New guidelines are up for bacterial vaginosis
Your next patient presents with a thin, grayish vaginal discharge with a foul-smelling odor. What’s your initial diagnosis?
Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age, according to the Atlanta-based Centers for Disease Control and Prevention (CDC).1 Prevalence estimates range from 10% among low-risk populations to 64% among women at high risk.2,3
About half of women with BV may be asymptomatic.4 Those who do have symptoms may notice a fish-like odor or a thin white or gray vaginal discharge. Women with BV also may have burning during urination or itching around the outside of the vagina.
In most cases, BV causes no complications. However, the infection can give rise to some serious risks, including increasing a woman’s susceptibility to HIV infection if she is exposed to the virus.5 Pregnant women with BV more often have babies who are born early or with low birth weight.
New diagnosis and treatment guidelines for BV will be included in the upcoming update to the 1998 Guidelines for Treatment of Sexually Transmitted Diseases, published by the CDC. The new guidelines are scheduled for publication in April 2002, says Emily Koumans, MD, MPH, a medical epidemiologist with the CDC. While there are no major changes in the guidelines for BV, clinicians should be vigilant in checking for symptoms of the infection, says Koumans.
"Any woman who is symptomatic should get an evaluation," says Koumans. "The evaluation for BV includes the pH [test], a wet mount, a test for amines, and examination of the discharge."
Follow diagnostic steps
Clinicians can diagnosis BV by using clinical or Gram stain criteria. Clinical criteria include the presence of clue cells on microscopic examination; a homogeneous, white, noninflammatory discharge that coats the vaginal walls; a pH reading of greater than 4.5 on vaginal fluid; and a fishy odor of vaginal discharge before or after addition of 10% potassium hydroxide (also known as the "whiff test.") (Check the February 1997 issue of Contraceptive Technology Update, p. 21, for vaginal infection diagnostic tips.)
The new CDC guidelines also note two diagnostic tools that were introduced following the 1998 publication: the FemExam pH and Amines TestCard (Litmus Concepts, Santa Clara, CA) and the Affirm VP III (Becton-Dickinson, Sparks, MD) laboratory test. The FemExam TestCard is a credit card-sized card that contains two colorimetric tests to determine the pH and presence of volatile amines in the vaginal fluid. The Affirm VP III is a nucleic-acid based probe test that can identify trichomoniasis and candidiasis, as well as bacterial vaginosis.6 (CTU reported on the FemExam card in its September 1997 issue, p. 110.)
Drug regimens revised
For treatment of nonpregnant women, the new recommended regimen includes the same three drugs as the 1998 guidelines; however, the order has been slightly revised, says Koumans. The new order is:
- metronidazole (Flagyl, G.D. Searle), 500 mg orally twice a day for seven days; or
- metronidazole gel 0.75% (MetroGel vaginal gel, 3M, St. Paul, MN), one full applicator (5 g) intravaginally twice a day for five days; or
- clindamycin cream 2% (Cleocin, Pharmacia Corp., Peapack, NJ), one full applicator (5 g) intravaginally at bedtime for seven days.
Alternate regimens now offer three options:
- metronidazole, 2 g orally, in a single dose; or
- clindamycin, 300 mg orally twice a day for seven days; or
- clindamycin ovules (Cleocin Vaginal Ovules, Pharmacia Corp.) 100 mg, intravaginally, once at bedtime, for three days. (CTU included information on Cleocin ovules in its November 2000 issue, p. 139.)
BV screening eyed
BV is a strong independent risk factor for adverse pregnancy outcomes.7 The question to screen and treat women in the general population of pregnant women has just been addressed by the third United States Preventive Services Task Force (USPSTF). The task force is a panel of independent, private-sector experts in prevention and primary care organized by the Rockville, MD-based Agency for Healthcare Research and Quality to systematically review medical evidence in developing recommendations for preventive care in the primary care setting.
"When the USPSTF reconvened in 1998, we went through a process of contacting experts, reviewing new literature, and surveying outside organizations to identify new prevention and screening topics that could benefit from a USPSTF assessment," says David Atkins, MD, MPH, coordinator for clinical preventive services at the agency’s Center for Practice and Technology Assessment. "We identified BV as a good candidate due to a lack of consensus on the benefits of screening and treatment and the availability of a number of important studies on the effect of antibiotic treatment of BV during pregnancy."
After a review of the evidence, the USPSTF concluded that there is insufficient evidence to recommend either for or against regular BV screening for women who have had a previous pre-term delivery.8 Such screening is an option for the clinician, however, the task force notes.
"Clinicians should consider the pregnant woman’s history of pre-term delivery, other risk factors for pre-term delivery, and the stage of her pregnancy when deciding whether to screen for BV," notes the USPSTF.
The task force recommends against regularly screening pregnant women who have no symptoms of BV and who have never had a pre-term delivery. Research is ongoing to see whether different treatments or earlier treatment is more effective than treatments tested in previous studies, the task force notes.
References
1. Centers for Disease Control and Prevention. National Center for HIV, STD, and TB Prevention. Bacterial Vaginosis. Atlanta; September 2000.
2. McGregor JA, French JI. Bacterial vaginosis in pregnancy. Obstet Gynecol Surv 2000; 55(5 suppl 1):S1-S19.
3. Schmid GP. The epidemiology of bacterial vaginosis. Int J Gynaecol Obstet 1999; 67(suppl 1):S17-S20.
4. Secor RM. Bacterial vaginosis: Common, subtle, and more serious than ever. Clinician Reviews 2001; 11:59-68.
5. Taha TE, Hoover DR, Dallabetta GA, et al. Bacterial vaginosis and disturbances of vaginal flora: Association with increased acquisition of HIV. AIDS 1998; 12:1,699-1,706.
6. Brown HL, Fuller DA, Davis TE, et al. Evaluation of the Affirm Ambient Temperature Transport System for the detection and identification of Trichomonas vaginalis, Gardnerella vaginalis, and Candida species from vaginal fluid specimens. J Clin Microbiol 2001; 39:3,197-3,199.
7. Guise JM, Mahon SM, Aickin M, et al. Screening for bacterial vaginosis in pregnancy. Am J Prev Med 2001; 20(3 Suppl):62-72.
8. Agency for Healthcare Research and Quality. Screening for Bacterial Vaginosis in Pregnancy. What’s New from the Third USPSTF. Rockville, MD; April 2001.
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