Category Archives: Legionnaires’ disease

Research – Legionellosis: A novel mechanism by which the bacterium Legionella pneumophila regulates the immune response of its host cells

Science Daily

Legionellosis or Legionnaires’ disease affected more than 1 800 people in France in 2019 and caused 160 deaths. This emerging disease is caused by Legionella pneumophila, an environmental bacterium that thrives in hot water systems. Researchers have discovered a mechanism that allows Legionella pneumophila to target the immune response of the cells it infects by secreting a small regulatory RNA. This mechanism, not described before, facilitates the survival and proliferation of Legionella pneumophila during infection. The work provides precious information on the strategies used by bacteria to manipulate their host cells.

Research – Emerging Legionella species data

HPS

Legionella_Plate_01

08 February 2022

Article: 56/502

In July 2021, the Legionella Control Association (LCA), in conjunction with the Health and Safety Executive (HSE), Public Health England (PHE) and local authorities, held a webinar aimed at raising awareness of increasing Legionella positivity rates post lockdown.  The data demonstrated that the average positive rate in the UK had increased by around 2% following the lockdowns in response to COVID-19.

To investigate if there were particular species that could have led to this increase, LCA approached the three commercial laboratories in the UK that use MALDI-ToF to confirm down to species level, and asked if they would share their data. This information has now been returned by some laboratories, with findings from over 70,000 positive result samples in a two-year period revealing:

  • over 53% of the results were L.anisa
  • over 32% of the positives were L. pneumophilia, both SeroGroup 1 and SeroGroup 2-15
  • nearly 1% of positives were for L. rubilucens
  • over 6.5% of the results did not confirm a species type
  • there were over a dozen other species identified in results that accounted for less than 1% of the data set

The first line clinical diagnostic tool used to confirm Legionnaire’s disease in the UK is commonly a urinary antigen test (UAT), and this method looks predominantly for L. pneumophilia SeroGroup 1. Given the data LCA has provided so far, this could potentially mean missing over 70% of Legionella infections in patients. It should be highlighted that this data is in its infancy, and LCA state that further research needs to take place before any significant changes are considered or undertaken.

Source: LCA, January 2022

Research – Bacterial Antagonistic Species of the Pathogenic Genus Legionella Isolated from Cooling Tower

MDPI

Legionella pneumophila is the causative agent of Legionnaires’ disease, a severe pneumonia. Cooling towers are a major source of large outbreaks of the disease. The growth of L. pneumophila in these habitats is influenced by the resident microbiota. Consequently, the aim of this study was to isolate and characterize bacterial species from cooling towers capable of inhibiting several strains of L. pneumophila and one strain of L. quinlivanii. Two cooling towers were sampled to isolate inhibiting bacterial species. Seven inhibitory isolates were isolated, through serial dilution plating and streaking on agar plates, belonging to seven distinct species. The genomes of these isolates were sequenced to identify potential genetic elements that could explain the inhibitory effect. The results showed that the bacterial isolates were taxonomically diverse and that one of the isolates may be a novel species. Genome analysis showed a high diversity of antimicrobial gene products identified in the genomes of the bacterial isolates. Finally, testing different strains of Legionella demonstrated varying degrees of susceptibility to the antimicrobial activity of the antagonistic species. This may be due to genetic variability between the Legionella strains. The results demonstrate that though cooling towers are breeding grounds for L. pneumophila, the bacteria must contend with various antagonistic species. Potentially, these species could be used to create an inhospitable environment for L. pneumophila, and thus decrease the probability of outbreaks occurring. View Full-Text

Research – Legionellosis: Diagnosis and Control in the Genomic Era

CDC

CDC legionella

Hundreds of books and textbook chapters, and thousands of journal review articles, have been published on Legionnaires’ disease and Legionella spp. bacteria over the past 45 years, making it important to decide whether this new and quite expensive compilation of reviews is worth acquiring (Figure). The field has become so specialized that even those who know one aspect of it may need a good review of other aspects to easily catch up on recent trends. The book contains chapters on the freshwater ecology of the bacterium; molecular and pathogenic aspects of virulence-associated bacterial secretion systems; very selected aspects of epidemiology; clinical aspects and treatment; laboratory diagnosis; and strain typing methods from serologic to whole-genome sequencing. Some chapters are more current than others. The most recent references for several chapters were published in 2016, and only 1 chapter cites references published in 2020. The book is lightly edited; some of the chapters contain overlapping material, but overall it has few typographical or spelling errors. Not all of the figures are properly labeled; for example, the figure legends in chapter 6 are reversed, and not all of the figure legends in chapter 3 fully explain the meanings of different colors and abbreviations.

