Cheryl Main

High Analytical Sensitivity and Low Rates of Inhibition May Contribute to Detection of Chlamydia trachomatis in Significantly More Women by the APTIMA Combo 2 Assay

ABSTRACT The clinical sensitivity of nucleic acid amplification tests may be determined by analytical sensitivity and inhibitors in patient samples. We established endpoints for detection of propagated Chlamydia trachomatis L2 434, diluted according to swab and urine protocols for APTIMA Combo 2 (AC2), ProbeTec ET (PT), and Amplicor (AMP) assays. AC2 was 1,000-fold more sensitive than PT and 10-fold more sensitive than AMP on mock swab specimens. For urine, AC2 analytical sensitivity was 100-fold greater than those of the other assays. Spiking an aliquot of each clinical-trial sample from 298 women demonstrated inhibition rates in first-void urine (FVU), cervical swabs (CS), and vaginal swabs (VS) of 12.1%, 12.8%, and 10.4% for AMP; 27.2%, 2%, and 2%, for PT; and 0.3%, 1.7%, and 1.3% for AC2. Inhibition of our C. trachomatis spike and the PT or AMP amplification controls from the manufacturers showed less than 50% correlation. Using an infected-patient reference standard (a specimen positive in at least two tests or a single test positive in two of three samples) in AC2, the VS identified 68/69 (98.6%) infected women compared to CS (89.9%) or FVU (81.2%). Significantly fewer women were identified by PT (65.2%, 63.8%, and 66.7%) or AMP (65.2%, 59.4%, and 56.5%) with the three specimens. By individual specimen type, AC2 confirmed virtually all PT- and AMP-positive specimens, but rates of AC2 confirmation by AMP or PT ranged from 62.9 to 80.3%. The AC2 test identified significantly more women infected with C. trachomatis (P = 0.001). Vaginal swabs appear to be the specimen of choice for screening.

Multifaceted intervention to optimize antibiotic use for intra-abdominal infections

OBJECTIVES Implementing evidence-based practice guidelines is challenging. We used a multifaceted, continuous educational approach to disseminate an up-to-date internal guideline adapted from published guidelines for management of intra-abdominal infections (IAI). PATIENTS AND METHODS The intervention consisted of continuing educational sessions, internal guideline pocket cards and posters with collaboration among all key stakeholders starting in December 2010. We emphasized risk stratification and the use of ceftriaxone/metronidazole for treatment of low-risk IAI, and discouraged the use of fluoroquinolones due to the high local resistance rates. We then compared patients with IAI before the intervention (April-November 2010) to those after implementation of the guideline (April-November 2011) in a surgical unit at a tertiary care teaching hospital in Hamilton, Ontario, Canada. Antibiotic use was measured in in-hospital days of antibiotic therapy (DOT) per 1000 patient days (PD). RESULTS 152 and 145 patients with IAI were included in the pre- and post-intervention periods, respectively. There was a significant reduction in the proportion of patients who received ciprofloxacin therapy from 74% to 34% (OR 0.18, 95% CI 0.11-0.31) and in DOT/1000 PD from 221 to 74 (OR 0.3, 95% CI 0.2-0.3). Also, a reduction in the DOT/1000 PD for piperacillin/tazobactam was seen (from 116 to 67; OR 0.6, 95% CI 0.5-0.7). There was an increase in the use of ceftriaxone from 1.3% to 53% of patients (OR 85, 95% CI 20-515) and from 6 to 92 DOT/1000 PD (OR 17, 95% CI 10-25). This change in practice was sustained over >2 years since the end of the active intervention, as shown in the unit-wide antimicrobial utilization data. CONCLUSIONS A multifaceted intervention aimed at all key stakeholders resulted in a high adherence to evidence-based treatment guidelines for IAI and has initiated a sustained culture change in prescribing of antibiotics.

