Key points for diagnosis of bacterial vaginosis

In recent years, it is believed that bacterial vaginosis (BV) is caused by the imbalance of vaginal flora, the reduction of lactobacilli, and the proliferation of other pathogens such as Gardnerella, various anaerobic bacteria, and Campylobacter. BV is actually a mixed infection dominated by Gardnerella. Since it was reported in 1954, it was once called Haemophilus vaginitis, Corynebacterium vaginitis, and nonspecific vaginitis due to unclear understanding of its pathogens. It was not until 1984 that it was officially named BV at a special international conference in Sweden.

Asymptomatic people are easily overlooked. BV can be diagnosed if 3 of the following 4 items are met, among which positive clue cells are essential.

a. Vaginal discharge is a uniform, thin leucorrhea.

b. Vaginal pH>4.5 (due to ammonia production by anaerobic bacteria).

c. Ammonia test is positive: take a small amount of vaginal secretions and place them on a glass slide. Add 1-2 drops of 10% potassium hydroxide solution. If a rotten fish-like fishy smell is produced, it is positive.

d. Clue cells are positive, and more than 20% of clue cells can be seen under a high-power microscope by the hanging drop method. Clue cells are superficial cells shed from the vagina, with a large number of granular substances (such as Gardnerella) attached to their surfaces, making the cell edges unclear.