Family clusters of campylobacter infection.

Possible family clusters of campylobacter infection among isolates referred to a single, large public health laboratory were reviewed to determine the proportion of clusters associated with more than one strain of campylobacter. A total of 23 clusters, each made up of members of a single household infected within two months of each other, were identified between September 1996 and January 1999. These accounted for about 5% of all campylobacter infections confirmed during the study period. Thirteen of these families were infected with single strains of C. jejuni and one with C. coli. In ten families specimens were taken over intervals ranging from six to 56 days. In eight clusters more than one strain of C. jejuni was identified and in one family two patients were infected with C. jejuni and one with C. lari. These findings are consistent with the observation that potential sources of campylobacter infection may be contaminated with more than one strain.