The vaginitis wet mount test (sometimes called a vaginal smear) is a test to detect an infection of the vagina or inflammation of the vagina and the area around the vagina (vulva). A vaginitis test looks for the cause of vaginal irritation and discharge, which is usually a yeast, bacterial, or parasitic infection. The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. Vaginitis is often caused by an infection, but it may also be caused by a reaction to vaginal products such as soap, bath oils, spermicidal jelly, or douches. Vaginitis may cause symptoms such as vaginal itching, pain, or discharge.
Infections that can cause vaginitis are common and include:
- Yeast infection. A vaginal yeast infection is caused by a type of yeast called Candida albicans. A yeast infection is also called a candida infection, or candidiasis. A vaginal yeast infection often causes itching and a white, lumpy discharge that looks like cottage cheese. It also causes pain with sexual intercourse. A yeast infection is not a sexually transmitted infection (STI) .
- Trichomoniasis. Trichomoniasis is an infection caused by a parasite ( Trichomonas vaginalis). It is sometimes called trichomonas infection, trichomonal infection, or simply trich (say “trick”). Trichomoniasis causes a vaginal discharge that is yellow-green, foamy, and bad-smelling. Pain with sex or urination may be present. Lower belly pain may also be present. Trichomoniasis is spread by sexual contact and is an STI.
- Bacterial vaginosis. Bacterial vaginosis is a change in the balance of bacteria that are normally present in the vagina. The vaginal discharge is thin and milky with a strong fishy odor. Many women have no symptoms. Bacterial vaginosis is not an STI.
- Other sexually transmitted infections (STIs). Infections such as chlamydia, genital warts, syphilis, herpes simplex, and gonorrhea can also affect the vagina. These infections are found by doing other tests.
A vaginal sample may be tested by:
- Wet mount. A sample of the vaginal discharge is placed on a glass slide and mixed with a salt solution. The slide is looked at under a microscope for bacteria, yeast cells, trichomoniasis (trichomonads), white blood cells that show an infection, or clue cells that show bacterial vaginosis.
- KOH slide. A sample of the vaginal discharge is placed on a slide and mixed with a solution of potassium hydroxide (KOH). The KOH kills bacteria and cells from the vagina, leaving only yeast for a yeast infection.
- Vaginal pH. The normal vaginal pH is 3.8 to 4.5. Bacterial vaginosis, trichomoniasis, and atrophic vaginitis often cause a vaginal pH higher than 4.5.
- Whiff test. Several drops of a potassium hydroxide (KOH) solution are added to a sample of the vaginal discharge. A strong fishy odor from the mix means bacterial vaginosis is present.
How the Test is Performed
- You lie on your back on the exam table. Your feet are supported by footrests.
- The health care provider gently inserts an instrument (speculum) into the vagina to hold it open so the provider can see inside.
- A sterile, moist cotton swab is gently inserted into the vagina to take a sample of discharge.
- The swab and speculum are removed.
The discharge is sent to a lab. There, it is placed onto a slide. It is then viewed under a microscope and checked for signs of infection.
How to Prepare for the Test
- In the 2 days before the test, DO NOT use creams or other medicines in the vagina.
- DO NOT douche. (You should never douche. Douching can cause infection of the vagina or uterus.)
How the Test will Feel
There may be slight discomfort when the speculum is inserted into the vagina.
Why the Test is Performed
The test looks for the cause of vaginal irritation and discharge.
Normal Results
A normal test result means there are no signs of an infection.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results mean there is an infection. The most common infections are due to one or a combination of the following:
- Bacterial vaginosis. Bacteria that normally live in the vagina overgrow, causing a heavy, white, fishy-smelling discharge and possibly a rash, painful intercourse, or odor after intercourse.
- Trichomoniasis, a sexually transmitted disease
- Vaginal yeast infection
Risks
There are no risks with this test.
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