The role of microscopy in the diagnosis of sexually transmitted infections in women.

INTRODUCTION Microscopy of genital secretions is routinely performed in female patients attending genitourinary medicine clinics. It diagnoses only 50-70% of gonorrhoea, 40-80% of trichomoniasis and has no value in the diagnosis of chlamydial infection. This study was therefore conducted to reassess the role of routine microscopy in female patients. SUBJECTS AND METHODS One thousand consecutive women attending the genitourinary medicine clinic of the General Hospital, Birmingham, were studied prospectively. The first 500 women had routine microscopy performed. The second 500 women had microscopy performed only if they complained of symptoms, were known gonorrhoea contacts, or when an abnormal vaginal discharge was noted by the examining clinician. RESULTS In the routine microscopy group, 46 (9.2%) women had gonorrhea; 30 of these were diagnosed by microscopy and subsequently confirmed on culture and 16 by culture alone; of these, two (4.3%) defaulted from follow-up and were not treated. In the selective microscopy group 139 women (28%) did not require microscopy. Thirty three women had positive culture for Neisseria gonorrhoeae. Of these, seven were diagnosed by microscopy, the rest by culture alone. All patients were successfully treated. No patients with trichomoniasis in the routine microscopy group and only two (4.3%) in the selective microscopy group were lost to follow-up. CONCLUSION In this study, the selective policy in the second group led to a significant reduction in microscopy. Such a policy has the benefits of saving time for patients and staff, more efficient utilisation of manpower and resources. It did not lead to any significant delay in the diagnosis and treatment of patients with sexually transmitted infections.