CASES/YEAR
1,660 (US); 16,600 (Global)
OTHER NAMES
Rabbit fever; Deer-fly fever; Francisella tularensis infection;
INCUBATION
1-14 days; usually 3-5 days; [CCDM]
INITIAL SYMPTOMS
Lymphadenopathy associated with a skin ulcer (ulceroglandular type) or ulcers of the mouth/throat, (oropharyngeal), or the eyes (oculoglandular). [CCDM]
PRECAUTIONS
Standard; "Not transmitted from person to person." [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
FINDINGS:
Most cases are the ulceroglandular/glandular form. Other forms are oculoglandular, oropharyngeal, typhoidal, and pneumonic. [Harrisons, p. 485] Ulceroglandular tularemia usually presents as a painful skin ulcer followed by painful regional lymphadenopathy. (The anthrax ulcer is not painful.) The lymph nodes may suppurate. Lymphatic vessels may become inflamed and nodular. Hepatosplenomegaly may be found in patients with tularemia. A relative bradycardia was detected in 42% of cases in one series. [ID, p. 62, 1446-51] Fever may be recurrent. Pharyngeal tularemia is another syndrome that may be seen in outbreaks. A pharyngeal membrane was reported in a few cases. In some patients, vesicles resembling herpes simplex are seen at the primary inoculation site. Skin rashes have been reported in up to 35% of cases and include pustules, erythema nodosum, erythema multiforme, diffuse maculopapular rash, and urticaria. Sometimes found are leukocytosis, thrombocytopenia, elevated transaminases, myoglobinuria, and pyuria. There is usually little or no sputum in pneumonic tularemia. Hemoptysis is uncommon. Ovoid or cavitary lesions are uncommon. In typhoidal tularemia, patients have diarrhea, abdominal pain, and vomiting. Pneumonia is common. Stools rarely contain blood, but infected children may develop foci of necrosis in the bowel. [PPID, p. 2765-9] Pneumonia has a case fatality rate of <2% with treatment and 7% without treatment. [ABX Guide: Francisella tularensis] "A nonspecific roseola-like rash may appear at any stage of the disease." [Merck Manual, p. 1598] Oropharyngeal tularemia may present as a stomatitis. [Cohen, p. 1089]
COMPLICATIONS:
Pneumonia may complicate any type of tularemia. It is common in typhoidal tularemia. Chest x-rays may show infiltrates, hilar lymphadenopathy, and pleural effusions. Mesenteric lymphadenitis and abdominal pain may follow ingestion of undercooked, infected game. [ID, p. 62, 1446-51] Brain abscesses may complicate meningitis. Fever, headaches, meningismus, vomiting, and diarrhea are symptoms of typhoidal tularemia. Severely ill patients with renal failure may have elevated creatine phosphokinase, myoglobinuria, and pyuria. Acute renal failure is associated with fatal disease. Other complications of severe disease are DIC and hepatitis; [PPID, p. 2765-9] Rare complications are mediastinitis, lung abscess, and meningitis. [Merck Manual, p. 1598]
DIFFERENTIAL DIAGNOSIS:
The differential diagnosis for ulceroglandular tularemia includes bubonic plague, chancroid, sporotrichosis, anthrax, and staphylococcal and streptococcal lymphadenitis. The differential diagnosis for glandular tularemia (lymphadenopathy without an ulcer) includes cat-scratch disease, tuberculosis, lymphogranuloma venereum, and bubonic plague. [ID, p. 62, 1446-51]
EPIDEMIOLOGY:
"Outbreaks of human tularemia usually occur in association with animal epizootics." Humans may be infected by biting insects, by handling infected meat or carcasses, and by consuming contaminated water or undercooked meat. Inhalation exposures occur in medical laboratory workers, hunters (pelts), and farmers (soil, grain, or hay dust). Reservoirs: ticks, some domestic animals, and wild animals (rabbits, voles, muskrats, beavers). Other vectors are mosquitoes (Russian Federation and Sweden) and deer flies. Drinking contaminated water is another source of infection. [CCDM, p. 652] Outbreaks have been reported after landscaping, mowing, and brush cutting. Farmers may become ill after handling hay contaminated with excreta of infected animals. The bacteria have been isolated from many species of birds. [ID, p. 1448] Ulceroglandular is the most common type of tularemia. Typhoidal tularemia (systemic disease with no indication of localized inoculation) is common, while the other five types are uncommon or rare. [Merck Manual, p. 1598]
BIODEFENSE:
In a bioterrorist attack using an aerosol, pneumonic tularemia is the most likely result. However, intentional air release could also cause other forms of tularemia. [JAMA. 2001;285: 2763-73] As a bioweapon, the expected clinical syndrome is a flu-like illness with pleuritic chest pain, dyspnea, skin rash, pharyngitis, conjunctivitis, and abnormal chest x-ray (infiltrates, cavitary lesions, and/or hilar adenopathy). [Cecil, p. 86, 1952-3]
DIAGNOSTIC
Paired sera; DFA testing, IHC staining, or PCR of exudates or aspirate; Culture is hazardous; [CCDM, p. 651] Confirmed case = clinical findings + positive PCR, positive culture or 4x rise in serology; [ABX Guide]
SCOPE
N. America, Europe, Middle East, former USSR, China, Japan; [CCDM]; About 125 cases/yr reported in USA with most in AR, MO, SD, and OK; [ID, p. 1447]
SIGNS & SYMPTOMS
-
>arthralgia
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>fatigue, weakness
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>fever
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>fever, biphasic or relapsing
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>myalgia
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>relative bradycardia
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E pharyngitis
