A 31-year-old male drug abuser presents with fever, chills and multiple bilateral lung abscesses. Right heart endocarditis is suspected. The following is/are true:

a. The organisms most likely responsible are gram-negative and fungal

The typical endocarditis in a drug-abuser involves fungal and gram-negative organisms which infect the tricuspid rather than the pulmonic valve. An echocardiogram is useful to confirm the presence of vegetations but it may overlook smaller ones so it cannot be used to exclude the diagnosis. Although valve replacement is usually preferable, the infected tricuspid valve can be excised without prosthetic replacement.