ArticlePDF Available

Residential Water Heater Temperature: 49 or 60 Degrees Celsius?

Authors:
Benoît Lévesque
Benoît Lévesque
Benoît Lévesque
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Michel Lavoie at Institut National de Santé Publique du Québec (INSPQ)
Michel Lavoie
Jean Joly
Jean Joly
Jean Joly
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Download full-text PDFDownload full-text PDF
Read full-text
Download citation
543567700cf2bf1f1f2a8a
b1.pdf
Content uploaded by Michel Lavoie
Author content
All content in this area was uploaded by Michel Lavoie on Oct 08, 2014
Content may be subject to copyright.
Residential Water Heater Temperature: 49 or 60 Degrees Celsiu
s?.pdf
Available via license: CC BY 3.0
Content may be subject to copyright.
Can J Infect Dis Vol 15 No 1 January/February 2004 11
Residential water heater temperature:
49 or 60 degrees Celsius?
Benoît Lévesque MD FRCPC1, Michel Lavoie MD FRCPC2, Jean Joly MD FRCPC3
1Institut National de Santé Publique du Québec, Direction des risques biologiques, environnementaux et occupationnels; 2Institut National de Santé
Publique du Québec, Direction développement des individus et des communautés; 3Institut National de Santé Publique du Québec, Direction
laboratoire de santé publique
Correspondence: Dr Benoît Lévesque, Institut National de Santé Publique du Québec, 945, Ave. Wolfe, Sainte-Foy, Quebec G1V 5B3.
Telephone 418-650-5115, ext 5214, fax 418-666-2776, e-mail Benoit.levesque@inspq.qc.ca
There are two opposing risks when it comes to water tem-
perature inside domestic water heaters; exposure to
Legionella, the bacteria responsible for Legionnaires’ disease
(pulmonary legionellosis), and the risk of scalding. In 1986,
this dilemma was the subject of an editorial in the Canadian
Medical Association Journal (1). A few months ago, Safe Kids
Canada launched a media campaign aimed at preventing
scalding by lowering domestic hot water temperature to 49°C
at the tap (2). Among the means considered to reach this
objective, Safe Kids Canada, with the support of some public
health organizations, suggests and seems to favour lowering the
temperature setting of domestic hot water heaters to 49°C.
Like other authors (3,4), including the World Health
Organization (WHO) who published a recent monograph on
the Legionella problem in drinking water (3), we believe that
there is evidence for the transmission of legionellosis through
the drinking water distribution systems in private homes. This
is a serious illness associated with high death rates (up to 12%).
Primary groups at risk (the elderly, smokers, the immunocom-
promised and patients suffering from chronic respiratory ill-
nesses), are groups who include a large proportion of the
population at home. Although we support prevention against
tap water scalds, we are against setting water heater thermo-
stats at 49°C because we believe this could facilitate prolifera-
tion of Legionella inside the tank and increase the risk of
legionellosis.
Domestic water heaters, particularly electric devices, can cer-
tainly be contaminated by Legionella. In Quebec, a study of 211
homes (178 electric water heaters, 33 oil or gas water heaters)
found Legionella contamination in 40% of electric water heaters.
No water heaters using fossil fuels were contaminated (5). The
authors concluded that, because of design variables, use of an
electric water heater was the most significant factor leading to
Legionella contamination in hot water (5) in the home.
The clinical and epidemiological significance of this find-
ing is much debated. However, in a case-control study of spo-
radic cases of community-acquired legionellosis, Straus et al
(6) concluded that the residential drinking water supply was
responsible for a substantial proportion of sporadic cases of
Legionnaires’ disease. These findings are supported by Stout et al
(7) in a study of 20 Pittsburgh patients with culture-
confirmed Legionnaires’ disease. A link with residential drink-
ing water contamination was established for eight (40%)
patients. This included three private homes (one single
dwelling, two multidwellings), two senior-citizen homes, two
out-patient hospital clinics, and one industrial plant. The
authors concluded that drinking water distribution systems
were a significant source of transmission of Legionnaires’ dis-
ease (7).
