Genital antisepsis--test methodology and efficacy of povidone-iodine

Indications for antiseptic prophylaxis include use prior to urinary catheterization and other transurethral instrumentations, diagnostic or therapeutic instrumentation of the cavum uteri, and operations on the external genitalia and the vagina. Indications for antiseptic therapy include treatment of wounds and of infections of the genital tract and also include treatment of the vaginas of pregnant women to prevent infection in the newborn. For prophylactic antisepsis the aim is the optimal reduction of potentially pathogenic microorganisms. In some fields of application, e.g. before urinary catheterization, an immediate effect on the mucous membrane is required, but on other occasions, such as transvaginal operations, an additional sustained effect is desired. Testing the efficacy of mucous membrane antiseptics, especially for the genital tract, necessitates the establishment of standardized test methods. The variability in vaginal flora at various ages makes it reasonable to study women aged 20-50 years. Studies presented in this paper indicate that microorganism sampling using a cotton swab moistened with neutralizing fluid can be favoured compared to using a rinsing technique and that anaerobic culture techniques enable the measurement of the high reduction factors achieved by very efficient antiseptic procedures. Test methods validated for hand disinfectants are used for calculations and statistical evaluation. The antimicrobial efficacy of six vaginal antiseptic procedures were compared in patients prior to vaginal surgery. Three minutes after treatment, the highest mean reduction (log RF) of the normal vaginal flora as well as of potentially pathogenic microorganisms was obtained by povidone-iodine solution undiluted and povidone-iodine solution 1:10 (log RF 3.60 and 2.68, respectively). Out of three detergents with antimicrobial efficacy, octenidine 0.1% was the most effective preparation (log RF 2.32). Chlorhexidine 0.1%, hexetidine 0.1% and chlorhexidine 0.05% led to lower reduction factors (log RF 1.80, 1.62 and 1.02, respectively). After 30 minutes the log reduction factors were approximating each other in nearly all procedures (log RF 2.79-3.25) except the log RF derived from the procedure performed using chlorhexidine 0.05% (log RF 2.07). Povidone-iodine solutions seem to be the method of choice for mucous membrane antisepsis where an immediate effect is required. If a long period of action is needed all procedures examined, except chlorhexidine 0.05%, are acceptable.