Functional analysis of the protocatechuate branch of the ß-ketoadipate pathway in Aspergillus niger.

Bacteria and fungi catabolize plant-derived aromatic compounds by funneling into one of seven dihydroxylated aromatic intermediates, which then undergo ring fission and conversion to TCA cycle intermediates. Two of these intermediates, protocatechuic acid and catechol, converge on ß-ketoadipate which is further cleaved to succinyl-CoA and acetyl-CoA. These ß-ketoadipate pathways have been well characterized in bacteria. The corresponding knowledge of these pathways in fungi is incomplete. Characterization of these pathways in fungi would expand our knowledge and improve the valorization of lignin-derived compounds. Here, we used homology to characterize bacterial or fungal genes to predict the genes involved in the ß-ketoadipate pathway for protocatechuate utilization in the filamentous fungus Aspergillus niger. We further used the following approaches to refine the assignment of the pathway genes: whole transcriptome sequencing to reveal genes upregulated in the presence of protocatechuic acid; deletion of candidate genes to observe their ability to grow on protocatechuic acid; determination by mass spectrometry of metabolites accumulated by deletion mutants; and enzyme assays of the recombinant proteins encoded by candidate genes. Based on the aggregate experimental evidence, we assigned the genes for the five pathway enzymes as follows: NRRL3_01405 (prcA) encodes protocatechuate 3,4-dioxygenase; NRRL3_02586 (cmcA) encodes 3-carboxy-cis,cis-muconate cyclase; NRRL3_01409 (chdA) encodes 3-carboxymuconolactone hydrolase/decarboxylase; NRRL3_01886 (kstA) encodes ß-ketoadipate:succinyl-CoA transferase; and NRRL3_01526 (kctA) encodes ß-ketoadipyl-CoA thiolase. Strain carrying ΔNRRL3_00837 could not grow on protocatechuic acid, suggesting that it is essential for protocatechuate catabolism. Its function is unknown as recombinant NRRL3_00837 did not affect the in vitro conversion of protocatechuic acid to ß-ketoadipate.

Healthcare visits for new neurodevelopmental problems before and during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic disrupted healthcare delivery. We hypothesized that children with neurodevelopmental problems would have reduced healthcare utilization during the pandemic compared to before the pandemic. METHODS: We conducted a population-based study of healthcare visits for new neurodevelopmental problems among children ages 0-6 years in Ontario, Canada. Our outcome measure was rate per 1000 children-months for healthcare visits for new neurodevelopmental problems. We compared changes in monthly rates before and during the pandemic using interrupted time series analysis (ITSA). RESULTS: The rate of new neurodevelopmental problems before the pandemic was 6.31 per 1000 children-months and during the pandemic was 6.58 per 1000 children-months. However, using ITSA, there were no differences in monthly rates of healthcare visits for new neurodevelopmental problems before and during the pandemic. The observed rate during the first 30 days of the pandemic dropped to 3.40 per 1000 children-months. CONCLUSION: We found no significant difference in rates of healthcare visits for new neurodevelopmental problems before and during the pandemic. There was a decrease in the number of visits during the first 30 days of the pandemic compared to all months prior. IMPACT: This study found no significant difference in rates of healthcare visits for new neurodevelopmental problems before and during the pandemic. There was a decrease in the number of visits during the first 30 days of the pandemic compared to all months prior. This study adds information on healthcare access for children during the COVID-19 pandemic. The rapid deployment of virtual healthcare delivery in Ontario, Canada may explain the fast recovery of healthcare utilization for children with neurodevelopmental problems.

Intravenous immunoglobulin G therapy for neonatal hyperbilirubinemia.

