Diagnosis of diphtheria
Last reviewed: 23.04.2024
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Diagnosis of diphtheria is established on a dense whitish-gray fibrinous film on the mucous membrane of the oropharynx, nose, larynx, and the like. With fibrinous inflammation, the pain and hyperemia of the mucous membrane are poorly expressed. The lymph nodes are enlarged according to the local process, dense to the touch, moderately painful. Sharp soreness in swallowing, bright hyperemia, prolonged fever are not characteristic of diphtheria and testify against this diagnosis. Expression of edema of the cervical tissue and oropharynx corresponds to the magnitude of plaque and the degree of general intoxication.
From the methods of laboratory diagnosis, bacteriological research is of the greatest importance. Material taken with a sterile cotton swab from the lesion site is sown on Klawberg's electrial blood Tellurium environment or its modifications. After growth in a thermostat at a temperature of 37 ° C for 24 hours, a bacterioscopic examination is carried out. In case of detection of corynebacteria, diphtheria is given a preliminary response. The final result of the laboratory test is reported 48-72 hours after studying the biochemical and toxigenic properties of the isolated culture. The study of isolated cultures for toxigenicity is crucial to confirm the diagnosis of diphtheria, especially in dubious and diagnostic cases.
To determine the toxigenicity of corynebacteria diphtheria can be found in guinea pigs, but in practical work, the determination is now carried out on dense nutrient media by precipitation in a gel according to Ouchterlony.
Specific antibodies in serum can be detected by the agglutination reaction (RA), RPGA, ELISA, etc.
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