The importance of Legionnaire’s disease is underestimated
because it is difficult to diagnose and because it is reported
through a passive surveillance system. In an active surveillance
study of pneumonia requiring hospitalization in Ohio, the inci-
dence of Legionnaire’s pneumonia was estimated to be approx-
imately seven cases per 100,000 people (8). With the
observations from the Stout et al (7) study, if active surveil-
lance was performed, an estimated two cases of Legionnaire’s
disease per 100,000 people per year could be attributable to
potable water in private homes and senior-citizen residences.
This is at least of the same order of magnitude as the annual
rates of 0.45 per 100,000 for hospitalization and 0.043 for
death due to scalding by tap water in Quebec (9).
The optimal temperature for Legionella proliferation in
water varies between 32°C and 35°C, but it can easily prolifer-
ate at temperatures of up to 45°C. Usually, there is no growth
above 55°C, and a temperature of over 60°C has a bactericidal
effect. Thus, the WHO recommends that water be heated and
stored at 60°C (3). However, studies in Quebec have shown,
even when the thermostat is set at 60°C, a high percentage
(approximately 40%) of electric water heaters remain contam-
inated because of the lower temperature, about 30°C to 40°C
at the bottom of the tank. The probability of contamination
will increase considerably if the temperature setting is lowered
to 49°C. The risk of contamination is much lower for water
heaters operating with fossil fuels, and is practically nonexist-
ent for these heaters set at 60°C.
In our opinion, it is important to reduce both the risk of
scalds and the risk of legionellosis associated with domestic
water supplies (9). For water heaters servicing a single housing
unit, electric water heater manufacturers need to market, as
quickly as possible, water heaters resistant to proliferation of
Legionella. At the least, all new water heaters must be preset at
60°C and equipped with antiscald devices to deliver water at
49°C to the entire household. Electric water heaters already
installed should be set at 60°C to limit the risk of Legionella
contamination. Gas or oil water heaters already installed
©2004 Pulsus Group Inc. All rights reserved
EDITORIAL
Levesque.qxd 2/6/04 3:09 PM Page 11
should be set at 49°C, because the risk of scalding is greater
with these devices. In fact, when there are repeated demands
for hot water, gas or oil water heaters are likely to deliver water
that is much hotter than the preset temperature, with a greater
risk of scalding in some situations (10). Water heaters servicing
multiple unit housing complexes equipped with more com-
plex water distribution systems are more likely to be contam-
inated, and the recommendations from the WHO should
apply no matter what type of water heater is used (3). These
recommendations state hot water must be stored at 60°C
inside the water heater by ensuring, at least once a day, the
temperature reaches at least 60°C in the entire tank.
Moreover, water should reach the tap at a temperature of at
least 50°C. Taps in these buildings, especially in the bath or
shower where most scalds occur, should be equipped with
antiscald devices to decrease the water temperature to 49°C
or less. Such a strategy would minimize the risk of scalding
and the risk of legionellosis for the population.
Lévesque et al
Can J Infect Dis Vol 15 No 1 January/February 200412
REFERENCES
1. Stanwick RS. Balancing the risks: Legionella pneumophila
pneumonia and tap water scalds in the home. Can Med Assoc J
1986;135:1251-2.
2. SécuriJeune Canada. Mémoire aux ministres sur la
modification des codes en vue d’empêcher les brûlures dues à
l’eau chaude du robinet. Programme national de prévention
des blessures dues à l’eau chaude de l’Hospital for Sick
Children. 2003.
3. World Health Organization (WHO). Legionella. In: Guidelines for
Drinking Water. Addendum: Microbiological Agents in Drinking
Water, 2nd edn, 2002.
4. Pedro-Botet ML, Stout JE, Yu VL. Legionnaires’ disease contracted
from patient homes: The coming of the third plague? Eur J Clin
Microbiol Infect Dis 2002;21:699-705.