BACKGROUND: Neonatal hyperbilirubinemia (NHb) results from increased total serum bilirubin and is a common reason for admission and readmission amongst newborn infants born in North America. The use of intravenous immunoglobulin (IVIG) therapy for treating NHb has been widely debated, and the current incidence of NHb and its therapies remain unknown. METHODS: Using national and provincial databases, a population-based retrospective cohort study of infants born in Ontario from April 2014 to March 2018 was conducted. RESULTS: Of the 533,084 infants born in Ontario at ≥35 weeks gestation, 29,756 (5.6%) presented with NHb. Among these infants, 80.1-88.2% received phototherapy, 1.1-2.0% received IVIG therapy and 0.1-0.2% received exchange transfusion (ET) over the study period. Although phototherapy was administered (83.0%) for NHb, its use decreased from 2014 to 2018 (88.2-80.1%) (P < 0.01). Similarly, the incidence of IVIG therapy increased from 71 to 156 infants (1.1-2.0%) (P < 0.01) and a small change in the incidence of ET (0.2-0.1%) was noted. CONCLUSION: IVIG therapy is increasingly being used in Ontario despite limited studies evaluating its use. The results of this study could inform treatment and management protocols for NHb. IMPACTS: Clinically significant neonatal hyperbilirubinemia still occurs in Ontario, with an increasing number of infants receiving Intravenous Immunoglobulin G (IVIG) therapy. IVIG continues to be used at increasing rates despite inconclusive evidence to recommend its use. This study highlights the necessity of a future prospective study to better determine the effectiveness of IVIG use in treating neonatal hyperbilirubinemia, especially given the recent shortage in IVIG supply in Ontario. The results of this study could inform treatment and management protocols for neonatal hyperbilirubinemia.

School-based health care: improving academic outcomes for inner-city children-a prospective cohort quasi-experimental study.

BACKGROUND: We examined whether a school-based health center model improved academic achievement compared to usual care. METHODS: This was a quasi-experimental prospective cohort study. The primary outcome was an academic achievement. In addition, we analyzed sociodemographic characteristics and their relationship to academic achievement, and the wait time for a developmental assessment. RESULTS: The differences in change of grades over time (from 2016/2017 to 2018/2019) were small for reading (-0.83, 95% CI -3.48, 1.82, p = 0.51), writing (-1.11, 95% CI -3.25, 1.03, p = 0.28), and math (0.06, 95% CI -3.08, 2.94, p = 0.98). The experimental arm's average wait time for developmental assessment was 3.4 months. CONCLUSION: In this small, quasi-experimental prospective cohort study, we did not find evidence that our SBHC model improved academic achievement; however, the wait time at the SBHCs was considerably less than the provincial wait time for a developmental assessment. TRIAL REGISTRATION: NCT04540003. IMPACT: This study describes a unique and innovative school-based health center model. Our findings support the benefits of school-based health centers in diagnosing and treating children with developmental and mental health disorders for disadvantaged communities. This study did not find an improvement in academic achievement for school-based health center users. This study found that the wait time to developmental assessment was shorter for school-based health center users compared to the wait time reported in the community. Pandemic-associated school disruptions have highlighted the importance of accessible school-based health services for children requiring mental health and developmental assessments and care.

Pre-phototherapy total serum bilirubin levels in extremely preterm infants.

BACKGROUND: Extremely preterm infants are prone to hyperbilirubinemia and its sequelae. Currently recommended thresholds for initiating phototherapy in these newborns are consensus-based (CB). METHODS: A multi-site retrospective cohort study of 642 infants born at 240/7 to 286/7 weeks' gestation, between January 2013 and June 2017, was conducted at three NICUs in Canada. Pre-phototherapy TSB percentile levels at 24 h of age were generated and contrasted with published CB thresholds. RESULTS: Among infants born 240/7 to 256/7 weeks' gestation, the differences between our TSB percentiles vs. the CB threshold of 85.0 µmol/L were 10.0 µmol/L (95% CI, 6.0-16.0) at the 75th percentile and 35.3 µmol/L (95% CI, 26.1-42.8) at the 95th percentile. Respectively, among infants born at 260/7 to 276/7 weeks, differences were 19.4 µmol/L (95% CI, 16.8-23.4) and 43.3 µmol/L (95% CI, 34.7-46.9). Born at 280/7 to 286/7 weeks' gestation, differences between our 75th and 95th TSB percentiles and the CB threshold of 103 µmol/L were 6.9 µmol/L (95% CI, 3.2-12.0) and 36.0 µmol/L (95% CI, 31.0-44.3), respectively. CONCLUSIONS: We provide statistically derived pre-phototherapy TSB levels that may clarify patterns of pre-phototherapy TSB levels in extremely preterm infants. IMPACT: We present statistically derived pre-phototherapy total serum bilirubin levels in a cohort of extremely preterm infants. Most of these preterm infants received phototherapy-some at below currently published thresholds. There are notable differences between our statistically derived pre-phototherapy TSB levels and currently published lower limit TSB thresholds for phototherapy. Our study results assist in the understanding of pre-phototherapy TSB levels in extremely preterm infants.

