Epidemiology of Malaria Presenting at British Columbia's Children's Hospital, 1984-2001: Lessons for Prevention

Article excerpt

ABSTRACT

Background: Few studies have examined the epidemiology of imported malaria in Canadian children. Identifying populations at increased risk in Canada would enable targeted malaria prevention strategies within those groups. The study objective was to describe the epidemiology of malaria diagnosed at British Columbia's Children's Hospital (BCCH) between 1984 and 2001.

Methods: This was a retrospective chart review of malaria cases identified at BCCH and confirmed through the British Columbia Centre for Disease Control. Demographic and clinical data were recorded on a standardized form.

Results: Malaria was diagnosed 42 times in 40 children (age 24 days to 14.8 years). Thirty cases (71.4%) occurred in 28 Canadian residents, and 12 (28.6%) occurred in immigrant or refugee children. Twenty-six children (65%) were male. Thirty-one children (77.5%) were of East Indian descent. Thirty-three exposures (78.6%) to malaria occurred in the Indian subcontinent. Plasmodium wVaxwas identified in 37 cases (88.1%), P. falciparum in 3 (7.1%), and the species was unknown in 2 (4.8%). Fourteen cases in the resident children (46.7%) reported pre-travel counselling. Ten resident cases (33.3%) were prescribed chemoprophylaxis, primarily chloroquine, and at least six of them (60%) were non-compliant. The duration of symptoms prior to diagnosis was < or =7 days in 27 cases (64.3%), 8 to 30 days in 10 (23.8%), > 30 days in 4 (9.5%) and the duration was unknown in 1 (2.5%). Twenty-four of 36 cases (66.7%) had seen 2 to more than 4 doctors before the diagnosis of malaria was made.

Conclusion: The majority of children in our review were of East Indian origin and were exposed to malaria in India. Most had not sought or had received inadequate pre-travel counselling and had been non-compliant with chemoprophylaxis. As malaria is a potentially lethal but preventable disease, strategies to ensure adequate pre-travel counselling for high-risk groups are required.

Malaria is a major cause of morbidity and mortality in children throughout the developing world and kills approximately 1 million children world-wide each year.' Despite this, there have been few studies examining imported malaria in the pédiatrie population. As global travel increases, the rate of imported malaria will continue to rise in Canada. In recent years, British Columbia has had one of the highest per capita rates of imported malaria in Canada, with peaks in 1996 and 1997 when it was two to three times the average Canadian rate.2

The goal of this study was to describe the epidemiology of malaria diagnosed at British Columbia's Children's Hospital (BCCH) between 1984 and 2001. Understanding the demographics of this disease in children may support the implementation of targeted malaria prevention strategies for high-risk groups. As delays in the diagnosis and treatment of malaria are associated with increased morbidity and mortality3'5 it is important to emphasize the value of prevention strategies and early recognition and treatment of disease, particularly for populations at increased risk.

METHODS

This retrospective chart review was undertaken at BCCH in Vancouver, British Columbia, Canada. BCCH is the only tertiary pediatrie referral centre in the province of British Columbia. This review recorded the epidemiologic factors and clinical presentation of all laboratoryconfirmed episodes of malaria seen at BCCH between 1984 and 2001. cases were identified by ICD-9 coding for malaria at BCCH and through the provincial reference laboratory (British Columbia Centre for Disease Control [BCCDC]). cases were children (< 16 years of age) who were either admitted to BCCH, or who were seen in the hospital emergency department or outpatient clinic, with an episode of laboratory-confirmed malaria. Each episode of malaria is defined as a case. Malaria parasites were identified and speciated on thin or thick smears by an experienced hematopathologist at BCCH. …