Isolation of Haemophilus species from the genital tract.

Haemophilus influenzae was isolated from the urethra of three of 85 men attending a sexually transmitted diseases clinic. These isolates of H. influenzae were nonencapsulated; one was biotype III, and two were biotype IV. Haemophilus parainfluenzae was isolated from the urethra or coronal sulcus of five men; three isolates were biotype II, and two were biotype III. Neither H. influenzae nor H. parainfluenzae was isolated from the genital secretions of 84 women. Haemophilus ducreyi and Haemophilus equigenitalis (contagious equine metritis bacterium) were not isolated from any of the 169 patients.