Clinical Characteristics of Capnocytophaga canimorsus: A Case Report and Systematic Literature Review

Aziz Mohammadi M* and Stahl S

Department of Plastic Surgery and Hand and Reconstructive Surgery, Clinical Hospital Luedenscheid, Germany

*Corresponding author: Aziz Mohammadi M, Department of Plastic Surgery, Hand and Reconstructive Surgery, Clinical Hospital Luedenscheid, Germany

Received: September 10, 2019; Accepted: October 23, 2019; Published: October 30, 2019

Abstract

Capnocytophaga canimorsus is a Gram-negative bacterium found in the oral cavity of dogs and cats. Infections with this rod-shaped bacterium can lead to life-threatening septicemia and multiple serious complications. Here, we report the case of a 64-year-old man with no reported risk factors who developed septic shock, multi organ failure, and gangrene of the extremities following a dog bite to the right index finger 3 days prior to the initial symptoms. The patient required intensive treatment, intravenous antibiotic therapy, and multiple surgical procedures including amputation of multiple fingers, toes, and right lower leg. A systematic literature review of 39 cases published in the last 10 years was performed to extrapolate the time to diagnosis and complications by highlighting the risk factors and initial symptoms. Time to diagnosis exceeded 13 days on average. Several cases suggest that smoking may be an underestimated risk factor. Initial symptoms include fever (58%), gastrointestinal manifestations (45%), pain (23%), and malaise (23%). Complication rates may be reduced by early polymerase chain reaction screening and surgical debridement as well as appropriate antibiotic therapy.

Keywords: Dog bite; Capnocytophaga canimorsus; Infection; Amputation; Sepsis; Hand bite

Introduction

Capnocytophaga canimorsus is a Gram-negative bacterium found in the oral cavity of between 25.5% and 74% of dogs and approximately 17% of cats [1,2]. Infections with this rod-shaped bacterium can lead to life-threatening septicemia, with an overall mortality rate of 26%, and is often accompanied with a history of exposure to canines [3]. It has been reported that patients with prior splenectomy, alcoholism, or immune deficiency are more susceptible to infection [3]. As described in several case reports, infection with C. canimorsus can lead to serious complications, including septic shock, organ failure, Disseminated Intravascular Coagulation (DIC), hemolytic-uremic syndrome, thrombotic thrombocytopenic purpura, endocarditis, gangrene of the extremities, and meningitis [3,4]. Here, we report the case of a patient with no related predisposition who developed septic shock, multi organ failure, and gangrene of the extremities following a dog bite to the right index finger. We also searched the Ovid MEDLINE database (January 1, 2007 to July 1, 2017) for “Capnocytophaga canimorsus” and “sepsis.”To minimize the effects of indexing bias, we further included literature from an extensive Internet search and indexed articles. Only English full-text articles were evaluated. Nonsystematic reviews of the scientific literature were classified as expert opinions. Our initial search provided us with 107 articles. We then excluded off-topic publications (e.g., genomic analysis, DNA sequencing, and association with joint arthroplasty) and literature reviews, which resulted in23relevant articles. The reasons for exclusion were documented systematically.

Case Report

A healthy 64-year-old man presented at our clinic with signs of septic shock. Three days before the onset of his symptoms, he had been bitten in the right index finger by his own dog. His medical history revealed transient ischemic attack in 2015 and hypertension. Alcohol abuse was ruled out, but he admitted smoking for 48 pack-years. On arrival, he was dyspnoeic, agitated, and complained of chills. Livedo racemosa was present over his entire body. Examination of his right hand revealed no sign of infection. Laboratory tests showed severe metabolic acidosis, thrombocytopenia, DIC, rhabdomyolysis, and renal failure. Hematologic disease was suspected after peripheral blood smear revealed atypical granulocytes und monocytes. The patient was transferred to our intensive care unit the following day.

