To identify risk factors for Klebsiella pneumoniae bloodstream infections (BSI) in neonates in a hospital in the Kingdom of Saudi Arabia (KSA).

Two case-control studies among hospitalized neonates during February 15-May 14, 1991, and a procedural and microbiological investigation.

Hospital A, a maternity and children's hospital in KSA.

Case patients had a blood culture positive for K pneumoniae after >2 days of hospitalization and had no evidence of a nonblood primary site of infection.

When the 20 case patients were compared with controls, hospitalization in a critical-care unit (odds ratio [OR], 5.5; 95% confidence interval [CI95], 1.20-51.1; P=.03) was identified as a risk factor. When the case patients were compared with a second set of controls matched by critical-care status, receipt of a particular intravenous fluid (D10%/0.2NS; OR, 11.0; CI95, 1.42-85.2; P=.009) or a blood product (OR undefined; P=.04) were identified as risk factors. Infusates were administered via umbilical catheters for most case and control patients (19/20 vs 15/20, P>.05); catheters were manipulated more frequently in patients in criticalcare units. Umbilical catheter tip, skin, or mucus membrane K pneumoniae colonization occurred in 47% and 53% of evaluated case and control patients, respectively. Available K pneumoniae isolates from blood cultures and colonization sites had identical antimicrobial susceptibility patterns. Emphasis on handwashing, careful preparation and administration of infusates, and aseptic technique for catheter insertion, maintenance, and manipulation was temporally associated with resolution of the epidemic.

This outbreak was probably due to infusion therapy practices that led to BSI in nursery patients colonized with K pneumoniae. Both catheter-related infections and extrinsic contamination of infusates may have occurred. Hospital personnel should be aware of their potential to spread nosocomial pathogens from person to person and should implement Centers for Disease Control and Prevention recommendations to decrease nosocomial BSIs.

The role of coagulase-negative staphylococci (CNS) in bacteremias continues to be controversial. Until the 1970s, CNS were mostly recognized as contaminants, being part of the cutaneous flora. Since then, several studies have reported increasing incidence and severity of infections due to CNS.

To review the literature concerning the epidemiology of CNS bacteremia in the United States and Europe with reference to the multiple definitions of infection versus contamination, considering the effect of potential biases influencing the validity of the reported results.

Literature search of the MEDLINE database from January 1980 to February 1998. Studies with fewer than 500 episodes of bloodstream infections or fewer than 100 episodes of CNS bacteremia were not included in the pooled analysis.

(1) CNS remain the most frequent contaminants (58%-83% of positive blood cultures); (2) the proportion of all bloodstream infections caused by CNS is increasing (R=.51); (3) the overall incidence of true CNS bacteremia is increasing (R=.54, P=.0014); (4) comparing the United States to Europe, there is an increasing trend in the incidence of nosocomial bacteremia due to CNS in the United States (R=.82, P=.0006), but no trend is seen in European studies; (5) the mortality associated with true CNS bacteremia varies between 4.9% and 28%.

This review confirms the increasing importance of CNS bacteremias, measured both as a proportion and as an incidence of bloodstream infections. The contributions of several possible explanations for the incidence increase and the difference between the United States and Europe need further evaluation: (1) increased recognition and awareness of CNS infections among clinicians; (2) a gradual change in the definition of true bacteremia from an obligatory two positive blood cultures to one positive blood culture associated with a clinical picture compatible with infection; (3) a change in blood culture practices and techniques; (4) an increase in the numbers of blood cultures performed, which is reported both in the United States and in Europe; (5) a shift toward more elderly patients with increasingly severe underlying illnesses; and (6) increasing use of intravascular devices.

The apparent trend of increasing CNS bacteremia seems to be valid. Whether there is a real difference between the United States and Europe concerning the increase of CNS bacteremia is difficult to establish due to the large number of confounding factors. Few studies take into account the number of blood cultures performed or the use of intravascular devices to adjust for the observed trends. Further on-site surveillance studies are needed to investigate the phenomenon more extensively.