Immunochromatographic rapid test to determine β-hemolytic streptococcus group A in patients with erysipelas

Abstract

Introduction. Traditionally, erysipelas has been associated with streptococcal infection. Taking into account the possibility of carriage of the pathogen on the mucous membranes of the upper respiratory tract, we assumed that in patients with erysipelas of various localization, β-hemolytic streptococcus of group A would be detected. Objective: Determine the effectiveness of immunochromatographic test for detecting β-hemolytic streptococcus group A in patients with erysipelas. Materials and methods: The study included 52 patients with various forms of erysipelas. The diagnosis of «Erysipelas» was established clinically. Patients were examined using routine clinical and laboratory methods. To identify the β-hemolytic streptococcus group A antigen, a smear was taken from the mucous membrane of the back wall of the pharynx and tonsils in all patients at the hospital, and a sandwich-membrane immunochromatographic test was used. In order to identify the pathogen from the source of inflammation, in the case of complicated forms of erysipelas, bacteriological method was used. Results: Immunochromatographic smear test revealed the presence of β-hemolytic streptococcus group A in 3 out of 52 patients (7%). Bacteriological examination of the contents of the wound, conducted by 16 patients (31%), did not reveal β-hemolytic streptococcus group A in any of the patients. One of these patients (with a fatal outcome) had a positive result of an immunochromatographic test (2%). In the wound discharge, 8 patients detected bacteria of the family Staphylococcaceae, including in combination with Enterococcus faecalis, Klebsiella mobilis, Proteus Mirabilis and Pseudomonas aeruginosa. In one case, Acinetobacter baumanii from the Moraxellaceae family was isolated. Conclusion: We have not established the effectiveness of the immunochromatographic test for determining β-hemolytic streptococcus group A in the emergency department of a surgical hospital in patients with erysipelas. This is probably due to the frequent use of antibacterial drugs in the prehospital phase. It is impossible to exclude the leading role of other etiological factors in the development of inflammation of soft tissues, clinically similar to streptococcal infection.

Keywords

• erysipelas
• group a streptococcus
• lateral flow test
• skin and soft tissue infections
• diagnostics