Nosocomial Legionnaires’ Disease: Risque and Prevention

Abstract

In 1977, Fraser et al. described an outbreak of pneumonia among legionnaires attending a convention at a hotel in Philadelphia in 1976. Legionnaires' disease (LD) can be nosocomial, community acquired or travel related. The incidence of hospital-acquired legionellosis appears to be increasing. Colonization of water systems by Legionella spp. is ubiquitous in hospitals throughout the world. The outbreak, which later became known as legionnaires' disease, was caused by a new pleomorphic, faintly staining gram-negative bacillus, L. pneumophila, which was isolated at the Center for Disease Control from lung tissues of legionnaires who died. Risk assessment for this disease forms the basis for the institution of control measures. Detection and quantification of Legionella spp. in the environment, in particular in the hospital water distribution system is one of the cornerstones of risk assessment. This review summarizes the current state-of-the-art regarding these aspects and points out important areas which require further study. The environmental surveillance revealed that the centralized hot water distribution system of the hospital was colonized with Legionella. Methods of prevention of the organisms for eradication involved in hospital water systems.

The impact of material surface roughness and temperature on the adhesion of Legionella pneumophila to contact surfaces

“…at 15 and 55°C, was also checked. The incubation temperatures at 15 and 55°C were selected because the Legionella reproduced in aquatic environments, where the water temperature is between 25 and 45°C (Tai et al 2012). We wanted to create unfavorable conditions for bacterial reproduction, so we decreased and increased the temperature by 10°C and observed their reproduction and adhesion to the test surfaces.…”

Caspase Exploitation by Legionella pneumophila

“…Since the clinical manifestation is an atypical pneumonia with potentially fatal outcome immediate antibiotic treatment is required. Nevertheless, the mortality rate according to the Center of Disease Control (CDC) varies from 5 to 30% with generally higher rates recorded in hospital-aquired cases ( Bartram, 2007 ; Tai et al, 2012 ). The risk of disease development increases with age, preexisting conditions like chronic lung diseases, cancer and compromised immune defense after organ transplantation, glucocorticoid treatment, or chemotherapy.…”

“…In addition to Legionnaires’ disease, Legionella species can also cause the non-pneumonic Pontiac fever. This self-limiting, influenza-like infection affects only the upper respiratory tract but is characterized by high attack rates ( Tai et al, 2012 ).…”

Contamination of Water Sources of Karaj Hospitals with Legionella pneumophila and Campylobacter jejuni

“…Legionella pneumophila is known as heterotrophic gramnegative bacilli. 1 L. pneumophila was first reported in Philadelphia in 1976, and afterward, the bacterium has been isolated from many sources in the environment. Water sources, especially hot water systems are the optimum condition for the growth of this bacterium.…”