Molecular characterization of Haemophilus ducreyi strains from Jackson, Mississippi, and New Orleans, Louisiana.

Chancroid, a sexually transmitted disease caused by Haemophilus ducreyi, is one of the most common genital ulcer diseases in developing countries. In the United States, while less common, the disease has been associated with outbreaks in inner cities, particularly among persons who engage in sex for drugs or money. Two outbreaks of chancroid were recently studied in the United States, one in New Orleans (from 1990 to 1992) and one in Jackson, Mississippi (from 1994 to 1995). By use of ribotyping, plasmid content, and antibiotic susceptibility, the chancroid cases in New Orleans were found to be due to a limited number of strains, consistent with a limited introduction of H. ducreyi into this community. The H. ducreyi isolates from New Orleans and Jackson had different ribotype patterns, suggesting that the two outbreaks were probably not linked.