. More in-depth analysis of these original RNA sequences in the current report reveals that the new DbPV genome shares only 86% amino acid identity with the RNA-dependent RNA polymerase of its closest relative, the African bat-borne mumps virus (AbMuV). While there is no obvious immediate cause for concern, it is important to continue investigating and monitoring bat-borne MuVs to determine the risk of human infection.

Appendiceal diverticulitis and inflammatory bowel disease.

Appendiceal diverticulitis is known as a rare pathology and its etiology remains largely unknown. We describe a case of a 41-year-old woman with a past history of inflammatory bowel disease (IBD) who was admitted to the Emergency Department at a rural hospital in Australia with right iliac fossa pain (RIF) and later was found to have acute appendiceal diverticulitis on histopathologic studies. Thus far, no literature has described IBD as one of the possible contributing factors of appendiceal diverticulitis. This paper aims to shed light on the possible causative relation between appendiceal diverticulitis and IBD.

Electrogram Morphology Recurrence for Mapping Persistent Atrial Fibrillation: Initial vs Redo Catheter Ablation.

BACKGROUND: Electrogram (EGM) morphology recurrence (EMR) mapping of persistent atrial fibrillation (AF) quantifies consistency of activation and is expected to be high and rapid near AF drivers. OBJECTIVES: The purpose of this study was to compare EMR in left atria (LA) and right atria (RA) in patients undergoing first vs redo ablation for persistent AF. METHODS: Multisite LA/RA mapping (LA: 281 ± 176 sites/patient; RA: 239 ± 166 sites/patient) before persistent AF ablation was performed in 42 patients (30 males, age 63 ± 9 years) undergoing first (Group 1, n = 32) or redo ablation (Group 2, n = 10). After cross-correlation of each automatically detected EGM with every other EGM per recording, the most recurrent electrogram morphology was identified and its frequency (Rec%) and recurrence cycle length (CLR) were computed. RESULTS: In Groups 1 and 2, minimum CLR was 172.8 ± 26.0 milliseconds (LA: 178.2 ± 37.6 milliseconds, RA: 204.4 ± 34.0 milliseconds, P = 0.0005) and 186.5 ± 28.3 milliseconds (LA: 196.1 ± 38.1 milliseconds vs RA: 199.0 ± 30.2 milliseconds, P = 0.75), with Rec% 94.7% ± 10% and 93.8% ± 9.2%. Group 2 minimum CLR was not different from Group 1 (P = 0.20). Shortest CLR was in the LA in 84% of Group 1 and 50% of Group 2 patients (P = 0.04). Only 1 of 10 patients in Group 2 had the shortest CLR in the pulmonary veins (PVs) compared with 19 of 32 in Group 1 (P = 0.01). Most sites (77.6%) had Rec% <50%. CONCLUSIONS: EMR identified the shortest CLR sites in the PVs in 59% of patients undergoing initial persistent AF ablation, consistent with reported success rates of ∼50% for PV isolation. The majority of sites have low recurrence and may reflect bystander sites not critical for maintaining AF. EMR provides a robust new method for quantifying consistency and rapidity of activation direction at multiple atrial sites.

Incidence and management of choledocholithiasis on routine intraoperative cholangiogram: a 5-year tertiary centre experience.

BACKGROUND: The incidence of choledocholithiasis on routine intraoperative cholangiogram (IOC) during cholecystectomy is approximately 12%. Cholecystectomy without IOC may lead to undiagnosed choledocholithiasis placing patients at risk of complications such as pancreatitis or cholangitis. This study aims to determine the incidence of choledocholithiasis intraoperatively as well as the associated risk factors and the methods of management. METHODS: A retrospective observational analysis of all laparoscopic cholecystectomies with IOC at the Gold Coast Hospital and Health Service from 1 January 2016 to 2 December 2021 was carried out. Patient demographics, operative data and cholangiogram findings were collected from electronic medical systems. RESULTS: A total of 3904 cholecystectomies were carried out over the study period. 3520 (90.1%) had an IOC, and 474 (13.4%) had positive IOC findings. 158 (33.3%) of the cases were managed intraoperatively with hyoscine butylbromide with or without intravenous glucagon followed by biliary tree flushing alone, 183 (38.6%) received transcystic bile duct exploration (TCBDE) with a success rate of 83% and 167 (35.2%) received endoscopic retrograde cholangiopancreatography (ERCP). Choledocholithiasis was incidental in 44 (9.28%) patients. CONCLUSION: Incidental choledocholithiasis during routine IOC is not uncommon. Management predominantly includes intraoperative TCBDE or postoperatively via an ERCP. This study has not found reliable preoperative factors to predict choledocholithiasis based on preoperative clinical, radiological and biochemical factors. A small proportion of patients received preoperative endoscopic intervention, and the decision-making process requires further investigation.

