Friday, July 25, 2014

Gardnerella Vaginalis

Definition

Gardnerella Vaginalis is an infection of the female genital tract by bacteria of the Gardnerella vaginalis strain, often in combination with various anaerobic bacteria. Also called bacterial vaginosis.

Description

Gardnerella vaginalis was originally described by Gardner and Dukes in 1955. The infection often produces a gray or yellow discharge with a "fishy" odor that increases after washing the genitalia with alkaline soaps.

Gardnerella vaginalis is the most common cause of bacterial vaginitis in the sexually active mature patient. The patient complains of a malodorous, nonirritating discharge, and examinations reveal homogenous, gray-white secretions. A transient "fishy odor" may be released on application of 10 percent potassium hydroxide to the vaginal secretion on a glass slide.

Causes

It is assumed that the infection is sexually transmitted. The bacteria are also found in women without a history compatible with a sexually transmitted disease, and often produces no symptoms.

Symptoms

Symptoms of infection typically include a vaginal discharge associated with a "musty" or "fishy" odor. The amount of discharge is quite variable, and there is little vulvar or vaginal irritation associated with this infection, but the pungent odor is usually the chief complaint.

Diagnosis

A wet mount preparation of physiologic saline mixed with vaginal secretions should be examined under low-power and high-power objectives. There are few white blood cells and lactobacilli. The characteristic "clue cells" are identified as numerous stippled or granulated epithelial cells. This appearance is caused by adherence of almost uniformly spaced G vaginalis organisms on their surfaces.

Clumps of G vaginalis organisms may also be noted attached to the edges of epithelial cells or floating free in the preparation. Cultures are seldom necessary to establish a diagnosis.

Treatment

The treatment of choice for G vaginalis is oral metronidazole, 500 mg twice daily for 6 days. A single dose of 2 g has proved effective in treatment of adolescent patients, but in general a 5- to 7-day course of treatment is more effective.

Although it is recommended that sexual partners be treated simultaneously, it is unclear whether this significantly decreases the incidence of recurrent disease.

Contraindications to metronidazole include certain blood dyscrasias and central nervous system diseases. An important side effect is intolerance to alcohol. The drug is contraindicated during early pregnancy and lactation.

Cephradine, 500 mg by mouth 4 times daily for 6 days, will eliminate G vaginalis from the vagina and relieve symptoms but has little effect on the anaerobic flora of the vagina.

Other oral and vaginal preparations have been prescribed but have not proved useful. Douching removes malodorous secretions temporarily but does not cure the infection.

Questions

Does a smear establish the diagnosis of Gardnerella vaginalis?

Is this sexually transmitted?

How can the odor be eliminated?

Will you prescribe a drug to treat the disease?

Should my partner take the medication too?

What are the side effects of metronidazole?

For how long should the drug be taken?

How can a recurrence be prevented?