Over the past few years, research in obstetric and gynecologic infectious diseases has led to improvements in diagnosis and management. Notable advances have been made in preventing group B streptococcus, sexually transmitted diseases, and postoperative pelvic infection.
Despite these successes and the development of broad-spectrum antibiotics, infection remains a serious cause of morbidity and mortality.
This update focuses on 3 studies from the past year:
- A randomized, controlled trial of famciclovir to suppress shedding of recurrent anogenital herpes simplex in women with and without symptoms,
- A randomized, controlled trial of metronidazole versus placebo in gravidas with asymptomatic bacterial vaginosis (BV), and
- The first non-observational investigation that explains the effects of labor on maternal neutrophil phenotype.
Using famciclovir to suppress shedding of recurrent anogenital herpes
Sacks SL. Famciclovir suppression of asymptomatic and symptomatic recurrent anogenital herpes simplex virus shedding in women: a randomized, double-blind, doubledummy, placebo-controlled, parallel-group, single-center trial. J Infect Dis. 2004;189:1341–1347.
- LEVEL I EVIDENCE: RANDOMIZED, CONTROLLED TRIAL
In this study, 169 women with frequently recurring, culture-proven, genital herpes simplex infection were randomized to famciclovir 125 mg, 250 mg, or placebo. Patients kept a daily diary of any symptoms, and each morning performed self-sampling from as high in the vagina as possible, with a second sample taken from external genitalia. This involved swabbing the mons pubis, clitoral hood, labia minora, labia majora, perineum, and the perianal area. Data were analyzed with appropriate statistical tests.
A significant reduction in asymptomatic viral shedding occurred with famciclovir treatment, compared with placebo (P<.0001 while reduction of viral shedding in symptomatic women was dose-dependent: for mg versus>P<.0001 versus for placebo>P<.0001>
This study is notable because viral shedding was reduced in both symptomatic and asymptomatic women. It also opens the door for studies in pregnant women known to have herpes, with the aim of reducing the risk of perinatal transmission.
Does metronidazole eliminate BV in asymptomatic gravidas?
Klebanoff MA, Hauth JC, MacPherson CA, et al. Time course of the regression of asymptomatic bacterial vaginosis in pregnancy with and without treatment. Am J Obstet Gynecol. 2004;190:363–370.
- LEVEL II-1 EVIDENCE: NONRANDOMIZED, CONTROLLED TRIAL
Resolution of BV was defined as a Nugent’s score of less than 7, and restoration of the normal vaginal microflora was defined as a score of less than 4. Overall, 72% and 55% of women in the metronidazole group had scores of less than 7 and less than 4, respectively, at follow-up. In the placebo group, these percentages were 21% and 11%, respectively.
Like most studies of BV, this one is flawed. The reason: Rather than conduct quantitative bacteriology, investigators used the Gram stain to interpret the microbiology of an ecosystem and then related it to a significant medical outcome: preterm birth. They attempted to define BV as an infectious disease and applied principles of infectious disease treatment to it. Most investigators define BV as an alteration in the endogenous microflora, specifically a flora dominated by obligate anaerobic bacteria. However, they treat it as an infection and administer an antibiotic to correct the alteration in the vaginal ecosystem.
Questions raised by this study include: How is asymptomatic BV defined? Is it truly asymptomatic, or have patients simply adapted to their condition? Do these patients have abnormal discharge in color, quantity, and odor?
In addition, the lack of definitive bacteriology in this study necessitates the following assumptions:
- All BV is similar; therefore, similar responses to antimicrobial therapy should be expected.
- A score below 7 but above 4 represents intermediate flora. This microflora is a precursor to BV or predisposes the patient to BV infection.
- A score below 4 represents Lactobacillus-dominant flora.