CASO CLINICO   

La Rivista Italiana della Medicina di Laboratorio 2020 Giugno;16(2):119-28

DOI: 10.23736/S1825-859X.20.00055-9

Copyright © 2020 EDIZIONI MINERVA MEDICA

lingua: Inglese

Ruolo del laboratorio in un caso di shock settico da Capnocytophaga canimorsus: un caso clinico

Monica TORELLO ¹ ✉, Stefania VALENTI ², Marco ROSETTI ¹, Vittorio SAMBRI ³, Romolo M. DORIZZI ¹

¹ Clinical Pathology Unit, Hub Laboratory, Romagna Greater Area, Pievesestina, Forlì-Cesena, Italy; ² Clinical Pathology Unit, Rapid Response Laboratory, Santa Maria degli Angeli Hospital, Romagna Greater Area, Ravenna, Italy; ³ Microbiology Unit, Hub Laboratory, Romagna Greater Area, Pievesestina, Forlì-Cesena, Italy

Capnocytophaga canimorsus infection is a zoonotic disease that could cause sepsis and meningitis, especially in the immunocompromised population. It is a gram-negative rod that belongs to the normal oral flora of dogs and cats and may be transmitted to humans by biting or licking. The diagnosis of infection due to an unusual organism was suspected in a Rapid Response Laboratory of Romagna Greater Area earlier in the course of management after review of the peripheral blood smear. We describe the role of laboratory in a case of sepsis due to C. canimorsus, the importance of the blood smear observation and its correlation with infection. The clinical signs and symptoms and the severity of this infection can be quite different as demonstrated by several recent case reports regarding different conditions (e.g. meningitis, acute abdomen and gastroenteritis, prostethic joint, emergency medicine, thrombotic thrombocytopenic purpura, fulminans purpura, endocarditis, exanthema/livedo racemosa, sensorineural hearing loss-deafness and fulminant sepsis) that are discussed. C. canimorsus infection is expected to increase over time because to own animals is fashionable and popular due to a public perception of domestic animals safety and rising incidence of splenectomy due to injuries and accidents and of impaired immune responses due to a high prevalence of alcoholism, immuno-suppressive therapies, aging of human population. In the past the diagnosis of C. canimorsus was extremely difficult because of its slow growth on microbiological media; today the gold standard in detecting the bacterium is the identification by MALDI-TOF MS. However gram-stain exam under the microscope shows multiple gram-negative, extracellular, fusiform rods and several intracellular copies of the pathogen in neutrophils and careful laboratory physicians and scientists can suspect the presence of C. canimorsus infection by observing toxic granulation in the cytoplasm of neutrophils in peripheral blood smear and collecting information about the medical history. Examination of peripheral blood smears is a simple laboratory test that should be performed in patients with septicaemia following close animal contact.

KEY WORDS: Capnocytophaga canimorsus; Sepsis; Meningitis; Dogs; Bites and stings; Dog.