5. Alary M, Joly JR. Risk factors for contamination of domestic hot
water systems by Legionnellae. Appl Environ Microb
1991;57:2360-7.
6. Straus WL, Plouffe JF, File TM, et al. Risk factors for domestic
acquisition of Legionnaires’ disease. Arch Intern Med
1996;156:1685-92.
7. Stout JE, Yu VL, Muraca P, et al. Potable water as a cause of
sporadic cases of community-acquired Legionnaires’ disease. New
Eng J Med 1992;326:151-5.
8. Marston BJ, Plouffe JF, File TM, et al. Incidence of community-
acquired pneumonia requiring hospitalization. Arch Intern Med
1997;157:1709-18.
9. Lavoie M, Lévesque B, Sergerie D. Prévention des cas de brûlures
et de légionelloses associés à l’eau chaude du robinet dans les
résidences privées. Institut National de Santé Publique du Québec,
Québec, 2003, <http://www.inspq.qc.ca/pdf/publications/
205_PrevBruluresLegionelResidencesPrivees.pdf> (Version current
at January 30, 2004).
10. Viola DW. Water temperature control and limitation. Plumbing
Manufacturers Institute. Schaumburg, Illinois, USA, 2002.
Levesque.qxd 2/6/04 3:09 PM Page 12
... Viable microbes intrinsic to the pipes and tanks of the facilities could thrive in the absence of residual chlorine. Water temperature also plays a key role to suppress the growth of pathogenic bacteria [32]. The WHO reported that bacteria can survive in hot water systems of 20~50 degrees Celsius and that an optimal temperature is 35~46 degrees Celsius [23]. ...
... The WHO reported that bacteria can survive in hot water systems of 20~50 degrees Celsius and that an optimal temperature is 35~46 degrees Celsius [23]. Several studies suggested that drinking water should be heated above 60 degrees Celsius and the hot water system should be kept above 50 degrees Celsius [16,32,33]. Chinese people cultivate the habit of drinking boiled water, and this has become a widespread preference among people of every geographic position. ...
Survey of School Direct-Drinking Water Access for Children and Youth in Shanghai, China
Article
Full-text available
  • Jun 2025
Background: Over the past decade, Shanghai primary and middle schools have installed and updated direct-drinking water facilities in compliance with local policies, but few studies have assessed the schools providing direct-drinking water access. Methods: A cross-sectional study was conducted with 167 public primary, middle, and high schools across Pudong New Area, Shanghai during Autumn 2024. The type, location, and working condition of all direct-drinking water facilities throughout each school were documented by trained research staff using a direct observation protocol. Information on school direct-drinking water quality was obtained from the routine monitoring program. Data were analyzed for comprehensive assessment of direct-drinking water facilities in the schools. Results: On average, each school had one faucet of direct-water facility per 41 students; 70% of the schools met the requirement for minimum direct-drinking water access, and >90% placed facilities in high-traffic areas. In addition, 83% of the schools selected water facilities with nanofiltration and a hot water system, and most only provided hot water (above 50 degrees Celsius). For school direct-drinking water quality, the concentrations of hardness, chemical oxygen demand (COD), and total dissolved solids (TDS), as well as pH values, were improved significantly, but the total bacteria count was prone to not meeting the requirement for standards in middle and high schools, which could be caused by insufficiency of chlorination in pumping stations or neglecting to clean facilities promptly. Conclusions: Wide usage of school direct-drinking water facilities could help most public schools to meet local policies for minimum student drinking water access in Shanghai, but microbial contamination was the potential threat. Water temperature is the key factor affecting students’ drinking water, providing an optional water temperature for students’ preferences and concerns. National sanitary standards of direct-drinking water quality and relevant additional regulations should be established and implemented in China.
View
... Pengambilan data pada setiap variasi panjang pipa diakhiri sampai suhu air mencapai 60 °C. Hal ini dikarenakan menurut [9,10] suhu air di dalam tangki water heater perlu mencapai 60°C dengan tujuan untuk menghilangkan bakteri Legionella yang ada pada air. ...
