Pasteurellosis

This page is about clinical aspects of the disease.  For microbiologic aspects of the causative organism(s), see Pasteurella multocida.

WikiDoc Resources for Pasteurellosis
Articles
Most recent articles on Pasteurellosis Most cited articles on Pasteurellosis Review articles on Pasteurellosis Articles on Pasteurellosis in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Pasteurellosis Images of Pasteurellosis Photos of Pasteurellosis Podcasts & MP3s on Pasteurellosis Videos on Pasteurellosis
Evidence Based Medicine
Cochrane Collaboration on Pasteurellosis Bandolier on Pasteurellosis TRIP on Pasteurellosis
Clinical Trials
Ongoing Trials on Pasteurellosis at Clinical Trials.gov Trial results on Pasteurellosis Clinical Trials on Pasteurellosis at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Pasteurellosis NICE Guidance on Pasteurellosis NHS PRODIGY Guidance FDA on Pasteurellosis CDC on Pasteurellosis
Books
Books on Pasteurellosis
News
Pasteurellosis in the news Be alerted to news on Pasteurellosis News trends on Pasteurellosis
Commentary
Blogs on Pasteurellosis
Definitions
Definitions of Pasteurellosis
Patient Resources / Community
Patient resources on Pasteurellosis Discussion groups on Pasteurellosis Patient Handouts on Pasteurellosis Directions to Hospitals Treating Pasteurellosis Risk calculators and risk factors for Pasteurellosis
Healthcare Provider Resources
Symptoms of Pasteurellosis Causes & Risk Factors for Pasteurellosis Diagnostic studies for Pasteurellosis Treatment of Pasteurellosis
Continuing Medical Education (CME)
CME Programs on Pasteurellosis
International
Pasteurellosis en Espanol Pasteurellosis en Francais
Business
Pasteurellosis in the Marketplace Patents on Pasteurellosis
Experimental / Informatics
List of terms related to Pasteurellosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Danitza Lukac

Synonyms and keywords: Shipping fever; bovine respiratory disease complex; fibrinous pneumonia; Pasteurella pneumonia; hemorrhagic septicemia; fowl cholera; snuffles

Overview

Pasteurellosis is an infection with a species of the bacterial genus Pasteurella. Pasteurella multocida (subsp. septica and subsp. multocida) is carried in the mouth and respiratory tract of various animals, including cats and dogs. It is a small Gram negative bacillus with bipolar staining on Wayson stain. Pasteurella is usually transmitted via the cutaneous route to the human host.Pasteurella uses a number of mechanisms for avoiding or suppressing bactericidal responses such as lipopolysaccharides (LPS) and the bacterias capsule. It is difficult to establish the true prevalence and incidence of pasteurellosis because disease reporting is not required. In the USA, the annual incidence of dog and cat bites has been reported as 300 bites per 100,000 individuals. The most important risk factor in the development of pasteurellosis is animal exposure. Individuals with high risk of developing pasteurellosis are children and inmunosuppressed individuals. If left untreated, patients with pasteurellosis may progress to develop soft tissue inflammation. Complications of pasteurellosis include cellulitis, pneumonia, and bacteremia. Patients with cutaneous infection have the most favorable prognosis when adequately treated. Physical examination of patients with pasteurellosis is usually remarkable for erythema, warmth, swelling and pain in the affected area. The mainstay of therapy for pasteurellosis includes both cleaning the wound and antibiotic pharmacotherapy using a combination of penicillin and beta-lactamase inhibitors.

Historical Perspective

• The genus Pasteurella is named after the French chemist and microbiologist, Louis Pasteur, who first identified the bacteria now known as Pasteurella multocida as the agent of chicken cholera.

Pathophysiology

Transmission

• Pasteurellosis is usually transmitted by close contact with pets, including sharing a bed, being licked by pets, kissing pets, animal scratches, or bites.
• Less commonly, pasteurellosis can be acquired by inhaling the bacteria, human-to human transmission or with unknown source of infection.
• Pasteurella can be transmitted when exposed to animals that have been exposed directly or indirectly to the animal oropharyngeal secretions through licking or sniffing.

