Pap Smear vs Gram Stained High Vaginal Smears to Detect Bacterial Vaginosis in Women Between (21-65) Years at Omnipath Medical Laboratories, Harare: A Retrospective Study (October 2023 to September 2024)

Abstract

Disagreement between Gram’s stain and Pap smear diagnostic tests leaves doctors uncertain on which test to trust for clinical decision-making. This study compares the effectiveness of Pap smear method against Gram stain method to detect bacterial vaginosis thereby determining the reliability of Pap smear as a diagnostic tool. Bacterial vaginosis (BV) is a common vaginal condition resulting from an imbalance in the normal bacterial flora. It is characterized by an overgrowth of certain bacteria and can lead to various health complications, including pelvic inflammatory disease and increased susceptibility to sexually transmitted infections. There are often discrepancies in the results obtained from Pap smear cytology reports and Gram’s stain diagnostic methods, leading to challenges in confirming the diagnosis. Bacterial vaginosis has been recorded as the second leading cause of newborn mortality and it costs $4.8 billion to treat annually. A retrospective crosssectional study was done from December 2024 to January 2025 at Omnipath Medical Laboratories involving 200 women aged between 21 and 65 years with suspected cases of bacterial vaginosis. Exclusion criteria included women below 21 years and those above 65 years. Systematic random sampling was used as choice of sampling method. Data collected was analyzed and presented in tables and graphs. Statistical methods including Cohen’s Kappa, specificity, sensitivity, negative and positive predictive values were used to analyze and summarize the data. The most participants were from the age group 21-35 years. From the 200 participants there were 300 samples provided, 173 were High Vaginal Smears (HVS) and 127 were Pap Smears. Hundred patients had provided both swabs and pap smear; 64 of the test results from Pap smear were negative and 36 were positive whereas results from Gram’s stain showed 86 positives and 14 negatives indicating a lack of agreement between two methods. The study highlighted that Pap smear had a low sensitivity when compared against Gram’s staining. The Cohen’s Kappa shows that there is no agreement between the two tests. Gram’s stain had a higher turn-around time compared to Pap smear. The study showed Gram’s staining is a simple procedure that can be done in various settings whereas pap smear is more complex due to the need for proper fixation and processing methods. Based on the observations made from this study, it is recommended that clinicians prioritize gram staining over pap smear in detecting bacterial vaginosis. It is also recommended to have training programs to enhance laboratory personnel skills in reporting HVS and Pap smear based on these findings.