Analisis Perpindahan Panas Water Heater Dengan Variasi Panjang Pada Pipa Bentuk Helical Memanfaatkan Panas Dari Pipa Kompresor AC Split 1 PK
Article
Full-text available
  • Oct 2024
Sumber energi utama dari air conditioner (AC) dan water heater adalah energi listrik. Menurut Badan Pusat Statistik, dari tahun 2018 sampai tahun 2022 sebesar 65% listrik yang dihasilkan di Indonesia berasal dari Pembangkit Listrik Tenaga Uap berbahan bakar batu bara.. Batu bara merupakan sumber energi yang tidak terbarukan dan penggunaannya dapat menimbulkan pencemaran lingkungan. Solusi alternatif dari permasalahan ini adalah peralihan sumber energi bagi water heater dari energi listrik ke energi panas yang berasal dari pipa kompresor AC. Pada penelitian ini dilakukan analisis perpindahan panas sensibel dari pipa kompresor AC ke air pada tangki water heater menggunakan pipa helical. Penelitian ini bertujuan untuk mengetahui pengaruh variasi panjang pipa helical terhadap lama operasi sistem, daya input, daya output dan efisiensi sistem.. Penelitian dilakukan dengan memvariasikan panjang pipa helical sebesar 6 m, 9 m, dan 12 m sebagai alat penukar panas di dalam tangki water heater. Penelitian dilakukan sampai suhu air di dalam tangki mencapai 60°C. Dari penelitian yang dilakukan dapat diketahui bahwa semakin panjang pipa helical yang digunakan maka waktu operasi sistem semakin pendek. Pada variasi panjang pipa 12 m memerlukan waktu operasi 59 menit, variasi panjang pipa 9 m memerlukan waktu operasi 62 menit, dan variasi panjang pipa 6 m memerlukan waktu operasi 89 menit. Nilai rata-rata daya input pada variasi panjang pipa 12 m adalah 0,779 kW, pada variasi panjang pipa 9 m adalah 0,785 kW, dan pada variasi panjang pipa 6 m adalah 0,809 kW. Nilai rata-rata daya output pada variasi panjang pipa 12 m adalah 0,226 kW, pada variasi panjang pipa 9 m adalah 0,183 kW, dan pada variasi panjang pipa 6 m adalah 0,122 kW. Nilai rata-rata efisiensi termal pada variasi panjang pipa 12 m adalah sebesar 32,15%, pada variasi panjang pipa 9 m adalah sebesar 25,16%, dan variasi panjang pipa 6 m adalah sebesar 15,44%.
View
... Safety standards to protect against such hazards do not aim for perfect safety but, rather, to achieve a reasonable balance between controlling risk and allowing effective use of a technology. For example, the World Health Organization (WHO) recommends that domestic hot water heaters maintain water at 60 °C to prevent growth of Legionella (which can cause life threatening infections); consumer protection agencies recommend a maximum tap water outflow temperature of 49 °C to prevent scalds [46]. However, neither limit is "safe"; water at 49 °C will cause scalds within a minute or two ( Figure 2). ...
Health Aspects of Millimeter-Wave Exposures in 5G and Beyond Millimeter Waves and Health
Article
  • Jan 2025
  • IEEE MICROW MAG
This article reviews, at a nontechnical level, the issue of potential health effects of millimeter wave exposure (30-300 GHz) as well as 5G NR exposure in the high band (presently, 24.25-52.6 GHz). MM-wave energy is chiefly absorbed in the top layers of skin. The established hazards from such energy are associated with excessive heating of tissue, including thermal damage to skin and the eye, and thermal pain. Present exposure limits to mm-waves in IEEE Standard C95.1-2019 and ICNIRP (2020) Guidelines are based on numerical modeling of tissue heating and on a limited number of human and animal studies, and appear to be quite conservative with respect to thermal hazards. The existence of many mm-wave bioeffects studies, many reporting biological effects of exposure over a wide range of frequencies and exposure levels but with high risk of bias and other limitations, introduces significant uncertainty in assessing the health effects literature. Health agencies have not identified hazards of 5G high band and mm-wave exposure at “nonthermal” levels below current exposure limits, but all recommend further research. The present authors suggest several lines of needed research, and point to the need to improve the quality of future bioeffects studies.
