Retrospective validation of a rapid Lyme fluorescent immunoassay in differentiating Lyme arthritis from other musculoskeletal presentations in children in a Lyme-endemic region

Lyme arthritis can present similarly to other causes of joint pain and swelling including septic arthritis and other acute and chronic arthropathies of childhood. Septic arthritis, although rare, constitutes an orthopedic emergency and requires early surgical intervention to reduce the risk of permanent joint damage. Currently, results of standard serologic tests to diagnose Lyme disease take days to weeks, which is unhelpful in acute clinical decision-making. Thus, some children with Lyme arthritis are treated empirically for septic arthritis undergoing unnecessary invasive procedures and hospital admission while on inappropriate antibiotic therapy. We retrospectively validated the Quidel Sofia Lyme Fluorescent Immunoassay, a rapid serologic assay that can detect IgG and/or IgM antibodies to Borrelia burgdorferi in 10 minutes, in residual serum samples collected from 51 children who had Lyme arthritis and 55 children with musculoskeletal presentations who were Lyme negative. The sensitivity and specificity of the Sofia IgG to identify cases of Lyme arthritis in children were 100% (95% confidence interval [CI] of 93.0%-100%) and 96.4% (95% CI: 87.5%-99.6%), respectively. The positive likelihood ratio (LR) was 27.5 (95% CI 7-107), and the negative LR was 0.00 (95% LR 0.00-0.15). We propose that the Sofia IgG, a rapid method for identifying Lyme arthritis, may be useful in differentiating Lyme arthritis from other forms of arthritis. Used in conjunction with readily available clinical and laboratory variables, it could help to rapidly identify children who are at low risk of septic arthritis in Lyme-endemic regions.

IMPORTANCE

Lyme arthritis is a common manifestation of Lyme disease in children, with clinical features overlapping with other causes of acute and chronic joint pain/swelling in children. We have demonstrated that the Sofia IgG is a reliable test to rule in and rule out the diagnosis of Lyme arthritis in children with musculoskeletal presentations in a Lyme-endemic region. When used in conjunction with clinical and laboratory variables routinely considered when differentiating Lyme arthritis from other diagnoses, the Sofia IgG has the potential to fill an important gap in care, especially when acute decision-making is necessary. The Sofia IgG should be included in prospective research studies examining clinical prediction tools to identify children at low risk of septic arthritis.

Evaluating the impact of incorporating clinical practice guidelines for the management of infectious diseases into an electronic application (e-app)

OBJECTIVES

To improve dissemination and accessibility of guidelines to healthcare providers at our institution, guidance for infectious syndromes was incorporated into an electronic application (e-app). The objective of this study was to compare empiric antimicrobial prescribing before and after implementation of the e-app.

DESIGN

This study was a before-and-after trial.

SETTING

A tertiary-care, public hospital in Halifax, Canada.

PARTICIPANTS

This study included pediatric patients admitted to hospital who were empirically prescribed an antibiotic for an infectious syndrome listed in the e-app.

METHODS

Data were collected from medical records. Prescribing was independently assessed considering patient-specific characteristics using a standardized checklist by 2 members of the research team. Assessments of antimicrobial prescribing were compared, and discrepancies were resolved through discussion. Empiric antimicrobial prescribing before and after implementation of the e-app was compared using interrupted time-series analysis.

RESULTS

In total, 237 patients were included in the preimplementation arm and 243 patients were included in the postimplementation arm. Pneumonia (23.8%), appendicitis (19.2%), and sepsis (15.2%) were the most common indications for antimicrobial use. Empiric antimicrobial use was considered optimal in 195 (81.9%) of 238 patients before implementation compared to 226 (93.0%) 243 patients after implementation. An immediate 15.5% improvement (P = .019) in optimal antimicrobial prescribing was observed following the implementation of the e-app.

CONCLUSIONS

Empiric antimicrobial prescribing for pediatric patients with infectious syndromes improved after implementation of an e-app for dissemination of clinical practice guidelines. The use of e-apps may also be an effective strategy to improve antimicrobial use in other patient populations.

Trends in Clostridioides difficile infection rates in Canadian hospitals during the coronavirus disease 2019 (COVID-19) pandemic

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

Antimicrobial use among paediatric inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program, 2017/2018

BACKGROUND

Antimicrobial resistance threatens the ability to successfully prevent and treat infections. While hospital benchmarks regarding antimicrobial use (AMU) have been well documented among adult populations, there is less information from among paediatric inpatients. This study presents benchmark rates of antimicrobial use (AMU) for paediatric inpatients in nine Canadian acute-care hospitals.

