Journal of the Dow University of Health Sciences (Dec 2012)
Sensitivity and Specificity of Rapid Clinical Diagnostic Test for Bacterial Vaginosis and its Analytical Value
Abstract
Objective Amsel criteria and microbiological techniques are two conventional methods for the diagnosis of bacterial vaginosis. The purpose of this study was to determine the etiology of bacterial vaginosis in low socioeconomic female population of Karachi by comparing Amsel criteria, a bedside technique with standard microbiological methods. Study Design A comparative study carried out at Essa laboratory Karachi from April 2011 to March 2012. Material and Method 373 consecutive high vaginal swabs were taken from women aged 18 to 70 years received at Essa laboratory, Karachi. Diagnosis was made by bedside Amsel criteria and two swabs sent promptly to the microbiology laboratory for gram staining and culture. Results Bacterial vaginosis was determined in 373 women belonging to low socioeconomic population, history along with demographic profile of patients were taken. Overall prevalence of bacterial vaginosis calculated by microbiological method was 78% and by Amsel criteria 62%. Clinical diagnosis of bacterial vaginosis was made if three characteristics of Amsel criteria were present. Amsel criteria had a sensitivity of 77%, specificity 91%, with a positive predictive value of 97% and a negative predictive value of 53%. By microbiologic techniques organism found in highest frequency was Staphylococcus aureus (46%) out of which (35%) were methicillin resistant (MRSA) as confirmed by cefoxitin disc diffusion method, Escherichia Coli (25%) followed by Klebsiella pneumoniae (16%), Enterococcus faecalis (6%), Psuedomonas species (5%) and Proteus species (2%). Conclusion Amsel criteria is convenient for diagnosing bacterial vaginosis at the bedside but its sensitivity is less compared to microbiological techniques which were taken as gold standard. Our study also highlights the high colonization rate of Staphylococcus aureus in particular multidrug resistant strains among females coming from low-socio economic background.
