The number of nosocomial infections due to Legionella pneumophila and Pseudomonas aeruginosa is probably underestimated in many countries. This article discusses the risk of legionellosis due to Legionella and P. aeruginosa for patients and hospitals staff members from the water system in different Palestinian hospitals. A total of 134 water samples were collected in 2005 from six governmental hospitals located in the West Bank. L. pneumophila serogroup 2-14 was isolated from 33 of 53 samples, and P. aeruginosa was isolated from 17 of 81 before thermal disinfection. Thermal disinfection at 80 • C and progressively flushing the hot water outlets around the system was successfully efficient to eliminate Legionella and P. aeruginosa pathogens in water distribution systems. The current study is an example of how microbiological methods and site history may be used to successfully track the source of bacterial water contamination and subsequently remediate it. Thorough contaminant characterization and forensic source identification is important for designing of appropriate management strategies.

In this article, we study stability and bifurcation of a fourth order rational difference equation. We give condition for local stability, and we show that the equation undergoes a Neimark‐Sacker bifurcation. Moreover, we consider the direction of the Neimark‐Sacker bifurcation. Finally, we numerically validate our analytical results.

The number of nosocomial infections due to Legionella pneumophila and Pseudomonas aeruginosa is probably underestimated in many countries. This paper discusses the risk of legionellosis due to Legionella and Pseudomonas aeruginosa for patients and hospitals staff members from the water system in different Palestinian hospitals. A total of 134 water samples were collected in 2005 from six governmental hospitals located in the West Bank. Legionella pneumophila serogroup 2-14 was isolated from 33 of 53 samples and Pseudomonas aeruginosa was isolated from 17 of 81 before thermal disinfection. Thermal disinfection at 80°C and progressively flushing the hot water outlets around the system was successfully efficient to eliminate Legionella and Pseudomonas aeruginosa pathogens in water distribution systems. The current study is an example on how microbiological methods along with site history could be used to successfully track the source of bacterial water contamination and subsequently remediate it. Thorough contaminant characterization and forensic source identification is important for designing of appropriate management strategies