METHODS

Acute-care hospitals participating in the Canadian Nosocomial Infection Surveillance Program submitted annual AMU data from paediatric inpatients from 2017 and 2018. All systemic antimicrobials were included. Data were available for neonatal intensive care units (NICUs), pediatric ICUs (PICUs), and non-ICU wards. Data were analyzed using days of therapy (DOT) per 1000 patient days (DOT/1000pd).

RESULTS

Nine hospitals provided paediatric AMU data. Data from seven NICU and PICU wards were included. Overall AMU was 481 (95% CI 409-554) DOT/1000pd. There was high variability in AMU between hospitals. AMU was higher on PICU wards (784 DOT/1000pd) than on non-ICU (494 DOT/1000pd) or NICU wards (333 DOT/1000pd). On non-ICU wards, the antimicrobials with the highest use were cefazolin (66 DOT/1000pd), ceftriaxone (59 DOT/1000pd) and piperacillin-tazobactam (48 DOT/1000pd). On PICU wards, the antimicrobials with the highest use were ceftriaxone (115 DOT/1000pd), piperacillin-tazobactam (115 DOT/1000pd), and cefazolin (111 DOT/1000pd). On NICU wards, the antimicrobials with the highest use were ampicillin (102 DOT/1000pd), gentamicin/tobramycin (78 DOT/1000pd), and cefotaxime (38 DOT/1000pd).

CONCLUSIONS

This study represents the largest collection of antimicrobial use data among hospitalized paediatric inpatients in Canada to date. In 2017/2018, overall AMU was 481 DOT/1000pd. National surveillance of AMU among paediatric inpatients is necessary for establishing benchmarks and informing antimicrobial stewardship efforts.

Trends in Severe Outcomes Among Adult and Pediatric Patients Hospitalized With COVID-19 in the Canadian Nosocomial Infection Surveillance Program, March 2020 to May 2022

Importance

Trends in COVID-19 severe outcomes have significant implications for the health care system and are key to informing public health measures. However, data summarizing trends in severe outcomes among patients hospitalized with COVID-19 in Canada are not well described.

Objective

To describe trends in severe outcomes among patients hospitalized with COVID-19 during the first 2 years of the COVID-19 pandemic.

Design, Setting, and Participants

Active prospective surveillance in this cohort study was conducted from March 15, 2020, to May 28, 2022, at a sentinel network of 155 acute care hospitals across Canada. Participants included adult (aged ≥18 years) and pediatric (aged 0-17 years) patients hospitalized with laboratory-confirmed COVID-19 at a Canadian Nosocomial Infection Surveillance Program (CNISP)-participating hospital.

Exposures

COVID-19 waves, COVID-19 vaccination status, and age group.

Main Outcomes and Measures

The CNISP collected weekly aggregate data on the following severe outcomes: hospitalization, admission to an intensive care unit (ICU), receipt of mechanical ventilation, receipt of extracorporeal membrane oxygenation, and all-cause in-hospital death.

Results

Among 1 513 065 admissions, the proportion of adult (n = 51 679) and pediatric (n = 4035) patients hospitalized with laboratory-confirmed COVID-19 was highest in waves 5 and 6 of the pandemic compared with waves 1 to 4 (77.3 vs 24.7 per 1000 patient admissions). Despite this, the proportion of patients with positive test results for COVID-19 who were admitted to an ICU, received mechanical ventilation, received extracorporeal membrane oxygenation, and died were each significantly lower in waves 5 and 6 when compared with waves 1 through 4. Admission to the ICU and in-hospital all-cause death rates were significantly higher among those who were unvaccinated against COVID-19 when compared with those who were fully vaccinated (incidence rate ratio, 4.3 and 3.9, respectively) or fully vaccinated with an additional dose (incidence rate ratio, 12.2 and 15.1, respectively).

Conclusions and Relevance

The findings of this cohort study of patients hospitalized with laboratory-confirmed COVID-19 suggest that COVID-19 vaccination is important to reduce the burden on the Canadian health care system as well as severe outcomes associated with COVID-19.

