Risk factors for endovascular infection due to nontyphoid salmonellae.

Nontyphoid salmonellae are major causes of foodborne infection worldwide. They still seriously affect human health, causing morbidity and mortality. They induce severe salmonellosis, even in modestly immunocompromised hosts, resulting in bacteremic spread, focal infection, and persistence in deep sites, including the en-dovascular region. Approximately 5% of individuals with gastrointestinal illness caused by nontyphoid salmonellae develop bacteremia. Children with certain underlying conditions or risk factors are at increased risk for bacteremia, which may lead to extraintestinal focal infection. These conditions and risk factors include very young age (р3 months), AIDS, presence of malignancies, receipt of immu-nosuppressive therapy, hemolytic anemia, and inflammatory bowel disease, among others [1–3]. In adults, nontyphoid Salmonella bacteremia is even more serious in patients with underlying disease because of both the tenacity of the organism and the multiple underlying diseases of adult patients who develop bacteremia. A feared complication of Salmonella bacteremia in adults is the development of infectious endarteritis, especially that which involves the abdominal aorta (also known as " aortitis " or " mycotic aneu-rysm "), because this complication previously was almost uniformly fatal. However , a recent review of 136 evaluable cases from 1948–1999 found a 62% survival rate (mortality rate, 38%) for all affected patients who were treated with combined surgical and medical therapy [4]. In this issue of Clinical Infectious Diseases, Hsu et al. [5] report the findings from a study of 301 patients with nontyphoid salmonel-losis who were seen at National Taiwan University Hospital (Taipei, Taiwan). Thirty-six people died in the hospital, including 4 patients with endovascular infection. The mortality rate among 28 patients with endovascular infection was 14.3%, which, when the severity of the condition is considered, is not higher than the rate for patients with bacteremia or other extraintestinal focal infections [5]. This low mortality rate was attained apparently with use of advanced diagnostic techniques, surgical care, and antimicro-bial therapy, all of which appear to have improved the survival rate for patients with serious complications of nontyphoid Salmonella bacteremia. However, a cautious approach is still warranted, especially for older patients with multiple underlying diseases. The study by Hsu et al. [5] was a retrospective survey, and, therefore, a patient regarded as having primary extrain-testinal infection might not, in fact, have had the attributed condition, because the patient might initially have had relatively mild enteritis and presented to the hospital only when he or she developed more-serious symptoms, such as bacteremia. …