Interim Federal Health Program: Survey of use of supplemental benefits by paediatric health care providers.

Objectives: The Interim Federal Health Program (IFHP) provides temporary healthcare coverage to refugees and refugee claimants. Previous research demonstrates that paediatric healthcare providers poorly utilize the IFHP, with low registration rates and limited understanding of the program. The objective of this study was to examine paediatric provider use of IFHP-covered supplemental benefits, and their experience with trying to access these benefits. Methods: A one-time survey was administered via the Canadian Paediatric Surveillance Program in February 2020. Of those who had provided care to IFHP-eligible patients, descriptive tables and statistics were created looking at provider demographics, and experience using the IFHP supplemental benefits. A multinomial logistic regression was built to look at provider characteristics associated with trying to access supplemental benefits. Results: Of the 2,753 physicians surveyed, there were 1,006 respondents (general paediatricians and subspecialists). Of the respondents, 526 had recently provided care to IFHP-eligible patients. Just over 30% of those who had recently provided care did not access supplemental benefits as they did not know they were covered by the IFHP. Of those who had tried to access supplemental benefits, over 80% described their experience as difficult, or very difficult. Conclusions: Paediatric providers have a poor understanding of IFHP-covered supplemental benefits, which is cited as a reason for not trying to access supplemental benefits. Of those who do try to access these benefits, they describe the process as difficult. Efforts should be made to improve provider knowledge and streamline the process to improve access to healthcare for refugee children and youth.

Tuberculosis Exposure from a Healthcare Worker to Patients in a Neonatal Intensive Care Unit (NICU).

The nosocomial spread of Mycobacterium tuberculosis from a healthcare worker with infectious pulmonary tuberculosis disease to patients remains a risk in the healthcare environment, including neonatal intensive care units. In this paper, we outlined a protocol for neonates exposed to tuberculosis in a neonatal intensive care unit that includes skin testing, chest X-ray imaging, and prophylactic isoniazid. Neonatal patients were followed up with tuberculosis skin testing at both three months corrected age and two months postexposure. To our knowledge, this is the first Canadian study to illustrate a protocol following tuberculosis exposure in a neonatal intensive care unit for exposed neonates.

Interim Federal Health Program: Survey of access and utilization by paediatric health care providers.

Background: The Interim Federal Health Program (IFHP) provides health care coverage to refugees and refugee claimants, yet remains underused by providers. The objective of this study was to assess Canadian paediatricians' current understanding and utilization of the IFHP, and perceived barriers to utilization. Methods: A one-time survey was administered via the Canadian Paediatric Surveillance Program in February 2020. In addition to descriptive statistics, multinomial logistic regressions were built to examine paediatrician use of the IFHP, and characteristics associated with registration and use. Results: Of the 2,753 physicians surveyed, there were 1,006 respondents (general paediatricians and subspecialists). 52.2% of respondents had provided care to IFHP-eligible patients in the previous 6 months. Of those participants, only 26.4% were registered IFHP providers, and just 16% could identify 80% or more of IFHP-covered services. Knowledge of 80% or more of IFHP-covered services was associated with registration status (adjusted odds ratio [aOR] 1.92; 95%CI 1.09 to 3.37). Among those who knew they were not registered, 70.2% indicated they did not know they had to register. aOR demonstrated that those with fewer years of practice had higher odds of not knowing that they had to register (aOR 1.22; 95%CI 1.01 to 1.49). Conclusions: We demonstrate that IFHP is poorly utilized by paediatric providers, with low registration rates and poor understanding of IFHP-covered supplemental services, even among those who have recently provided care to IFHP-eligible patients. Efforts to improve registration and knowledge of IFHP are essential to improving access to health care for refugee children and youth.

