Category Archives: Legionnaires’ disease

Research – Positive Legionella Water Tests Understanding Detection Thresholds & Corrective Actions

Posted on July 13, 2024 by | Leave a comment

Legionella Control

This water safety guide examines how the Responsible Person and others tasked with ensuring workplace water safety deal with positive legionella test results.
The guide looks in detail at the UK’s detection thresholds used for Legionella bacteria in water, what these mean in practice and what you need to do if your water samples return a positive result. The article also considers the different types of Legionella bacteria, water sampling strategies and corrective actions to take if a problem is identified.

Legionella Controls

Warren Bruce Court
Warren Bruce Road
Manchester M17 1LB
United Kingdom
t: 0330 223 36 86
e: info@legionellacontrol.com
w: legionellacontrol.com

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Posted in Food Microbiology Research, Legionella, Legionnaires’ disease, Research, Water, water microbiology, Water Safety

Information – Legionnaires’ disease (legionellosis)

Posted on January 19, 2024 by | Leave a comment

Health NZ

Legionnaires’ disease is a chest infection (pneumonia) caused by the Legionella bacteria. People usually catch the disease by breathing in water droplets that contain the bacteria from sources like soil, compost, potting mix, or spa pools and water systems.

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Posted in Food Microbiology Research, Legionella, Legionnaires’ disease, Research

What is ACOP L8 & What Does It Say About Controlling Legionella?

Posted on November 5, 2023 by | Leave a comment

Legionella Control

The Health and Safety Executive Approved Code of Practice L8 (ACOP L8) is a key document, offering essential direction and guidance to help business owners and those responsible for workplace safety manage the risks associated with legionella and Legionnaires’ disease.

In this guide the water safety specialists at Legionella Control International help to demystify the ACOP L8 to explain what it is, its special legal status, how to interpret it, and the role of the duty holder and responsible person.

A version of this guide to the HSEs ACOP L8 and how to interpret it first appeared in Legionella Control International’s newsletter. To get it in your inbox, sign up for free here.

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Posted in ACOP L8, Contaminated water, Food Microbiology Research, Legionella, Legionnaires’ disease, Research, Water, water microbiology, Water Safety

Research – Waterborne Infectious Diseases Associated with Exposure to Tropical Cyclonic Storms, United States, 1996–2018

Posted on August 6, 2023 by | Leave a comment

CDC

Abstract

In the United States, tropical cyclones cause destructive flooding that can lead to adverse health outcomes. Storm-driven flooding contaminates environmental, recreational, and drinking water sources, but few studies have examined effects on specific infections over time. We used 23 years of exposure and case data to assess the effects of tropical cyclones on 6 waterborne diseases in a conditional quasi-Poisson model. We separately defined storm exposure for windspeed, rainfall, and proximity to the storm track. Exposure to storm-related rainfall was associated with a 48% (95% CI 27%–69%) increase in Shiga toxin–producing Escherichia coli infections 1 week after storms and a 42% (95% CI 22%–62%) in increase Legionnaires’ disease 2 weeks after storms. Cryptosporidiosis cases increased 52% (95% CI 42%–62%) during storm weeks but declined over ensuing weeks. Cyclones are a risk to public health that will likely become more serious with climate change and aging water infrastructure systems.

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Posted in Contaminated water, Cryptosporidiosis, Cryptosporidium, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, STEC, STEC E.coli, Water, water microbiology, Water Safety

Research – Is Legionella Bacteria Becoming Antibiotic Resistant?

Posted on July 4, 2023 by | Leave a comment

Legionella Control

In this article the water safety specialists at Legionella Control International look at the role of antibiotics in protecting humans against pathogenic organisms, paying particular attention to waterborne bacteria including Pseudomonas aeruginosa and legionella.

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Posted in Antibiotic Resistance, Contaminated water, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Water, water microbiology, Water Safety

Research – Increased Incidence of Legionellosis after Improved Diagnostic Methods, New Zealand, 2000–2020

Posted on June 14, 2023 by | Leave a comment

cdc

Abstract

Legionellosis, notably Legionnaires’ disease, is recognized globally and in New Zealand (Aotearoa) as a major cause of community-acquired pneumonia. We analyzed the temporal, geographic, and demographic epidemiology and microbiology of Legionnaires’ disease in New Zealand by using notification and laboratory-based surveillance data for 2000‒2020. We used Poisson regression models to estimate incidence rate ratios and 95% CIs to compare demographic and organism trends over 2 time periods (2000–2009 and 2010–2020). The mean annual incidence rate increased from 1.6 cases/100,000 population for 2000–2009 to 3.9 cases/100,000 population for 2010–2020. This increase corresponded with a change in diagnostic testing from predominantly serology with some culture to almost entirely molecular methods using PCR. There was also a marked shift in the identified dominant causative organism, from Legionella pneumophila to L. longbeachae. Surveillance for legionellosis could be further enhanced by greater use of molecular typing of isolates.

