Head of Unit
Institut Pasteur de Madagascar, Madagascar
Chancroid, an ulcer resembling syphilis but soft and also named ulcus molle, was differentiated from syphilis or ulcus durum in 1852. The origin, infectious or not, was under debate for several decennia until the bacillus of Ducreyi could be cultivated at the beginning of the 20th century, and pure cultures of Haemophilus ducreyi were obtained from 4 cases: 2 were genital, and 2 were extra-genital cases. H. ducreyi is a fine, short, Gram-negative coccobacillus characterised by the appearance of a school of fish when smears are microscopically observed.
While chancroid was prevalent in the Western world early 20th century, it was reported to have almost disappeared in the 1930s but was at the same time highly present in Africa. Authors argued that the disappearance of chancroid in the higher income countries could be explained by improved living standards, better hygiene, overall better health conditions of the population, and perhaps circumcision. However, resurgences and local outbreaks of chancroid were reported in parts of the western world introduced by soldiers, sailors, or travellers.
Chancroid has been reported as a prevalent sexually transmitted infection among men and women in several African countries during 1979- 2000. The few studies published after that period reported much lower numbers. Recent and up-to-date data and reports on chancroid in Africa are scarce. The paucity of data is explained by the absence of rapid and simple diagnostic tools, the application of syndromic management for genital ulcer diseases, and chancroid not being part of surveillance programs. However, H. ducreyi is nowadays found among children with chronic skin ulcers resembling yaws in Africa and the South Pacific region. While chancroid as a genital ulcer disease might be less frequent in Africa nowadays, H. ducreyi is still circulating eventually causing non-genital ulcers.