Epidemiology of primary and recurrent healthcare-associated and community-associated pediatric Clostridioides difficile infection in Canada, 2015-2020

Clostridioides difficile infection (CDI) among children remains a concerning cause of morbidity in hospital settings. We present epidemiological and molecular trends in healthcare- and community-associated CDI among children in Canadian inpatient and outpatient settings, including those who experienced recurrent infections.

Characterization of Healthcare-Associated and Community-Associated Clostridioides difficile Infections among Adults, Canada, 2015-2019

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015–2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015–2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control.

Pertussis Disease and Antenatal Vaccine Effectiveness in Australian Children

BACKGROUND

Population-level studies of severe pertussis extending beyond infancy are sparse, and none in the context of antenatal vaccination. We compared hospitalized pertussis cases from birth to 15 years of age before and after introduction of antenatal immunization.

METHODS

Active surveillance of laboratory-confirmed pertussis hospitalizations in a national network of pediatric hospitals in Australia January 2012 to June 2019. Impact of maternal vaccination was assessed by vaccine effectiveness (VE) in cases and test-negative controls with <2 months of age and by before-after comparison of age distribution of cases. Among cases eligible for one or more vaccine doses, we examined proportions age-appropriately immunized and with comorbidities by age group.

RESULTS

Among 419 eligible cases, the proportion <2 months of age significantly decreased from 33.1% in 2012 to 2014 compared with 19.6% in 2016 to 2019 when mothers of only 4 of 17 (23.5%) cases <2 months of age had received antenatal vaccination. VE was estimated to be 84.3% (95% CI, 26.1-96.7). Across all years (2012-2019), of 55 cases 4-11 months of age, 21 (38%) had ≥2 vaccine doses, whereas among 155 cases ≥12 months of age, 122 (85.2%) had ≥3 vaccine doses. Prevalence of comorbidities (primarily cardiorespiratory) increased from 5 (2.1%) <6 months of age to 36 (24.2%) ≥12 months of age (P < 0.001), with 6/16 (38%) cases ≥12 months of age who required intensive care having comorbidities.

CONCLUSIONS

Below the age of 12 months, prevention of severe pertussis will be maximized by high maternal antenatal vaccine uptake and timeliness of infant vaccine doses. Despite full immunization, we found children ≥12 months of age accounted for 27% of hospitalizations <15 years, with 24% having comorbities, suggesting new vaccine strategies, such as additional doses or more immunogenic vaccines, require evaluation.

COVID-19 and missed routine immunizations: designing for effective catch-up in Canada

COVID-19 has led to disruption in routine immunization programs around the globe and here in Canada. The National Advisory Committee on Immunization (NACI) in Canada has indicated that this sets the stage for serious outbreaks of vaccine-preventable diseases. The World Health Organization has evidence-based guidance on how to address missed opportunities for vaccination, albeit predominately applicable for low- and middle-income countries. In Canada, immunization applies beyond infant and childhood immunization, with immunization across the life course being recommended by NACI. Three components stand out and must be integrated and used concurrently for best effect on catch-up in Canada: (1) Identify who has been missed across the life course; (2) detect delivery gaps, adapt and adjust, and develop multipronged tailored strategies for catch-up; and (3) communicate, document, evaluate and readjust the immunization programs. All must be adapted to the reality of the evolving COVID-19 pandemic. We cannot go back to a pre-COVID-19 world. However, ensuring that routine immunization and catch-up programs are done well during this pandemic strengthens the immunization foundation in Canada for when COVID-19 vaccines become available.

Maternal transmission of SARS-COV-2 to the neonate, and possible routes for such transmission: a systematic review and critical analysis

Background

Early reports of COVID‐19 in pregnancy described management by caesarean, strict isolation of the neonate and formula feeding. Is this practice justified?

Objective

To estimate the risk of the neonate becoming infected with SARS‐CoV‐2 by mode of delivery, type of infant feeding and mother‐infant interaction.

Search strategy

Two biomedical databases were searched between September 2019 and June 2020.

Selection criteria

Case reports or case series of pregnant women with confirmed COVID‐19, where neonatal outcomes were reported.

Data collection and analysis

Data were extracted on mode of delivery, infant infection status, infant feeding and mother–infant interaction. For reported infant infection, a critical analysis was performed to evaluate the likelihood of vertical transmission.

