Canada Communicable Disease Report

1 December 2007 Volume 33 Number 13

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Initial health screening results for Karen refugees: a retrospective review

A Denburg, MD (1); M Rashid, MD (2); J Brophy, MD (1); T Curtis, MD (2); P Malloy, RN (1); J Audley, RN (2); W Pegg, MD (2); S Hoffman, MD (2); A Banerji, MD (2)

1 Hospital for Sick Children, Toronto, Ontario
2 Access Alliance Multicultural Community Health Centre, Toronto, Ontario

Over 25,000 refugees arrive in Canada each year. These refugees often have unique health needs that may present a challenge to physicians. A set of guidelines to direct caregivers in the initial assessment of refugees would help ensure that these needs are well met. Although there have been efforts to develop such guidelines they have yet to be incorporated into a national resettlement policy in Canada⁽¹⁾.

In the fall of 2006, Canada resettled 810 ethnic Karen refugees from Thailand. Forcibly displaced from their homes in Myanmar by a decades-old civil war, they had been living in refugee camps along the Thai-Myanmar border. While refugee status guaranteed them access to publicly funded health services upon arrival in Canada, no federal stipulations for standardized health assessment and care were articulated. Apart from national screening provisions for tuberculosis, medical management was planned and coordinated in an ad hoc manner by independent health care providers throughout the country. Sixty-eight of the Karen refugees arrived in Toronto and were assessed by a multidisciplinary group of health care providers. For many of the Karen refugees, travel to Canada represented their first time outside a refugee camp.

The purpose of this retrospective study was two-fold. First, by describing the burden of illness in this specific group of refugees we hope to give Canadian medical practitioners an impression of the unique health needs of the Karen population. Second, we hope to add to the growing body of literature that argues for specific screening guidelines in newly arrived refugee populations. The importance of our clinical findings and the development of an approach to screening new refugees to our country is accentuated by the fact that 2,000 more Karen refugees are set to arrive in Canada within the next 2 years.

Methods

The cohort of 68 Karen refugees who arrived in Toronto were managed by a multidisciplinary team that included primary care physicians and specialists in collaboration with Toronto Public Health and a local refugee reception centre (COSTI). The content of this medical assessment was generated with input from specialists on the basis of perceived risk. A comprehensive medical assessment, including history, physical examination, laboratory testing, immunization and treatment, was conducted for each refugee within 10 days of arrival in Canada. All Karen refugees also had a chest radiograph within 24 hours of arrival in Canada. Tuberculin skin testing and laboratory testing were done for all individuals. Age-appropriate immunizations were administered as recommended by the Canadian Immunization Guide⁽²⁾. Formally trained Karen interpreters were used for patient interviews.

Charts were reviewed at Access Alliance Multicultural Community Health Centre. Informed consent was sought from all patients or their parents for use of their medical information.

Results

The results of the chart review, including patient demographic information, results of screening investigations, results from stool examinations in particular, and growth parameters for the children < 18 years of age are presented in Tables 1 to 4 respectively. Percentile rankings for growth were determined using growth charts from the US Centers for Disease Control and Prevention.

 

Table 1. Study group by age and sex

Age, years
	0 - 5	6 - 10	11 - 18	19 - 65	> 65	Total
Male	6	8	7	17	0	48
Female	4	6	5	14	1	30
Total	10	14	12	31	1	68

 

Table 2. Results of screening investigations

Screening test (n)	Test value (n)
Hemoglobin (Hb), g/L (68)	Hb >115 (53)	Hb 100-115 (11)	Hb < 100 (4)
Mean cell volume, fL (68)	>100 (0)	80-100 (49)	< 80 (19)
Eosinophil count, × 109/L (68)	< 400 (34)	≥ 400 (34)
Hepatitis B (HB) testing (64)	HB surface antigen (HBsAg) + (9)	HB surface antibody (HbsAb) + (28)	Neither HBsAg nor HBsAb + (27)
Hepatitis C serology (68)	Positive (0)	Negative (67)	Indeterminate (1)
HIV serology	Positive (0)	Negative (68)
Syphilis serology for those > 15 years (36)	Positive (0)	Negative (36)
Varicella serology (for those > 5 years) (58)	Positive (51)	Negative (7)
Strongyloides serology (67)	Positive (5)	Negative (61)	Indeterminate (1)
G6PD* level (68)	Low (14)	Indeterminate (4)	Normal (50)
Stool for ova and protozoa (3 samples) (68)	Positive (49)	Negative (19)	Multiple pathogens (21)
Chest radiography (68)	Abnormal (0)	Normal (68)
Tuberculin skin test (68)	< 10 mm (49)	≥ 10 mm (19)
Hb electrophoresis for those < 18 years (36)	Normal (29)	Abnormal (7)
Lead level (Um/L) for those < 8 years (13)	< 48 (11)	≥ 48 (2)

*Glucose-6-phosphate dehydrogenase

 

