Etiology of urethritis in Thai men

The etiology of urethritis was determined for 303 Thai men with urethral discharge containing 5 or more polymorphonuclear cells (PMN)/high power field (hpf) and 132 men with a discharge containing less than 5 PMN/hpf. Neisseria gonorrhoeae was isolated significantly more often from men with greater than or equal to 5 PMN/hpf than from men with less than 5 PMN/hpf (42% vs 1%, P less than .0001). Chlamydia trachomatis was also isolated more often from patients with greater than or equal to 5 PMN/hpf than from men with less than 5 PMN/hpf (16% vs 8%, P less than .03). Ureaplasma urealyticum was isolated with nearly equal frequency from both groups of patients (45% vs 37%). Among men with a urethral exudate containing greater than or equal to 5 PMN/hpf, N. gonorrhoeae was isolated as the only pathogen from 19% and in combination with C. trachomatis or U. urealyticum in 23% of these men. C. trachomatis or U. urealyticum, but not N. gonorrhoeae, was isolated from 30%, and no pathogen was isolated from 28% of these men. Among men with urethral exudate containing less than 5 PMN/hpf, N. gonorrhoeae was isolated from only 1%, C. trachomatis or U. urealyticum from 41%, and no pathogen from 58%. These findings suggest that all Thai men with urethral discharge containing greater than or equal to 5 PMN/hpf should be treated for non-gonococcal urethritis and for gonococcal urethritis if gram-negative diplococci are demonstrated on gram stain of the urethral discharge. Men with urethritis with less than 5 PMN/hpf should be treated for only non-gonococcal urethritis.