Bronchiolitis in Inuit children from a Canadian central arctic community, 1995-1996.

During the winter and summer of 1996 two outbreaks of bronchiolitis occurred among Inuit children in the Canadian arctic community of Arviat. The epidemiology and clinical features of these epidemics were studied through a chart review of bronchiolitis cases occurring from September 1, 1995 to August 31, 1996. The attack rate over the year was 57% and the incidence was 1.25 cases per child-year at risk. The median age of cases was 9 months. Children developing bronchiolitis were more likely to be male (p = 0.006). Respiratory syncytial virus (RSV) was isolated from 17 cases occurring in January/February. The hospitalization rate during those two months was 38%, mortality was 3.3%, and demands upon local health care resources were high. Parainfluenza virus type 3 was isolated from 8 cases occurring during a second smaller outbreak in July/August. Hospitalized children were more likely to be bottle-fed (p = 0.01), and duration of hospitalization was greater for RSV positive versus negative children (p = 0.002). Among those hospitalized 22% required a second admission for the same illness. Identification of prevention strategies awaits an improved understanding of the role of agent, host and environmental factors in the pathophysiology of bronchiolitis in this population.

An enzyme-linked immunosorbent assay-based isolation procedure for verotoxigenic Escherichia coli.

A colony enzyme-linked immunosorbent assay using the hydrophobic grid membrane filter format was developed for the isolation of verotoxigenic Escherichia coli from human and food samples. The method utilizes monoclonal antibodies directed against the verotoxins and is sensitive to all verotoxin 1- and/or 2-producing serotypes. E. coli that produced a minimum of 2 x 10(2) and 2 x 10(3) 50% cytotoxic doses per ml of verotoxins 1 and 2, respectively, were detectable. In a method comparison using human stool specimens, this procedure isolated 29% more E. coli O157 than did the standard sorbitol-MacConkey agar procedure, with no false-positive reactions. When applied to meat, 11 of 20 samples positive for verotoxin by polymyxin extraction yielded verotoxigenic E. coli of a variety of serotypes including O157:H7. Four false positives were noted. This procedure provides a sensitive means for the isolation of verotoxigenic E. coli and should facilitate recovery of those serotypes that are otherwise indistinguishable from nonpathogenic strains.