Table 3. Results of stool microscopy

Positive stools (%)
Helminths
Ascaris lumbricoides	18 (26.5)
Hookworm species	11 (16.2)
Enterobius vermicularis	4 (5.9)
Trichuris trichiura	4 (5.9)
Strongyloides stercoralis	1 (1.5)
Protozoa
Dientamoeba fragilis	22 (32.3)
Entamoeba histolytica/dispar	11 (16.2)
Giardia lamblia	5 (7.3)

 

Table 4. Growth centiles of children (< 18 years)

	< 3%	3% - 10%	11% - 25%	25% - 50%	50% - 75%	75% - 90%	Total
Height (No. of children)	14	13	6	2	1	0	36
Weight (No. of children)	10	9	9	5	2	1	36

 

The initial assessment of this group of Karen refugees was notable for the absence of many significant illnesses. There were no cases of HIV, syphilis, active tuberculosis or hepatitis C in this population. A number of our results are consistent with the limited data available on disease burden in Karen populations⁽³⁾.

Only four individuals had anemia with hemoglobin < 100 g/L; this result was surprising given the significant prevalence of stunting (39%) and wasting (28%) in the children of this group. Of the 19 individuals who had a low mean cell volume (MCV), five had hemoglobin E trait/disease and three had beta-thalassemia trait. All of those with hemoglobinopathies had a low MCV. Of the remaining individuals with low MCV, all had iron deficiency. Two individuals had malaria upon arrival along with severe iron deficiency. There were no cases of active tuberculosis diagnosed in this group, though 28% had latent TB infection. From a public health perspective, the low incidence of tuberculosis in this study population is reassuring. Previous groups of refugees from Thailand have suffered from significant rates of multidrug-resistant tuberculosis⁽⁴⁾. While this finding could relate to a selection bias in the group, the difference observed between groups might instead underscore the limitations inherent in generalizing between different groups of refugees, even those from the same countries of origin. The burden of illness was most pronounced with respect to hepatitis B infection and enteric parasites. Thirteen percent of individuals were positive for HBsAg (hepatitis B surface antigen). Forty percent of the refugees assessed were susceptible to hepatitis B. Given the strong social network and close contact within such communities upon arrival in Canada, there is a public health implication associated with the high rates of hepatitis B. We would recommend offering hepatitis B immunization to all those who are susceptible.

Stool examinations demonstrated a high prevalence of intestinal parasites. Other studies of ethnic populations along the Thai-Myanmar border have documented similar levels of stool parasitism⁽⁵⁾. Given the worrisome rates of failure to thrive in the children, screening and treatment of intestinal parasites may be particularly salient. Our results also demonstrated a low yield from Strongyloides serology. Forty-eight percent of individuals were infected with at least one nematode. This may indicate some merit to treatment with a medication for nematodes before travel. Of the 58 patients who had varicella titres drawn, 51 were immune. Of the seven who were susceptible, five were < 18 years of age. Varicella is considered to be less common in the tropics, and its epidemiology is skewed toward a slightly older age group. Despite this, our study showed that varicella exposure was common among the Karen refugees. This may reflect the exposure risk in confined refugee camps and might differ from the risk in other immigrant groups also arriving from the tropics.

Discussion

The initial assessment of the Karen refugees identified medical needs through the implementation of an effective screening protocol. Identification of both infectious and non-infectious issues allowed for early interventions. We feel that such assessments are in the best interests of the refugees and that all new arrivals deserve such attention. Unfortunately, evidence-based guidelines are lacking to illustrate the usefulness of such screening.

By characterizing the spectrum of disease in this study cohort, we hope to identify health issues that are paramount in this population. We believe this will assist primary care physicians with the screening and care of the second wave of Karen refugees that is now arriving in Canada.

The absence of a national strategy for the health screening and care of new Canadians such as the Karen refugees stems in part from the paucity of medical literature available to guide such efforts. By delineating the burden and patterns of disease in this population, we are hoping studies such as this one will help contribute to the development of an effective screening protocol for newly arrived refugees. This study, though limited in size and constrained by its retrospective design, ventures to add to the body of literature that characterizes health care needs in new immigrants. We hope that it will spur further interest and investment in enhancing health care for Canada’s newest citizens

References

1. Stauffer WM, Karnat D, Walker PF. Screening of international immigrants, refugees, and adoptees. Prim Care 2002;29(4):879-905.

2. Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada. Canadian immunization guide, 7th ed. Ottawa: PHAC, 2006.

3. Ishida T, Takao S, Settheetham-Ishida W et al. Prevalence of hepatitis B and C virus infection in rural ethnic populations of Northern Thailand. J Clin Virol 2002;24 (1-2):31-5.

4. Centers for Disease Control and Prevention. Multidrug-resistant tuberculosis in Hmong refugees resettling from Thailand into the United States, 2004-2005. MMWR 2005;54:741-4.

5. Saksirisampant W, Prownebon J, Kanmarnee P et al. Prevalence of parasitism among students of the Karen hill-tribe in Mae Chame district, Chiang Mai province, Thailand. J Med Assoc Thai 2004;87(Suppl 2):S278-83.

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