Background: Streptococcus agalactiae is a known causal agent of neonatal meningitis, sepsis and puerperal infections. The incidence of invasive infections caused by Streptococcus agalactiae has increased in recent years in non gestating adults: in the elderly, patients receiving prolonged steroid treatment or those with chronic immunosuppressive diseases. The clinical and epidemiological characteristics and risk factors associated to invasive infections caused by S. agalactiae were analyzed.
Method: A retrospective study was undertaken in patients with invasive disease by S. agalactiae attended in the Hospital Universitari Germans Trias i Pujol in Badalona (Barcelona), Spain, from 1983 to 1993.
Results: S. agalactiae was isolated in 51 patients including 13 (25%) neonates. Three patients presented invasive puerperal infection. Thirty-five adult patients with a mean age of 62 years presented invasive disease. Infection involved bacteremia in 26 (74.2%) patients. S. agalactiae was isolated in the ascitic fluid of 4 patients with liver cirrhosis with spontaneous bacterial peritonitis (one with bacteriemia) and in the peritoneal exudate of two patients with peritonitis secondary to intestinal perforation. Of 5 patients with septic arthritis, 3 involved bacteremia. Two patients presented empyema by S. agalactiae. Mortality was 28%, being directly related with infection in 4 cases (7.8%).
Conclusions: Without taking pregnant women into account, 68% of the cases of invasive infections by S. agalactiae were observed in adults with associated base disease, with liver cirrhosis, neoplasms and diabetes mellitus being the most frequent. Advanced age was also found to be an important predisposing factor.