ABSTRACT
DEFINITION, ETIOLOGY AND EPIDEMIOLOGY Chancroid is a sexually transmitted genital ulcer disease, caused by Haemophilus ducreyi, a small, fastidious, gram-negative rod. The World Health Organization estimated that the annual global prevalence of chancroid was 7 million cases in 19951. Although uncommon in North America and declining worldwide, chancroid incidence once exceeded that of syphilis worldwide2,3. Endemic areas include Africa, Asia, and Latin America and there is a strong association with prostitution4. In the USA, episodic outbreaks have been known to occur in the inner cities with the number of cases peaking at a high of 5,001 in 19885. These outbreaks were associated with crack cocaine use and sex in exchange for drugs or money. Since 1988, the numbers have sharply declined to an all-time low of 8 cases reported in the USA in 20115. These data should be interpreted with caution, however, because H. ducreyi is difficult to culture, and as a result, may be underdiagnosed and under-reported5.