Empiric antibiotic treatment with piperacillin/tazobac was initiated after blood samples were obtained for culture. Laboratory data on the second day of admission showed no improvement, so the antibiotic regimen was switched to meropenem with the addition of clindamycin on the following day. Both antibiotics were administered for 6 weeks. Penicillin G and vancomycin were administered intravenously for 3 days until the antibiogram arrived, after which sulbactam/ampicillin was added and continued for 25 days. Continuous venovenous hemodialysis with citrate was initiated 3 days after the first patient contact and continued for 1 month. The patient also received repeated plasmapheresis, packed red blood cell transfusion, and fresh-frozen plasma because of DIC with purpura fulminans and hemolysis.

On the fourth day of admission, surgical debridement of the bite wound was performed. The metacarpophalangeal joint of the index finger was exposed and debrided. No evidence of purulent infection or septic arthritis was found. No bacterial growth was reported on tissue culture obtained during surgery. The wound was covered with polyurethane-silica hybrid foam (Syspur-derm; Hartmann).

The patient developed dry gangrene of multiple digits, toes, and right lower leg. Amputations of the end phalanx of the third digit of both hands, middle phalanx of the fourth digit of the left hand, all toes of the left foot, and second to fifth toes of the right foot were performed on the ninth day of admission (Figure 1). Vacuumassisted closure was applied on the right lower leg. Two days later, debridement was repeated, the left foot was covered with a splitthickness skin graft from the thighs, and the metacarpophalangeal joint of the right index finger was covered with a fasciocutaneous rotational flap. Necrosis of the right lower leg required amputation below the knee. The patient was extubated, vasopressor therapy was reduced, and he was transferred to the medical ward after 30 days of intensive treatment. He recovered well and was released 66 days after admission in good general condition.

Figure 1: Patient postoperative photographs. Multiple amputations of upper and lower extremities following a severe Capnocytophaga canimorsus infection.

    
    
    Figure 1: Patient postoperative photographs. Multiple amputations of upper
and lower extremities following a severe Capnocytophaga canimorsus
infection.

Discussion

This case demonstrates the necessity for rapid diagnosis, early surgical debridement, and antibiotic treatment. A literature review was performed to summarize the clinical characteristics of severe C. canimorsus infection in order to reduce the time to diagnosis (Table 1). All patients had been in contact with a canine; with the exception of 1 patient who had been scratched by a cat (Figure 2). Our review revealed that 45% of patients with septic shock involving C. canimorsus had none of the commonly reported risk factors at the time of admission. However, we noticed that little research has been conducted on comorbidities, such as cardiovascular, respiratory, endocrinological, and hematologic diseases, as possible risk factors. Furthermore, in the majority of case reports, smoking was not considered as a risk factor. Nonetheless, tobacco use has been reported to enhance C. Canimorsus growth by increased acquisition of iron, which provides a favorable environment for the bacteria to grow [5]. Only 4 other cases with altered confusional state have been reported (Figure 3) [6-9]. Livedo racemosa and sepsis due to C. canimorsus infection was described in 2 cases [10]. Furthermore, in accordance with previous reports, organ failure followed by acute respiratory distress syndrome was the most common clinical presentation (Figure 3) [3,11,12].

Table 1: Literature review. Clinical course: 1 = death, 2 = amputation, 3 = shock, 4 = disseminated intravascular coagulation, 5 = thrombotic thrombocytopenic purpura, 6 = organ failure ([a] kidney failure, [b] liver failure), 7 = thrombocytopenia, 8 = acute respiratory distress syndrome, 9 = vertebral osteomyelitis, 10 = purpura fulminans. Time to surgery was defined as days until first surgical intervention (day of admission = 0).




  
    Case
    Reference
    Type of study
    Patients (n)
    Age

      (years)
    Sex
    Clinical course
    Surgical intervention
    Time to surgery (days)
  
   
  
    1
    Submitted
    Case report
    1
    64
    M
    2, 4, 6a, 10
    Yes
    4
  
  
    2
    Hawkins J et al., 2017 [5]
    Case report
    1
    68
    M
    1,4
    Yes
    6
  
  
    3
    Morandi E et al., 2017 [6]
    Case report
    1
    41
    M
    2, 3, 4, 8
    Yes
    Not reported
  
  
    4
    Eefting M et al., 2017 [7]
    Case report
    1
    29
    M
    3, 4, 8
    Unknown
    n.a.
  
  

