[1] This species causes the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia.

[1] Chancroid starts as an erythematous papular lesion that breaks down into a painful bleeding ulcer with a necrotic base and ragged edge.

It has also been found to cause chronic skin ulceration away from the genitalia, infect children and adults, and behave in a manner that mimics yaws.

[1] This species of bacterium has pili, fine and tangled appendages composed predominantly of protein, that allow bacteria to attach to surfaces, including those of cells.

This bond can make it difficult to isolate a single cell of Haemophilus ducreyi, hindering the genetic studies that have been done on the microbe.

[1] There are specific temperature and nutritional necessities for the pathogen to grow, requiring advanced laboratory equipment to study the bacteria.