Multiresistant Enterobacter cloacae outbreak in an intensive care unit associated with therapeutic beds
© BioMed Central Ltd 2006
Published: 13 February 2006
We report a multiresistant Enterobacter cloacae outbreak in an intensive care unit, associated with mattresses and with antibacterial-treated and vapour-permeable polyurethane synthetic mattress covers of therapeutic beds.
An increased risk of infection and pressure sores is associated with contaminated mattresses [1–6]. This is mostly due to disruption of the integrity of the mattress cover surface . Antibacterial-treated and vapour-permeable polyurethane synthetic mattress covers have been developed to reduce bacterial and fungal colonisation of mattresses. These are currently widely used on therapeutic beds. These covers are considered easy to clean and to disinfect.
We report an outbreak associated with recently developed therapeutic beds in an intensive care unit in which there appeared to be satisfactory nursing procedures and in which the mattress covers appeared to be visually intact. Our observations allow us to propose additional measures to the recommended maintenance procedure to avoid this type of hospital infection.
The observation of stained foam where the seams of the covers were situated suggested a fault in the impermeability of the covers at this point and suggested that fluids penetrated the foam of the mattress through the seams. As the cleaning procedure recommends vigorous cleaning around the seams, it is probable that the cleaning procedure altered the cover, causing a loss of impermeability at the seams. This may also explain the observed stained foam where the patient was situated, which is a place that is intensively and frequently cleaned due to urine contamination. As the covers no longer remained an effective impermeable barrier, any spilt body fluids would make the mattress foam wet. The mattresses then acted as a bacterial reservoir capable of sustaining the growth of Enterobacteriaceae because, as previously demonstrated, soluble material within permeable polyurethane can serve as carbon and nitrogen sources for bacterial growth . The weight of the patient then caused bacteria-containing aerosols, which contaminated the patient's surroundings despite daily cleaning of the cover, thus generating transmission.
We believe this study is the first report of mattress contamination associated with recently developed therapeutic beds for decreasing the risk of infection and pressure sores. Our data suggest that the actual recommended maintenance procedure may be ineffective and could be potentially dangerous. We therefore propose stricter conditions for checking of the mattresses, including the systematic removal of the mattress cover once the patient has been discharged. Any stained mattresses should be discarded. Our observations also suggest the need for studying the clinical circumstances leading to the regular replacement of covers to prevent the problems of their rapid loss of impermeability.
- Fujita K, Lilly HA, Kidson A, Ayliffe GAJ: Gentamicin-resistant Pseudomonas aeruginosa infection from mattresses in a burn unit. Br Med J 1981, 283: 219-220.View ArticleGoogle Scholar
- Ndawula EM, Brown L: Mattresses as reservoirs of epidemic MRSA [letter]. Lancet 1991, 337: 488. 10.1016/0140-6736(91)93420-EView ArticlePubMedGoogle Scholar
- O'Donoghue MAT, Allen KD: Costs of an outbreak of wound infections in an orthopaedic ward. J Hosp Infect 1992, 22: 73-79. 10.1016/0195-6701(92)90132-6View ArticlePubMedGoogle Scholar
- Orr KE, Gould FK, Perry JD, Ford M, Morgan S, Sisson PR, Morrison D: Therapeutic beds: the Trojan horses of the 1990s? Lancet 1994, 342: 65-66. 10.1016/S0140-6736(94)91092-8View ArticleGoogle Scholar
- Peto R, Calrow A: An audit of mattresses in one teaching hospital. Professional Nurse 1996, 11: 623-626.Google Scholar
- Thomas S: Observations on mattress covers: results of a pilot study. J Tissue Viability 1998, 8: 5-11.View ArticlePubMedGoogle Scholar
- Rithalia S: Pressure sores: which foam mattress and why? J Tissue Viability 1996, 6: 115-119.View ArticleGoogle Scholar
- Jenkins RO, Sherburn RE: Growth and survival of bacteria implicated in sudden infant death syndrome on cot mattress materials. J Appl Microbiol 2005, 99: 573-579. 10.1111/j.1365-2672.2005.02620.xView ArticlePubMedGoogle Scholar