    5
    Hastbacka J et al., 2016 [8]
    Cohort study
    16
    55.5 

      (50.5–57.5)
    M (63%), F (37%)
    1 (18%), 2 (18%), 3 (56%), 6 (81%), 7 (94%), 8    (56%)
    25%
    Not reported
  
  
    6
    Dedy N et al., 2016 [9]
    Case report
    1
    68
    F
    2, 3, 4, 6a, 8
    Yes
    0
  
  
    7
    Hloch E et al., 2014 [10]
    Case report
    1
    62
    F
    4, 6ab, 7, 8
    Unknown
    n.a.
  
  
    8
    Shahani L et al., 2014 [11]
    Case report
    1
    62
    M
    2, 4, 6a, 7
    Yes
    14
  
  
    9
    Tan V et al., 2014 [12]
    Case report
    1
    54
    M
    2, 3, 4, 6a, 8
    Yes
    24
  
  
    10
    Nishioka H et al., 2014 [13]
    Case report
    1
    80
    F
    1, 4
    None
    n.a.
  
  
    11
    Ugai T et al., 2013 [14]
    Letter to editor
    1
    53
    F
    3
    None
    n.a.
  
  
    12
    Yamamoto U et al., 2013 [15]
    Case report
    1
    49
    M
    3, 4, 6ab
    None
    n.a.
  
  
    13
    Ma A et al., 2013 [16]
    Case report
    1
    56
    M
    5, 8
    None
    n.a.
  
  
    14
    Brichacek M et al., 2012 [17]
    Case report
    1
    72
    M
    1, 5, 8
    None
    n.a.
  
  
    15
    Matulionyte? R et al., 2012 [18]
    Case report
    1
    46
    F
    1, 3, 4, 8
    Yes
    3
  
  
    16
    Christiansen C et al., 2012 [19]
    Case report
    2
    59, 59
    M (50%), F (50%)
    2, 4, 7, 8
    Yes
    Not reported
  
  
    17
    Sacks R et al., 2012 [20]
    Case report
    1
    42
    F
    1, 3
    Unknown
    n.a.
  
  
    18
    Chary S et al., 2011 [21]
    Case report
    1
    67
    M
    3, 6a
    None
    n.a.
  
  
    19
    Band R et al., 2011 [22]
    Case report
    1
    52
    M
    4, 6a, 7, 8
    Unknown
    n.a.
  
  
    20
    O'Rourke G et al., 2010 [23]
    Case report
    1
    53
    F
    2, 4, 6a, 7, 8
    Yes
    Not reported
  
  
    21
    Stiegler D et al., 2010 [24]
    Case report
    1
    40
    M
    1
    Unknown
    n.a.
  
  
    22
    Low S et al., 2008 [25]
    Case report
    1
    48
    F
    2, 3, 4, 6a, 8
    Yes
    19
  
  
    23
    Nelson M et al., 2008 [26]
    Case report
    1
    31
    M
    9
    None
    None
  
  
    24
    Wald K et al., 2007 [27]
    Case report
    1
    61
    F
    4, 8
    Unknown
    n.a.
  
  
    Descriptive statistics
    
    Σ = 40
    μ = 55.1
    M (60%), F (40%)
    
    
    μ = 10



Table 1: Literature review. Clinical course: 1 = death, 2 = amputation, 3 = shock, 4 = disseminated intravascular coagulation, 5 = thrombotic thrombocytopenic purpura,
6 = organ failure ([a] kidney failure, [b] liver failure), 7 = thrombocytopenia, 8 = acute respiratory distress syndrome, 9 = vertebral osteomyelitis, 10 = purpura fulminans.
Time to surgery was defined as days until first surgical intervention (day of admission = 0).

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Citation: Aziz Mohammadi M and Stahl S. Clinical Characteristics of Capnocytophaga canimorsus: A Case Report and Systematic Literature Review. Austin J Surg. 2019; 6(22): 1221.

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Clinical Characteristics of Capnocytophaga canimorsus: A Case Report and Systematic Literature Review

Abstract

Introduction

Case Report

Discussion

References