The accuracy and validity of a weekly point-prevalence survey for evaluating the trend of hospital-acquired infections in a university hospital in Turkey

Objective: To evaluate the validity of a weekly point-prevalence survey (WPS) by comparing it with a prospective-active incidence survey (PIS). Methods: WPS and PIS were conducted at a tertiary referral hospital between January and December 2006. Each Wednesday, an infection control team reviewed all clinical records of patients with hospital-acquired infections (HAIs) by WPS. Routine PIS was conducted with daily visits by the same team. The Rhame and Sudderth formula was used for converting the data between WPS and PIS. Results: During the study period, 1287 HAIs were detected in 37 466 patients by WPS. The mean observed prevalence and calculated prevalence were 5.42% and 5.45%, respectively. The reanimation intensive care unit (ICU) (49.4%) and burns unit (27.6%) had the highest prevalence rates. Pneumonia (0.94%) and urinary tract infections (0.37%) were the most frequent infections. Overall 602 HAIs were detected in 545 patients by PIS. The mean observed incidence and calculated incidence were 2.42/1000-admissions and 2.41/1000-admissions, respectively. The Critical care ICU (37.0/1000-admissions) and burns unit (24.8/1000-admissions) had the highest incidences of HAI. Pneumonia (0.64/1000-admissions) and urinary tract infections (0.37/1000-admissions) were the most frequent infections. Conclusions: This study confirms a close relationship between prevalence and incidence data. WPS may be a useful method for following HAIs when PIS cannot be performed. (C) 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.