Main results

Forty nine studies included information on mode of delivery and infant infection status for 655 women and 666 neonates. In all, 28/666 (4%) tested positive postnatally. Of babies born vaginally, 8/292 (2.7%) tested positivecompared with 20/374 (5.3%) born by Caesarean. Information on feeding and baby separation were often missing, but of reported breastfed babies 7/148 (4.7%) tested positive compared with 3/56 (5.3%) for reported formula fed ones. Of babies reported as nursed with their mother 4/107 (3.7%) tested positive, compared with 6/46 (13%) for those who were reported as isolated.

Conclusions

Neonatal COVID‐19 infection is uncommon, rarely symptomatic, and the rate of infection is no greater when the baby is born vaginally, breastfed or remains with the mother.

Tweetable abstract

Risk of neonatal infection with COVID‐19 by delivery route, infant feeding and mother‐baby interaction.

Risk of neonatal infection with COVID‐19 by delivery route, infant feeding and mother‐baby interaction.

This article includes Author Insights, a video abstract available at https://vimeo.com/rcog/authorinsights16362

Antimicrobial use among adult inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program: 2009 to 2016

BACKGROUND

Antimicrobial resistance is a growing threat to the world's ability to prevent and treat infections. Links between quantitative antibiotic use and the emergence of bacterial resistance are well documented. This study presents benchmark antimicrobial use (AMU) rates for inpatient adult populations in acute-care hospitals across Canada.

METHODS

In this retrospective surveillance study, acute-care adult hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) submitted annual AMU data on all systemic antimicrobials from 2009 to 2016. Information specific to intensive care units (ICUs) and non-ICU wards were available for 2014-2016. Data were analyzed using defined daily doses (DDD) per 1000 patient days (DDD/1000pd).

RESULTS

Between 2009 and 2016, 16-18 CNISP adult hospitals participated each year and provided their AMU data (22 hospitals participated in ≥1 year of surveillance; 11 in all years). From 2009 to 2016, there was a significant reduction in use (12%) (from 654 to 573 DDD/1000pd, p = 0.03). Fluoroquinolones accounted for the majority of this decrease (47% reduction in combined oral and intravenous use, from 129 to 68 DDD/1000pd, p < 0.002). The top five antimicrobials used in 2016 were cefazolin (78 DDD/1000pd), piperacillin-tazobactam (53 DDD/1000pd), ceftriaxone (49 DDD/1000pd), vancomycin (combined oral and intravenous use was 44 DDD/1000pd; 7% of vancomycin use was oral), and ciprofloxacin (combined oral and intravenous use: 42 DDD/1000pd). Among the top 10 antimicrobials used in 2016, ciprofloxacin and metronidazole use decreased significantly between 2009 and 2016 by 46% (p = 0.002) and 26% (p = 0.002) respectively. Ceftriaxone (85% increase, p = 0.0008) and oral amoxicillin-clavulanate (140% increase, p < 0.0001) use increased significantly but contributed only a small component (8.6 and 5.0%, respectively) of overall use.

CONCLUSIONS

This study represents the largest collection of dispensed antimicrobial use data among inpatients in Canada to date. Between 2009 and 2016, there was a significant 12% decrease in AMU, driven primarily by a 47% decrease in fluoroquinolone use. Modest absolute increases in parenteral ceftriaxone and oral amoxicillin-clavulanate use were noted but contributed a small amount of total AMU. Ongoing national surveillance is crucial for establishing benchmarks and antimicrobial stewardship guidelines.

1143. Measuring Up! Benchmarking Antimicrobial Use in Canadian Children’s Hospitals

Background

Inappropriate antimicrobial use (AU) is recognized as a leading cause of antimicrobial resistance. However, quantifying AU in hospitals is challenging due to variability in information systems. Point prevalence surveys (PPS) provide a means to quantify AU in a cross-sectional manner within and between institutions. The aim of the study was to describe and compare the prescription patterns of AU across pediatric hospitals in Canada using PPS.

Methods

Two PPS (November 2018 and February 2019) were conducted at each of the 15 Canadian pediatric hospitals. For each PPS, AU data were collected for all inpatients ≤ 18 years (excluded mental health and birthing units) on the survey date. Data, including admitting diagnosis, age, comorbidities, Infectious Diseases consult, admitting service, documented pathogen(s), and antimicrobial(s) prescribed, was collected and entered into a RedCap database.

