Assessment of handwashing practices with chemical and microbiologic methods: Preliminary results from a prospective crossover study

Background: Handwashing (HW) by clinical staff is the single most important measure for preventing transmission of nosocomial infection (NI). The primary objectives of this study were to improve the motivation and awareness of the importance of HW practices among health care workers (HCWs) and to assess the effectiveness of a new chemical system in checking HW compliance. In addition, we evaluated the efficacy and tolerability of 2 soap solutions used during regular working hours by HCWs at our institution. Method: A preliminary short training course was performed to promote HW compliance and awareness. We chose 2 surgical wards at our 1200-bed teaching hospital. Sampling of hands was conducted weekly during routine activities of HCWs without advance warning. We used the staff list as a sampling frame to select subjects. Data were collected anonymously. On the basis of a crossover study design, a plain soap and one containing 4% chlorhexidine gluconate (CHG) were used alternatively in each ward for 4 consecutive months. Hand samples were evaluated with microbiologic cultures and with a commercially available kit that measures adenosine triphosphate (ATP) bioluminescence. As additional process indicators, we examined the amount of hand soap and CHG solution distributed and rate of NIs. Results: A total of 74 HCWs were evaluated for hand contamination. During the 4-month study, we found a significant reduction in colony-forming unit counts (P