View
... PCM is used in heating water systems and it is usually done through two methods: it can be either integrated into a storage tank or integrated directly into solar collectors [95]. In both methods, selection of PCM and its melting point is crucial where it must be in the range of 49 to 60 °C in the first method [96] and up to 80 °C for the second [8]. Murthy and Gumtapure [97] analyzed the behavior of a mixture of organic fatty acids as bio-PCM which was thermally stable with an operating temperature range of 46-59 °C. ...
Prospects and challenges of bio-based phase change materials: An up to date review
Article
  • Jun 2024
In recent years intensive research has been conducted on phase change materials (PCMs) for both energy storage and thermal regulation of equipment and buildings. However, a great number of PCMs are derived from fossil fuel industry such as paraffin. Thus, bio-sourced PCM can be utilized and hence contribute to achieve the sustainability goals. The objective of the present study is to highlight the latest development as well as perspectives of the potential of bio-PCM for improvement of the performance of various thermal applications and draw recommendations that can direct future research. The reviewed literature includes development of bio-based PCMs, determination of their physical and thermal properties, and evaluation of their thermal performance in domestic and industrial applications such as heating, air conditioning, cooling of photovoltaic panels and lithium-ion batteries, water treatment and distillation, inclusion in commercial and domestic refrigerators, food conservation, refrigeration of pharmaceutical products and vaccines. Some drawbacks of bio-based PCMs such as degradation due to microorganisms, thermal and chemical instabilities, and degradation due to cycling and other long-term effects need further research and developments. Finally, these limitations along with other research gaps are highlighted for future consideration.
View
... 61 Legionellosis can be avoided by not using or thoroughly cleaning devices that aerosolize water and keeping hot water tanks at least at 50 C, although a higher temperature of 60 C may provide better protection against Legionella but needs to be balanced against the risk of scalding. 62 Listeria monocytogenes is carried in the gastrointestinal tract of ruminants and can grow at 4 C and thus can continue to grow on refrigerated products. Soft cheeses and deli meats have been classically associated with outbreaks of listeriosis; however, raw vegetable products such as lettuce and coleslaw are now more commonly implicated due to contamination by agricultural runoff. ...
Infectious Disease Prophylaxis During and After Immunosuppressive Therapy
Article
Full-text available
  • Apr 2024
Immune-mediated renal diseases are a diverse group of disorders caused by antibody, complement, or cell-mediated autosensitization. Although these diseases predispose to infection on their own, a growing array of traditional and newer, more targeted immunosuppressant medications are used to treat these diseases. By understanding their mechanisms of action and the infections associated with suppression of each arm of the immune system, nephrologists can better anticipate these risks and effectively prevent and recognize opportunistic infections. Focusing specifically on nonkidney transplant recipients, this review discusses the infections that can be associated with each of the commonly used immunosuppressants by nephrologists and suggest interventions to prevent infectious complications in patients with immune-mediated renal disease.
View
View
Mitigation of opportunistic pathogens in hot water systems: a review focused on premise plumbing in South Africa
Article
Full-text available
  • May 2025
Water reticulation systems (i.e., premise plumbing) serve as a reservoir for opportunistic premise plumbing pathogens (OPPPs) to survive within these premise systems. OPPPs can be transmitted to individuals mainly via inhalation of aerosols from these water systems. These OPPPs can adapt, thrive and survive under a range of different conditions, which include high temperatures and low oxygen levels during stagnation, conditions often associated with household plumbing systems, including hot water systems (HWS). Hospitals are of specific concern as infections caused by OPPPs predominantly affect individuals who have underlying illnesses or health conditions. The current South African National Standard (SANS) 241 for drinking water does not provide information regarding testing for the presence of OPPPs, while the SANS 893 and 893-1 standards only provide a guideline for Legionella in water systems. The presence of OPPPs within HWS and premise plumbing is a concern, and a need exists to establish remediation and mitigation measures to control the presence of OPPPs in buildings. This review addresses risk analysis, evaluation and measures, which include the control of geyser temperatures and training of plumbers, as well as sampling and detection of OPPPs. This should limit the number of infections amongst individuals and will thus lessen the financial burden on health care systems and the economy.
