title: Standardization of the experimental model of Haemophilus ducreyi infection in human subjects.
abstract: Human volunteers were challenged with Haemophilus ducreyi. Twenty subjects were inoculated with 2 doses (approximately 30 cfu) of live and 1 dose of heat-killed bacteria at 3 sites on the arm. Eight subjects were assigned to biopsy 1 or 4 days after inoculation, and 12 were biopsied after they developed a painful pustular lesion or were followed until disease resolved. Papules developed at 95% of 40 sites infected with live bacteria (95% confidence interval [CI], 83. 1%-99.4%). In 24 sites followed to end point, 27% of the papules resolved, 69% (95% CI, 47.1%-86.6%) evolved into pustules, and 4% remained at the papular stage. Recovery rates of H. ducreyi from surface cultures ranged from 13% to 41%. H. ducreyi was recovered from biopsies of 12 of 15 pustules and 1 of 7 papules, suggesting that H. ducreyi replicates between the papular and pustular stages of disease.
authors.affiliation: Departments of Medicine, Microbiology, and Immunology, Indiana University, Indianapolis, IN 46202, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Al-Tawfiq
authors.forename: A C
authors.initials: AC
authors.lastname: Thornton
authors.forename: B P
authors.initials: BP
authors.lastname: Katz
authors.forename: K R
authors.initials: KR
authors.lastname: Fortney
authors.forename: K D
authors.initials: KD
authors.lastname: Todd
authors.forename: A F
authors.initials: AF
authors.lastname: Hood
authors.forename: S M
authors.initials: SM
authors.lastname: Spinola
mesh_terms: D000328:Adult; D002602:Chancroid / Q000473:pathology* / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006191:Haemophilus ducreyi / Q000302:isolation & purification; D006801:Humans; D008297:Male; D012867:Skin / Q000473:pathology; D013997:Time Factors