Results

In total, we surveyed 3826 patient-days. The mean proportion of children receiving at least one antimicrobial was 35.2% [range 25.1% to 42.9%]. Of the 1951 antimicrobials prescribed, the most common were third-generation cephalosporins [3GC] (16%; 321), aminopenicillins (15%; 297), TMP-SMX (11%; 207), piperacillin–tazobactam (10%; 193) and first-generation cephalosporins (9%; 181). Overall, the frequency of carbapenems, quinolones and vancomycin use was 4% (79), 3% (65) and 8% (151), respectively. Of the antimicrobials used for targeted or empiric therapy (n = 1541), 373 (24.2%) were for pneumonia, 278 (18%) for intra-abdominal infections and 251 (16.3%) for fever without a source. For the treatment of community-acquired pneumonia (CAP) (n = 178), aminopenicillins and 3GC use was 31% and 37%, respectively.

Conclusion

Our study used a standardized approach to assess AU to obtain benchmarking data for Canadian pediatric hospitals. About one-third of children hospitalized in Canadian pediatric hospitals are prescribed at least one antimicrobial. Of patients on treatment for CAP, only 31% were prescribed aminopenicillins. More detailed analysis of the rationale for AU, and assessment of appropriateness is required to fully understand antimicrobial prescribing practices in pediatric hospitals and develop stewardship initiatives.

Disclosures

All authors: No reported disclosures.

1135. The 2018 Global Point Prevalence Survey of Antimicrobial Consumption and Resistance: Pediatric Results from 26 Canadian Hospitals

Background

Inappropriate antimicrobial use (AMU) is strongly associated with antimicrobial resistance. The Global Point Prevalence Survey (Global-PPS) is a standardized tool that is used worldwide to characterize inpatient AMU. We report pediatric results from 26 Canadian hospitals that participated in the Global-PPS in 2018.

Methods

The survey was completed by each site on the Global-PPS website for all patients aged 0–17 years hospitalized in a neonatal or pediatric ward on a chosen day between January and December 2018. Data collected included ward type, demographics, antimicrobials prescribed, diagnosis, type of indication (community-acquired [CA] vs. healthcare-associated [HA]) and type of therapy (empiric vs. targeted). Quality indicators included guideline compliance, medical record documentation of diagnosis, antimicrobial stop/review date, and surgical prophylaxis (SP) duration.

Results

Of the 26 sites, 23 were mixed and 3 were pediatric hospitals, with data on 767 inpatients. Overall, 25.8% (n = 198) of patients received at least one antimicrobial, and 21.9% (n = 168) were on at least one antibiotic. The highest AMU was found in Hematology-Oncology (84%), Pediatric Intensive Care (55.3%) and surgical (42.1%) units. Of the 330 antimicrobial prescriptions, 40.9% were for CA infections, 23% for medical prophylaxis, 20% for HA infections and 2.7% for SP. The most commonly treated infections were sepsis (16%) and lower respiratory tract infection (12.1%). The top five prescribed antibiotics were aminopenicillins (20.4%), aminoglycosides (16.1%), third-generation cephalosporins (15.4%), piperacillin–tazobactam (7.5%) and trimethoprim-sulfamethoxazole (7.5%). Diagnosis and stop/review date were documented for 88.1% and 65.1% of prescriptions, respectively. Compliance to local guidelines was found in 91.5% of therapies. SP exceeded 24 hours in 88.9% of courses.

Conclusion

The Global-PPS generated Canada-wide data on inpatient pediatric AMU, which will allow hospitals to benchmark and develop local quality improvement interventions to enhance appropriate AMU. Targets for improvement include suboptimal antimicrobial stop/review date documentation and prolonged SP.

Disclosures

All authors: No reported disclosures.

856. Invasive Haemophilus influenzae Disease in Children: A Canadian MultiCenter Study on Emerging Serotypes

Background

Our objective was to describe the serotype distribution and clinical spectrum of invasive Haemophilus influenza (Hi) disease in children admitted to participating centers within the Paediatric Investigator’s Collaborative Network on Infections in Canada (PICNIC).

Methods

All cases of Hi bacteremia were identified from the PICNIC Database of Gram-negative bacteremia (2013–2017). Disease was defined as complicated if the following occurred: (a) >2 sites were affected, (b) surgical intervention was required, (c) organ failure, (d) ICU admission, (e) seizures, (f) sensory or motor deficits, (g) treatment-related complications, or (h) death.

