Multicenter Evaluation of Clinical Diagnostic Methods for Detection and Isolation of Campylobacter spp. from Stool.

The use of culture-independent diagnostic tests (CIDTs), such as stool antigen tests, as standalone tests for the detection of Campylobacter in stool is increasing. We conducted a prospective, multicenter study to evaluate the performance of stool antigen CIDTs compared to culture and PCR for Campylobacter detection. Between July and October 2010, we tested 2,767 stool specimens from patients with gastrointestinal illness with the following methods: four types of Campylobacter selective media, four commercial stool antigen assays, and a commercial PCR assay. Illnesses from which specimens were positive by one or more culture media or at least one CIDT and PCR were designated "cases." A total of 95 specimens (3.4%) met the case definition. The stool antigen CIDTs ranged from 79.6% to 87.6% in sensitivity, 95.9 to 99.5% in specificity, and 41.3 to 84.3% in positive predictive value. Culture alone detected 80/89 (89.9% sensitivity) Campylobacter jejuni/Campylobacter coli-positive cases. Of the 209 noncases that were positive by at least one CIDT, only one (0.48%) was positive by all four stool antigen tests, and 73% were positive by just one stool antigen test. The questionable relevance of unconfirmed positive stool antigen CIDT results was supported by the finding that noncases were less likely than cases to have gastrointestinal symptoms. Thus, while the tests were convenient to use, the sensitivity, specificity, and positive predictive value of Campylobacter stool antigen tests were highly variable. Given the relatively low incidence of Campylobacter disease and the generally poor diagnostic test characteristics, this study calls into question the use of commercially available stool antigen CIDTs as standalone tests for direct detection of Campylobacter in stool.

Impact of rurality, broiler operations, and community socioeconomic factors on the risk of campylobacteriosis in Maryland.

OBJECTIVES: We evaluated the combined impact of community-level environmental and socioeconomic factors on the risk of campylobacteriosis. METHODS: We obtained Campylobacter case data (2002-2010; n = 3694) from the Maryland Foodborne Diseases Active Surveillance Network. We obtained community-level socioeconomic and environmental data from the 2000 US Census and the 2007 US Census of Agriculture. We linked data by zip code. We derived incidence rate ratios by Poisson regressions. We mapped a subset of zip code-level characteristics. RESULTS: In zip codes that were 100% rural, incidence rate ratios (IRRs) of campylobacteriosis were 6 times (IRR = 6.18; 95% confidence interval [CI] = 3.19, 11.97) greater than those in urban zip codes. In zip codes with broiler chicken operations, incidence rates were 1.45 times greater than those in zip codes without broilers (IRR = 1.45; 95% CI = 1.34, 1.58). We also observed higher rates in zip codes whose populations were predominantly White and had high median incomes. CONCLUSIONS: The community and environment in which one lives may significantly influence the risk of campylobacteriosis.

Racial differences in disease phenotypes in patients with Crohn's disease.

BACKGROUND: Our objectives were to assess the differences in perforating disease behavior, disease severity, and extraintestinal manifestations (EIM) in patients with Crohn's disease (CD) by race. MATERIALS AND METHODS: We identified outpatients with CD evaluated at the University of Maryland Gastroenterology Faculty Practice office or the Baltimore Veterans Affairs Maryland Health Care System, from 1997 to 2005. We assessed age at diagnosis, disease behavior, disease location, need for surgery and EIM. RESULTS: Race was not associated with perforating disease behavior (relative risk [RR] 0.79, 95% confidence interval [CI] 0.46-1.35), need for surgery (RR 0.89, 95% CI 0.56-1.12), and EIM of CD (RR 0.77, 95% CI 0.46-1.27). White patients were significantly more likely to have ileal disease, whereas African American patients were significantly more likely to have ileocolonic and colonic disease. Age at diagnosis younger than 40 years (odds ratio [OR] 4.41, 95% CI 1.84-10.56) and ileocolonic disease (OR 2.39, 95% CI 1.24-4.63) were independent risk factors for perforating disease behavior. Similarly, age at diagnosis younger than 40 (OR 2.79, 95% CI 1.45-5.33), ileal disease (OR 3.76, 95% CI 1.66-8.48), and ileocolonic disease (OR 2.57, 95% CI1.21-5.46) were associated with the need for surgery. Female gender (OR 4.23, 95% CI 1.87-9.58) and a positive family history of CD (OR 3.45, 95% CI 1.49-8.0) were associated with joint manifestations of CD. DISCUSSION: We did not detect differences in disease behavior, severity, or joint EIM by race. Although African American patients were more likely to have ileocolonic or colonic disease, these factors did not affect disease behavior or severity.