Laura MacDougall

Spread of Cryptococcus gattii in British Columbia, Canada, and Detection in the Pacific Northwest, USA

Cryptococcus gattii, emergent on Vancouver Island, British Columbia (BC), Canada, in 1999, was detected during 2003–2005 in 3 persons and 8 animals that did not travel to Vancouver Island during the incubation period; positive environmental samples were detected in areas outside Vancouver Island. All clinical and environmental isolates found in BC were genotypically consistent with Vancouver Island strains. In addition, local acquisition was detected in 3 cats in Washington and 2 persons in Oregon. The molecular profiles of Oregon isolates differed from those found in BC and Washington. Although some microclimates of the Pacific Northwest are similar to those on Vancouver Island, C. gattii concentrations in off-island environments were typically lower, and human cases without Vancouver Island contact have not continued to occur. This suggests that C. gattii may not be permanently colonized in off-island locations.

Spread of Cryptococcus gattii into Pacific Northwest Region of the United States

This organism should be recognized as an emerging pathogen in the United States.

Epidemiology of Cryptococcus gattii, British Columbia, Canada, 1999–2007

Incidence is high, but the predominant strain does not seem to cause greater illness or death than do other strains.

Community-associated Methicillin-resistant Staphylococcus aureus, Canada

A total of 184 methicillin-resistant Staphylococcus aureus (MRSA) strains were collected from patients who sought treatment primarily for skin and soft tissue infections from January 1, 1999, to March 31, 2002, in east-central Saskatchewan, Canada. Molecular subtyping analysis using pulsed-field gel electrophoresis showed 2 major clusters. Cluster A (n = 55) was composed of a multidrug-resistant MRSA strain associated with a long-term care facility and was similar to the previously reported nosocomial Canadian epidemic strain labeled CMRSA-2. Cluster B (n = 125) was associated with cases identified at community health centers and was indistinguishable from a community-associated (CA)-MRSA strain identified previously in the United States (USA400). Cluster B remained susceptible to a number of classes of antimicrobial agents and harbored the lukF-PV and lukS-PV toxin genes. Over 50% of both clonal groups displayed high-level resistance to mupirocin. This is the first report of the USA400 strain harboring the lukF-PV and lukS-PV toxin genes in Canada.

Cryptococcus gattii Dispersal Mechanisms, British Columbia, Canada

C. gattii may be spread through soil disturbances, wind, water, distribution of tree and soil byproducts, and human movement.

Population distribution and burden of acute gastrointestinal illness in British Columbia, Canada

BackgroundIn developed countries, gastrointestinal illness (GI) is typically mild and self-limiting, however, it has considerable economic impact due to high morbidity.MethodsThe magnitude and distribution of acute GI in British Columbia (BC), Canada was evaluated via a cross-sectional telephone survey of 4,612 randomly selected residents, conducted from June 2002 to June 2003. Respondents were asked if they had experienced vomiting or diarrhoea in the 28 days prior to the interview.ResultsA response rate of 44.3% was achieved. A monthly prevalence of 9.2% (95%CI 8.4 – 10.0), an incidence rate of 1.3 (95% CI 1.1–1.4) episodes of acute GI per person-year, and an average probability that an individual developed illness in the year of 71.6% (95% CI 68.0–74.8), weighted by population size were observed. The average duration of illness was 3.7 days, translating into 19.2 million days annually of acute GI in BC.ConclusionThe results corroborate those from previous Canadian and international studies, highlighting the substantial burden of acute GI.

Risk Factors for Cryptococcus gattii Infection, British Columbia, Canada

To determine whether particular environmental, medical, or behavioral risk factors existed among Cryptcoccus gattii–infected persons compared with the general population, we conducted a sex-matched case−control study on a subset of case-patients in British Columbia (1999–2001). Exposures and underlying medical conditions among all case-patients (1999–2007) were also compared with results of provincial population–based surveys and studies. In case−control analyses, oral steroids (matched odds ratio [MOR] 8.11, 95% confidence interval [CI] 1.74–37.80), pneumonia (MOR 2.71, 95% CI 1.05–6.98), and other lung conditions (MOR 3.21, 95% CI 1.08–9.52) were associated with infection. In population comparisons, case-patients were more likely to be >50 years of age (p<0.001), current smokers (p<0.001), infected with HIV (p<0.001), or have a history of invasive cancer (p<0.001). Although C. gattii is commonly believed to infect persons with apparently healthy immune systems, several immunosuppressive and pulmonary conditions seem to be risk factors.

Frozen chicken nuggets and strips--a newly identified risk factor for Salmonella Heidelberg infection in British Columbia, Canada.

Salmonella enterica var. Heidelberg was isolated from an unusual food source during routine case follow-up, prompting a case control investigation of frozen chicken nuggets and strips. Most frozen nuggets and strips are raw; however, par-frying lends a cooked appearance. As such, suitable food preparation precautions might not be undertaken by consumers. Cases were confirmed in the laboratory between 1 January and 1 April 2003. Controls were generated through forward-digit dialing and individually matched by age category. Telephone interviews were conducted, and limited sampling of unopened product was performed. Eighteen matched pairs were interviewed. The odds of infection were 11 times higher in individuals who had consumed frozen processed chicken nuggets and strips (95% confidence interval, 1.42 < odds ratio < 85.20). One-third of cases and controls considered frozen nuggets and strips to be precooked, and one quarter used the microwave, an ill-advised cooking method. Consumer misconceptions contributed to the risk of infection. Clear labels identifying nuggets and strips as raw poultry are needed.

Protective Behavior Survey, West Nile Virus, British Columbia

We investigated personal protective behaviors against West Nile virus infection. Barriers to adopting these behaviors were identified, including the perception that DEET (N,N-diethyl-m-toluamide and related compounds) is a health and environmental hazard. Televised public health messages and knowing that family or friends practiced protective behaviors were important cues to action.

Challenges of Investigating Community Outbreaks of Cyclosporiasis, British Columbia, Canada

Investigations of community outbreaks of cyclosporiasis are challenged by case-patients’ poor recall of exposure resulting from lags in detection and the stealthy nature of food vehicles. We combined multiple techniques, including early consultation with food regulators, traceback of suspected items, and grocery store loyalty card records, to identify a single vehicle for a cyclosporiasis outbreak in British Columbia, Canada, in 2007.