Results

There were 98 cases of Hi bacteremia. Male to female ratio was 64:34 and median age was 12 (IQR: 7–48; range 0–216) months. Hi serotypes included: a (N = 31; 32%), b (N = 9; 9%), f (N = 15; 13%), c (N = 1;1%), e (N = 1; 1%), nontypeable (N = 34; 35%) and unknown (N = 7; 7%). Clinical foci included: bacteremia without a focus (N = 19; 19%), meningitis (N = 29; 30%), cellulitis (N = 8; 8%), septic arthritis (N = 6; 6%), pneumonia (n = 33; 34%), epiglottitis (N = 1; 1%), and endovascular infection (n = 3; 3%). Complicated disease occurred in 29 (30%) cases; there was one (1%) death. Where serotyping was available, complication rates were: 42%, 22%, 100%, 0%, 33%, and 21% for Hia, Hib, Hic, Hie, Hif and nontypeable Hi, respectively. Factors associated with complicated disease were: age <5 years (P = 0.009), bacteremia without a focus (P = 0.006) and a CNS focus (P < 0.001). Hia was the leading serotype in meningitis (55%; P = 0.022). Nontypeable Hi was most frequent in pneumonia cases (56%; P = 0.003) and never caused cellulitis (0% vs. 14%; P = 0.023). Neonatal disease (N = 5) was predominantly caused by nontypeable Hi (80%; P = 0.040). Of note, 26 (27%) of our Hi isolates were ampicillin resistant.

Conclusion

In the era of efficacious conjugate Hib vaccines, serotype has emerged as the leading cause of typeable Hi disease in Canada and is highly associated with meningitis, especially in young children. Strategies for preventing Hi disease need to target this emerging serotype and efforts should be focused toward developing an effective vaccine for serotype a disease.

Disclosures

All Authors: No reported Disclosures.

Looking for the "connection": A clinical vignette on pediatric chest wall masses

Chest wall masses in the pediatric population are relatively rare, and the differential diagnosis predominantly includes neoplastic soft tissue or osseous tumours, either benign or malignant in etiology, although local infectious processes represent additional diagnostic possibilities. Among recent immigrants, a more diverse array of less commonly observed pathogens warrant consideration. Here, we present a case of a chest wall mass in an immunocompetent child who had recently immigrated from the Philippines.

Challenges and opportunities of school-based HPV vaccination in Canada

Primary prevention of human papillomavirus (HPV) through vaccination is a high priority in Canada's cancer prevention efforts. All Canadian provinces and territories have introduced publicly funded, school-based vaccination programs against HPV, but vaccine uptake remains suboptimal in some jurisdictions. We conducted a descriptive qualitative study to better understand the determinants of low HPV vaccine uptake and identify strategies to enhance vaccine acceptance using the socio-ecological model. In Quebec, interviews and focus groups were held in 2015-2016 with 70 key informants including immunization managers, school nurses, school principals, teachers and parents of Grade 4 students (9 years of age). Our findings showed that HPV vaccine uptake was dependent on many interrelated factors at the individual and interpersonal level (e.g. knowledge and attitudes of the different players involved in the vaccination system), at the community level (e.g. social group values and norms, media coverage around the HPV vaccine), at the organizational level (e.g. allocated resources, information provision, consent process, immunization setting and environment) and at the policy level (e.g. changes in provincial HPV vaccine program). We are using the data collection and interpretation tools and approaches developed by our team and used in Quebec to expand our study to four other provinces (British Columbia, Alberta, Ontario and Nova Scotia). We are conducting environmental scans, semi-structured interviews and a survey to better understand the determinants of low HPV vaccine uptake and identify strategies to enhance vaccine acceptance. Having an in-depth understanding of the determinants of HPV vaccination in school settings is critical in order to identify root causes of the suboptimal vaccine uptake and to develop tailored interventions to address these on both supply- and demand-side issues.

1261. Utility of a Multiplex Molecular Gastrointestinal Panel in Rapid Identification and Control of a Norovirus Outbreak in a Pediatric Tertiary Care Center

Background

Norovirus is one of the most common viral pathogens implicated in gastroenteritis outbreaks in community and healthcare settings. The virus’ short incubation period and high attack rate allow its rapid spread through inpatient wards to patients (Patients), staff and visitors. Early identification and appropriate implementation of infection prevention and control measures is essential to interrupt transmission.

