A 22-year-old man has a low-grade fever with malaise for the past two weeks. He becomes more acutely ill toward the end of the week, with peripheral edema. He sees a physician, who auscultates a shrill systolic murmur. A chest xray shows bilateral pleural effusions. There are several nodular densities in both lungs, one of which in the right upper lobe reveals an air-fluid level. Echocardiography is performed. A blood culture is taken.

Question 2.1

What pre-existing disease do you think this patient had?

Rheumatic heart disease, with thickening and shortening of chordae of one leaflet.

Question 2.2

Where do you think the infection is?

The right side of the heart is involved because of the distribution of lesions to the lungs. The tricuspid valve is pictured in the gross photograph

Question 2.3

Explain the pulmonary lesions.

The pulmonary lesions are abscesses resulting from septic emboli. Liquefactive necrosis in an abscess results in the air-fluid levels.

Question 2.4

What is the organism?

This is a streptococcal organism. The features suggests viridans group.

Question 2.5

Name other implantable devices that may be complicated by infection.

Indwelling catheters; pacemaker wires; defibrillators

Question 2.6

What antibiotic regimen is indicated?

Penicillin G plus gentamicin; if penicilin resistant, then ceftriaxone or vancomycin.