Vaginal fluid pH as a screening test for vaginitis

OBJECTIVE: To assess how effective the pH test can detect infectious vaginitis. METHODS: Ambulatory gynecological patients attending the gynecological out-patient department of Srinagarind Hospital from May 1 to July 31, 1997 were assessed for vaginitis by history, overall physical examination and vaginal examination. Specimens were collected for microbiological examination and measurement of pH level. RESULTS: Among 422 women recruited, a vaginal fluid pH level greater than 4.5 was found in 149 (35.3%) cases. The vaginal fluid pH as a screening test for infectious vaginitis showed a sensitivity of 49.7% (95% C.I.: 42.6-56.9). When using vaginal fluid pH combined with clinical symptoms and signs to screen for vaginitis the sensitivity was 67.5% (95% C.I.: 60.4-73.9). If a pH test was used to screen for BV, its sensitivity was 73.4% (95% C.I.; 60.7-83.3). Using a pH test in combination with clinical symptoms and signs of vaginitis to screen for BV, its sensitivity was 81.3% (95% C.I.: 69.2-89.5). CONCLUSION: Vaginal fluid pH combined with clinical symptoms and signs had a considerably high sensitivity to screen for BV.