Prevalence of positive tuberculin skin tests in foreign-born children

Immigrant child health in Canada: a scoping review

Introduction

Understanding the health of immigrant children from birth to 18 years of age is important given the significance of the early childhood years and complexity of factors that may influence the health status of immigrant populations. Thus, the purpose of this review was to understand the extent and nature of the literature on the health of immigrant children in Canada.

Methods

We conducted a scoping review of the literature. The review was focused on studies of first-generation and second-generation immigrant children aged 0–18 years. We completed standardised data extraction of immigration status, immigration route, age of children, data source, health or clinical focus, country of origin and major findings.

Results

In total, 250 published papers representing data from 237 studies met the inclusion criteria for this study. A total of 178 articles used quantitative methodologies (mostly survey and cross-sectional study designs), 54 used qualitative methodologies and 18 used mixed methodologies. The articles considered in this review included 147 (59%) focusing on physical health, 76 (30%) focusing on mental health and 37 (15%) focusing on the social aspects of health for refugee and first-generation and second-generation immigrant children across the provinces and territories of Canada.

Conclusions

Several literature gaps exist with respect to child immigrant health in Canada. For instance, there are no exclusive studies on immigrant boys and limited studies on children of international students.

The impact of migration on tuberculosis epidemiology and control in high-income countries: a review

Tuberculosis (TB) causes significant morbidity and mortality in high-income countries with foreign-born individuals bearing a disproportionate burden of the overall TB case burden in these countries. In this review of tuberculosis and migration we discuss the impact of migration on the epidemiology of TB in low burden countries, describe the various screening strategies to address this issue, review the yield and cost-effectiveness of these programs and describe the gaps in knowledge as well as possible future solutions.The reasons for the TB burden in the migrant population are likely to be the reactivation of remotely-acquired latent tuberculosis infection (LTBI) following migration from low/intermediate-income high TB burden settings to high-income, low TB burden countries.TB control in high-income countries has historically focused on the early identification and treatment of active TB with accompanying contact-tracing. In the face of the TB case-load in migrant populations, however, there is ongoing discussion about how best to identify TB in migrant populations. In general, countries have generally focused on two methods: identification of active TB (either at/post-arrival or increasingly pre-arrival in countries of origin) and secondly, conditionally supported by WHO guidance, through identifying LTBI in migrants from high TB burden countries. Although health-economic analyses have shown that TB control in high income settings would benefit from providing targeted LTBI screening and treatment to certain migrants from high TB burden countries, implementation issues and barriers such as sub-optimal treatment completion will need to be addressed to ensure program efficacy.

A systematic review on TST and IGRA tests used for diagnosis of LTBI in immigrants

BACKGROUND

High immigration rates from tuberculosis (TB) endemic countries to low-incidence countries have caused new TB guidelines in these countries to reconsider latent TB infection (LTBI) screening in these immigrants.

OBJECTIVES

We performed a systematic review with the primary outcome of evaluating the number of cases recommended LTBI treatment with the tuberculin skin test (TST) or interferon gamma release assay (IGRA). Secondary objectives were to examine prevalence of positive LTBI diagnostic tests stratified by age and incidence of TB in country of origin.

METHODS

We performed a systematic search of seven electronic databases for studies assessing TST and/or IGRA performance in immigrant populations to low incidence countries. Demographics, LTBI diagnosis, longitudinal TB development, and test result data were the primary data extracted from the studies. Prevalence of positive test data was stratified by age and country of origin. Studies were evaluated using a modified SIGN checklist for diagnostic studies. Data was compared using Fisher's exact test or χ (2) test, where appropriate.

RESULTS

Our literature search yielded 51 studies (n = 34 TST, n = 9 IGRA, n = 8 both). Recommendation of LTBI treatment was less common in those tested with an IGRA compared to TST (p < 0.0001), while long-term development of active TB appears higher in those with a positive IGRA. There was no difference in the sensitivity and specificity of the IGRA and TST for prevalent TB (p > 0.05). Prevalence of a positive test was significantly lower in those who were <18 years of age compared to those ≥18 years of age (p < 0.0001) and those from low TB incidence countries compared to high incidence countries (p < 0.0001) for both TST and IGRA. When comparing the two tests within the 2 subgroups: age and TB incidence in country of origin, the prevalence of positive results was significantly lower for the IGRA than the TST (p < 0.0001).

LIMITATIONS

The number of available studies evaluating the IGRA and longitudinal active TB development in those tested limits this study.

CONCLUSION

Prevalence of positive test results were significantly lower in immigrants who were tested with an IGRA, resulting in fewer immigrants being recommended for LTBI treatment compared to TST. Coupled with comparable performance for detecting prevalent TB cases, the IGRA appears to exhibit better specificity than the TST and may be preferred as the standard of care for detecting LTBI in immigrants moving to low TB incidence countries.

Tuberculin skin test in bacille Calmette-Guérin-vaccinated children: how should we interpret the results?

BACKGROUND

The tuberculin skin test (TST) is the most useful method for the diagnosis of tuberculosis (TB). There is no evidence about the effect of bacillus Calmette-Guerin (BCG) vaccine on the interpretation of TST results.

OBJECTIVE

The aim of this study was to evaluate TST results in a population of immigrants and adopted children, analyzing the effect of the vaccine on TST.