Pathogenesis

• The mechanisms of pathogenesis of Pasteurella infection in its natural host species and in humans are still not completely understood, and further studies are needed.
• Pasteurella is usually transmitted via the cutaneous route to the human host.
• Pasteurella uses a number of mechanisms for avoiding or suppressing bactericidal responses:
  • Lipopolysaccharides (LPS) and the bacterias capsule probably play a substantial role in intracellular survival
  • P. multocida capsule has been shown in strains belonging to serogroups A and B to help resist phagocytosis by host immune cells and capsule type A has also been shown to help resist complement-mediated lysis
  • The LPS produced by P. multocida consists of a hydrophobic lipid A molecule (that anchors the LPS to the outer membrane), an inner core, and an outer core, both consisting of a series of sugars linked in a specific way
  • Formation of stress fibers may aid in the endocytosis of P. multocida
  • The host cell cycle is modulated by the P. multocida toxin, which can act as an intracellularmitogen
• Pasteurella needs iron to grow.
  • P. multocida has developed mechanisms acquire iron from hemoglobin, ferritin, lactoferrin and transferrin.

Causes

• Pasteurellosis is caused by an infection with Pasteurella spp.
• Pasteurella is a Gram-negative, facultatively anaerobic bacteria.
• Most Pasteurella species are catalase-positive and oxidase-positive.
• Most common species that cause pasteurellosis in humans is P. multocida.
• Pasteurella is part of the normal cavity flora of many animals such as cats, dogs and frequently rabbits.
  • Cats oral cavity colonization of P. multocida is between 70%–90%
  • Dogs oral cavity colonization of P. multocida is between 50%–60%

Differentiating Pasteurellosis from other Diseases

Pasteurellosis must be differentiated from:

• Cat scratch disease
• Abscesses:
  • Abdominal
  • Brain
  • Liver
  • Lung
  • Perinephric
  • Due tu amebas, streptococcus, staphylococcus, and anaerobic bacteria
• Cellulitis
• Animal Bites
• Pneumonia:
  • Bacterial
  • Comminuty-adquired
• Abdominal sepsis
• Haemophilus spp. infections
• Actinobacillus actinomycetemcomitans infection
• Cardiobacterium hominis infection
• Eikenella corrodens infection
• Kingella spp infection
• Peritonitis
• Meningitis

Epidemiology and Demographics

• It is difficult to establish the true prevalence and incidence of pasteurellosis because disease reporting is not required
• P. multocida oral cavity colonization in cats, dogs and other animals is common worldwide
• An estimated 4.4 million animal bites occur each year in the United States
• In the USA, the annual incidence of dog and cat bites has been reported as 300 bites per 100,000 individuals
• The case mortality rate of pasteurellosis is approximately 25-30%
• The case mortality rate of pasteurellosis patients with meningitis and neurological manifestations is approximately 17-29%
• The case mortality rate of pasteurellosis patients with bacteremia is approximately 40-63%

Risk Factors

• Animal exposure
• Children: Among children, the rate of dog bite related injuries is highest for those 5 to 9 years old
• Men: Men are more likely than women to be bitten by a dog
• Elderly
• Pregnant women
• Immunosuppressed individuals

Natural History, Complications and Prognosis

Natural History

• Pasteurellosis incubation period occurs within 24 hours.
• Initial presentation usually shows as soft tissue inflammation.
• If left untreated, patients with pasteurellosis progress to develop complications.

Complications

• Pasteurellosis complications include:
  • Cellulitis
  • Subcutaneous abscesses
  • Septic arthritis
  • Lower respiratory tract infections
  • Upper respiratory tract infections
  • Osteomyelitis
  • Bacteremia
  • Endocarditis
  • Meningitis
  • Peritonitis

Prognosis

• The prognosis varies with the type of infection; cutaneous infections have the most favorable prognosis with adequate treatment.
• Prognosis is generally poor for patients who develop bacteremia, endocarditis and meningitis.