View
View
Sustainable Solar Energy: Repurposing Discarded Materials in Parabolic Concentrator Fabrication
Conference Paper
  • Jan 2024
This study explores an alternative approach to fabricating parabolic solar concentrators (PSC) by incorporating discarded materials like dish antennas, recycled aluminum foil, and broken mirrors. The study evaluates the efficiency and practicality of utilizing these unconventional resources for PSC production. By adopting this innovative method, the researchers aim to contribute to sustainable and eco-friendly PSC manufacturing processes. This research investigates the technical aspects and potential benefits of using such materials, shedding light on their viability in solar energy usage and applications. Ultimately, this research presents a sustainable perspective on obtaining alternative materials to create efficient solar systems. By utilizing discarded materials and evaluating their performance within PSCs, we demonstrate a promising pathway toward achieving both environmental and energy efficiency goals.
View
Empowering sustainable hotels: a guest-centric optimization for vehicle-to-building integration
Article
Full-text available
  • Sep 2024
In light of global warming, hotels account for one of the highest energy demands within the building sector, offering great decarbonization potential. As electrification increases, so does the demand for electric vehicles (EVs) charging stations at hotels and the proportion of Vehicle-to-Building-capable EVs. Therefore, the study explores the potential of guest-centric energy management. To accomplish this, we develop an optimization model for an energy management system that focuses on either cost-efficiency or carbon dioxide equivalents (CO2)-efficiency, grounded in a real-world case study. Through scenario analyses considering seasons as well as different guest mobility behaviors, this study discusses the expenses associated with CO2 savings using digital solutions. It emphasizes the currently perceived conflict between cost reduction and decarbonization goals to achieve a sustainable design of information systems. Thereby, this study highlights the critical importance of individual mobility behavior in enabling sustainable energy management for hotels.
View
Incidence of Community-Acquired Pneumonia Requiring HospitalizationResults of a Population-Based Active Surveillance Study in Ohio
Article
Full-text available
  • Aug 1997
  • ARCH INTERN MED
Background: Pneumonia is the leading cause of death due to infectious diseases in the United States; however, the incidence of most infections causing community-acquired pneumonia in adults is not well defined. Methods: We evaluated all adults, residing in 2 counties in Ohio, who were hospitalized in 1991 because of community-acquired pneumonia. Information about risk factors, symptoms, and outcome was collected through interview and medical chart review. Serum samples were collected from consenting individuals during the acute and convalescent phases, and specific etiologic diagnoses were assigned based on results of bacteriologic and immunologic tests. Results: The incidence of community-acquired pneumonia requiring hospitalization in the study counties in 1991 was 266.8 per 100 000 population; the overall case-fatality rate was 8.8%. Pneumonia incidence was higher among blacks than whites (337.7/100 000 vs 253.9/ 100 000; P<.001), was higher among males than females (291.4 vs 244.8; P<.001), and increased with age (91.6/100 000 for persons aged <45 years, 277.2/ 100 000 for persons aged 45-64 years, and 1012.3/ 100 000 for persons aged ≥65 years; P<.001). Extrapolation from study incidence data showed the projected annual number of cases of community-acquired pneumonia requiring hospitalization in the United States to be 485 000. These data provide previously unavailable estimates of the annual number of cases that are due to Legionella species (8000-18 000), Mycoplasma pneumoniae (18 700-108 000), and Chlamydia pneumoniae (5890-49 700). Conclusions: These data provide information about the importance of community-acquired pneumonia and the relative and overall impact of specific causes of pneumonia. The study provides a basis for choosing optimal empiric pneumonia therapy, and allows interventions for prevention of pneumonia to be targeted at groups at greatest risk for serious illness and death.Arch Intern Med. 1997;157:1709-1718
View
Potable Water as a Cause of Sporadic Cases of Community-Acquired Legionnaires' Disease
