Development and application of a wipe sampling method for detection of antibiotic surface contamination in hospital...

Antibiotics are handled in large amounts at hospitals at many different wards due to the wide range of bacterial infections that are treated. Unnecessary use and occupational exposure to antibiotics should be avoided due to the risk of bacterial resistance development and adverse health effects including skin and respiratory hypersensitivity reactions in persons handling these drugs.

To develop a wipe test method for sampling and quantification of surface contaminations of antibiotics, to assess the current contamination levels in Swedish hospitals, and to propose hygienic guidance values for antibiotics based on these measurements.

A screening wipe test method and subsequent mass spectrometric analysis of 6 of the most frequently used antibiotics in healthcare was developed and applied in a screening campaign of 16 hospital wards. Wipe tests were sampled from surfaces such as workbenches, floors, storage shelves and handles in medicine rooms, patient rooms, rinsing rooms, utility rooms and corridors.

Antibiotics were detected in most of the samples (cefotaxime 84% positive samples, piperacillin 81%, cloxacillin 65%, metronidazole 53%, ciprofloxacin 20%, and penicillin V 14%). Median values ranged from not detected up to 160 pg/cm2 for the 6 different compounds and the highest results from an individual wipe sample were 27 × 106 pg/cm2 (cefotaxime) and 3.0 × 106 pg/cm2 (piperacillin). For cloxacillin, piperacillin, and metronidazole, lower levels of contamination were observed in medicine rooms when closed systems were used compared with samples collected in rooms where preparations were made without closed systems. Comparison of contamination levels showed that there were significant differences between different surface categories. Out of the most frequently detected antibiotics, ie cloxacillin, piperacillin, and cefotaxime, highest median values were found for surface categories floor and storage whereas lower median values were found for workbenches.

A widespread environmental contamination of antibiotics was observed in hospital wards that potentially can contribute to the development of antibiotic-resistant bacteria as well as health impacts of exposed personnel. Probable sources include compounding, handling and administration of drug tablets, antibiotic contaminated waste as well as other sources such as excretions from patients and contaminated drug vials. Current surface cleaning routines do not sufficiently reduce spills and leakage regardless of source.