Fatal Legionnaires' pneumonia: frequency of legionellosis in autopsied patients with pneumonia from 1969 to 1985

In 89 of 3027 (2.9 per cent) patients in whom pneumonia was found at autopsy during the period from 1969 to 1985, legionella pneumonia was diagnosed. Legionellae were demonstrated through the direct fluorescent antibody test by screening lung tissue sections. All 89 cases were caused by Legionella pneumophila. Suspicious typical rod-shaped organisms were demonstrated in all cases by the modified Dieterle stain whereas conventional histological stains failed to detect causative bacteria. The frequency per year of legionellosis in patients with pneumonia at autopsy ranged from 1.4 per cent (3/212 cases) to 6.8 per cent (12/177 cases). In patients who have died of unexplained pneumonia, examinations for the demonstration of legionellae should be carried out.     

临床与环境标本中的军团菌检验方法学

军团菌是引起军团菌病的重要病原体,在世界各地时有暴发流行。我们对军团菌检验方法作了系列实验研究,改进了传统的细菌分离培养和生化试验,建立了聚合酶链反应(polymerase chain reaction, PCR)酶切分型、巢式PCR、荧光定量PCR、荧光原位杂交、单核苷酸多态性(single-nucleotide polymorphisms, SNP)分析与基因测序分析等系列军团菌分子生物学检测法。为临床与环境卫生的军团菌检验提供了精准、快速、可靠的病原学诊断依据,对预防和控制军团菌病暴发流行具有重要意义。     

Potential Association of Legionnaires’ Disease with Hot Spring Water,Hot Springs National Park and Hot Springs,Arkansas, USA, 2018–2019

Legionella pneumophila is the cause of Legionnaires’ disease, a life-threatening pneumonia that occurs after inhalation of aerosolized water containing the bacteria. Legionella growth occurs in stagnant, warm-to-hot water (77°F–113°F) that is inadequately disinfected. Piped hot spring water in Hot Springs National Park, Arkansas, USA, has naturally high temperatures (>135°F) that prevent Legionella growth, and Legionnaires’ disease has not previously been associated with the park or other hot springs in the United States. During 2018–2019, Legionnaires’ disease occurred in 5 persons after they visited the park; 3 of these persons were potentially exposed in spa facilities that used untreated hot spring water. Environmental testing revealed Legionella bacteria in piped spring water, including 134°F stagnant pipe water. These findings underscore the importance of water management programs to reduce Legionella growth in plumbing through control activities such as maintaining hot water temperatures, reducing stored water age, and ensuring adequate water flow.     

在生活饮用水卫生标准中新增军团菌项目的探讨

军团菌可在生活饮用水中存活甚至繁殖，在使用生活饮用水过程中可将其转入气溶胶中。吸入被军团菌污染的气溶胶可导致军团菌感染和军团菌病的暴发流行。因此军团菌与生括饮用水有着密切的关系，建议将军团菌列入生括饮用水卫生标准的项目中。     

Reusable terminal tap water filters for nosocomial legionellosis prevention

Hospital water supplies often contain Legionella spp. and therefore represent a source of nosocomial infection especially for immunocompromised patients in intensive care or organ transplant units. Therefore, pathogen-free water should be provided for the care of these patients. Approaches of long-term Legionella spp. eradication from the plumbing system are rarely successful. Exposition prophylaxis might be another reasonable approach in high-risk patient care. To investigate the ability to provide water free of Legionella spp. with reusable water filters, a surveillance of splash water samples was performed. After determining the burden of Legionella spp. in the plumbing system of a paediatric oncological ward by ten unfiltered splash water samples, ten designated water taps were provided with terminal tap water filters that could be reprocessed by thermal disinfection. A further 129 samples were taken after a usage interval of 7 days and 10 more samples after a usage interval of 21 days before reprocessing the filters. All samples were checked for growth of Legionella spp. as well as other pathogenic bacteria. A total germ count of all samples was also performed. Half of the unfiltered splash water samples revealed growth of Legionella spp. All filtered water samples remained free of Legionella. Total germ count did not increase before a usage interval of 7 days. We believe the water filters tested are suitable for prevention of nosocomial legionellosis when reprocessed after 7 days as recommended by the manufacturer. To avoid retrograde contamination of filters, education of staff and patients in handling these devices is mandatory.     

Risk and management in hospital water systems for Legionella pneumophila: a case study in Rio de Janeiro-Brazil

This article analyses the water used at hospitals in Rio de Janeiro, Brazil. The research, based on microbiological and physical-chemical aspects, suggests subsidies for normalization of hospital potable water systems and makes recommendations for standardization of operational procedures for inspection for Legionella pneumophila. A total of 16 hospitals were inspected and positive results for the presence of L. pneumophila were found at five hospitals. These hospitals were integrated in a research project aiming at the detection and quantification of this pathogen. During 10 consecutive weeks, four collections representing a total of 200 analyses were done at the five researched hospitals. In this way seven physical-chemical parameters and three microbiological parameters were observed to evaluate the quality of water in each hospital. The results showed that routine surveillance for a hospital water distribution system is fundamental for public health and must include, as a priority, monitoring of L. pneumophila. The water quality varies in accordance with the hospital water system involved. It is important and necessary to implement environmental culturing in order to minimize hospital infection, in particular, pneumonia data and also to provide the basis for disinfection of the water system.     

儿童散发性军团菌病流行特征的研究

用ＥＬＩＳＡ方法对１９９１年４月至１９９２年４月从省级医院收集的儿科住院病儿３１７例及健康体检儿童８６例进行９种１５型军团菌ＩｇＭ抗体的检测。３５例（１１．０４％）住院病儿诊为军团菌病，呼吸系统疾病患者中有２５例（１１．６８％）、肾脏疾病、血液病有５例（５／１５），其它疾病有１例（１．４５％）为军团菌病患者；２例（２．３３％）健康儿童为军团菌近期感染。病原以Ｔａｔｌｏｃｋｉａｍｉｃｄａｄｅｉ（２０例，４７．６２％）及Ｌｐ＿１６（１０例，２３．８１％）多见，Ｆｌｕｏｒｉｂａｃｔｅｒｂｏｚｅｍａｎａｅ占１４．２９％，其它种型较少见。军团菌病的分布特点是年长儿童发病多，夏季发病比例高，城乡居住者发病比例差别无统计学意义。