Article
Full-text available
  • Feb 1992
The environmental sources of sporadic, community-acquired legionnaires' disease are largely unknown, and culturing of water sources after identification of a case is currently not recommended. We conducted a prospective study of sporadic cases of community-acquired legionnaires' disease to determine whether the environmental reservoirs could be identified. We cultured samples of potable water obtained from sources to which each of 20 patients with culture-confirmed, community-acquired legionnaires' disease had been exposed during the two weeks before the onset of symptoms. Monoclonal-antibody subtyping and restriction-endonuclease analysis were performed on the legionella isolates recovered from both the patients and the associated environmental cultures. For 8 of the 20 patients, isolates of Legionella pneumophila with identical subtypes were identified in cultures from both the patient and the potable water to which the patient had been exposed. The environmental reservoirs linked to the infections were the water supplies of two private residences, two nursing homes, two hospital outpatient clinics, and an industrial plant. Potable-water supplies that harbor L. pneumophila are an important source of community-acquired legionnaires' disease. Future studies should include attempts to identify the environmental sources of this infection.
View
Risk factors for contamination of domestic hot water systems by Legionellae
Article
Full-text available
  • Sep 1991
To assess risk factors associated with the contamination of the domestic environment by legionellae, 211 houses in the Quebec City area were randomly selected and water samples were collected from the hot water tank, the shower heads, and the most frequently used faucet. After centrifugation, concentrated samples were seeded in triplicate on BCYE and GPV media. Data on the characteristics of the hot water system and plumbing in the house and on the personal habits of the occupants were collected for each house. Among these 211 houses, hot water was provided by either an oil or gas heater in 33 and by an electric heater in 178. Legionellae were isolated from none of the samples from houses with oil or gas heaters and from 39% (69 of 178) of those with electric water heaters (P less than 0.0001). This association remained highly significant after control for water temperature and other variables in a stratified analysis. In the 178 houses with an electric heater, 12% of the faucets, 15% of the shower heads, and 37% of the water heaters were contaminated. Legionella pneumophila serogroups 2 and 4 were the most frequently isolated strains. Logistic regression showed that factors associated with electric water heater contamination were (i) location of the house in older districts of the city (P less than 0.0001), (ii) old age of the water heater (P = 0.003), and (iii) low water temperature (P = 0.05). Contamination of the water heater was the only factor significantly associated with the contamination of peripheral outlets (P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
View
Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group
Article
  • Aug 1997
  • ARCH INTERN MED
Pneumonia is the leading cause of death due to infectious diseases in the United States; however, the incidence of most infections causing community-acquired pneumonia in adults is not well defined. We evaluated all adults, residing in 2 counties in Ohio, who were hospitalized in 1991 because of community-acquired pneumonia. Information about risk factors, symptoms, and outcome was collected through interview and medical chart review. Serum samples were collected from consenting individuals during the acute and convalescent phases, and specific etiologic diagnoses were assigned based on results of bacteriologic and immunologic tests. The incidence of community-acquired pneumonia requiring hospitalization in the study counties in 1991 was 266.8 per 100,000 population; the overall case-fatality rate was 8.8%. Pneumonia incidence was higher among blacks than whites (337.7/100,000 vs 253.9/ 100,000; P or = 65 years; P
View
View
Risk Factors for Domestic Acquisition of Legionnaires Disease
Article
  • Aug 1996
  • ARCH INTERN MED
