Haemophilus ducreyi as a cause of skin ulcers
Authors: Stanley M Spinola
Journal: The Lancet Global Health (2014)

In a yaws-endemic area, Oriol Mitjà and colleagues1Mitjà O Lukehart SA Pokowas G et al.Haemophilus ducreyi as a cause of skin ulcers in children from a yaws-endemic area of Papua New Guinea: a prospective cohort study.Lancet Glob Health. 2014; 2: e235-e241Summary Full Text Full Text PDF Scopus (85) Google Scholar show that Haemophilus ducreyi causes skin ulcers in about 7% of children. In the context of empirical therapy, this important work underscores the need to periodically assess assumptions about epidemiology. H ducreyi was thought to be exclusively transmitted by abrasions that occur during sexual intercourse. In human inoculation experiments, 106 H ducreyi cells did not infect intact skin, but as few as one bacterium delivered by a puncture wound caused infection.2Spinola SM Wild LM Apicella MA Gaspari AA Campagnari AA Experimental human infection with Haemophilus ducreyi.J Infect Dis. 1994; 169: 1146-1150Crossref PubMed Scopus (112) Google Scholar The high prevalence of skin ulcers could be due to minor trauma and contact between infected children or a clone of H ducreyi that can penetrate intact skin. 64% of the villagers infected with H ducreyi were male.1Mitjà O Lukehart SA Pokowas G et al.Haemophilus ducreyi as a cause of skin ulcers in children from a yaws-endemic area of Papua New Guinea: a prospective cohort study.Lancet Glob Health. 2014; 2: e235-e241Summary Full Text Full Text PDF Scopus (85) Google Scholar In experimental infection, men were twice as likely as women to develop pustules,3Janowicz DM Ofner S Katz BP Spinola SM Experimental infection of human volunteers with Haemophilus ducreyi: fifteen years of clinical data and experience.J Infect Dis. 2009; 199: 1671-1679Crossref PubMed Scopus (62) Google Scholar and there was no immunity to reinfection;4Spinola SM Bong CTH Faber AL et al.Differences in host susceptibility to disease progression in the human challenge model of Haemophilus ducreyi infection.Infect Immun. 2003; 71: 6658-6663Crossref PubMed Scopus (36) Google Scholar sex and an absence of immunity might contribute biologically to the prevalence of skin ulcers. Single-dose azithromycin prevented infection from weekly H ducreyi inoculation for nearly 2 months.5Thornton AC O'Mara Jr, EM Sorensen SJ et al.Prevention of experimental Haemophilus ducreyi infection: a randomized, controlled clinical trial.J Infect Dis. 1998; 177: 1608-1613Crossref PubMed Scopus (32) Google Scholar If strains are susceptible, mass treatment of yaws with azithromycin could treat and prevent H ducreyi infection. Mitjà and colleagues1Mitjà O Lukehart SA Pokowas G et al.Haemophilus ducreyi as a cause of skin ulcers in children from a yaws-endemic area of Papua New Guinea: a prospective cohort study.Lancet Glob Health. 2014; 2: e235-e241Summary Full Text Full Text PDF Scopus (85) Google Scholar speculate that syndromic management of genital ulcers drove H ducreyi into the paediatric population. Most genital strains are susceptible to only quinolones, macrolides, and third-generation cephalosporins. Penicillin is used empirically to treat skin ulcers in the south Pacific; so far, all cutaneous isolates have been β-lactamase negative.6Ussher JE Wilson E Campanella S Taylor SL Roberts SA Haemophilus ducreyi causing chronic skin ulceration in children visiting Samoa.Clin Infect Dis. 2007; 44: e85-e87Crossref PubMed Scopus (47) Google Scholar, 7Marckmann P Hojbjerg T von Eyben FE Christensen I Imported pedal chancroid: case report.Genitourin Med. 1989; 65: 126-127PubMed Google Scholar The cutaneous strains might be older clone(s) of H ducreyi that flew under the empirical radar. I declare no competing interests. Haemophilus ducreyi as a cause of skin ulcers in children from a yaws-endemic area of Papua New Guinea: a prospective cohort studyIn this yaws-endemic community, H ducreyi is an important and previously unrecognised cause of chronic skin ulceration. Reactive syphilis serology caused by latent yaws can occur in ulcers with the presence of H ducreyi alone. The introduction of PCR for ulcer surveillance could improve the accuracy of diagnosis in countries with yaws eradication campaigns. Full-Text PDF Open Access