Infants affected by Rh sensitization: A 2-year Canadian National Surveillance Study.

INTRODUCTION: Rh sensitization occurs when Rh(D)-negative women develop anti-Rh(D) antibodies following exposure through pregnancy or transfusion. Rh disease may cause jaundice, anemia, neurological impairment, and death. It is rare in countries where Rh Immune Globulin (RhIg) is used. Canadian Rh sensitization and disease rates are unknown. METHODS: This survey-based study was conducted using a Canadian Paediatric Surveillance Program questionnaire sent to Canadian paediatricians and paediatric subspecialists to solicit Rh disease cases from May 2016 to June 2018. Paediatricians reported Rh-positive infants ≤ 60 days of age, born to Rh-negative mothers with RhD sensitization. RESULTS: Sixty-two confirmed cases of infants affected by Rh(D) sensitization were reported across Canada. The median gestational age of neonates was term, age at presentation was 2 hours, and hemoglobin at presentation was 137.5 g/L (33 to 203 g/L). The median peak bilirubin and phototherapy duration were 280 µmol/L (92 to 771 µmol/L), and 124 hours, respectively. Thirty (48%) infants received Intravenous immune globulin (IVIG) (median two doses). Seventeen (27%) received one to three simple transfusions; 10 (16%) required exchange transfusions. Six (10%) infants presented with acute bilirubin encephalopathy, and less than five presented with seizures. Fourteen mothers with affected infants were born outside of Canada. DISCUSSION: Rh disease continues to exist in Canada. Additional efforts are needed to raise awareness of Rh disease, prevent disease, and minimize sequelae when it does occur. The ongoing global burden of Rh Disease, as well as the possibility of emerging Rh immunoglobulin refusal are among factors that could be taken into consideration in future prevention efforts.

Paediatric hyperthermia-related deaths while entrapped and unattended inside vehicles: The Canadian experience and anticipatory guidance for prevention.

An average of 37 children die of hyperthermia inside parked vehicles annually in the USA. The majority of cases are due to a caregiver forgetting them (~55%), while ~13% are due to intentionally leaving children unattended and ~28% occur when children climb into unlocked vehicles. The cause of four per cent is unknown. There are no published data on incidence in Canada. Through information provided from provincial and territorial coroner's offices, Canadian government agencies and media reports, six cases of vehicular hyperthermia deaths were confirmed since 2013. Three were attributed to children left unintentionally in vehicles; one occurred after a child climbed into an unlocked vehicle and two cases are undetermined. Attention or memory lapses are hypothesized to occur due to distraction, stress, fatigue, or routine changes. Educating caregivers about the dangers of leaving children in vehicles and providing preventative strategies through anticipatory guidance may reduce these tragedies (see graphic abstract).

The Infant Cuddler Study: Evaluating the effectiveness of volunteer cuddling in infants with neonatal abstinence syndrome.

OBJECTIVES: St. Michael's Hospital launched a volunteer cuddling program for all infants admitted into the neonatal intensive care unit in October 2015. The program utilizes trained volunteers to cuddle infants when caregivers are not available. This was a pilot study to assess the impact of a volunteer cuddle program on length of stay (LOS) and feasibility of implementation of the program. METHODS: A mixed methods approach was utilized to measure both quantitative and qualitative impact. A pilot cohort study with a retrospective control group assessed the feasibility of implementing a volunteer cuddling program for infants with neonatal abstinence syndrome (NAS). Length of stay was used as a surrogate marker to measure the impact of cuddling on infants being treated for Neonatal Abstinence Syndrome. Focus groups using semi-structured interviews were conducted with volunteers and nurses at the end of the pilot study. RESULTS: LOS was reduced by 6.36 days (U=34, P=0.072) for infants with NAS in the volunteer cuddling program. Focus groups with both bedside nurses and program volunteers described a positive impact of cuddling programs on infants, families, staff, and volunteers alike. CONCLUSIONS: The study results suggest that the volunteer cuddling program may reduce LOS in infants with NAS and have potential economic savings on hospital resources. However, larger prospective cohort studies are needed to confirm these results.

