A rare case of Waterhouse-Friderichsen syndrome caused by Capnocytophaga canimorsus in an immunocompetent patient

The Great pretender: the first case of septic shock due to Capnocytophaga canimorsus in Sardinia. A Case report and review of the literature

Capnocytophaga canimorsus (C. canimorsus) is an emerging pathogen in critical care. C. canimorsus is a Gram-negative bacillus, commonly isolated as a commensal microorganism of the oral flora of healthy dogs and cats. A 63-year-old woman came to the emergency department with fever, chills, and malaise 2 days after a minor dog bite. After admission to the medicine ward, she developed respiratory failure and livedo reticularis. In the intensive care unit (ICU), she presented full-blown septic shock with thrombocytopenia, coagulopathy, severe acute kidney injury, and liver injury. We describe the first case of septic shock with Multiple Organ Dysfunction Syndrome related to Capnocytophaga canimorsus infection in Sardinia and its treatment in a tertiary hospital ICU. We also review recent literature on the relevance of C. canimorsus in human disease and critical illness.

Lethal Waterhouse-Friderichsen syndrome caused by Capnocytophaga canimorsus in an asplenic patient

Background

Capnocytophaga canimorsus, a Gram-negative rod, belongs to the Flavobacteriaceae family and colonizes the oropharynx of dogs and cats. Infections with C. canimorsus are rare and can induce a systemic infection with a severe course of the disease. So far, only five case reports of C. canimorsus infections associated with Waterhouse–Friderichsen Syndrome (WFS) have been reported with only two of the patients having a history of splenectomy.

Case presentation

Here, we report a fatal case of WFS due to C. canimorsus bacteremia and mycetal superinfection in a 61-year-old female asplenic patient. Despite extensive therapy including mechanical ventilation, antibiotic coverage with meropenem, systemic corticosteroids medication, vasopressor therapy, continuous renal replacement therapy, therapeutic plasma exchange, multiple transfusions of blood products and implantation of a veno-arterial extracorporeal membrane oxygenation the patient died 10 days after a dog bite. The autopsy showed bilateral hemorrhagic necrosis of the adrenal cortex and septic embolism to heart, kidneys, and liver. Diagnosis of C. canimorsus was prolonged due to the fastidious growth of the bacteria.

Conclusions

The occurrence of a severe sepsis after dog bite should always urge the attending physician to consider C. canimorsus as the disease-causing pathogen. A therapeutic regimen covering C. canimorsus such as aminopenicillins or carbapenems should be chosen. However, despite maximum therapy, the prognosis of C. canimorsus-induced septic shock remains very poor. Asplenic or otherwise immunocompromised patients are at higher risk for a severe course of disease and should avoid exposure to dogs and cats and consider antibiotic prophylaxis after animal bite.

Septic shock caused by Capnocytophaga canimorsus in a patient with heterozygous Pelger-Huët anomaly

Capnocytophaga canimorsus is a Gram-negative bacillus of the commensal flora of dogs and cats that can cause infections in humans through bites, scratches or contact with oral secretions. It can be difficult to identify in clinical microbiology laboratories because of the need for specific culture media. We present the case of a patient with no relevant medical history who was admitted with septic shock, where blood smear examination was crucial for the etiologic diagnosis of Capnocytophaga canimorsus infection. The patient was also diagnosed Pelger-Huët anomaly, a condition causing a defect in neutrophil chemotaxis, which may have contributed to the severity of the infection.

A case of septic arthritis caused by Capnocytophaga canimorsus in an HIV patient

Invasive infections caused by Capnocytophaga canimorsus, a Gram-negative rod found in the oral cavity of healthy dogs and cats, are rare but they are increasing worldwide. We report a case of septic arthritis in a native knee joint due to this micro-organism. A 57-year-old man, with a well-controlled chronic HIV infection, attended the Emergency Department because of left knee pain and shivering without measured fever. A knee arthrocentesis and a computed tomography scan were performed, revealing septic arthritis with collections in the left leg posterior musculature. He was admitted to the Infectious Diseases Department for antibiotic treatment. Initial synovial fluid was inoculated in blood culture bottles, and the anaerobic one was positive after 63 h. Gram stain revealed fusiform Gram-negative rods, identified as C. canimorsus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) directly from the bottle. Identification was confirmed by 16S rRNA sequencing and serotyping was performed by PCR, with serovar A as the outcome. Due to an unfavourable clinical course, the patient required two surgical cleanings and after appropriate antibiotic treatment he was discharged 2 months later.

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

Background

Capnocytophaga canimorsus infection is rare, with a high fatality rate; however, there are few cases of death with a rapid course. This study reports a progressively fatal case of C. canimorsus.

Case Presentation

A 68‐year‐old immunocompetent Japanese man was bitten and scratched on his right hand by a dog 6 days before emergency transportation to the emergency room with abdominal pain, back pain, and melena. The patient developed multiple‐organ failure. Despite antibiotic therapy, transfusion, vasopressor therapy, and continuous renal replacement therapy, the patient died from uncontrolled metabolic acidosis 4.5 h after admission. Approximately 80 h after admission, blood cultures were positive for C. canimorsus.

Conclusions

Capnocytophaga canimorsus infection can lead to rapid progression even in immunocompetent patients.

