Question
What is the relation of vaginal leukocyte (WBC) counts to vaginal and cervical infections in non-pregnant women with bacterial vaginosis (BV)?

Design
This article describes a retrospective study that evaluated whether an elevated vaginal WBC count in non-pregnant women with BV diagnosed at a routine first time STD clinic visit was associated with the presence of vulvovaginal candidiasis (VVC) or STDs and explored the relation of vaginal WBC counts to clinical manifestations of these diseases.  

Participants
Two hundred ninety-six women who were seen by a single provider for a routine first time visit at the Jefferson County Department of Public Health Clinic and who were diagnosed with BV were included.  Women being treated for an STD, pregnant, with a previous hysterectomy, or with missing data were excluded.  The median age was 24 years (range = 14 to 61 years) and 81% were African-American.  Sixteen percent of the 296 women used oral contraceptives, and 46%, 28%, 15%, and 13% reported vaginal discharge, vaginal odor, genital itching, and lower abdominal pain, respectively.  On examination, 87%, 20%, and 16% had abnormal vaginal discharge, vaginal erythema, and mucopurulent cervical discharge, respectively.  

Description of Tests and Diagnostic Standard
Demographic and laboratory data were collected retrospectively.  Vaginal WBCs were quantified in a minimum of 5 X400 microscope fields and categorized as either < 5 WBC per field in all fields or > 5 WBC in at least one field.  Diagnosis of BV was by Amsel criteria.  C. trachomatis was detected by culture of an endocervical swab on McCoy cells; N. gonorrhoeae was detected by culture of an endocervical swab on modified Thayer-Martin medium or by Gonostat (Sierra Diagnostics, Inc., Sonora, CA); T. vaginalis was detected by vaginal wet preparation and also by culture in modified Diamond’s medium for a subset of women; VVC was diagnosed based on vaginal discharge; and genital herpes was diagnosed by clinical findings.  

Main Outcome Measures
The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of vaginal WBC count for the diagnosis of VVC or an STD were calculated.  

Main Results
The vaginal WBC count was elevated in 125 (42%) of 296 women.  Women with an elevated WBC count were more likely to present with abnormal vaginal discharge (p<0.0001), vaginal erythema (p=0.008), mucopurulent cervical discharge (p<0.0001), cervical motion tenderness (p=0.01), or abdominal tenderness (p=0.03).   Women with an elevated WBC count were more likely on multivariate analysis to have VVC (odds ratio (OR) 7.9), chlamydia (OR 3.1), gonorrhea (OR 2.7) or trichomoniasis (OR 3.4).  The performance of vaginal WBC count for diagnosis of VVC or an STD is shown in the table.  

Performance of vaginal leukocyte count for diagnosis of vaginal or cervical infections in 296 nonpregnant women with bacterial vaginosis

Authors’ Conclusions
In non-pregnant women with BV, elevated WBC counts were associated with VVC, trichomoniasis, chlamydia, or gonorrhea.  Vaginal WBC counts had moderate sensitivity and specificity, a low positive predictive value, and a high negative predictive value for vaginal and cervical infections, and have a potential role in assessing STD risk and need for empiric therapy in more resource limited, high STD risk settings that rely predominately on syndromic management for cervical infections.    

Source of funding:  Centers for Disease Control and Prevention Sexually Transmitted Disease Faculty Expansion Program grant.  

For correspondence:  William M. Geisler, UAB STD Program, 703 19^th St. South, 242 Zeigler Research Building, Birmingham, AL 35294-0007.  E-mail address:  wgeisler@uab.edu.