It is able to become attached to the heart lining in areas where the normal strong cleansing flow is interrupted in swirls and eddies by the abnormal hole or malformed heart valve. Once a tiny colony of the bacteria is established on the inner surface of the heart, it grows into a large vegetation. Bits of this solid mass of germs then break off to seed any part of the body with colonies of bacteria. Spiking fever results. Diagnosis is made by suspicion, by ultrasound of the heart, and by blood culture tests to determine the causative organism and the best antibiotic choices.
Treatment is long-term intravenous antibiotic therapy.
The germ is usually sensitive to penicillin, which is routinely prescribed as a preventative before any kind of dental work or bowel surgery to children with known predisposing conditions such as septal defects or heart valve malformations.