Early-onset neonatal sepsis: Organism patterns between 2009 and 2014.

OBJECTIVE: To evaluate trends in organisms causing early-onset neonatal sepsis (EONS). Congruent with recent reports, we hypothesized there would be an increase in EONS caused by Escherichia coli. STUDY DESIGN: National data on infants admitted to neonatal intensive care units from 2009 to 2014 were compared to previously reported data from 2003 to 2008. We report 430 cases of EONS from 2009 to 2014. Bivariate analyses were used to analyze the distribution of causative organisms over time and differences by gestational age. Linear regression was used to estimate trends in causative organisms. RESULTS: Since 2003, there has been a trend of increasing numbers of cases caused by E coli (P<0.01). The predominant organism was E coli in preterm infants and Group B Streptococcus in term infants. CONCLUSIONS: With the majority of EONS cases now caused by E coli, our findings emphasize the importance of continued surveillance of causative organism patterns and developing approaches to reduce cases caused by E coli.

Patient navigators: Mapping the route toward accessibility in health care.

Children and youth with developmental and mental health conditions require a wide range of clinical supports and social services to improve their quality of life. However, few children and youth are currently able to adequately access these clinical, community and social services, and newcomers or those living in poverty are even further disadvantaged. Patient navigator programs can bridge this gap by facilitating connections to social services, supporting family coping strategies and advocating for patient clinical services. Although there are few paediatric-focused patient navigator programs in the literature, they offer the potential to improve short and long-term health outcomes. As social and clinical services, particularly for developmental and mental health conditions, become increasingly complex and restricted, it is important that physicians and policymakers consider implementing patient navigator programs with a rigorous evaluation framework to improve accessibility and health outcomes. This can ultimately facilitate policymakers in creating more equitable resources in challenging fiscal climates.

Population-based study of early-onset neonatal sepsis in Canada.

OBJECTIVE: To determine the incidence, types of organisms and resistance patterns involved in early-onset neonatal sepsis in Canada. STUDY DESIGN: Early-onset neonatal sepsis cases were identified through the Canadian Paediatric Surveillance Program. Neonates were excluded if they were asymptomatic or if intracranial procedures preceded a positive cerebrospinal fluid culture. RESULTS: One hundred and twenty-seven cases were identified (0.17 cases per 1000 live births). Group B Streptococcus accounted for 41.7%, Escherichia coli for 35.4%. Antibiotic resistance was present in 33.9% of all cases. 55.6% of E coli cases were resistant, most commonly to ampicillin. Infecting organism species were associated with gestational age, being very low birth weight, time at sepsis presentation, maternal antibiotic prophylaxis and rupture of membranes lasting over 18 hours. Group B Streptococcus was most common in term and E coli in preterm neonates. Twenty-two per cent of E coli cases presented after 48 hours, compared to 6% of Group B Streptococcus cases. CONCLUSION: We identify a lower rate of early-onset neonatal sepsis than historically suggested, with differing dominant organisms based on gestational ages and other factors, as well as high rates of resistance especially among E coli cases.

Hypoglycemia in unmonitored full-term newborns-a surveillance study.

BACKGROUND AND OBJECTIVES: Hypoglycemia monitoring is not recommended for most full-term newborns. We wished to determine the incidence, presentation and case characteristics of hypoglycemia in low-risk newborns. METHODS: With the assistance of the Canadian Paediatric Surveillance Program, we conducted a national study of severe hypoglycemia in apparently low-risk full-term newborns. Paediatricians who reported a case were sent a detailed questionnaire and the data were analyzed. RESULTS: All 93 confirmed cases were singletons, 56% were first-borns and 65% were male. An 8% rate of First Nations cases was twofold the population rate. Maternal hypertension rate was 23%, fourfold the general pregnancy rate. Maternal obesity was double the general pregnancy rate at 23%. Concerning signs or feeding issues were noted in 98% at the time of diagnosis. Median time to diagnosis was 4.1 hours. Mean blood glucose at intravenous (IV) start was 1.4 ± 0.5 hours (SD). Seventy-eight per cent had at least one of four potential stress indicators and were more likely to have early diagnosis (P=0.03). Major signs were present in 20%. Those cases presented later and had lower glucose levels (median=0.8 mmol/L versus 1.6 mmol/L, [P<0.001). Twenty-five per cent of cases had birth weight less than the 10th centile. Neurodevelopmental concern was reported in 20%. Of the 13 cases which had brain magnetic resonance imaging, 11 were abnormal. CONCLUSION: Hypoglycemia in unmonitored newborns is uncommon but is associated with significant morbidity. We provide a range of clues to help identify these newborns soon after birth. Widespread adoption of norm-based standards to identify small-for-gestational age infants is supported.

