A clinical case of Streptococcus equi subsp. ruminatorum infection in a 9-year-old child

Abstract

Streptococcus equi subsp. ruminatorum is a zoonotic disease that can cause serious morbidity in immunocompromised people. The first case of infection in human was described in 2007. We describe a case of infection in a 9-year-old child with a history of liver transplantation, who was hospitalized for differential diagnosis of high fever on continuous immunosuppressive therapy with Tacrolimus. The examination revealed an increase in the level of systemic inflammatory response markers, cholestasis and cytolysis syndrome markers, which indicated cholangitis. Acute graft rejection was excluded. Streptococcus. equi subsp. ruminatorum was identified in the patient’s blood cultures, which made it possible to diagnose a generalized zoonotic infection (the child was often in contact with horses) with a possible focus in the bile ducts, which required antibiotic therapy in combination with short-term, within 1 day, withdrawal and then a lower dose of immunosuppressive therapy (temporary adjustment of tacrolimus dosage). During the treatment, clinical and laboratory signs of the infectious process improved, and the functional state of the liver graft normalized. Therapy was stopped after negative blood cultures were obtained. This case confirms that S. equi subsp. ruminatorum can cause human disease. We emphasize the utility of molecular biological tests and MALDI-TOF mass spectrometry to be performed in patients with infections caused by group C streptococci.