Strep will giv'r to your liver

Watch out for liver disease in patients with endocarditis
from S bovis infections

By Samuel Munson

Giancarlos Valentino, 59, felt as hot as the wood oven he uses to make his famous anchovy pizzas at Louigi's, the local pizza joint. He then had chest pains, which he chalked up to indigestion. When things didn't improve, however, he went to his doctor's office for help. The blood cultures his doctor had ordered showed that he had endocarditis. The HACEK gang (Haemophilus, Actinobacillus, Cardiobacteri-um, Eikenella and Kingella species) are common culprits for such infections but Romano's troubles were caused by Streptococcus bovis, a form of endocarditis that's less common. A research team from Naples, where this disease has been increasing in frequency, reported on this phenomenon in the May 15 issue of Clinical and Infectious Diseases. The study headed by Dr Marie-Francoise Tripodi of Second University of Naples Medical School turned up some pretty surprising and disturbing data. It turns out that more often than not chronic liver disease coincides with S bovis heart infections.

Such a study is a bit of a black hole as the predisposing conditions and the relative severity of this form of endocarditis are still a mystery. To try and get a handle on the problem, Dr Tripodi and colleagues prospectively followed 199 patients diagnosed with endocarditis since 1990. S bovis was the culprit in 30 of these cases. The proportion of cases caused by S bovis has jumped from 7% in the 90s to 25.3% in 2000, becoming the second leading cause of infectious endocarditis in Naples.

Exactly why this marked increase occurred remains unknown. What was discovered was that the upsurge had big consequences for patients' health. The researchers found that S bovis infections struck two heart valves over 43% of the time, while non-S bovis endocarditis involved two valves only about 8% of the time. S bovis infections were also more likely to result in an embolism than were the non-S bovis variety.

What's more, seven patients with S bovis endocarditis, but only one with a non-S bovis endocarditis, also had diskitis � an infection of the space between the discs.

Finally, and particularly ominously, the S bovis infection was coincident with advanced liver disease in almost 57% of the cases, compared to only 15.4% of the non-S bovis infections. Delayed detection of the liver damage proved lethal for almost 17% of the patients.

Liver function tests in patients with endocarditis would be a good idea to consider, according to the researchers. They also note that "unusual complications such as diskitis may delay the diagnosis and worsen the prognosis."

While the reasons behind the rise of S bovis endocarditis are inscrutable, it's clear that the pesky parasite represents a whole lot more trouble than previously thought.