Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain.
CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.
Sci Rep. 2021 Jan 21;11(1):1916. doi: 10.1038/s41598-021-81625-6.
Healthcare-related Legionnaires' disease has a devastating impact on high risk patients, with a case fatality rate of 30-50%. Legionella prevention and control in hospitals is therefore crucial. To control Legionella water colonisation in a hospital setting we evaluated the effect of pipeline improvements and temperature increase, analysing 237 samples over a 2-year period (first year: 129, second year: 108). In the first year, 25.58% of samples were positive for Legionella and 16.67% for amoeba. Assessing the distance of the points analysed from the hot water tank, the most distal points presented higher proportion of Legionella colonisation and lower temperatures (nearest points: 6.4% colonised, and temperature 61.4 °C; most distal points: 50% and temperature 59.1 °C). After the first year, the hot water system was repaired and the temperature stabilised. This led to a dramatic reduction in Legionella colonisation, which was negative in all the samples analysed; however, amoeba colonisation remained stable. This study shows the importance of keeping the temperature stable throughout the circuit, at around 60 °C. Special attention should be paid to the most distal points of the circuit; a fall in temperature at these weak points would favour the colonisation and spread of Legionella, because amoeba (the main Legionella reservoir) are not affected by temperature.
医疗相关军团病对高危患者有毁灭性影响，病死率为 30-50%。因此，医院的军团菌防控至关重要。为了控制医院环境中的军团菌水定植，我们评估了管道改进和温度升高的效果，在两年期间分析了 237 个样本（第一年：129 个，第二年：108 个）。在第一年，25.58%的样本中存在军团菌，16.67%的样本中存在阿米巴虫。评估分析点与热水箱的距离，最远端的点呈现出更高的军团菌定植率和更低的温度（最近的点：6.4%定植，温度 61.4°C；最远的点：50%定植，温度 59.1°C）。在第一年之后，热水系统得到了修复，温度也稳定下来。这导致军团菌定植率显著降低，所有分析的样本均为阴性；然而，阿米巴虫定植率保持稳定。本研究表明了在整个循环中保持稳定温度（约 60°C）的重要性。应特别注意循环中最远的点；这些薄弱点的温度下降会有利于军团菌的定植和传播，因为阿米巴虫（军团菌的主要储存库）不受温度影响。