Laparoscopic Cholecystectomy in Pregnancy: A Seven-Year Retrospective Study From an Australian Tertiary Center.

Background Cholecystectomy is the second most common non-obstetric indication for surgery during pregnancy; however, there is little recent literature specifically exploring perioperative care approaches, and a paucity of Australian data exists. This study investigates the incidence of laparoscopic cholecystectomy (LC) during pregnancy, peri-operative management, and post-operative outcomes in a single Australian tertiary center. Methods A retrospective analysis of LCs performed on pregnant patients between the ages of 16 and 50 years at a tertiary hospital between 2016 and 2023 was completed. Results Twenty-three patients underwent LC. The median gestational age was 17+4 weeks (4+3-30+6). Cases were performed in all three trimesters, with the majority in the second trimester (n=12, 52.2%). Surgery indications were recurrent biliary colic (n=11, 47.8%), acute cholecystitis (n=8, 34.8%), and gallstone pancreatitis (n=4, 17.4%). Obstetrics and Gynecology (O&G) consultations occurred in 56.5% (n=13) of cases. Fetal heart rate (FHR) was recorded perioperatively in 82.6% (n=19) of cases. Preoperative steroids were given to 40% of eligible patients. An intraoperative cholangiogram was performed in 12 (52.2%) cases, of which eight (66.7%) utilized abdominal shielding. There was no perioperative maternal mortality nor fetal loss. Surgical morbidities were pancreatitis (n=1), bile leak (n=1), and intraoperatively recognized bile duct injury (n=1). Two threatened preterm labors and five (26.3%) preterm deliveries occurred. Conclusion Performing LC in pregnancy does carry a risk of major morbidity; however, there was no mortality or fetal loss across all trimesters. The decision to perform abdominal shielding during an intraoperative cholangiogram should be approached sensitively in a case-by-case manner, given recent paradigm shifts in radiology. A multidisciplinary approach with standardized local perioperative care policies regarding procedures such as O&G consultation, perioperative steroid use, and FHR monitoring is strongly recommended.

Alcohol intake is associated with a decreased risk of developing primary biliary cholangitis.

BACKGROUND: Primary biliary cholangitis (PBC) is a chronic progressive liver disease of unknown aetiology characterised by immune-mediated destruction of small and medium-sized intrahepatic bile ducts. There are few well-established risk factors and epidemiological studies are needed to further evaluate the pathogenesis of the disease. AIM: To evaluate the relationship between alcohol intake, smoking and marijuana use with PBC development. METHODS: We conducted a prevalent case control study of 200 cases and 200 age (within a five year age band) and sex-matched controls, identified from the Victorian PBC prevalence study. We assessed lifetime alcohol intake and smoking behaviour (both tobacco and marijuana) prior to PBC onset and used conditional logistic regression for analyses. RESULTS: Alcohol intake consistently showed a dose-dependent inverse association with case status, and this was most substantial for 21-30 years and 31-40 years (P trend < 0.001). Smoking was associated with PBC, with a stronger association with a longer duration of smoking [e.g., adjusted OR 2.27 (95%CI: 1.12- 4.62) for those who had smoked for 20-35 years]. There was no association between marijuana use and PBC. CONCLUSION: Alcohol appears to have an inverse relationship with PBC. Smoking has been confirmed as an environmental risk factor for PBC. There was no association between marijuana use and PBC.