Evaluation of vaginal cytology through clue cell detection and Nugent’s score in the laboratory diagnosis of Bacterial Vaginosis in women of reproductive age

Abstract

Background: Diagnosis of various causes of vaginal discharge is done by detailed history taking, physical examination and laboratory investigations. Use Nugent’s score as laboratory tests remains the gold standard however, its use presents challenges in resource limited set ups. Bacterial vaginosis (BV) result from supplanted Lactobacillus species leading to disruption in the normal vaginal microbiome. Objective: The main aim of the study was to evaluate vaginal cytology through clue cell detection and Nugent’s score in the laboratory diagnosis of BV in women of reproductive age. Specifically, the study determined the association between vaginal pH and the quantity of clue cells in BV, and the correlation between vaginal pH and polymorphonuclear cell in BV among non-pregnant women of reproductive age residents this Kisumu County. Methodology: The study was done at Jaramogi Oginga Odinga Teaching and Referral Hospital in 238 female participants aged (15-49yrs) presenting with vaginal discharge at Family Planning and Out Patient Department clinics. Clinical examination was done and laboratory specimens were collected to investigate the causative pathogens of vaginal discharge. Nugent’s score was performed to detect bacterial morphotypes and clue cell in BV using one swab while the other swab was used for high vaginal swab examination was performed using wet mount technique. Results: Results revealed positive correlation between clue cells and vaginal pH (ῥ=0.597, P<0.001). At the same time women without BV [mean (SEM), 4.32 (± 0.05)] had significantly low vaginal pH relative to those with BV [mean (SEM), 4.90, (± 0.05)], P<0.001. Moreover there was, positive correlation between vaginal pH and PMNs (ῥ=0.271, P<0.001). Conclusion: Clue cell detection and vaginal pH are the most useful criteria in the diagnosis of BV among symptomatic patients in resource limited settings as confirmed by the determined associations. However, PMNs should not be considered a criterion in diagnosis of BV even if it correlates well with vaginal pH. Keywords: Bacterial vaginosis, Nugent’s score, pH, Gram stain, Normal flora