Obesity and nosocomial infections.

BACKGROUND: The prevention of healthcare-associated infections (HCAIs) is a major goal in modern healthcare. Intrinsic, patient-related factors may contribute to the risk of HCAIs. AIM: To review the association between obesity and the risk and outcome of HCAIs.
METHODS: A PubMed search of relevant studies on obesity and nosocomial infections and obesity and dosing of antimicrobials. Search terms were: 'obesity', 'infection', 'nosocomial infection', 'surgical site infection', 'critical care unit', 'bacteremia', 'urinary tract infection', 'health care associated infection'.
FINDINGS: Obesity has been shown to be associated with an increased risk of HCAIs in several studies. The association is most clear in cardiac, vascular, orthopaedic and gastrointestinal surgery. Body mass index (BMI) data are frequently recorded in patients undergoing surgical and invasive procedures. The recording of BMI data is not systematic in the literature and in many studies median BMI of the control group or reference group (normal weight) also indicates overweight or obesity. Thus, clear BMI cut-offs for increased infection risk cannot be determined. Obesity is frequently associated with underdosing of antimicrobials in both prophylaxis and treatment of HCAIs. Studies indicate that obesity affects the pharmacokinetics of antimicrobial drugs. However, there are no dosing recommendations for antimicrobial use in obesity.
CONCLUSIONS: Obesity increases the risk of nosocomial infections and is frequently associated with underdosing of antimicrobials in both prophylaxis and treatment of HCAIs. A challenge in future hospital hygiene prevention lies in our capacity to combat obesity epidemics.