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Diagnosis of dysentery (shigellosis)
Medical expert of the article
Last reviewed: 06.07.2025
The diagnosis of dysentery (shigellosis) is established on the basis of clinical and epidemiological data with mandatory laboratory confirmation.
PCR, as well as bacteriological and serological methods of research are used. The coprological method, as well as the results of rectoscopy, are of auxiliary importance.
The bacteriological method is the most widely used. The best results are obtained by seeding feces directly at the patient's bedside, before prescribing antibacterial therapy, and with delivery of the material to the bacteriological laboratory within the first 2 hours from the moment of collection. For the study, particles of feces containing pathological impurities are selected, but not blood. The biomaterial is seeded on selective media: Ploskirev, Levin, etc. A negative result of the bacteriological study of feces can be given on the 3rd-5th day, and a positive one, as a rule, on the 5th-7th day from the moment the material is delivered to the bacteriological laboratory. The frequency of positive results (seeding and identification of the pathogen), even with typical clinical manifestations of shigellosis, does not exceed 60-70%.
Serological methods of diagnosing dysentery (shigellosis) are usually used in doubtful cases and with negative results of bacteriological examination of feces. The titer of specific antibodies in the patient's blood serum and the antigen in the feces are determined. To determine the titer of antibodies, RIGA is usually used, less often - RPGA or PA. The antigens are a suspension of a daily culture of shigella (PA) or an erythrocyte diagnosticum from Zoine and Flexner shigella (RPGA, RIGA). A positive diagnostic titer of antibodies for Sonne shigellosis is 1:100, and for Flexner shigellosis 1:200. An increase in antibody titers over time should be considered more reliable.
For rapid diagnostics, ELISA and latex agglutination reactions are used.
Differential diagnosis of dysentery (shigellosis)
Dysentery (shigellosis) in young children must be differentiated from "simple dyspepsia", salmonellosis, staphylococcal enterocolitis, enteropathogenic Escherichia coli, surgical pathology of the abdominal organs, etc.
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