scholarly journals The Effect of Hydrogen Peroxide on Reducing the Colonization of Legionella spp. in a Hospital Water Network

Author(s):  
Beatrice Casini ◽  
Francesco Aquino ◽  
Michele Totaro ◽  
Mario Miccoli ◽  
Irio Galli ◽  
...  

Objectives: To evaluate the effectiveness of hydrogen peroxide (HP) use in the hospital water network disinfection to control Legionella spp. colonization. Methods: Following the detection of high levels of Legionella contamination in a 136-bed general hospital water network, an HP treatment of the hot water (25 mg/L) was adopted. During a period of 34 months, the effectiveness of HP on Legionella colonization was assessed. Legionella was isolated in accordance with ISO-11731 and identification was carried out by sequencing of the mip gene. Results: Before HP treatment L.pneumophila sg 2-15 was isolated in all sites with a mean count of 9950±8279 CFU/L. After one month of HP-treatment, we observed the disappearance of L. pneumophila 2-15, however other Legionella species never cultured before appeared; Legionella pneumophila 1 was isolated in 1 out of 4 sampling sites (2,000 CFU/L) and other non-pneumophila species in all sites (mean load 3,000 ±2887 CFU/L). Starting from September 2013, HP-treatment was modified adding food-grade polyphosphates and in the following months we observed a progressive reduction of the mean load of all species (p<0.05), until to a substantial disappearing of Legionella colonization. Conclusion: Hydrogen peroxide demonstrated a good efficacy in controlling Legionella. Although in the initial phases of treatment it seemed unable to eliminate all the species, by keeping HP levels to 25 mg/L and adding food-grade polyphosphates, a progressive and complete control of colonisation was obtained.

2018 ◽  
Vol 98 (1) ◽  
pp. 60-63 ◽  
Author(s):  
M. Totaro ◽  
P. Valentini ◽  
A.L. Costa ◽  
S. Giorgi ◽  
B. Casini ◽  
...  

2004 ◽  
Vol 50 (1) ◽  
pp. 281-285 ◽  
Author(s):  
A.-S. Lepeuple ◽  
M. Jovic ◽  
M.-R. de Roubin

The RAPD (random amplified polymorphic DNA) technique has been developed for the molecular typing of Legionella in order to characterise the populations of hot water systems. During this study, 22 primers were tested and the four most informative ones were selected. The optimisation of the PCR conditions allowed the setting up of a powerful discriminative genotyping method. Moreover, the definition of a quality management method allowed definition of the key steps and the number of replicates to ensure reproducibility of the RAPD pattern. The RAPD was used to study the hot water network of a building. Legionella colonies (91) were isolated from seven locations and genotyped. The diversity of the population in one sample could vary from one to seven different strains. The study of the traceability showed that, in most of the cases, different populations could be present at different locations of the same network.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Dimitra Dimitriadi ◽  
Emmanuel Velonakis

The aim of this research was the isolation ofLegionellaspp. from domestic water supply networks in the Prefecture of Arta. A total of 100 water samples, from 25 houses, were collected. Half of the samples concerned the cold water and half the hot water supply. Purpose was to detect colonization of the water networks withLegionellaspp. >500 cfu/L by using the method of filtration (ISO 11731). Out of 100 samples, 6 samples from 3 houses were positive forLegionellaspp.Legionella pneumophilaserogroup 2–14 was isolated in 5 of 6 samples, whereas in the sixth sampleLegionella anisawas identified. Only three of the samples had residual chloride over 0.2 mg/L, rate which is necessary for potable water, according to the Greek hygienic practice. Concerning the temperature of hot water, the mean temperature of the negative forLegionellasamples was higher compared to the mean temperature of the positive forLegionellasamples (49.9°C versus 45.5°C). It is estimated that there is risk of infection through the use of showers. The low concentration of chloride and the temperature, which was found within the limits favorable to developingLegionellaspp. (20–45°C), provide fertile ground for proliferation of the bacteria.