METHODS

Cross-sectional observational study including immigrants or adopted children evaluated in our unit between January 2003 and December 2008 was made. Children diagnosed with TB, live attenuated virus vaccinated 2 months earlier, HIV-infected, chronically ill, or under treatment with immunosuppressive agents were excluded. TST was considered the dependent variable. Independent variables were gender, age, geographical origin, BCG scar, nutritional status, immune status, and intestinal parasites infestation.

RESULTS

One thousand seventy-four children were included, 69.6 % are female; their origin includes China (34.7 %), Latin America (20.8 %), India/Nepal (19.4 %), Eastern Europe (15.7 %), and Africa (9.3 %). BCG scar was present in 79 % of children. Mantoux = 0 mm in 84.4 %, <10 mm in 4.1 %, and ≥10 mm in 11.4 %. Only two variables, age and BCG scar, influenced TST result. Risk of a TST false-positive due to BCG disappears 3 years after vaccine administration.

CONCLUSIONS

A history of BCG vaccination at birth does not interfere with TST results in children >3 years old. Under 3 years of age, BCG does interfere with and may cause a false-positive TST result. In these cases, the use of interferon-gamma release assays (IGRAs) is recommended. If IGRAs are not available or when results are indeterminate, ignoring the antecedent of the vaccine is recommended.

Tertiary paediatric refugee health clinic in Western Australia: analysis of the first 1026 children

AIM

Children account for approximately half of the humanitarian refugees currently resettled in Australia. A multidisciplinary refugee health clinic (RHC) was established at the tertiary paediatric hospital in Western Australia to address burgeoning referrals of refugee children following voluntary post-resettlement health assessment. The aim of this study is to describe the epidemiology of common conditions in resettled paediatric refugees attending a tertiary multidisciplinary RHC.

METHODS

Standardised clinical and demographic data were routinely collected during first visit clinical assessment at the RHC. Descriptive analyses of the first 1026 children are presented.

RESULTS

One thousand twenty-six refugee children from 475 families and over 30 different ethnicities were described. Nine hundred twenty-seven (90.4%) children were referred following post-resettlement health assessment. Median age was 7.8 years. Common reasons for referral were: vitamin D deficiency (400, 39%), iron deficiency (226, 22%), positive Helicobacter pylori serology (206, 21%), poor appetite (175, 17.1%), and schistosomiasis (170, 16.6%). Comorbidities identified by the RHC included tinea capitis and corporis (297, 28.9%), and dental disease (228, 22.2%). Two-thirds of children (680, 66.3%) had at least one abnormal finding on clinical examination that identified pathologies that were not evident from the history. Three hundred eighty children (37%) were referred to sub-specialty services.

CONCLUSIONS

A multidisciplinary paediatric RHC facilitated and strengthened the management of refugee children with multiple and complex health needs. Evidenced-based culturally appropriate methods to identify developmental delay, psychological morbidity and quantify social needs of this vulnerable population remain uncertain. These findings are relevant to the continuing evolution of paediatric refugee health care in Australia and other high income countries.

Tuberculosis in quebec: a review of trends

The aim of this research was to conduct a thorough review on the literature of tuberculosis in Canada and the Province of Quebec. To achieve this aim, an exhaustive literature review of tuberculosis in the Province of Quebec was undertaken. Data was collected with the goal of creating an epidemiological and public health evidence base to forecast the spread of tuberculosis. A keyword search strategy was used to find relevant articles from the peer-reviewed literature using the electronic search engine PubMed and a search of other relevant federal and provincial government databases. Twenty-nine peer-reviewed publications and twenty government reports containing information about the incidence or prevalence of tuberculosis in the Province of Quebec were included in the analysis. An analysis of the data revealed that while tuberculosis rates have been decreasing in both Canada and Quebec with an overall incidence below 3 per 100,000 of population in 2007, among immigrants and the Inuit communities in Quebec, the incidence and prevalence of the disease still remains high and reached 18 per 100,000 and 100 per 100,000, respectively in 2007. In general, while tuberculosis does not pose a significant burden to the general population, it does continue to affect certain sub-groups disproportionately, including select immigrants and Inuit communities in Quebec. Efforts to ensure that cost-effective healthcare interventions are delivered in a timely fashion should be pursued to reduce the associated morbidity and mortality of tuberculosis in the Province of Quebec.

ACKNOWLEDGMENTS

Funding for this research was provided to Medmetrics Inc., by McGill University, Montreal, Quebec, Génome Québec and the Ministère de Développement Economique, Innovation et Exportation du Gouvernement du Québec. The authors also wish to thank Drs. John White and Marcel Behr, both of McGill University and Dr Suneil Malik of the Infectious Disease Program in the Office of Biotechnology, Genomics and Population Health at the Public Health Agency of Canada for comments and suggestions on earlier drafts of this manuscript.

Renal and miliary tuberculosis in an internationally adopted infant

Renal tuberculosis is rare in children and particularly in infants. We present a case of miliary tuberculosis with focal renal involvement in a 5-month-old male infant recently adopted from Ethiopia, and review the literature on miliary and renal tuberculosis in infants and children. Salient points regarding tuberculosis screening in internationally adopted patients are also addressed.