Microscopy of vaginal discharge according to Hay-Ison criteria

Microscopy of vaginal discharge according to Hay-Ison criteria allows you to assess the state of the vaginal microflora and determine whether its composition corresponds to normal lactobacillary flora or has signs of bacterial vaginosis.

The main object of assessment is the microscopic picture of the vaginal smear after staining. The laboratory specialist determines the number and ratio of morphotypes of lactobacilli and mixed bacterial flora. Bacterial vaginosis is characterized by a decrease in the number of lactobacilli and a predominance of mixed bacterial flora. PubMed Central (PMC)

Hay-Ison criteria:

• First degree — normal flora, Lactobacillus morphotypes predominate.
• II degree — intermediate state: the number of lactobacilli is reduced, mixed bacterial flora is present.
• III degree — a picture typical of bacterial vaginosis: lactobacilli are few or absent, mixed bacterial morphotypes predominate. PubMed Central (PMC)

Some laboratory versions of the description also use 0 and IV degrees: 0 — no bacteria are detected in the smear, IV — gram-positive cocci predominate. King's College London

When is research recommended?

The test may be ordered if there is a change in the nature of vaginal discharge, an unpleasant odor, discomfort, or to clarify the state of the vaginal microflora on the recommendation of a doctor. Bacterial vaginosis can occur without pronounced symptoms. rcpath.org

Research material

For analysis use vaginal discharge (swab), which are examined microscopically.

Preparation

Before collecting the material, it is advisable to follow the recommendations of the laboratory and the doctor. If the patient uses vaginal medications, undergoes antibacterial or antifungal treatment, the medical professional should be informed about this, as the treatment may affect the composition of the microflora and the results of the study.

How to evaluate the result

The detection of Hay-Ison grade II or III should not be considered in isolation from clinical manifestations. The result is evaluated together with symptoms, examination and, if necessary, other laboratory tests. Grade III corresponds to the microscopic picture characteristic of bacterial vaginosis, while stage II describes an intermediate state of microflora.