Background: Cystic echinococcosis (CE) or hydatid disease caused by the cestode Echinococcus granulosus sensu lato is an uncommon infection in Canada especially among children. There are limited reports describing the clinical presentation and management in Canadian children. Methods: The medical records of all children diagnosed with CE at a quaternary paediatric centre in Ontario between January 1988 and August 2021 were retrospectively reviewed. The clinical course, management, and outcomes of each case were summarized. Results: We report two paediatric cases of cystic echinococcosis (CE) in detail and review four additional cases seen at our institution over 33.5 years. The first case was a previously healthy 12-year-old boy with pulmonary CE resulting in unilateral lung collapse and mediastinal shift, who was presumedly infected while living in the Middle East. The second case was a previously healthy 3-year-old girl with pulmonary CE acquired locally in southern Ontario. Four other cases of CE with hepatic involvement (median age 12.5 years) were identified during the study period. Five out of six patients received both surgical and medical therapy. Conclusion: CE is a rare but serious disease seen in southern Canada that has historically been associated with travel or migration. Due to changes in urban wildlife landscapes and increased global migration, CE may become more prevalent in Canadian children. We describe the first locally acquired case in rural southern Ontario diagnosed at our centre. Prompt recognition of this infection in children by health care providers is important to prevent morbidity and mortality.
• 3 closed lines of 14 families of CD1 mice (2 Selected and 1 Control lines). • At 8 weeks, measure body mass and tibia length within Selected line families, rank individuals based on absolute and relative tibia length. • Select top-ranked male and female in each family to become breeders with members of other families (no sib-mating). • In Control line, mice are selected to breed at random. • μCT scan mice using Skyscan 1173 scanner (resolution of 44.7 μm). • Using Amira 5.4.2 visualization software, the tibia, femur, humerus, ulna and skull are landmarked to determine bone length. These data were then analyzed. This project provides important insight into the heritability of bones across the skeleton and investigates the genetic basis of different aspects of limb-bone morphology. This research may also provide empirical support for a portion of evolutionary theory that has never been thoroughly tested before. Figure 4: Forelimb and upper skeleton of a mouse Breeding Program and Data Collection Results
Mammals show a predictable scaling relationship between limb bone size and body mass. This relationship has a genetic basis which likely evolved via natural selection, but it is unclear how much the genetic correlation between these traits in turn impacts their capacity to evolve independently. We selectively bred laboratory mice for increases in tibia length independent of body mass, to test the hypothesis that a genetic correlation with body mass constrains evolutionary change in tibia length.Over 14 generations, we produced mean tibia length increases of 9-13%, while mean body mass was unchanged, in selectively bred mice and random-bred controls. Using evolutionary scenarios with different selection and quantitative genetic parameters, we also found that this genetic correlation impedes the rate of evolutionary change in both traits, slowing increases in tibia length while preventing decreases in body mass, despite the latter's negative effect on fitness.Overall, results from this ongoing selection experiment suggest that parallel evolution of relatively longer hind limbs among rodents, for example in the context of strong competition for resources and niche partitioning in heterogeneous environments, may have occurred very rapidly on geological timescales, in spite of a moderately strong genetic correlation between tibia length and body mass.
Abstract Background Since 2015, the incidence of congenital syphilis (CS) in Canada has increased significantly. Vertical transmission of syphilis can be prevented through timely treatment of infected pregnant persons; however, difficulty engaging in prenatal care can preclude diagnosis, and consequently treatment. Canadian data on sociobehavioural risk factors associated with poor engagement in prenatal care is limited, yet needed to inform prevention efforts. Objectives Our primary objective is to identify sociobehavioural risk factors of mothers with infants affected by syphilis, as well as describe the screening and treatment they receive. Our secondary objective is to describe the presentation and management of affected infants in Canada. Design/Methods Cases of confirmed and probable CS were elicited from paediatricians through the Canadian Paediatric Surveillance Program between June 2021 and October 2022. Survey responses were analyzed using descriptive statistics. Results In total, 143 cases were reported: 78% originated from the prairies (Alberta n=39, Saskatchewan n=50, Manitoba n=23) and 34% resided rurally. The median age was 27 years (range 17-39). Among the 143 women, 94 (66%) reported substance use, 42 (29%) child protection involvement with a previous child, and 25 (17%) housing insecurity; however, “unknown” responses were frequent for many variables. Of those reporting substance use, methamphetamines (n=46/94, 49%) and opioids (n=34/94, 36%), were the most common. Most women (n=73/143, 51%) had no known sexually transmitted co-infection, but among those who did, chlamydia was the most common (n=38/70, 54%). Only 22% (n=32/143) reported at least one prenatal visit per trimester. Of the 85/143 mothers known to have a positive syphilis screen, 22% (n=19/85) did not receive treatment. Of the 28 cases where specific barriers to accessing prenatal care were reported, 8 reported substance use, 6 reported housing insecurity, and 6 reported attitudinal barriers. Most affected infants had no physical exam findings of CS (n=83/143, 58%), but among those who did, rash and hepatomegaly were the most common findings (n=17/143, 12% and n=15/143, 11% respectively). Of the 136 with long bone x-rays completed, 70% (n=95) were normal. Most cases (138/143, 96%) were identified within the first month of life, and 89% (n=127/143) began antibiotic treatment within a week of life. Conclusion Substance use during pregnancy is common in mothers of children with CS; however, the presence of other sociobehavioural risk factors is often not known by reporting paediatricians. Most affected infants are asymptomatic but are diagnosed and treated early. Findings will inform public health strategies for preventing CS and combatting the current epidemic.
