Clue Cells on Vaginal Wet Preparation Are Not Associated with Urinary Tract Infections or Positive Urine Cultures

Q: What was the study trying to determine about clue cells and UTIs?

The study assessed whether clue cells on vaginal wet preparation in the emergency department were associated with emergency physician diagnoses of UTIs and with positive urine cultures.

Q: What did the results show regarding UTI diagnoses?

Emergency physicians diagnosed significantly fewer UTI cases among clue cell-positive women compared with those without clue cells.

Q: Were clue cells linked to positive urine cultures or Escherichia coli growth?

No. Clue cells were not associated with a higher likelihood of positive urine cultures or with urine cultures growing Escherichia coli, including among pregnant women.

Sep 27, 2026

Uploaded by lilac

Clue cells on vaginal wet preparation indicate disruption of the vaginal microbiome and have been proposed to increase urinary tract infection (UTI) risk. A retrospective emergency department study analyzed 14,952 encounters in women aged 18+ who had both genital wet preparation and urine testing. Clinicians diagnosed fewer UTI cases among clue cell-positive patients, and clue cells were not linked to positive urine cultures or urine Escherichia coli growth, including in pregnant women.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages5

Reading Time13 min

AccessFree to download

Introduction

Methods

Statistical Analysis

Results

Conclusion

Clue Cells on Vaginal Wet Preparation Are Not Associated with Urinary Tract Infections or Positive Urine Cultures Johnathan Michael Sheele, MD, MHS, MPH* Carolyn Mead-Harvey, MS† Nicole Hodgson, MD‡ * Mayo Clinic, Department of Emergency Medicine, Jacksonville, Florida † Mayo Clinic, Division of Clinical Trials and Biostatistics, Phoenix, Arizona ‡ Mayo Clinic, Department of Emergency Medicine, Phoenix, Arizona Section Editor: Stephen Liang, MD Submission history: Submitted October 5, 2021; Revision received March 3, 2022; Accepted February 8 2022 Electronically published June 18, 2022 Full text available through open access at [http://escholarship.org/uc/uciem_westjem](http://escholarship.org/uc/uciem_westjem) [DOI: 10.5811/westjem.2022.2.55000](DOI: 10.5811/westjem.2022.2.55000) Introduction: Clue cells result from aberrant vaginal microflora and are associated with an increased vaginal pH, which can allow colonization of uropathogens in the vaginal introitus, increasing the risk for urinary tract infections (UTI) . We sought to determine whether clue cells on vaginal wet preparation in the emergency department (ED) are associated with emergency physician diagnoses of UTIs and positive urine cultures. Methods: We conducted a retrospective analysis examining a dataset of women (≥18 years of age) who received both a genital wet preparation and urine testing in the ED. Both chi-square and multivariable regression analysis were performed. Results: We analyzed 14,952 encounters. On both univariable and multivariable analyses, emergency physicians diagnosed significantly fewer clue cell-positive women with a UTI (10 .9% diagnosed with UTI vs 13. 1% without UTI) (P < .001) . Women with clue cells on vaginal wet preparation were not more likely to have a positive urine culture or have a urine culture growing Escherichia coli. Pregnant women with clue cells on vaginal wet preparation were not more likely to have a UTI or have a positive urine culture. Conclusion: Emergency physicians diagnosed significantly fewer women with UTIs when they found clue cells on vaginal wet preparation. Clue cells on vaginal wet preparation were not associated with an increased likelihood of a positive urine culture or having E. coli growing in the urine. [West J Emerg Med. 2022;23(4)468–472 .] INTRODUCTION Genitourinary tract infections, especially urinary tract infections (UTI), are common in the emergency department (ED) .1 Emergency physicians frequently perform vaginal wet preparation on women with genitourinary complaints, especially when there are concerns of vaginitis or sexually transmitted infections (STI). Vaginal wet preparation results can help risk-stratify ED patients for STIs.2 Bacterial vaginosis (BV) is the most common cause of vaginitis in outpatient medicine and results when anaerobic bacteria replace the normal lactobacilli colonizers of the vagina.3 Clue cells are vaginal epithelial cells covered in bacteria from an overgrowth of Gardnerella vaginalis, Mycoplasma hominis, Mobiluncus species, and Peptostreptococcus species.3 Clue cells on wet preparation represent a disruption of the vaginal microbiome and have about a 53-90% sensitivity and 40-100% specificity for BV.4 Some of the risk factors for BV overlap with UTI, including frequent sexual activity, use of spermicide, alterations of vaginal flora, and vaginal douching.3,5 Previous studies suggest that BV is associated with both UTI and positive urine culture.6-11 Some propose that a higher vaginal pH and fewer lactobacilli found with BV allow uropathogens to thrive in the vaginal introitus leading to increased risk for UTI and bacteriuria. 12,13 Women with recurrent UTIs are more likely to have vaginal coliform bacteria, and this colonization often precedes bacteriuria.14 We sought to determine whether the presence of vaginal clue cells was associated with a diagnosis of UTI in the ED, and secondarily whether vaginal clue cells were associated

FAQs

What was the study trying to determine about clue cells and UTIs?

The study assessed whether clue cells on vaginal wet preparation in the emergency department were associated with emergency physician diagnoses of UTIs and with positive urine cultures.

What did the results show regarding UTI diagnoses?

Emergency physicians diagnosed significantly fewer UTI cases among clue cell-positive women compared with those without clue cells.

Were clue cells linked to positive urine cultures or Escherichia coli growth?

No. Clue cells were not associated with a higher likelihood of positive urine cultures or with urine cultures growing Escherichia coli, including among pregnant women.

Sep 27, 2026

Uploaded by lilac