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Posted in Contaminated water, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Water, water microbiology, Water Safety

Research – Heterotrophic Plate Count Can Predict the Presence of Legionella spp. in Cooling Towers

Posted on March 18, 2023 by | Leave a comment

MDPI

Abstract

Legionella pneumophila (Lp) colonizes aquatic environments and is a potential pathogen to humans, causing outbreaks of Legionnaire’s disease. It is mainly associated with contaminated cooling towers (CTs). Several regulations, including Spanish legislation (Sl), have introduced the analysis of heterotrophic plate count (HPC) bacteria and Legionella spp. (Lsp) in management plans to prevent and control Legionella outbreaks from CTs. The 2003 Sl for CTs (RD 865/2003) considered that concentrations of HPC bacteria ≤10,000 cfu/mL and of Lsp ≤100 cfu/L are safe; therefore, no action is required, whereas management actions should be implemented above these standards. We have investigated to what extent the proposed standard for HPC bacteria is useful to predict the presence of Lsp in cooling waters. For this, we analyzed Lsp and HPC concentrations, water temperature, and the levels of chlorine in 1376 water samples from 17 CTs. The results showed that in the 1138 water samples negative for Legionella spp. (LN), the HPC geometric mean was significantly lower (83 cfu/mL, p < 0.05) than in the positive Lsp. samples (135 cfu/mL). Of the 238 (17.3%) LP samples, 88.4% (210/238) were associated with values of HPC ≤10,000 cfu/mL and most of them showed HPC concentrations ≤100 (53.7%). In addition, a relatively low percentage of LP (28/238, 11.6%) samples were associated with HPC bacteria concentrations >10,000 cfu/mL, indicating that this standard does not predict the colonization risk for Legionella in the CTs studied. The present study has demonstrated that a threshold concentration ≤100 cfu/mL of HPC bacteria could better predict the higher concentration of Legionella in CTs, which will aid in preventing possible outbreaks.

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Posted in Cooling Towers, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Water, water microbiology, Water Safety

Research – Exploring the Link Between Legionnaires’ Disease and Pneumonia

Posted on March 14, 2023 by | Leave a comment
Legionella Control
CDC legionella

Most of us have heard of Legionnaires’ disease and we are all likely to be aware of pneumonia too, but did you know there is a link between the two?

There are many illnesses and conditions that can affect the lungs. Legionnaires’ disease presents as a serious type of pneumonia. This is an inflammation of the lungs. Below, we’ll go into more detail about the link between Legionnaires’ disease and pneumonia. Both can be fatal, particularly among those who are more susceptible to this type of infection than others.

A version of this story exploring the link between Legionnaires’ disease and pneumonia appeared in Legionella Control International’s newsletter. To get it in your inbox, sign up for free at the link above

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Posted in Contaminated water, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Uncategorized, Water, water microbiology, Water Safety

Research – Legionella pneumophila Risk from Air–Water Cooling Units Regarding Pipe Material and Type of Water

Posted on March 2, 2023 by | Leave a comment

MDPI

Legionella A

Abstract

Legionellosis is a respiratory disease related to environmental health. There have been manifold studies of pipe materials, risk installations and legionellosis without considering the type of transferred water. The objective of this study was to determine the potential development of the causative agent Legionella pneumophila regarding air–water cooling units, legislative compliance, pipe material and type of water. Forty-four hotel units in Andalusia (Spain) were analysed with respect to compliance with Spanish health legislation for the prevention of legionellosis. The chi-square test was used to explain the relationship between material–water and legislative compliance, and a biplot of the first two factors was generated. Multiple correspondence analysis (MCA) was performed on the type of equipment, legislative compliance, pipe material and type of water, and graphs of cases were constructed by adding confidence ellipses by categories of the variables. Pipe material–type of water (p value = 0.29; p < 0.05) and legislative compliance were not associated (p value = 0.15; p < 0.05). Iron, stainless steel, and recycled and well water contributed the most to the biplot. MCA showed a global pattern in which lead, iron and polyethylene were well represented. Confidence ellipses around categories indicated significant differences among categories. Compliance with Spanish health legislation regarding the prevention and control of legionellosis linked to pipe material and type of water was not observed.

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Posted in Contaminated water, Cooling Towers, Decontamination Microbial, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Water, water microbiology, Water Safety

USA – FDA investigates cases of Legionnaires disease on cruise ships

Posted on February 28, 2023 by | Leave a comment

Food Safety News

FDA Warning Letters

American Cruise Lines
Guilford, CT

American Cruise Lines is on notice from the Food and Drug Administration (FDA) after an inspection of their American Star and American Heritage vessels. According to the warning letter, the FDA continues to have concerns with the potential exposure of passengers and crew members to Legionella onboard American Cruise Lines’ vessels.

In Jan. 24, 2023, warning letter, the FDA described an April 30 through June 17, 2022, an inspection of American Cruise Lines’ American Star and American Heritage vessels.

The warning letter includes information about failed water tests for a sink in the galley and hand-washing sinks for wait staff. The FDA also found that disinfection was ineffective.

American Star
Presence of Legionella Onboard the Vessel

On April 30, 2022, FDA investigators collected 10 biofilm swabs and 14 bulk one-liter potable water samples from various locations on the vessel. The Maryland Department of Health laboratory recovered Legionella from:

Biofilm Swabs with 60 percent of samples positive:

American Heritage

Presence of Legionella Onboard the Vessel

On June 15, 2022, FDA investigators collected 24 biofilm swabs and 29 bulk one-liter potable water samples from various locations on their vessels. The Maryland Department of Health laboratory recovered Legionella from:

Biofilm Swabs with 8 percent of samples positive:

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Legionella, Legionnaires’ disease, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Water, water microbiology, Water Safety