Methods

The IWK Health Centre is a 250-bed tertiary care Pediatric and Women’s hospital serving the Maritime Provinces, Canada. We describe a norovirus outbreak in our Pediatric Medical Unit, a 24-bed, single room ward with individual bathrooms for patients and families. Hospital-acquired norovirus definition: Patients admitted ≥48 hours with lab-confirmed norovirus AND ≥ 1 of: (1) acute onset diarrhea (no noninfectious cause) or (2) ≥2 of: nausea, vomiting, abdominal pain, fever, or headache. In 2017 the FilmArray Gastrointestinal (GI) Panel was introduced in the Clinical Microbiology Laboratory as part of a prospective post-implementation study. Since then, stool samples sent for viral, bacterial, or parasitic testing are evaluated by PCR. The panel tests for 22 GI analytes, including five viruses, with a 2-hour turnaround time. Previously, in-house stool viral testing was limited to adeno- and rotavirus antigen. Patient characteristics were collected and analyzed for this study.

Results

Patients 1, 2, and 3 had new onset diarrhea and emesis; Pt 1 on day 0, and Patients 2 and 3 on day 1. Patient 3’s parents (likely source) had had diarrhea and emesis on days 3 and 2, and used the ward kitchen. Two care-givers of Patient 2, and 1 medical resident developed diarrhea and emesis over days 0 to 2. The outbreak was declared over on day 7. Patients 1, 2, and 3 all tested positive for norovirus in stool on day 1. On days 2–3, six other patients with diarrhea tested norovirus negative. All symptomatic patients were immediately placed on contact precautions, room/ward cleaning frequency increased and proper hand hygiene was reinforced. Common areas (playroom/kitchen) were closed until the outbreak was over. All patients with loose stool were tested during the outbreak.

Conclusion

FilmArrayGI panel enabled same-day identification of norovirus in this single-ward outbreak and permitted real-time identification of the termination of the outbreak.

Disclosures

All authors: No reported disclosures.

Impact of a publicly funded monovalent rotavirus vaccination program in the Province of Quebec (Canada)

In November 2011, the province of Quebec, Canada implemented a publicly funded rotavirus (RV) vaccination program using the monovalent RV vaccine (RV1). To assess its impact, trends in passive RV laboratory detection and Emergency Department (ED) visits for gastroenteritis (GE) at two pediatric centers were evaluated.

METHODS

RV tests performed were extracted from the virology laboratory databases and ED visits for GE between July 1, 2006 and June 30, 2013, from the ED databases of The Montreal Children's Hospital (MCH) and Centre Hospitalier Universitaire de Sherbrooke (CHUS). The percent positive RV tests over time and season duration were assessed using 5-week moving averages. We defined season start and end as the first two and the last two consecutive weeks where the percent positive RV tests were ≥ 10%, respectively.

RESULTS

Comparing the pre- and post-vaccination program periods, a decrease in the proportion of positive RV tests was seen: 15.9% vs. 5.1% (p<0.001). Pre-vaccination program, RV seasons started between December and February, peaked in March or April and ended in May. In 2011-2012, the season started in March, peaked in April, and ended in May. In 2012-2013, the season lasted 3 weeks in May. ED visits for GE decreased post-introduction of the RV1 program: from 4.8% to 3.4% in 2011-2012, and 4.2% in 2012-13 (p<0.001). In children <2 years of age, ED GE visits decreased from 7.5% to 4.8% in 2011-2012, and 5.2% in 2012-2013 (p<0.001). Admissions for GE also decreased significantly from 0.41% of all ED visits to 0.14% in 2011-2012 and 0.22% in 2012-2013 (p<0.005).

CONCLUSION

Implementation of a publicly funded RV vaccination program had a major impact on the epidemiology of RV infections in Quebec: RV seasons have started later and been of shorter duration, peak positives were fewer, and ED visits for GE decreased.

Salmonella enterica serotype Typhi infections in a Canadian pediatric hospital: a retrospective case series

BACKGROUND

In developed countries, typhoid fever generally occurs in travellers or recent immigrants from endemic areas. Our aim was to describe the epidemiology of Salmonella enterica serotype Typhi infections among children presenting to a pediatric teaching hospital in Montréal, Quebec.

METHODS

We included all patients less than 18 years of age who presented to the Montreal Children's Hospital between 1991 and 2011 with a laboratory-confirmed diagnosis of typhoid fever (Salmonella enterica ser. Typhi isolated from blood or stool) in a retrospective case series.

