Endocarditis, infective is infection of the heart, usually with bacteria (commonly, streptococci or staphylococci) or fungi. Neurological symptoms from emboli occur in 15-35% of cases. About 30-40% of patients develop congestive heart failure.
CASES/YEAR
16,500 (US); 330,000 (Global)
OTHER NAMES
Subacute bacterial endocarditis (progresses over weeks to months); Acute bacterial endocarditis (progresses over days);
INCUBATION
Days to weeks; usually within 2 weeks of bacteremia; [ID, p. 573]
INITIAL SYMPTOMS
Fever, myalgias, arthralgias, back pain, petechiae;
COMMENTS
FINDINGS:
Neurological symptoms from emboli occur in 15-35% of cases. Injection drug users often present with infected tricuspid valves and chest pain, cough, and infiltrates from pulmonary emboli. [Harrisons, p. 388-9] About 30-40% of patients develop congestive heart failure. Strokes or encephalopathy complicates 15-35% of cases. [Harrison ID, p. 237-8] Meningitis, brain abscesses, and glomerulonephritis are possible complications. Osler's nodes are "painful erythematous subcutaneous nodules on the tips of digits." [Merck Manual, p. 707-8] About 11% of patients have splenomegaly. Cerebral emboli occur in 20% of cases. Neurologic symptoms include seizures and neuropathy (cranial and peripheral). Petechiae are present in 20% to 40% of cases. Janeway lesions are hemorrhagic plaques often seen on the palms and soles. Fever is absent in 5% of cases. About 15% of patients have abdominal pain, and nausea/vomiting is common in subacute cases. Patients may present with cortical blindness. Mycotic aneurysms of the hepatic artery cause fever, abdominal pain, jaundice, and GI hemorrhage. Emboli to the splenic artery may cause abdominal pain with radiation to the left shoulder and left pleural effusion. [PPID, p. 1076-9] Myocarditis and pericardial effusions are frequent findings in acute infective endocarditis. Shock may be due to sepsis or cardiac failure. [Cohen, 3rd Ed, p. 518] Diagnosis is particularly difficult in the elderly who may complain of fatigue, confusion, and weight loss. The elderly are at increased risk for congestive heart failure and arterial emboli. [PPID, 8th Ed, p. 3462] Complications are of four types: direct valvular damage; embolic phenomena; bacteremic seeding of infections; and immunologic effects. Petechiae are most likely to be found on the conjunctiva, palate, and extremities. Chorioretinitis, endophthalmitis, and CNS embolic events are often present in cases of fungal endocarditis. [Cecil, p. 420, 426]
LABORATORY:
In drug addicts with fever, the most reliable signs are vegetations by echocardiography and embolic phenomena by physical exam. Transesophageal echocardiography (95% sensitivity) is superior to transthoracic echocardiography (65% sensitivity) in the detection of vegetations. The most important lab test is the blood culture. Lab tests are usually positive for anemia (70% to 90% of cases), sedimentation rate (60%), and proteinuria (50% to 65%). About 30% to 60% of patients have microscopic hematuria. [PPID, p. 1079-82] Some of "culture negative" causal agents can be diagnosed by serology (C. burnettii, Brucella species, Bartonella, and C. psittaci) and others by PCR. [Cecil, p. 422]
DIAGNOSTIC
Clinical; Blood cultures; Echocardiography; see Duke criteria; [ID, p. 574]
SIGNS & SYMPTOMS
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>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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G abdominal pain
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G blood in stool
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G jaundice
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G nausea, vomiting
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H anemia
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H hypergammaglobulinemia
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H leukocytosis
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H splenomegaly
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N confusion, delirium
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N headache
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N lethargy
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N muscle weakness
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N seizure
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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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S petechiae and ecchymoses
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S rash on palms
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S skin or subcutaneous nodule
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U hematuria
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U pyuria
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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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*arthritis
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*blindness
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*brain abscess or lesion
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*cranial neuropathy
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*endocarditis
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*glomerulonephritis
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*meningitis
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*myocarditis
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*osteomyelitis
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*paralysis
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*pericarditis
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*peripheral neuropathy
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*pneumonia
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*sepsis
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*shock
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*stupor, coma
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*uveitis
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*weight loss
ENTRY
Inhalation, Ingestion, Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva), Animal Bite, Sexual Contact
VECTOR
Fleas, Lice, Ticks
SOURCE
Person-to-Person, Animal Excreta, Animal Tissue, Eating Contaminated Food, Eating Contaminated or Infected Meat, Eating Unpasteurized Milk or Cheese, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Birds and Poultry, Cattle, Goats and Sheep, Cats, Deer, Elk and Antelope, Dogs, Horses, Rabbits, Rodents, Swine, Human, Wild Animals
REFERENCES FOR CASES/YEAR
1. (US) About 4 to 7 cases per 100,000 per year in developed countries; [Harrison ID, p. 235] Calculate: 5.5 x 3000 = 16,500;
2. (Global) 20 X US cases/yr;