A Controlled Quasi-Experimental Study of an Educational Intervention to Reduce the Unnecessary Use of Antimicrobials For Asymptomatic Bacteriuria

Background Asymptomatic bacteriuria (ABU) should only be treated in cases of pregnancy or in-patients undergoing urologic procedures; however, unnecessary treatment of ABU is common in clinical practice. Objective To identify risk factors for unnecessary treatment and to assess the impact of an educational intervention focused on these risk factors on treatment of ABU. Design Quasi-experimental study with a control group. Setting Two tertiary teaching adult care hospitals. Participants Consecutive patients with positive urine cultures between January 30th and April 17th, 2012 (baseline) and January 30th and April 30th, 2013 (intervention). Intervention In January 2013, a multifaceted educational intervention based on risk factors identified during the baseline period was provided to medical residents (monthly) on one clinical teaching unit (CTU) at one hospital site, with the CTU of the other hospital serving as the control. Results During the baseline period, 160/341 (46.9%) positive urine cultures were obtained from asymptomatic patients at the two hospitals, and 94/160 (58.8%) were inappropriately treated with antibiotics. Risk factors for inappropriate use included: female gender (OR 2.1, 95% CI 1.1-4.3), absence of a catheter (OR 2.5, 1.2-5), bacteriuria versus candiduria (OR 10.6, 3.8-29.4), pyuria (OR 2.0, 1.1-3.8), and positive nitrites (OR 2.2, 1.1-4.5). In 2013, only 2/24 (8%) of ABU patients were inappropriately treated on the intervention CTU as compared to 14/29 (52%) on the control CTU (OR 0.10; 95% CI 0.02-0.49). A reduction was also observed as compared to baseline on the intervention CTU (OR 0.1, 0.02-0.7) with no significant change noted on the control CTU (OR 0.47, 0.13-1.7). Conclusions A multifaceted educational intervention geared towards medical residents with a focus on identified risk factors for inappropriate management of ABU was effective in reducing unnecessary antibiotic use.

Self-disinfecting sink drains reduce the Pseudomonas aeruginosa bioburden in a neonatal intensive care unit.

Water in sink drains is a known source of gram‐negative bacteria. We aimed to evaluate the impact of self‐disinfecting sink drains on the emission of aerosolised bacteria and on Pseudomonas aeruginosa acquisition among neonates.

Drug use prior to incarceration and associated socio-behavioural factors among males in a provincial correctional facility in Ontario, Canada

OBJECTIVES: To describe the prevalence of drug use in males in a provincial detention centre during the year before incarceration and to examine the association between socio-demographic and behavioural factors and drug use.METHODS: In 2009, 500 adult males completed a survey after admission to a provincial detention centre in Ontario. Past-year prevalence rates were calculated for the use of opioids, cocaine, crack and methamphetamine, and by route of administration. Bivariate logistic regression was used to examine associations between drug use and socio-demographic and behavioural factors.RESULTS: More than 56% of participants reported use of opioids, cocaine, crack or methamphetamine in the previous year. Risk factors for blood-borne and sexually transmitted infections were commonly reported for the previous year: 12.2% had injected drugs, 78.0% had had unprotected sex, and 48.0% had had more than one sexual partner. In unadjusted analyses, participants who were older than 24 years were more likely to have used any drugs and to have injected drugs in the previous year.CONCLUSIONS: This study provides the first Canadian data in the past decade on drug use by recently incarcerated adults. We found that drug use and behaviours that increase the risk of transmission of sexually transmitted and blood-borne infections remain very common in this population. Incarceration provides an opportunity to provide services and links to programs for people who use drugs, which could decrease drug-related harms to individuals and society.RésuméOBJECTIFS: Décrire la prévalence de la consommation de drogue dans la population carcérale masculine d’un centre de détention provincial durant l’année précédant l’incarcération et examiner l’association entre les facteurs sociodémographiques et comportementaux et la consommation de drogue.MÉTHODE: En 2009, 500 hommes adultes ont rempli un questionnaire après leur arrivée dans un centre de détention provincial en Ontario. Les taux de prévalence de l’année antérieure ont été calculés pour la consommation d’opioïdes, de cocaïne, de crack et de méthamphétamine, et selon la voie d’administration de ces drogues. Une régression logistique bivariée a servi à examiner les liens entre la consommation de drogue et les facteurs sociodémographiques et comportementaux.RÉSULTATS: Plus de 56 % des participants ont déclaré avoir consommé des opioïdes, de la cocaïne, du crack ou de la méthamphétamine au cours de l’année antérieure. Des facteurs de risque d’infections transmissibles sexuellement et par le sang ont souvent été déclarés pour l’année antérieure: 12,2 % s’étaient injecté de la drogue, 78 % avaient eu des rapports sexuels non protégés, et 48 % avaient eu plus d’une ou d’un partenaire sexuel. Selon nos analyses non ajustées, les participants de plus de 24 ans étaient plus susceptibles d’avoir consommé l’une de ces drogues et de s’être injecté de la drogue au cours de l’année antérieure.CONCLUSIONS: Cette étude présente les premières données canadiennes de la dernière décennie sur la consommation de drogue chez des adultes récemment incarcérés. Nous constatons que la consommation de drogue et les comportements qui augmentent le risque de transmission des infections transmissibles sexuellement et par le sang sont encore très courants dans cette population. L’incarcération présente la possibilité d’offrir des services aux personnes qui consomment de la drogue et de les aiguiller vers des programmes, ce qui pourrait réduire les méfaits liés à la drogue au niveau individuel et sociétal.