Severe Neonatal Hyperbilirubinemia Decreased after the 2007 Canadian Guidelines.

OBJECTIVES: To estimate the incidence of severe neonatal hyperbilirubinemia in Canada from 2011-2013 following the implementation of the Canadian Pediatric Society's published guidelines on the management of hyperbilirubinemia in 2007. Our previously reported incidence of hyperbilirubinemia in Canada was 1 in 2480. STUDY DESIGN: Term infants ≤ 60 days of age, with a peak serum total bilirubin level > 425 µmol/L or who had an exchange transfusion were followed prospectively through the Canadian Pediatric Surveillance Program from 2011-2013. Infants with rhesus isoimmunization or born < 35 weeks gestation were excluded. RESULTS: Ninety-one cases of severe neonatal hyperbilirubinemia were confirmed. Sixty-nine infants (76%) were readmitted to hospital, 47 (52%) of them within 6 days of age. The remaining 22 infants (24%) were identified with severe neonatal hyperbilirubinemia before they were discharged from the hospital. The mean reported peak bilirubin level was 484 µmol/L (range 181-788; SD ± 92). An etiology was identified in 57 (63%) cases, with ABO incompatibility (n = 35) and glucose-6-phosphate dehydrogenase deficiency (n = 11) being the most common. An infant was 3.5 times more likely to be diagnosed with severe neonatal hyperbilirubinemia from 2002-2004 compared with 2011-2013 (95% CI 2.72-4.47). CONCLUSIONS: The minimum estimated incidence of severe neonatal hyperbilirubinemia in Canada is 1 in 8352 live births. Introduction of the Canadian Pediatric Society guidelines and improved physician awareness of severe neonatal hyperbilirubinemia in the last 10 years likely made positive contributions to this trend.

Nontherapeutic neonatal hypothermia.

The case presented advocates for prolonged resuscitation, and aggressive rewarming in neonates with severe hypothermia (core temperature <32.0°C). The importance of rewarming has not been extensively studied in current guidelines, whereas the importance of cardiopulmonary resuscitation is well established. This abandoned, severely hypothermic (found with temperature of 27.9°C) newborn had an excellent neurological outcome at two years of age with aggressive resuscitation and rewarming techniques initiated at the time of presentation. Active core rewarming with warm saline lavages, intravenous fluids and warm air may be used at a rate of 1.8°C/h to 5.3°C/h according to most guidelines. Rewarming guidelines for asphyxiated infants undergoing therapeutic hypothermic may not be applicable to infants with accidental exposure, as in the present case. The present case of a near-term severely hypothermic infant reinforces the current recommendation of continuing resuscitative measures, irrespective of response to resuscitation, until the infant has been rewarmed.