I found that several of the chapters contained quite useful information that would be hard to find elsewhere, including a thorough review of L. pneumophila virulence secretory systems, as well as a review of the freshwater ecology of the bacterium, the clinical microbiology and clinical significance of Legionella spp. other than L. pneumophila, and regulatory and risk management strategies for control of the disease. Other readers, depending on their fields of interest and expertise, will find other chapters of particular interest. The chapter on non–whole-genome sequencing methods for strain typing for epidemiologic investigation is well done and could be of interest for those trying to dissect the older literature. Missing from the book, presumably by design, are a chapter reviewing in detail the ecology of the bacterium in the built environment, practical guidance on outbreak investigation, advanced techniques in epidemiologic source investigation, molecular and cellular pathogenesis other than secretion systems, and the molecular evolution of the bacterium, all of which can be found in other sources.

Is this book good value for money? Perhaps not for those who have a narrow interest in a specific field, because there are more up-to-date reviews on many of the topics in journal articles and some textbooks. For those who want to gain an overview of the topics covered in the book, some of which are more comprehensive than those found in textbooks or recent reviews, this may be a useful addition to their libraries.

Slovakia – Report on zoonoses, foodborne diseases and waterborne diseases in the Slovak Republic in 2020

MPSR

 

The protection of human and animal health can only be achieved through the active cooperation of experts in the field of control and research in the human and veterinary field. The report on zoonoses, foodborne diseases and waterborne diseases in the Slovak Republic for 2020 contains data from official inspections carried out in the field of agriculture and health care, as well as from research institutes and universities. The preparation of the report was coordinated by the National Contact Point for Scientific and Technical Cooperation with the European Food Safety Authority (EFSA EFSA), which is established at the Department of Food Safety and Nutrition of the Ministry of Agriculture and Rural Development of the Slovak Republic (MPRV SR).

The report serves as a basis for the EFSA NCB and scientific experts to set priorities and own national food safety risk assessments. At the same time, the report serves as one of the bases for the Community risk assessment carried out by the European Food Safety Authority (EFSA). Scientific risk assessment is the basis for risk management. The report describes the situation in  35 zoonotic agents, 5 foodborne diseases (ie foodborne diseases) without zoonotic potential and 4 waterborne pathogens. Of the 44 agents monitored, 23 are bacterial, 10 parasitic, 10 viral and prion.

It presents the summary results of examinations and tests performed in 2020 in the Slovak Republic and the evaluation of the national epidemiological situation in humans and animals with a focus on trends and sources of zoonotic and foodborne diseases.

The report presents the summary results of examinations and tests carried out in 2020 and an assessment of the national epidemiological situation in humans and animals , focusing on trends and sources of zoonotic and foodborne diseases . The number of monitored authors, cooperating organizations and experts is growing every year. A wide team of more than 70 experts from 24 scientific and control organizations in the Slovak Republic took part in its elaboration .

In 2020, 17,067 human diseases caused by the study agents were reported, with 29.1% related to campylobacteriosis, 20.9% to Clostridium dificille and 20.4% to salmonellosis. Rotavirus 11.6%, Norwalk virus 5.1%, Borrelia burgdorferi sl 5.6% and  Escherichia coli 1.2% also contributed to a higher percentage of diseases.

Seven of the study agents caused 380 human epidemics, of which 56.6% were salmonellosis, 23.2% were campylobacteriosis and 12.6% of epidemics were caused by rotavirus. Norwalk virus accounted for 5.5%, tick-borne encephalitis virus 1.3%, shigella and 0.5% and yersinia 0.3%.  

35,957 food samples were examined for the presence of 15 pathogens with a positive finding in 2.2% of samples. Higher percentages of positive findings were in  Yersinia spp. 48.1%, Enterococcus spp. 46.3% and  Vibrio spp. 31.8%.

The presence of 30 pathogens was monitored in 2,483,239 samples originating from livestock and wild animals, pets and zoos taken as part of official control, preventive monitoring, research, as well as from sick or dead animals. Positive findings accounted for 0.1% of samples. Higher percentages of positive findings were recorded for  Aeromonas spp. 59.3%, Clostridium spp. 55.4%, Francisella tularensis 50.4%, Babesia spp. 41.1%, Dirofilaria spp. 34.8%, Campylobacter spp. 18.3%, Yersinia spp. 18.3%, Staphylococcus aureus 18.1%, hepatitis E virus 14.1%, Listeria monocytogenes  11.8%, Toxocara spp. 10.5%.

Feed – 385 samples were examined for the presence of Salmonella spp. (1.5% positive samples), Escherichia coli (60.0% positive samples) and Clostridium spp.

(1.7% positive samples).

35,746 water samples were examined for the presence of 9 agents, of which 7.4% were positive, of which Legionella spp. 47.1% and Vibrio spp. 39.5%.

44,633 samples from the environment were examined for the presence of 8 pathogens, of which 2.3% were positive, of which Legionella spp. 36.0%, Vibrio spp. 6.8%,  E.coli 3.6% and  Enterococcus spp. 2.6%.

The report also includes the results of examinations for the resistance of microorganisms to antimicrobials, which has a growing trend worldwide and poses a real danger in the treatment of infections. Microbial resistance was monitored in Salmonella spp., E. coli , Campylobacter spp., Staphylococcus aureus and  Enterococcus spp.