RESULTS

During the study period, we identified 39 cases of typhoid fever (mean age of patient 7.5 yr). Four (10.3%) of these cases occurred in newly arrived immigrants shortly after their arrival in Canada (median 15.5 d). Most cases (76.9%) occurred in children who had visited friends and relatives in their home country. None of the travellers had received a vaccination against typhoid fever before their departure. All cases presented with high fever (mean temperature 40.4°C) that lasted for a mean of 15.8 days. Common accompanying symptoms included anorexia, abdominal pain, vomiting and diarrhea. All 39 isolates of S. enterica ser. Typhi were susceptible to third-generation cephalosporins, and 7 were resistant to ciprofloxacin. Ampicillin resistance occurred in 10 (25.6%) of the isolates. No deaths occurred among the study participants.

INTERPRETATION

Most cases of typhoid fever occurred in children who had travelled to endemic areas to visit friends and relatives. Thus, there is a role for increased awareness on the part of family physicians and pediatricians caring for these children to discuss travel-related infections during regularly scheduled appointments, because parents might not consult travel clinics or discuss their travel plans before travelling back to their home country.

Direct mitochondrial dysfunction precedes reactive oxygen species production in amiodarone-induced toxicity in human peripheral lung epithelial HPL1A cells

Amiodarone (AM), a drug used in the treatment of cardiac dysrrhythmias, can produce severe pulmonary adverse effects, including fibrosis. Although the pathogenesis of AM-induced pulmonary toxicity (AIPT) is not clearly understood, several hypotheses have been advanced, including increased inflammatory mediator release, mitochondrial dysfunction, and free-radical formation. The hypothesis that AM induces formation of reactive oxygen species (ROS) was tested in an in vitro model relevant for AIPT. Human peripheral lung epithelial HPL1A cells, as surrogates for target cells in AIPT, were susceptible to the toxicity of AM and N-desethylamiodarone (DEA), a major AM metabolite. Longer incubations (> or =6 h) of HPL1A cells with 100 microM AM significantly increased ROS formation. In contrast, shorter incubations (2 h) of HPL1A cells with AM resulted in mitochondrial dysfunction and cytoplasmic cytochrome c translocation. Preexposure of HPL1A cells to ubiquinone and alpha-tocopherol was more effective than that with Trolox C or 5,5-dimethylpyrolidine N-oxide (DMPO) at preventing AM cytotoxicity. These data suggest that mitochondrial dysfunction, rather than ROS overproduction, represents an early event in AM-induced toxicity in peripheral lung epithelial cells that may be relevant for triggering AIPT, and antioxidants that target mitochondria may potentially have beneficial effects in AIPT.

Aryl radical involvement in amiodarone-induced pulmonary toxicity: Investigation of protection by spin-trapping nitrones

Amiodarone (AM), an antidysrrhythmic drug, can produce serious adverse effects, including potentially fatal AM-induced pulmonary toxicity (AIPT). AM-induced cytotoxicity and pulmonary fibrosis are well recognized, but poorly understood mechanistically. The hypothesis of aryl radical involvement in AM toxicity was tested in non-biological and biological systems. Photolysis of anaerobic aqueous solutions of AM, or N-desethylamiodarone (DEA) resulted in the formation of an aryl radical, as determined by spin-trapping and electron paramagnetic resonance (EPR) spectroscopy experiments. The non-iodinated AM analogue, didesiodoamiodarone (DDIA), did not form aryl radicals under identical conditions. The toxic susceptibility of human lung epithelioid HPL1A cells to AM, DEA, and DDIA showed time- and concentration-dependence. DEA had a more rapid and potent toxic effect (LC(50)=8 microM) than AM (LC(50)=146 microM), whereas DDIA cytotoxicity was intermediate (LC(50)=26 microM) suggesting a minor contribution of the iodine atoms. Incubation of human lung epithelial cells with the spin-trapping nitrones alpha-phenyl-N-t-butylnitrone (PBN, 10 mM) or alpha-(4-pyridyl N-oxide)-N-t-butylnitrone (POBN, 5.0 mM) did not significantly protect against AM, DEA, or DDIA cytotoxicity. Intratracheal administration of AM to hamsters produced pulmonary fibrosis at day 21, which was not prevented by 4 days of treatment with 150 mg/kg/day PBN or 164 mg/kg/day POBN. However, the body weight loss in AM-treated animals was counteracted by PBN. These results suggest that, although AM can generate an aryl radical photochemically, its in vivo formation may not be a major contributor to AM toxicity, and that spin-trapping reagents do not halt the onset of AM toxicity.