Abstract Background Shorter courses of antibiotic therapy are increasingly recommended to reduce antibiotic exposure. However, quantifying the real-world impact of duration of therapy is hindered by bias common in observational studies. We aimed to evaluate the harms and benefits of longer versus shorter duration of therapy in older adults. Methods This was a population-based cohort study using administrative health data from Ontario, Canada. We included outpatients aged 66–110 years who received a prescription for amoxicillin, cephalexin, and/or ciprofloxacin. Prescriptions were categorized as short (3–7 days) or long (8–14 days) duration. The primary outcome was a composite of antibiotic-related harms, including adverse reactions, Clostridioides difficile infection, and antibiotic resistance. The secondary outcome was a composite of safety measures including repeat antibiotic prescriptions, hospital visits, and mortality. To reduce risk of bias, we used an instrumental variable analysis where the instrument was prescriber proportion of antibiotics that were long duration. Results Among 117 682 eligible patients, there was no difference in the primary harms outcome for patients receiving longer versus shorter courses of antibiotics (adjusted odds ratio and 95% confidence interval [CI]): amoxicillin, 0.99 (.84–1.15); cephalexin, 1.11 (.90–1.38); ciprofloxacin, 0.94 (.74–1.20). Secondary safety outcomes were similar, with longer compared to shorter courses of antibiotic therapy (odds ratio and 95% CI): amoxicillin, 1.01 (.94–1.08); cephalexin, 1.06 (.97–1.17); ciprofloxacin, 0.99 (.85–1.15). Conclusions In this instrumental variable analysis of community-dwelling older adults, longer antibiotic courses were not associated with an increased benefit or harm compared to shorter courses.
Abstract Background Acute Otitis Media (AOM) is a leading cause of antibiotic prescription in children. Watchful waiting is the preferred strategy for AOM management for mildly ill children ≥ 2-years-old however current clinical practice varies. This study aims to compare published AOM guidelines by the Canadian Pediatric Society (CPS) with clinical practice in a Canadian academic tertiary care emergency department (ED). Methods We performed a retrospective review on AOM ED visits at the Children’s Hospital of Eastern Ontario (CHEO) from 1/2021 to 12/2021. Measures of non-adherence to the CPS AOM guideline were defined as follows: missed opportunity for watchful waiting, diagnostic criteria absent or not recorded, prolonged duration of treatment, lack of immediate treatment, and inappropriate agent. Additionally we explored if guideline-discordant antibiotic prescribing practices differ by geographic locale (rural vs non-rural as determined by postal code) and preferred language. The postal code was linked to a Material and Social Deprivation Index (MSDI) from INSPQ as a proxy for socio-economic status. Results 442 patients were included (Table 1). 66.5% patients met criteria of non-adherence (Table 2). 41.9% patients received antibiotics despite being categorized as mildly ill. 29.6% patients received antibiotics, despite having no/undocumented middle ear effusion or bulging tympanic membrane. 6.6% received longer duration of antibiotics (10 days) despite lack of complications such as perforation. 4.1% received non-penicillin antibiotics as first-line treatment. 1.4% received parachute prescriptions despite being categorized as severely ill. After controlling for language and rurality, the odds of being in any non-adherence group were not higher for patients in higher deprivation quintiles compared to those in the lowest deprivation quintile (Figure 1, 2).Figure 1.Distribution of Material Deprivation Quintiles by Non-adherence Type Conclusion 2/3rd of ED patients met criteria of guideline non-adherence. Material deprivation was not a predictor of non-adherence. The two domains of watchful waiting and applying diagnostic criteria can serve as specific benchmarks to improve antibiotic prescribing practices in ED settings. Pragmatic management of AOM using current guidelines may be biased towards immediate treatment rather than timely follow-up.Figure 2.Odds ratio of any non-adherence for material deprivation quintile adjusted for language and rurality Disclosures All Authors: No reported disclosures
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