The changing face of Canadian immigration: Implications for infectious diseases

Infections and the development of childhood acute lymphoblastic leukemia: a population-based study

An infectious trigger for childhood acute lymphoblastic leukemia is hypothesized and we assessed the association between the rate, type, and critical exposure period for infections and the development of acute lymphoblastic leukemia. We conducted a matched case-control study using administrative databases to evaluate the association between the rate of infections and childhood acute lymphoblastic leukemia diagnosed between the ages of 2-14 years from Ontario, Canada and we used a validated approach to measure infections. In 1600 cases of acute lymphoblastic leukemia, and 16 000 matched cancer-free controls aged 2-14 years, having >2 infections/year increased the odds of childhood acute lymphoblastic leukemia by 43% (odds ratio = 1.43, 95% confidence interval 1.13-1.81) compared to children with ≤0.25 infections/year. Having >2 respiratory infections/year increased odds of acute lymphoblastic leukemia by 28% (odds ratio =1.28, 95% confidence interval 1.05-1.57) compared to children with ≤0.25 respiratory infections/year. Having an invasive infection increased the odds of acute lymphoblastic leukemia by 72% (odds ratio =1.72, 95% confidence interval 1.31-2.26). Having an infection between the age of 1-1.5 years increased the odds of acute lymphoblastic leukemia by 20% (odds ratio = 1.20, 95% confidence interval 1.04-1.39). Having more infections increased the odds of developing childhood acute lymphoblastic leukemia and having an infection between the ages of 1-1.5 years increased the odds of childhood acute lymphoblastic leukemia.

The knowledge needs for Canadian paediatric emergency physicians in the diagnosis and management of tropical diseases: A national physician survey

OBJECTIVES

To assess the knowledge gaps and need for continuing medical education (CME) resources for Canadian paediatric emergency department (PED) physician management of common tropical diseases.

METHODS

A cross-sectional survey study of Canadian PED was performed from May to July 2017 using the Pediatric Emergency Research Canada (PERC) database.

RESULTS

The response rate was 56.4% (133/236). The mean performance on the case-based vignettes identifying clinical presentation of tropical illnesses ranged from 59.9% to 76.0%, with only 15.8% (n=21) to 31.1% (n=42) of participants scoring maximum points. Those who 'always' asked about fever performed better than those who only 'sometimes' asked (40.4% versus 23.8%). For management cases, the majority of the participants (59.4% to 89.5%) were able to interpret investigations; however, many were unsure of subsequent actions relating to initial treatment, discharge instructions, and reporting requirements. Many would consult infectious diseases (87.8% to 99.3%). Fifty-three per cent of the participants reported a low comfort level in diagnosing or managing these patients. They rated the importance of CME materials with a median of 50/100, via various modalities such as case studies (71.9%), emphasizing a need for PED-specific content.

CONCLUSION

This study identified a knowledge gap in the recognition and management of pediatric tropical diseases by Canadian PED physicians. There is a need for formal CME materials to supplement physician practice.

Differences in growth of Canadian children compared to the WHO 2006 Child Growth Standards

BACKGROUND

To evaluate if there are departures from the WHO Child Growth Standards (WHO-CGS) in postnatal growth of healthy 'Canadian' children in Ontario up to age 2 years, including by infant feeding and ethnicity.

METHODS

We included data on 9964 healthy, singleton children born in Ontario, Canada. Smoothed weight, length and body mass index (BMI) percentile curves were generated using quantile regression for the Canadian cohort from birth to age 2 years. Differences in percentile values were calculated comparing Canadian children vs. the WHO-CGS.

RESULTS

Canadian children under age 2 years were longer than the WHO-CGS at the 10th (0.8 cm), 50th (1.3 cm) and 90th (1.9 cm) percentiles. Canadian children incrementally surpassed the WHO-CGS in weight after age 6 months, and in BMI after 9 months. By age 2 years, the 50th percentile weight of Canadian males was 823 g (95% confidence interval (CI) 680, 965) higher than the WHO-CGS 50th percentile. Weight differences were seen regardless of feeding practice, and were greatest among children of mothers born in Canada and Europe/Western nations, and least for those of East Asian/Pacific or South Asian heritage. Among Canadian breastfed males, 18% (95% CI 16, 19) of newborns and 26% (95% CI 20, 33) toddlers aged 2 years were classified by WHO-CGS as weighing >90th percentile - much higher than the expected rate of 10%. Similarities were seen for differences in BMI.

CONCLUSIONS

Healthy Canadian infants/toddlers are longer and heavier than the WHO-CGS norms. Explanations for these discrepancies require further elucidation.

Preterm preeclampsia in relation to country of birth

OBJECTIVE

To examine the association between maternal country of birth and the risk of preeclampsia+preterm birth (PTB).

STUDY DESIGN

We completed a population-based study in the entire province of Ontario, where there is universal access to obstetrical care. We included 881 700 singleton livebirths among Canadian-born mothers and 305 547 births among immigrant mothers. Adjusted risk ratios (aRRs) were adjusted for maternal age, parity and income quintile.

RESULTS

Compared with a rate of preeclampsia+PTB of 4.0 per 1000 among Canadian-born mothers, the aRR of preeclampsia+PTB at 24 to 36 weeks was significantly higher for immigrant women from Nigeria (1.79, 95% confidence interval (CI) 1.12 to 2.84), the Philippines (1.54, 95% CI 1.30 to 1.86), Colombia (1.68, 95% CI 1.04 to 2.73), Jamaica (2.06, 95% CI 1.66 to 2.57) and Ghana (2.12, 95% CI 1.40 to 3.21). The aRRs generally followed a similar pattern for secondary outcomes. Specifically, women from Ghana were at highest risk of preeclampsia+very PTB (4.55, 95% CI 2.57 to 8.06), and women from Jamaica at the highest risk of preeclampsia+indicated PTB (1.89, 95% CI 1.43 to 2.50).

CONCLUSION

The risk of preeclampsia+PTB is highest among women from a select number of countries. This information can enhance initiatives aimed at reducing the risk of PTB related to preeclampsia.

Migration and health in Canada: health in the global village

BACKGROUND

Immigration has been and remains an important force shaping Canadian demography and identity. Health characteristics associated with the movement of large numbers of people have current and future implications for migrants, health practitioners and health systems. We aimed to identify demographics and health status data for migrant populations in Canada.

METHODS

We systematically searched Ovid MEDLINE (1996-2009) and other relevant web-based databases to examine immigrant selection processes, demographic statistics, health status from population studies and health service implications associated with migration to Canada. Studies and data were selected based on relevance, use of recent data and quality.

RESULTS

Currently, immigration represents two-thirds of Canada's population growth, and immigrants make up more than 20% of the nation's population. Both of these metrics are expected to increase. In general, newly arriving immigrants are healthier than the Canadian population, but over time there is a decline in this healthy immigrant effect. Immigrants and children born to new immigrants represent growing cohorts; in some metropolitan regions of Canada, they represent the majority of the patient population. Access to health services and health conditions of some migrant populations differ from patterns among Canadian-born patients, and these disparities have implications for preventive care and provision of health services.

INTERPRETATION

Because the health characteristics of some migrant populations vary according to their origin and experience, improved understanding of the scope and nature of the immigration process will help practitioners who will be increasingly involved in the care of immigrant populations, including prevention, early detection of disease and treatment.