1988 ◽  
Vol 9 (5) ◽  
pp. 194-199 ◽  
Author(s):  
L.P. Jette ◽  
N.G. Lambert

AbstractTwo models of hot water washer disinfectors (Decomat 128 and Hospital A, Euroclean Canada Inc; Ontario, Canada) were evaluated by two methods for their efficacy in disinfecting anesthesia equipment. In the first method, three different microbial suspensions were each sealed into 30 capillary tubes. In the second method, corrugated anesthesia tubes were rinsed with suspensions of each of two bacterial strains. The tubes then underwent a standard cycle in the hot water washer disinfectors and were subsequently tested for growth of microorganisms. All experiments were repeated three times, and the temperature was registered in all cases. In the capillary test, growth was rarely detected (13/540 tubes) and the inactivation factor for both apparatus was > 5 log,,. In the rinse test, no growth was detected. The mean temperature for 15 disinfection cycles was 84.2 ± 0.8°C for Decomat 128 and 88.9 ± 0.5% for Hospital A. However, for Decomat 128 we observed a variation of 3°C from one disinfection cycle to another and a progressive reduction of 2.2°C over a series of five consecutive complete cycles. Both methods gave reproducible results. Under our experimental conditions, both hot water washer disinfectors proved to be efficacious for the disinfection of reusable anesthesia equipment.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 209 ◽  
Author(s):  
Luna Girolamini ◽  
Ada Dormi ◽  
Tiziana Pellati ◽  
Paolo Somaroli ◽  
Davide Montanari ◽  
...  

Legionella surveillance is an important issue in public health, linked to the severity of disease and the difficulty associated with eradicating this bacterium from the water environment. Different treatments are suggested to reduce Legionella risk, however long-term studies of their efficiency are lacking. This study focused on the activity of a new formulation of hydrogen peroxide and silver salts, WTP828, in the hospital hot water network (HWN) to contain Legionella contamination during two years of treatment. The effectiveness of WTP828 was tested measuring physical-chemical and microbiological parameters such as Legionella, Pseudomonas aeruginosa (P. aeruginosa), and a heterotopic plate count (HPC) at 36 °C. Legionella isolates were identified by serotyping and genotyping. WTP 828 induced a reduction in Legionella–positive sites (60% to 36%) and contamination levels (2.12 to 1.7 log10 CFU/L), with isolates belonging to L. pneumophila SG1 (ST1 and ST104), L. anisa and L. rubrilucens widely distributed in HWN. No relevant contamination was found for other parameters tested. The long-term effect of WTP828 on Legionella containment suggest the easy and safe application of this disinfectant, that combined with knowledge of building characteristics, an adequate environmental monitoring and risk assessment plan, become the key elements in preventing Legionella contamination and exposure.


Author(s):  
Michele Totaro ◽  
Paola Valentini ◽  
Anna Laura Costa ◽  
Lorenzo Frendo ◽  
Alessia Cappello ◽  
...  

Although the European reports highlight an increase in community-acquired Legionnaires’ disease cases, the risk of Legionella spp. in private houses is underestimated. In Pisa (Italy) we performed a three-year survey on Legionella presence in 121 buildings with an independent hot water production (IB); 64 buildings with a central hot water production (CB); and 35 buildings with a solar thermal system for hot water production (TB). From all the 220 buildings Legionella spp. was researched in two hot water samples collected either at the recirculation point or at on the first floor and on the last floor, while the potable water quality was analyzed in three cold water samples collected at the inlet from the aqueduct network, at the exit from the autoclave, and at the most remove remote? tap. Legionella pneumophila sg1, Legionella pneumophila sg2-16 and not-pneumophila Legionella species were detected in 26% of the hot water networks, mostly in CB and TB. In these buildings we detected correlations between the presence of Legionella and the total chlorine concentration decrease or/and the increase of the temperature. Cold water resulted free from microbiological hazards, with the exception of Serratia liquefaciens and Enterobacter cloacae isolated at the exit from two different autoclaves. We observed an increase in total microbial counts at 22 and 37°C between the samples collected at the most remote taps compared to the ones collected at the inlet from the aqueduct. The study highlights a condition of potential risk for susceptible categories of population and supports the need for measures of risk assessment and control.


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 210 ◽  
Author(s):  
Michele Totaro ◽  
Tommaso Mariotti ◽  
Costanza Bisordi ◽  
Erica De Vita ◽  
Paola Valentini ◽  
...  

