How is bacterial vaginosis diagnosed?

For bacterial vaginosis, laboratory tests are very necessary for the diagnosis of this disease. The disease cannot be diagnosed without laboratory tests if there is an increase in leucorrhea. Laboratory tests include smear, amine test, culture method, biochemical method, fluorescent antibody method, etc. Smear method and amine test are simple and easy to operate laboratory methods, which are very helpful for diagnosis. If conditions permit, culture or fluorescent antibody test can be performed.

(1) Smear microscopy

Clue cells can be found by taking secretions for smear. Clue cells are epithelial cells with a large number of Gardnerella bacteria attached to their surface. The characteristic is that the surface of the epithelial cells is rough or has fine particles, as if sprinkled with a layer of flour. The bacteria are Gram-negative coccobacilli.

(2) Amine test

Take a drop of potassium hydroxide solution and add it to the vaginal secretions. You can smell the "fishy" ammonia released. This is because the secretions contain a high amount of amines, which can release an ammonia smell when they come into contact with alkali.

(3) Cultivation method

It should be isolated before culture, and round, opaque, smooth-surfaced colonies with a diameter of 0.5 mm can be seen.

(4) Biochemical method

Vaginal secretions were taken for biochemical analysis. Normal women had high lactate levels and low succinate levels, while women with this disease had the opposite values.

(5) Fluorescent antibody method

The smear was stained with fluorescent antibody and examined under a microscope.