Legionnaires disease is a common cause of adult pneumonia. Outbreaks of legionnaires disease have been well described, but little is known about sporadically occurring legionnaires disease, which accounts for most infections. Exposure to contaminated residential water sources is I plausible means of disease acquisition. Employing a matched case-control study design in 15 hospitals in 2 Ohio counties, we prospectively enrolled 146 adults diagnosed as having nonepidemic, community-acquired legionnaires disease and compared each with 2 hospital-based control patients, matched for age, sex, and underlying illness category. An interview regarding potential exposures was followed by a home survey that included sampling residential sources for Legionella. Interview and home survey data were analyzed to estimate the risk of acquiring legionnaires disease associated with various exposures. Multivariate analysis showed that a nonmunicipal water supply (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.17-4.37), recent residential plumbing repair (OR, 2.39; 95% CI, 1.10-5.18), and smoking (OR, 3.48; 95% CI, 2.09-5.79) were independent risk factors for legionnaires disease. Univariate analysis suggested that electric (vs gas) water heaters (OR, 1.97; 95% CI, 1.10-3.52), working more than 40 hours weekly (OR, 2.13; 95% CI, 1.12-4.07), and spending nights away from home before illness (OR, 1.68; 95% CI, 1.03-2.74) were additional possible risk factors. Lower chlorine concentrations in potable water and lower water heater temperatures were associated with residential Legionella colonization. A proportion of sporadic cases of legionnaires disease may be residentially acquired and are associated with domestic potable water and disruptions in residential plumbing systems. Potential strategies to reduce legionnaires disease risk include consistent chlorination of potable water, increasing water heater temperatures, and limiting exposure to aerosols after domestic plumbing repairs.
View
Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group
Article
  • Aug 1997
  • ARCH INTERN MED
Pneumonia is the leading cause of death due to infectious diseases in the United States; however, the incidence of most infections causing community-acquired pneumonia in adults is not well defined. We evaluated all adults, residing in 2 counties in Ohio, who were hospitalized in 1991 because of community-acquired pneumonia. Information about risk factors, symptoms, and outcome was collected through interview and medical chart review. Serum samples were collected from consenting individuals during the acute and convalescent phases, and specific etiologic diagnoses were assigned based on results of bacteriologic and immunologic tests. The incidence of community-acquired pneumonia requiring hospitalization in the study counties in 1991 was 266.8 per 100,000 population; the overall case-fatality rate was 8.8%. Pneumonia incidence was higher among blacks than whites (337.7/100,000 vs 253.9/ 100,000; P < .001), was higher among males than females (291.4 vs 244.8; P < .001), and increased with age (91.6/100,000 for persons aged < 45 years, 277.2/ 100,000 for persons aged 45-64 years, and 1012.3/ 100,000 for persons aged > or = 65 years; P < .001). Extrapolation from study incidence data showed the projected annual number of cases of community-acquired pneumonia requiring hospitalization in the United States to be 485,000. These data provide previously unavailable estimates of the annual number of cases that are due to Legionella species (8000-18,000), Mycoplasma pneumoniae (18,700-108,000), and Chlamydia pneumoniae (5890-49,700). These data provide information about the importance of community-acquired pneumonia and the relative and overall impact of specific causes of pneumonia. The study provides a basis for choosing optimal empiric pneumonia therapy, and allows interventions for prevention of pneumonia to be targeted at groups at greatest risk for serious illness and death.
View
View
Prévention des cas de brûlures et de légionelloses associés à l'eau chaude du robinet dans les résidences privées
  • Mar 2003
  • M Lavoie
  • B Lévesque
  • D Sergerie
Lavoie M, Lévesque B, Sergerie D. Prévention des cas de brûlures et de légionelloses associés à l'eau chaude du robinet dans les résidences privées. Institut National de Santé Publique du Québec, Québec, 2003, <http://www.inspq.qc.ca/pdf/publications/ 205_PrevBruluresLegionelResidencesPrivees.pdf> (Version current at January 30, 2004).
Water temperature control and limitation. Plumbing Manufacturers Institute
  • Jan 2002
  • D W Viola
Viola DW. Water temperature control and limitation. Plumbing Manufacturers Institute. Schaumburg, Illinois, USA, 2002.