Extra-intestinal manifestations of salmonella infections

Abstract

While salmonellosis is often considered to affect primarily the gastrointestinal tract, infection at other sites may occur, producing characteristic clinical syndromes. We reviewed cases from our institutions and the literature on focal manifestations of salmonella infections. In the past, most extra-intestinal salmonella infections were caused by S. choleraesuis; however, we found S. typhimurium to be the predominant serotype. The mortality rate for patients in our series was considerably lower than the rate described for focal infections in other reviews. This may in part be due to lower proportion of infections due to S. choleraesuis, improved microbiologic and diagnostic techniques, increased use of ampicillin, and improved surgical techniques. Salmonella endocarditis usually occurs in patients with preexisting heart disease. Unlike other salmonella infections, S. choleraesuis is the most frequent serotype. Salmonella endocarditis is often very destructive, with a fatality rate of 70%. Nonvalvular (mural) endocarditis occurs in one-fourth of patients and survival has not been reported. While antibiotic therapy should be tried initially, if response is not prompt the clinician should look for an associated site of infection (intra- or extra-cardiac abscess), which will often require surgery. Salmonella pericarditis often presents with cardiac or pulmonary symptoms, but typical signs of pericardial disease (pulsus paradoxus, friction rub) or characteristic electrocardiographic changes (low voltage, elevated ST segments) are uncommon. Early diagnosis, before infection involves other areas of the heart, is crucial for survival. In addition to antibiotic therapy, pericardiocentesis or pericardiectomy is required. Salmonella may infect the peripheral or visceral arteries, but the abdominal aorta is the most frequent site of vascular infection. Most patients are men over age 50 with preexisting atherosclerosis of the aorta who do not have a previous history of gastroenteritis. About one-fourth of patients have associated lumbar osteomyelitis. No patients have been reported to survive with medical therapy alone. Specific guidelines for surgical removal of infected aneurysms have been proposed and these (in addition to increased use of ampicillin) may be responsible for higher survival rates in recent years. Due to the high incidence of relapses, postoperative blood cultures should be done routinely. Arterial infection should be considered in any elderly patient with salmonella bacteremia especially with prolonged fever or bacteremia after an "adequate course" of antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)