Rectal gonorrhoea in men – is microscopy still a useful tool?

Abstract

Rectal gonorrhoea (GC) in men may cause anal discharge or proctitis, but these symptoms have been shown to correlate poorly with rectal infection. Culture of Neisseria gonorrhoeae from an exposed site offers a readily available, sensitive and cheap diagnostic test, and is currently the gold standard for diagnosis; however, these results can take a few days and therefore do not offer an instant diagnosis. Gram staining of rectal smears for N. gonorrhoeae has a low sensitivity but a high specificity when performed by experienced personnel. We audited whether rectal microscopy increased the number of patients diagnosed and treated for rectal GC at initial presentation at one inner London genitourinary clinic over a 12-month period. One hundred and thirty-six episodes of rectal GC were identified in 132 men. In all, 134/136 had rectal microscopy of whom, 47/134 (35%) were smear-positive for GC. Of the 136 cases, 90 received antibiotics for GC at their first presentation. Twenty-four of 90 (27%) would not have been treated until culture results were available, if rectal microscopy had not been performed. These results suggest that rectal microscopy remains an important tool and increases the proportion of men treated for GC at their first attendance.