The comprehensive report, which will be published as a publication, has a length of more than 130 pages, will be published in printed form, as a publication with an assigned ISBN. Summaries of individual chapters will be translated into English and published in an electronic version as a publication with an assigned ISBN.

See the appendices for more information.

Attachments (downloadable documents)

 

Research – Legionella Occurrence beyond Cooling Towers and Premise Plumbing

MDPI

Legionella_Plate_01

Legionella is an environmental pathogen that is responsible for respiratory disease and is a common causative agent of water-related outbreaks. Due to their ability to survive in a broad range of environments, transmission of legionellosis is possible from a variety of sources. Unfortunately, a disproportionate amount of research that is devoted to studying the occurrence of Legionella in environmental reservoirs is aimed toward cooling towers and premise plumbing. As confirmed transmission of Legionella has been linked to many other sources, an over-emphasis on the most common sources may be detrimental to increasing understanding of the spread of legionellosis. This review aims to address this issue by cataloguing studies which have examined the occurrence of Legionella in less commonly investigated environments. By summarizing and discussing reports of Legionella in fresh water, ground water, saltwater, and distribution system drinking water, future environmental and public health researchers will have a resource to aid in investigating these pathogens in relevant sources. View Full-Text

Spain – Legionellosis outbreak reported in Montmeló and Montornès del Vallès

Outbreak News Today

Legionella_Plate_01

Health officials in Spain are reporting a legionellosis outbreak in the municipalities of Montmeló and Montornès del Vallès in the Vallès Oriental region.

To date, 26 cases have been detected. The cases have started symptoms between November 5 and 15. And, of the 26 cases, 10 did not require hospital admission, 2 cases required admission but have already been discharged and 14 cases are still hospitalized.

Those affected are 19 men and 7 women between 37 and 92 years old. And all the cases have had exposure in the municipalities of Montmeló or Montornès del Vallès.

USA – Legionnaires’ Disease outbreak in New Jersey ongoing, Additional cases reported

Outbreak News Today

Legionella_Plate_01

The New Jersey Department of Health (NJDOH) reported this week four cases of Legionnaires’ disease in Hamilton Township, Mercer County between May-August 2021, along with an additional reported case from November 2020.

State and local health officials continue to work closely to investigate these cases as part of a larger investigation, which was initiated in August 2020 following a reported cluster of four cases.

Hamilton Township reported two deaths in August 2020 and an additional death was reported late last month in an elderly township resident among the nine reported cases.

Legionnaires’ disease is a type of pneumonia that people can get after breathing in aerosolized water (small droplets of water in the air) containing Legionella bacteria. Symptoms of Legionnaires’ disease include cough, shortness of breath, fever, muscle aches, and headaches which are similar to symptoms caused by other respiratory infections, including COVID-19.

Ireland – Legionnaires’ disease

HSE

CDC legionella

Legionnaires’ disease is a lung infection you can catch by inhaling droplets of water from things like air conditioning or hot tubs. It’s uncommon but can be very serious.

How you get Legionnaires’ disease

You can catch Legionnaires’ disease if you breathe in tiny droplets of water containing bacteria that cause the infection.

It’s usually caught in places like hotels, hospitals or offices where the bacteria have got into the water supply. It’s very rare to catch it at home.

You can catch it from things like:

  • air conditioning systems
  • spa pools and hot tubs
  • showers, taps and toilets

You cannot usually get it from:

  • drinking water containing the bacteria
  • other people with the infection
  • places like ponds, lakes and rivers

When to get medical help

Urgent advice:Get advice from your GP now if

you have a bad cough and:

  • it does not go away
  • you cannot breathe properly
  • you have severe chest pain
  • you have a high temperature or feel hot and shivery
  • you feel like you have severe flu

These could be symptoms of Legionnaires’ disease.

You should contact your GP and tell them where you have been in the past 10 days, such as if you stayed in a hotel, spa or hospital. Your GP will assess and advise you.

If you are unable to contact a GP and you are very unwell, you may need to go to your emergency department (ED).

Research – Legionella – Can Point-of-Use Water Filters Control Legionella & Other Waterborne Pathogens?

Legionella Control

CDC legionella

This expert water safety article looks at the role of point-of-use water filters, and asks if they can be used to control the health risks from legionella and other waterborne pathogens that can contaminate engineered water systems.

The article considers how these specialist water filters work to protect people from legionella and other waterborne pathogens, and where and under what circumstances they should be used.

Can point-of-use water filters control legionella risk?

You might already suspect the answer to that question is yes, but let’s take a more detailed look. The bigger question to answer is how these filters can help maintain water safety standards, and why you might consider installing point-of-use (POU) water filters in a specific building.

We’ll explain more about these high performance water filters here, so you can better understand their role, the scenarios that might call for them, and how they complement rather than replace other water safety control measures.