276 - Chancroid

Abstract

Haemophilus ducreyi is a gram-negative facultative anaerobic bacterium that causes chancroid, which is a genital ulcer disease that is endemic in Africa and Asia and that facilitates transmission of HIV-1. H. ducreyi is sexually transmitted but is also a major cause of nonsexually transmitted cutaneous ulcers in children in yaws-endemic countries of Africa and the South Pacific islands. In chancroid, infected female sex workers serve as a reservoir for H. ducreyi, and transmission is thought to occur via microabrasions during intercourse. In cutaneous ulcers, asymptomatic colonization of the skin, flies, and fomites provide environmental reservoirs that allow the bacterium to cause infection following minor skin trauma. In genital ulcers, H. ducreyi is frequently cotransmitted with herpes simplex virus and Treponema pallidum, the causative agent of syphilis. In cutaneous ulcers, coinfection is common with Treponema pallidum subsp. pertenue, which is the causative agent of yaws. Although genital and cutaneous ulcers caused by H. ducreyi are typically nonindurated and very painful with ragged edges, clinical diagnosis is unreliable, so definitive diagnosis requires either a positive culture or polymerase chain reaction test. The most reliable treatment regimens are macrolides, quinolones, or third-generation cephalosporins.