Modifiable risk factors for invasive meningococcal disease during an Edmonton, Alberta outbreak, 1999-2002.
BACKGROUND
An outbreak of invasive meningococcal disease (IMD) in metro Edmonton, Alberta, Canada between December 1999 and June 2002 resulted in 84 laboratory-confirmed cases. Most cases were infected with Neisseria meningitidis serogroup C, and the highest age-specific incidence was observed in the 15-19 year age group.


METHODS
A case-control study was conducted to identify modifiable IMD risk factors among outbreak cases. Two controls were matched to each case on age and sex, and were recruited through random-digit dialing. A questionnaire was telephone-administered to 132 study participants (44 cases, 88 controls). Conditional logistic regression was utilized to calculate risk measures.


RESULTS
Multivariate analysis revealed three statistically significant risk factors: bar patronage (OR 35.2; 95% CI: 2.64-468), "rave" attendance (OR 12.8; 95% CI: 1.47-111) and maternal smoking (OR 8.88; 95% CI: 1.67-47.4). Humidifier use in the home was protective (OR 0.07; 95% CI: 0.009-0.64).


CONCLUSIONS
While the precision of risk estimates was low in the multivariate model, this study has identified rave attendance as an emergent IMD risk factor.
Honish
Lance
L
Department of Public Health Sciences, School of Public Health, University of Alberta, Edmonton, AB. lhonish@cha.ab.ca
Soskolne
Colin L
CL
Senthilselvan
Ambikaipakan
A
Houston
Stan
S
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000416:Alberta / Q000453:epidemiology; D000428:Alcohol Drinking / Q000009:adverse effects; D016022:Case-Control Studies; D003441:Crowding; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D015999:Multivariate Analysis; D009345:Neisseria meningitidis / Q000302:isolation & purification*; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000150:complications; D011795:Surveys and Questionnaires