Legionella spp. control is a critical issue in hospital with old water networks. Chemical disinfection methods are applied as a control measure over prolonged time periods, but Legionella may be resistant to chemical agents in pipeworks with low flow and frequent water stagnation. We evaluated Legionella spp. colonization in the hot water network of Italian hospitals after the installation of time flow taps (TFTs). In the period between 2017 and 2019, TFTs were installed in four hospital water networks. They were programmed in order to obtain a hot water flow of 192 L/day from each TFTs. A continuous chlorination system (chlorine dioxide) and a cold water pre-filtration device were applied in all the buildings. Before and after TFT installation, Legionella spp. was investigated at scheduled times. Before TFT installation, Legionella pneumophila was detected in all the hospitals with counts ranging from 2 × 102 to 1.4 × 105 CFU/L. After TFT installation, a loss in Legionella pneumophila culturability was always achieved in the period between 24 h and 15 days. Total chlorine concentration (Cl2) was detected in the range between 0.23 and 0.36 mg/L while temperature values were from 44.8 to 53.2 °C. TFTs together with chemical disinfection represent a method which improve water quality and disinfectant efficacy, reducing Legionella colonization in dead-end sections.


2013 ◽  
pp. 50-56
Author(s):  
Quoc Tinh Nguyen ◽  
Thi Cu Nguyen

Background: Diarrhea is a leading cause of morbidity and mortality in children in developing countries. Rotavirus is the most important factor cause of severe diarrhea and mortality in children, especially under 2 years. Objective: To study Clinical and paraclinical characteristitics of rotavirus diarrhea in children less than 5 years old in the Pediatric Department of Binh Dinh General Hospital. Methods: Cross observational study, 417 children from 2 months to 5 years old who were hospitalized for acute diarrhea without blood in stool in Pediatric Department of Binh Dinh general hospital, from 15/3/2012 to 14/3/2013. There were 228 patients with rotavirus - positive stool specimens and 189 patients with rotavirus - negative stool specimens. Tested for rotavirus A classification by agglutination techniques. Results: Percentage of Rotavirus diarrhea in children <5 years was 54.7%. The mean age of rotavirus diarrhea was 14.83 ± 9.08 tháng months. Ages with the highest cases of rotavirus diarrhea are 2 - 12 months: 48.2%. Rotavirrus diarrhea is experienced in every month but, the highest prevalence is experienced in the spring - summer) with 71,5%. Clinical characteristitics of rotavirus diarrhea: Vomit presents in 91,7% of cases. 32.9% of the initial symptoms of the disease is vomiting. Mean number of vomiting episodes per day: 7 ± 3.57 times, significantly higher compared with non-rotavirus acute diarrhea (p <0,01). Mean number of bowel movement per day: 10.61±4.18 times, mean duration of diarrhea: 6.66 ± 2.52 days. Younger children have higher frequency and duration of diarrhea compared to older children. Paraclinical characteristitics of rotavirus diarrhea: the mean number leukocyte: 9.74 ±3.61 (x 109/l). 2.2% with low blood sodium status; 8.8% with reduction in serum potassium concentration. 26.3% with low blood calcium and glucose status. Laboratory characteristics of stool: 8.8% with white blood cells in stool, 41.7% with carbohydrate in stool. Conclusion: Rotavirus accounting for 54.7% of the causes of diarrhea in children. Rotavirus diarrhea is experienced throughout the year but the highest prevalence is in the spring-summer. Prominent symptoms of the disease are vomiting and watery stool. Children <24 months experience higher frequency and duration of diarrhea compared to older age groups. Key words: Diarrhea, Rotavirus.


1971 ◽  
Vol 16 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Gavin Shaw ◽  
Bernard Groden ◽  
Evelyn Hastings

The establishment, staffing and structure and observations made in the first year of the existence of coronary care in an intensive care unit in a general hospital are recorded. Two hundred and twenty eight patients were admitted during the year in whom the diagnosis of myocardial infarction was confirmed. There were 29 deaths in the unit and 14 deaths occurred in the wards of the hospital after discharge from the unit. 49.1 per cent of the patients were admitted within 4 hours of the onset of symptoms and the mean duration of stay in the unit was 86.5 hours. The type of arrhythmia detected in the unit, and the treatment given to the patients both before and after admission to the intensive care unit are described.


The Lancet ◽  
1982 ◽  
Vol 319 (8280) ◽  
pp. 1073 ◽  
Author(s):  
S.P Fisher-Hoch ◽  
M.G Smith ◽  
J.S Colbourne

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