Clinical characteristics of Haemophilus ducreyi genital ulcer disease in Malawi

Background: Chancroid, a sexually transmitted infection (STI) caused by Haemophilus ducreyi resulting in genital ulcer disease (GUD), is now considered rare in many parts of the world. However, chancroid has remained highly prevalent in Malawi since the 1990s. Methods: We combined data from two recent studies conducted in Malawi (2019-2022, 2021) that screened and enrolled patients > 18 years of age presenting to a STI clinic with GUD. Polymerase chain reaction (PCR) was conducted for H. ducreyi and other STIs from ulcer swabs. We evaluated demographic, sexual and clinical characteristics of participants with positive H. ducreyi PCRs to describe the epidemiology of chancroid using descriptive statistics. Results: Among 618 participants with GUD, 137 (22%) tested positive for H. ducreyi by PCR. Of these, most were male 85 (63%), the median age was 27 years (interquartile range [IQR]: 23, 33) and 19 (17%) had HIV co-infection. About a third (n=42, 31%) were co-infected with other STIs. Among 15 (11%) enrolled participants with additional clinical data, most reported one sexual partner in the past month (median = 1 [IQR: 1, 1). However, a history of prior transactional sex was reported by 5/15 (33%). The clinical presentation of the ulcers varied and over half presented with multiple ulcers (53%). Most ulcers (89%) were associated with pain, but few (20%) had associated inguinal lymphadenopathy. Conclusions: This review confirmed the high prevalence and persistence of chancroid in Malawi. However, additional investigations are needed to further characterize the epidemiology of chancroid and determine the reasons for its persistence in Malawi.