A descriptive analysis of notifiable gastrointestinal illness in the Northwest Territories, Canada, 1991–2008

OBJECTIVES To describe the major characteristics of reported notifiable gastrointestinal illness (NGI) data in the Northwest Territories (NWT) from January 1991 through December 2008. DESIGN Descriptive analysis of 708 reported cases of NGI extracted from the Northwest Territories Communicable Disease Registry (NWT CDR). SETTING Primary, secondary and tertiary health care centres across all 33 communities of the NWT. POPULATION NWT residents of all ages with confirmed NGI reported to the NWT CDR from January 1991 through December 2008. MAIN OUTCOME MEASURE Laboratory-confirmed NGI, with a particular emphasis on campylobacteriosis, giardiasis and salmonellosis. RESULTS Campylobacteriosis, giardiasis and salmonellosis were the most commonly identified types of NGI in the territory. Seasonal peaks for all three diseases were observed in late summer to autumn (p<0.01). Higher rates of NGI (all 15 diseases/infections) were found in the 0-9-year age group and in men (p<0.01). Similarly, rates of giardiasis were higher in the 0-9-year age group and in men (p<0.02). A disproportionate burden of salmonellosis was found in people aged 60 years and older and in women (p<0.02). Although not significant, the incidence of campylobacteriosis was greater in the 20-29-years age group and in men (p<0.07). The health authority with the highest incidence of NGI was Yellowknife (p<0.01), while for salmonellosis and campylobacteriosis, it was Tlicho (p<0.01) and for giardiasis, the Sahtu region (p<0.01). Overall, disease rates were higher in urban areas (p<0.01). Contaminated eggs, poultry and untreated water were believed by health practitioners to be important sources of infection in cases of salmonellosis, campylobacteriosis and giardiasis, respectively. CONCLUSIONS The general patterns of these findings suggest that environmental and behavioural risk factors played key roles in infection. Further research into potential individual and community-level risk factors is warranted.