Le cas présenté plaide en faveur d'une réanimation prolongée et d'un réchauffement agressif chez les nouveau-nés présentant une grave hypothermie (température centrale de moins de 32,0 °C). Les directives à jour ne contiennent pas d'étude approfondie sur l'importance du réchauffement, mais celle de la réanimation cardiorespiratoire est bien établie. Ce nouveau-né abandonné en hypothermie grave (température de 27,9 °C lorsqu'il a été trouvé) présentait d'excellents résultats neurologiques à l'âge de deux ans, alors que des techniques de réanimation et de réchauffement agressives avaient été adoptées au moment de la présentation. On peut procéder au réchauffement actif de la température centrale à l'aide de lavages de sérum physiologique tiède, de liquides intraveineux et d'air tiède, à un rythme de 1,8 °C/h à 5,3 °C/h selon la plupart des directives. Les directives sur le réchauffement des nourrissons asphyxiés qui subissent une hypothermie thérapeutique ne s'appliquent peut-être pas aux nourrissons exposés accidentellement aux éléments, comme dans le cas présent. Ce cas d'un nourrisson presque à terme en grave hypothermie renforce la recommandation actuelle de poursuivre les mesures de réanimation, quelle que soit la réponse, jusqu'à ce que le nourrisson soit réchauffé.

Housing and sexual health among street-involved youth.

Street-involved youth (SIY) carry a disproportionate burden of sexually transmitted diseases (STD). Studies among adults suggest that improving housing stability may be an effective primary prevention strategy for improving sexual health. Housing options available to SIY offer varying degrees of stability and adult supervision. This study investigated whether housing options offering more stability and adult supervision are associated with fewer STD and related risk behaviors among SIY. A cross-sectional study was performed using public health survey and laboratory data collected from Toronto SIY in 2010. Three exposure categories were defined a priori based on housing situation: (1) stable and supervised housing, (2) stable and unsupervised housing, and (3) unstable and unsupervised housing. Multivariate logistic regression was used to test the association between housing category and current or recent STD. Secondary analyses were performed using the following secondary outcomes: blood-borne infection, recent binge-drinking, and recent high-risk sexual behavior. The final analysis included 184 SIY. Of these, 28.8 % had a current or recent STD. Housing situation was stable and supervised for 12.5 %, stable and unsupervised for 46.2 %, and unstable and unsupervised for 41.3 %. Compared to stable and supervised housing, there was no significant association between current or recent STD among stable and unsupervised housing or unstable and unsupervised housing. There was no significant association between housing category and risk of blood-borne infection, binge-drinking, or high-risk sexual behavior. Although we did not demonstrate a significant association between stable and supervised housing and lower STD risk, our incorporation of both housing stability and adult supervision into a priori defined exposure groups may inform future studies of housing-related prevention strategies among SIY. Multi-modal interventions beyond housing alone may also be required to prevent sexual morbidity among these vulnerable youth.

The association between obstetrical interventions and late preterm birth.

OBJECTIVE: There is concern that obstetric interventions (prelabor cesarean section and induced delivery) are drivers of late preterm (LP) birth. Our objective was to evaluate the independent association between obstetric interventions and LP birth and explore associated independent maternal and fetal risk factors for LP birth. STUDY DESIGN: In this population-based cross-sectional study, the BORN Information System was used to identify all infants born between 34 and 40 completed weeks of gestation between 2005 and 2012 in Ontario, Canada. The association between obstetric interventions (preterm cesarean section and induced delivery) and LP birth (34 to 36 completed weeks' gestation vs 37 to 40 completed weeks' gestation) was assessed using generalized estimating equation regression. RESULTS: Of 917,013 births between 34 and 40 weeks, 49,157 were LP (5.4%). In the adjusted analysis, "any obstetric intervention" (risk ratio [RR], 0.65; 95% confidence interval [CI], 0.57-0.74), induction (RR, 0.71; 95% CI, 0.61-0.82) and prelabor cesarean section (RR, 0.66; 95% CI, 0.59-0.74) were all associated with a lower likelihood of LP vs term birth. Several independent potentially modifiable risk factors for LP birth were identified including previous cesarean section (RR, 1.28; 95% CI, 1.16-1.40), smoking during pregnancy (RR, 1.28; 95% CI, 1.21-1.36) and high material (RR, 1.1; 95% CI, 1.03-1.18) and social (RR, 1.09; 95% CI, 1.02-1.16) deprivation indices. CONCLUSION: After accounting for differences in maternal and fetal risk, LP births had a 35% lower likelihood of obstetric interventions than term births. Obstetric care providers may be preferentially avoiding induction and prelabor cesarean section between 34 and 37 weeks' gestation.