EMERGENCE OF HAEMOPHILUS-DUCREYI RESISTANCE TO TRIMETHOPRIM-SULFAMETHOXAZOLE IN RWANDA

The in vitro susceptibilities of 112 clinical isolates of Haemophilus ducreyi to six antimicrobial agents were determined. These isolates we re obtained in Kigali, Rwanda, during three studies on genital ulcer d isease performed in 1986 (18 isolates), 1988 (23 isolates), and 1991 ( 71 isolates). All H. ducreyi isolates were susceptible to azithromycin , ceftriaxone, ciprofloxacin, and erythromycin; all isolates obtained in 1986 were also susceptible to trimethoprim and to the combination t rimethoprim-sulfamethoxazole. In contrast, 39 and 9% of the isolates o btained in 1988 and 59 and 48% of the isolates obtained in 1991 were r esistant to trimethoprim (MIC, greater than or equal to 4.0 mg/liter) and trimethoprim-sulfamethoxazole (MIC, greater than or equal to 4.0/7 6 mg/liter), respectively. These data indicate that trimethoprim-sulfa methoxazole can no longer be recommended for use in the treatment of c hancroid in Rwanda, and possibly elsewhere in Africa.