Capnocytophaga canimorsus - a potent pathogen in immunocompetent humans - systematic review and retrospective observational study of case reports

Purpose: Severe and fatal Capnocytophaga canimorsus infection has been described in immunocompromised patients. Data of C. canimorsus infection in immunocompetent and risk factors of severe courses are missing. Our aims were to describe the epidemiology of C. canimorsus infection and to identify potential risk factors of sepsis and fatal outcome.Methods: Observational study and systematic review of all cases reported in immunocompetent subjects between 2002 and 2019.Results: A total of 128 cases of C. canimorsus infection in immunocompetent individuals were reported. Male gender comprised 74.2%, the median age was 58 years and 47.7% were admitted with sepsis. Case-fatality rate was 29.7% and especially high in septic patients (55.7%). Transmission by bite (OR = 2.37, 95% CI: 1.05-6.52) and incubation time ≤3 d (OR = 7.98; 95% CI: 2.33-27.34) were identified as risk factors of sepsis on admission, and early wound cleansing as protective (OR = 0.42; 95% CI: 0.14-0.96). Sepsis (OR = 23.67; 95% CI: 2.85-197.89) and septic shock (OR = 45.50; 95% CI: 3.08-676.55) were risk factors of fatal outcome, whereas early wound cleansing (OR = 0.05; 95% CI: 0.01-0.72), initial penicillin therapy with beta-lactamase inhibitors (OR = 0.48; 95% CI: 0.16-0.92) and surgical removal of infectious focus (OR = 0.38; 95% CI: 0.06-0.95) were protective factors.Conclusions: Immunocompetent patients with C. canimorsus infection frequently develop sepsis. A shorter incubation period in cases of sepsis might be related to higher infectious dose. Fatal outcome may be prevented by early wound cleansing, initial use of penicillins in combination with beta-lactamase inhibitors and surgical removal of an infectious focus.

A unique fatal case of Waterhouse-Friderichsen syndrome caused by Proteus mirabilis in an immunocompetent subject: Case report and literature analysis

INTRODUCTION

The Waterhouse-Friderichsen syndrome (WFS), also known as purpura fulminans, is a potentially lethal condition described as acute hemorrhagic necrosis of the adrenal glands. It is often caused by infection. Classically, Neisseriae meningitidis represents the main microorganism related to WFS, although, infrequently, also other infectious agents are reported as a possible etiologic agent. The authors report the first case of death due to Proteus mirabilis infection, with postmortem evidence of WFS.

PATIENT CONCERNS

After a facial trauma that provoked a wound on the nose, the subject, a healthy 40-years old man, was conducted to the local hospital (in Sicily, Italy) after the primary care he was discharged. Subsequently, after 2 days of general malaise, he returned to the hospital due to the worsening of the clinical condition. During the hospitalization, hypotension, and neurological impairment appeared; the laboratory analysis showed leukocytosis and the alteration of renal, hepatic and coagulative parameters. Microbiological blood analysis resulted positive for a P mirabilis infection.

DIAGNOSIS

Multiorgan failure (MOF) with disseminated intravascular coagulation (DIC) due to sepsis was diagnosed.

INTERVENTIONS

The practitioners administered intensive support, antibiotic therapy, antithrombin III, vitamin K, and plasma.

OUTCOMES

After 3 days the subject died. The autopsy and the microscopic investigation were performed revealing, also, the adrenal diffuse micronodular hyperplasia associated with a cortico-medullary hemorrhagic apoplexy.

CONCLUSION

To our knowledge, this is the first case of MOF with WFS due to P mirabilis infection. This case report suggests that P mirabilis should be added to the list of unusual bacteria causing WFS. Furthermore, it supports the theory that any bacterium which causes DIC may cause adrenal hemorrhage and should suggest to clinicians the importance to consider a potential adrenal involvement in every patient with sepsis and DIC.

Purpura Fulminans and Septic Shock due to Capnocytophaga Canimorsus after Dog Bite: A Case Report and Review of the Literature

Primary infection by Capnocytophaga canimorsus after dog bite is rare but may be difficult to identify and rapidly lethal. We describe a case of fatal septic shock with fulminant purpura occurred in a patient without specific risk factor two days after an irrelevant dog bite. The patient was brought to hospital because of altered mental status, fever, and abdominal pain. In a few hours patient became hypoxic and cyanotic. The patient became extremely hypotensive with shock refractory to an aggressive fluid resuscitation (40 ml/kg crystalloids). She received vasoactive drugs, antibiotic therapy, and blood purification treatment, but cardiac arrest unresponsive to resuscitation maneuvers occurred. Case description and literature review demonstrated that, also in patients without specific risk factors, signs of infection after dog bite should be never underestimated and should be treated with a prompt antibiotic therapy initiation even before occurrence of organ dysfunction.

Capnocytophaga canimorsus sepsis in a methotrexate-treated patient with rheumatoid arthritis

Capnocytophaga canimorsus is a gram-negative rod that can be transmitted primarily by dog bites. This life-threatening organism commonly causes sepsis in patients with splenectomy or alcoholism. A 53-year-old rheumatoid arthritis male treated with methotrexate (MTX) for 5 years was admitted for a 4-day history of fever and dyspnea. He had been bitten on a finger by the family dog 4 days before onset. Laboratory tests revealed pancytopenia, acute renal failure, and evidence of disseminated intravascular coagulation, and he subsequently developed acute respiratory distress syndrome. Furthermore, blood cultures grew gram-negative bacilli and despite intensive treatment, he died 5 days after admission. Later, C. canimorsus was identified from his culture samples using a species-specific polymerase chain reaction. C. canimorsus infections should be considered in the differential diagnosis of sepsis for immunocompromised hosts following animal bites.