Compliance With Personal Precautions Against Exposure to Bloodborne Pathogens Among Laboratory Workers: A Canadian Survey

A survey was conducted in laboratories across Canada to determine rates of compliance with recommended safety precautions against exposure to bloodborne pathogens and the rationale for current behaviors. Laboratory workers reported high rates of exposure to bodily fluids and poor rates of compliance with personal protective behaviors. This national study has identified several deficiencies and strategies for improvement.

Treatment of septic arthritis

Raheem Kherani and Kam Shojania recently provided a comprehensive overview of septic arthritis; however, I have some concerns about the antimicrobial therapies outlined in their article.[1][1] The authors recommend that gram- positive cocci identified in Grams staining of synovial fluid should be

Short-course antimicrobial therapy for paediatric respiratory infections (SAFER): study protocol for a randomized controlled trial

BackgroundCommunity-acquired pneumonia (CAP) is commonly diagnosed in children. The Infectious Disease Society of America guidelines recommend 10 days of high-dose amoxicillin for the treatment of non-severe CAP but 5-day “short course” therapy may be just as effective. Randomized trials in adults have already demonstrated non-inferiority of 5-day short-course treatment for adults hospitalized with severe CAP and for adults with mild CAP treated as outpatients. Minimizing exposure to antimicrobials is desirable to avoid harms including diarrhoea, rashes, severe allergic reactions, increased circulating antimicrobial resistance, and microbiome disruption.MethodsThe objective of this multicentre, randomized, non-inferiority, controlled trial is to investigate whether 5 days of high-dose amoxicillin is associated with lower rates of clinical cure 14–21 days later as compared to 10 days of high-dose amoxicillin, the reference standard. Recruitment and enrolment will occur in the emergency departments of McMaster Children’s Hospital and the Children’s Hospital of Eastern Ontario. All children in the study will receive 5 days of amoxicillin after which point they will receive either 5 days of a different formulation of amoxicillin or a placebo. Assuming a clinical failure rate of 5% in the reference arm, a non-inferiority margin of 7.5%, one-sided alpha set at 0.025 and power of 0.80, 270 participants will be required. Participants from a previous feasibility study (n = 60) will be rolled over into the current study. We will be performing multiplex respiratory virus molecular testing, quantification of nasopharyngeal pneumococcal genomic loads, salivary inflammatory marker testing, and faecal microbiome profiling on participants.DiscussionThis is a pragmatic study seeking to provide high-quality evidence for front-line physicians evaluating children presenting with mild CAP in North American emergency departments in the post-13-valent pneumococcal, conjugate vaccine era. High-quality evidence supporting the non-inferiority of short-course therapy for non-severe paediatric CAP should be generated prior to making changes to established guidelines. Trial registrationClinicalTrials.gov, NCT02380352. Registered on 2 March 2015.