Invasive streptococcal (group A) infection of soft tissues in a Moscow surgical hospital

Objective: To study features and risk factors of soft tissue's invasive streptococcal infection in surgical unit's patients: a) emm-types of the most often recovered streptococcus; b) human immune response for streptococcal antigens (streptolysin-O and the group A carbohydrate antigen); c) main patient's conditions that complicate the course of soft tissue's streptococcal infection.

Methods: 101 surgical unit's patients with soft tissue's infection, which group A streptococcal (GAS) nature, were examined. Emm-types were determined by comparison ofemm gene sequenced part with data of CDC Streptococcus Laboratory. ASO and specific anti-group-carbohydrate IgM were measured with photometry and ELISA4 accordingly. Patient's personal data were analyzed by standard statistical programs.

Results: Among 34 emm-types of all streptococcal isolates emm28 and emm64 were registered only in invasive infection. Emm-types 1, 49, 60, 66, 77, 84, 88 were most often. Among 23 sera from invasive GAS-infection's patients, 15(65%) were ASO-negative, 6 (26%) were ASO-low-positive, and 2 (8%) were positive, but negative for the anti-group-A-carbohydrate IgM.

Conclusions: Lower levels of the humoral immune response as well as risk factors such as trauma, alcoholism, diabetes, chronic venous insufficiency contributed to development of severe forms of GAS-infection. The main streptococcal emm-types for soft tissue's invasive GAS infection in one of Moscow surgical unit's patients in 2008-2011 were registered.