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E stomatitis
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G abdominal pain
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G blood in stool
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G diarrhea
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G hepatomegaly
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G jaundice
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G liver function test, abnormal
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G nausea, vomiting
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H leukocytosis
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H lymphadenopathy
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H splenomegaly
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H thrombocytopenia
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N confusion, delirium
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N headache
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N stiff neck
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O conjunctivitis, acute
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O oculoglandular syndrome
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R chest pain
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R cough
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R dyspnea
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R hemoptysis
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R sputum production
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S entry wound with lymph nodes
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S lymphadenitis, acute
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S lymphangitis
-
S nodular lymphangitis
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S papules or plaques
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S pustule
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S rash (exanthem)
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S skin blister or vesicles
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S skin or subcutaneous nodule
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S ulcer of skin
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S urticaria
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U pyuria
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X cystic or cavitary lesions
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X hilar lymphadenopathy
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X lung infiltrates
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X pleural effusions
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*acute renal failure
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*ARDS
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*arthritis
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*bleeding tendency
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*brain abscess or lesion
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*encephalitis
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*endocarditis
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*erythema nodosum
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*hepatitis
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*mediastinitis
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*meningitis
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*osteomyelitis
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*paralysis
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*pericarditis
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*pneumonia
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*rhabdomyolysis
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*sepsis
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*shock
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*weight loss
ENTRY
Inhalation, Ingestion, Skin or Mucous Membranes (Includes Conjunctiva), Animal Bite
VECTOR
Biting Flies, Mosquitoes, Ticks
SOURCE
Animal Excreta, Animal Tissue, Soil or Dust (Ingesting or Inhaling), Eating Contaminated Food, Eating Contaminated or Infected Meat, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Birds and Poultry, Cattle, Goats and Sheep, Cats, Dogs, Horses, Monkeys, Rabbits, Rodents, Swine, Wild Animals
RISK FACTORS
- Eat undercooked meat or fish
- Handle animal carcasses or placentas
- Handle dog or cat (bite or scratch)
- Handle infected rodents (not bite)
- Ingest infectious agents in food/water
- Travel to endemic area
- Victim--air release of infectious agents
- Work in a medical or research lab
- Work or play in tick-infested area
REFERENCES FOR CASES/YEAR
1. (US) Published in MMWR 2011 = 166; Use correction factor of 10 for reported diseases: 166 X 10 = 1660;
2. (Global) Occurs in the Northern Hemisphere, but not found in the UK; Has not been reported in Africa, South America, or Australia; [Gorbach, p. 396] Ulceroglandular and glandular forms comprise about 75-85% of the total cases. [Harrison ID, p. 566] Case reports have been absent from UK, Africa (only one), South America, and first case reported in Australia in 2003; Was common in US before World War II, but since 2001 reported at 0.05 cases per 100,000 or less; [PPID, p. 2762] 110 cases reported in Turkey between 2010 and 2012; [PMID 24216516] Tularemia occurs in the Northern Hemisphere in Europe, states of the former USSR, and in northern China, Korea, and Japan; [ID, p. 1447] Assumption: tularemia in 1/2 the worlds population at an incidence equal to that in the US; Calculate: 10 x 1660 = 16,600;