Severe sepsis caused by Capnocytophaga canimorsus complicated by thrombotic microangiopathy in an immunocompetent patient

Abstract

CaseA 61‐year‐old man with an unremarkable medical history was admitted with fever 7 days after being bitten by his dog. On day 3, he showed altered mental status, and laboratory data showed progressive hemolytic anemia, thrombocytopenia, hyperbilirubinemia, renal dysfunction, coagulopathy, and schistocytosis. Severe sepsis complicated with thrombotic microangiopathy caused by Capnocytophaga canimorsus was suspected.OutcomePlasma exchange was applied to treat the thrombotic microangiopathy and resulted in platelet count increase and improved renal function, hyperbilirubinemia, and schistocytosis. Blood culture results confirmed the presence of C. canimorsus. The patient was discharged in good condition.Conclusion Capnocytophaga canimorsus is rare cause of severe sepsis, and should be suspected even in immunocompetent patients with dog‐bite history. Capnocytophaga canimorsus infection may be complicated by thrombotic microangiopathy, for which plasma exchange should be considered prior to definitive diagnosis of thrombotic microangiopathy.

An Immunocompetent Case of <i>Capnocytophaga canimorsus</i> Infection Complicated by Secondary Thrombotic Microangiopathy and Disseminated Intravascular Coagulation

“…We searched the PubMed, for English-language reports of cases of C. canimorsus infection complicated by TMA and identified 10 cases, summarized in Table (1,6-13). The ADAMTS13 activity was measured in only two previous case reports (6,7) and was normal, as in the present case. This phenomenon has been described in some pathogenic organisms, such as bacteria, angioinvasive fungi, viruses, and rickettsiae, that cause endothelial injury (14).…”

Capnocytophaga canimorsus infection led to progressively fatal septic shock in an immunocompetent patient

“…Similarly, systemic bleeding and DIC could be the causes of death in our patient. Some previous reports have indicated that C. canimorsus sepsis causes secondary thrombotic microangiopathy, which improves with antimicrobial agents, plasma transfusion, and plasma exchange 12–14 . However, these reports did not include a progressively fatal case similar to ours.…”

“…Some previous reports have indicated that C. canimorsus sepsis causes secondary thrombotic microangiopathy, which improves with antimicrobial agents, plasma transfusion, and plasma exchange. [12][13][14] However, these reports did not include a progressively fatal case similar to ours. In our case, few findings suggested hemolysis, and fibrinogen levels decreased, which is not typical for thrombotic microangiopathy.…”

Capnocytophaga canimorsus peritonitis diagnosed by mass spectrometry in a diabetic patient undergoing peritoneal dialysis: a case report

“…However, C. canimorsus causes sepsis, especially in patients with prior splenectomy, or meningitis [13]. A recent report described severe sepsis with thrombotic microangiopathy caused by C. canimorsus in an immunocompetent patient [14]. Capnocytophaga species are extremely rare as the causative organism of PD-related peritonitis.…”