History and Symptoms

History

• Patients with pasteurellosis most commonly report contact with pets, including sharing a bed, being licked by, or kissing the pets

Symptoms

Symptoms related to cellulitis (most common) include:

• Fever
• Pain or tenderness in the affected area
• Skin redness or inflammation that gets bigger as the infection spreads
• Skin sore or rash that starts suddenly, and grows quickly in the first 24 hours
• Tight, glossy, "stretched" appearance of the skin
• Warm skin in the the area of redness

Symptoms related to pneumonia include:

• Dyspnea
• Productive cough (greenish or yellow sputum)
• Fever (high grade) with sweating, chills, and rigor

• Pleuritic chest pain
• Rapid, shallow breathing
• Shortness of breath

Symptoms related to septicaemia include:

• High fever
• Rigor
• Vomit

Physical Examination

Physical examination related to cellulitis (most common) include:

Skin

• Redness, warmth, and swelling
• Possible drainage, if there is an infection
• Swollen lymph nodes near the affected area

Physical examination related to pneumonia include:

Vital Signs

• Decreased oxygen saturation
• Fever
• Hypotension < 90 mm Hg
• Tachycardia > 125 beats/min
• Tachypnea

Lungs

• Palpation
  • Increased tactile fremitus

• Percussion
  • Dullness on percussion

• Auscultation
  • Decreased breath sounds
  • Bronchial breath sounds
  • Rhonchi
  • Crackles, Rales
  • Increased vocal fremitus

Physical examination related to septicaemia include:

Vital Signs

• Hypotension
• Sepsis is considered present if infection is highly suspected or proven and two or more of the following systemic inflammatory response syndrome (SIRS) criteria are met:
  • Heart rate > 90 beats per minute
  • Temperature < 36 (96.8 °F) or > 38 °C (100.4 °F)
  • Tachypnea > 20 breaths per minute or, on blood gas, a PaCO2 < 32 mm Hg

Skin

• Cyanosis
• Throat
• Lymphadenopathy

Extremities

• Decreased peripheral pulses

Neurologic

• Altered sensorium, lethargy, and coma.

Diagnosis

• Diagnosis is made with isolation of Pasteurella multocida in a normally sterile site (blood, pus or cerebrospinal fluid)
• P. multocida has been observed invading and replicating inside host amoebae, causing lysis in the host. P. multocida will grow at 37 °C on blood or chocolate agar
  • Colony growth is accompanied by a characteristic "mousy" odor due to metabolic products
• Being a facultative anaerobe, it is oxidase-positive and catalase-positive, and can also ferment a large number carbohydrates in anaerobic conditions

Treatment

• As the infection is usually transmitted into humans through animal bites, cleaning the wound and antibiotics usually treat the infection
• Pasteurellosis is usually treated with penicillin AND beta lactamase inhibitor
• Patients with penicillin allergies or resistant to beta lactamase inhibitor should be treated with doxycycline, levofloxacin or moxifloxacin
• Therapy for patients with cellulitis infection last approximately 10 days
• Therapy for patients with tenosynovitis infection last approximately 3 weeks
• Therapy for patients with septic arthritis infection last approximately 4 weeks
• Therapy for patients with osteomyelitis infection last approximately 6 weeks

Prevention

Preventing dog and cat bites

• Do:
  • Remain motionless (e.g., "be still like a tree") when approached by an unfamiliar dog or cat
  • Curl into a ball with your head tucked and your hands over your ears and neck if a dog knocks you over
• Don't:
  • Approach an unfamiliar dog or cat
  • Run from a dog or car
  • Panic or make loud noises
  • Disturb a dog or cat that is sleeping, eating, or caring for puppies
  • Pet a dog without allowing it to see and sniff you first
  • Encourage your dog to play aggressively
  • Let small children play with a dog or cat unsupervised

For more information: Bites

See also

• Hemorrhagic septicemia
• Pasteurellaceae

External links

• Pasteurella multocida-related diseases in sheep and goats