Serogrouping Neisseria gonorrhoeae: correlation of coagglutination serogroup WII with homosexually acquired infection.

With coagglutination reagents prepared against W antigens, 205 clinical isolates of Neisseria gonorrhoeae were classified into three serogroups WI, WII, and WIII. Of 195 strains isolated from patients who acquired their infection in the Edinburgh area, 85 (44%) belonged to serogroup WI and 110 (56%) to serogroup WII. Serogroup WII accounted for 90% of all isolates from homosexual men and for 34% and 47% of isolates from heterosexual men and women respectively (p less than 0.001). In homosexual men serogroup WII predominated regardless of the anatomical site from which the strain was isolated, and accounted for 94% of rectal, 90% of urethral, and 81% of pharyngeal isolates.