BACKGROUND We recently reported an increased risk of herpes zoster (shingles or zoster) in children with asthma, but little is known about whether it is true for adults with asthma. We determined whether asthma is associated with an increased risk of zoster in adults. METHODS This study was designed as a population-based case-control study. Zoster cases during the study period were identified among adults (aged ≥ 50 years) who resided in Olmsted County, Minnesota. We compared the frequency of asthma between zoster cases and birthday- and gender-matched controls (1:2 matching) without a history of zoster. Asthma status was ascertained by predetermined criteria. Conditional logistic regression model was used to assess the association of asthma with risk of zoster. RESULTS A total of 371 zoster cases and their 742 matched controls were enrolled. Of the 371 cases, 246 (66%) were females, 348 cases (94%) were Caucasians, and the mean (± standard deviation) age was 66.8±10.7 years. Twenty-three percent (N=87) of zoster cases had a history of asthma, compared to 15% (N=114) in controls. Controlling for pertinent covariates and confounders, there was a significant association between a history of asthma and risk of zoster (adjusted odds ratio: 1.70, 95% CI: 1.20–2.42, p=0.003). Population-attributable risk percent for asthma was about 10%. CONCLUSIONS Asthma is an unrecognized risk factor for zoster in adults. Consideration for immunizing adults with asthma aged over 50 years as a target group should be given.

A risk score was recently derived to predict mortality in adult patients with Gram-negative bloodstream infection (BSI). The aim of this study was to provide external validation of the BSI mortality risk score (BSIMRS) in a population-based cohort. All Olmsted County, Minnesota, residents with Escherichia coli and Pseudomonas aeruginosa BSI from 1/1/1998 to 12/31/2007 were identified. Logistic regression was used to examine the association between BSIMRS and mortality. Area under receiver operating characteristic curve (AUC) was calculated to quantify the discriminative ability of the BSIMRS to predict a variety of short- and long-term outcomes. Overall, 424 unique Olmsted County residents with first episodes of E. coli and P. aeruginosa BSI were included in the study. Median age was 68 (range: 0–99) years, 280 (66%) were women, 61 (14%) had cancer and 9 (2%) had liver cirrhosis. The BSIMRS was associated with 28-day mortality (p<0.001) with an AUC of 0.86. There was nearly 56% increase in 28-day mortality for each point increase in BSIMRS (odds ratio 1.56, 95% confidence intervals: 1.40–1.78). A BSIMRS ≥ 5 had a sensitivity of 74% and a specificity of 87% to predict 28-day mortality with a negative predictive value of 97%. The BSIMRS had AUC of 0.85, 0.85 and 0.81 for 7-, 14- and 365-day mortality, respectively. BSIMRS stratified mortality with high discrimination in a population-based cohort that included patients of all age groups who had a relatively low prevalence of cancer and liver cirrhosis.

ObjectivesAsthmatics have increased risks of airway-related infections. Little is known about whether this is true for non-airway-related serious infections such as Escherichia coli bloodstream infection (BSI). We assessed whether asthma is associated with a risk of developing community-acquired E coli BSI.DesignThe study was designed as a population-based retrospective case–control study.SettingThis population-based study was conducted in Olmsted County, Minnesota.ParticipantsThe study included 259 all eligible community-acquired E coli BSI cases in Olmsted County, MN between 1998 and 2007 and 259 birthday-matched, gender-matched and residency-matched controls.Primary and secondary outcome measuresOnly community-acquired E coli BSI cases as the primary outcome was included. Asthma status as an exposure was ascertained by predetermined criteria. An adjusted OR and 95% CI for the association between asthma and risk of community-acquired E coli BSI was calculated using conditional logistic regression.ResultsOf 259 eligible cases, 179 (69%) were women and mean age was 61±22 years. Of the 259 cases 37 (14%) and 16 (6%) of 259 controls had a prior history of asthma (adjusted OR 2.74; 95% CI 1.11 to 6.76; p=0.029). The population attributable risk of asthma for community-acquired E coli BSI was 9%. Although not statistically significant, there was a borderline association between having a history of food allergy and increased risk of community-acquired E coli BSI (6% vs 2%; adjusted OR 3.51; 95% CI 0.94 to 13.11; p=0.062).ConclusionsBased on the findings of the current population-based, case–control investigation, a history of asthma may be associated with risk of community-acquired E coli BSI. The impact of asthma on risk of microbial infections may go beyond airways.