Legionnaires` Disease
Odds & Sods
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TIPSHEET Highlights from the Journals of the American Society for Microbiology
RECENTLY IDENTIFIED BACTERIUM CAUSES DISEASE
Scientists at the Fairfield Hospital in Australia and the VA Medical Center in Pittsburgh report what they believe to be the second case ever of illness caused by a recently discovered bacterium. The study appears in the July 1997 issue of the Journal of Clinical Microbiology.
The report describes the case of 75-year-old Australian man who came to the hospital after 3 days of fever, chills, sweats, lethargy and anorexia. An initial treatment with antibiotics did not improve his condition, but after changing the antibiotics his condition improved and he recovered. Laboratory tests indicated that the organism that caused his fever was a recently described bacterium known as Desulfovibrio fairfieldensis.
Desulfovibrio bacteria are commonly found in nature and can be isolated from most water and soil types. They are anaerobic, meaning they can only grow in the absence of oxygen. Only five cases of human infection by Desulfovibrio have ever been described and this case represents only the second by this species.
"Laboratories need to be aware of the
anaerobic, motile, vibrioid-like organisms, in particular Desulfovibrio species,
as rare causes of human disease," say the researchers.
(R. McDougall, J. Robson, D. Paterson, and W. Tee. 1997.
Bacteremia caused by a recently described novel Desulfovibrio species. Journal
of Clinical Microbiology. 35:1805-1808.)
FIRST REPORT OF LEGIONELLA SPECIES IN HUMAN DISEASE
A bacterium from the Legionella family, not previously associated with human disease, has been identified as the cause of pneumonia in a woman in France. Researchers from the Hopital Paul Brousse in Villejuif, France, report this first case in the July 1997 issue of the Journal of Clinical Microbiology.
The researchers report on a 34-year-old woman who, 4 weeks after a liver transplant, developed severe pneumonia. She suffered neurological deterioration and eventually went into a coma. After several weeks of various antibiotic treatments and a second liver transplant, she recovered.
The cause of her pneumonia was found to be the
bacterium Legionella parisiensis. This bacterium was first identified in a
cooling tower in Paris in 1985 and since then no further isolations of this
organism have been reported until this case. The family Legionellaceae comprises
42 species among which 18 have been isolated from patients with pneumonia. The
most well known species is Legionella pneumophila, the cause of Legionnaire's
disease, which accounts for nearly 90% of Legionella infections.
(F.L. Presti, S. Riffard, F. Vandenesch, M. Reyrolle, E. Ronco, P.
Ichai, and J. Etienne. 1997. The first clinical isolate of Legionella
parisiensis from a liver transplant patient with pneumonia. Journal of Clinical
Microbiology. 35:1706-1709.)
HEALTH AND SAFETY EXECUTIVE E115:97 1 July 1997
NEW LEAFLET SETS RECORD STRAIGHT ON RISKS OF LEGIONELLA IN NURSING AND
RESIDENTIAL CARE HOMES
Nursing and
Residential care home owners will be sent a free purpose designed leaflet by the
Health and Safety Executive (HSE) to help them control the risk of their
patients and residents developing potentially fatal Legionnaires' Disease. The
decision to produce the leaflet - Controlling Legionella in Nursing and
Residential Care Homes - is the result of a recent survey carried out by the
HSE. It showed that many home owners and managers were unaware of the existing
HSE guidance on Legionella control, despite the fact that owners and managers of
these homes have a legal duty to assess the risks to patients and residents from
Legionella and adopt appropriate precautions. The leaflet, based on existing HSE
guidance, offers managers clear and simple practical guidance on the steps they
need to take to control the risks from Legionella - the bacteria which causes
Legionnaires' Disease . The simplest and most effective control, which is
accepted internationally, is to keep water hot enough to kill the bacteria. HSE
guidance recommends that hot water should be stored above 60 degsC and
distributed at above 50 degsC but it also emphasises that managers need to take
appropriate precautions to avoid scalding elderly and vulnerable patients and
residents. The best way of minimising the scalding risks to such people - who
may be disabled or unaware of the danger - is to fit inexpensive thermostatic
mixing valves to bath taps and showers. Before producing the leaflet HSE
consulted widely with local authorities, representatives of nursing homes and
asked for expert opinion from a joint HSE/Department of Health group on
Legionellosis. Copies of Controlling Legionella in Nursing and Residential Care
Homes, IND(G)253L are available from HSE Books, PO Box 1999, Sudbury, Suffolk,
CO10 6FS, tel: 01787-881165 or fax: 01787-313995. Notes to Editors 1. The
Legionella bacterium can cause a range of illnesses, commonly known as
Legionnaires' Disease, including fatal pneumonia. Elderly people are
particularly vulnerable to developing Legionnaires' Disease. The bacteria occur
commonly in natural and artificial water systems. They can survive at low
temperatures and thrive at temperatures between 20 degs and 50 degsC. They are
killed at higher temperature and this is the main method used for their control
in domestic water systems. 2. A survey of nursing and residential care homes was
carried out by HSE and Local Authority Inspectors in June and July 1996. A
questionnaire asking for details of the hot water system and measurement of bath
outlet temperature was completed by the inspector as part of normal inspection
visits. 3. Scalding is a significant risk nursing and residential care homes.
There have been over 30 fatal accidents to patients or residents in such homes
the last 10 years and more than 40 other major scalding accidents. 4. The
results of the survey are being presented at the 3rd International Conference on
occupational health for healthcare workers in Edinburgh (29 June - 2 July). 5.
The Joint HSE/DH working group on legionellosis consists of officials from HSE,
Department of Health, Department of Environment, Department of Energy, Welsh
Office and the Health and Safety Authority Northern Ireland; scientists and
experts from the Public Health Laboratory Service, the Centre for Applied
Microbiology and Research, Porton Down and Thames Water, all of whom have a
direct interest and considerable practical experience in various aspects of
Legionella and its control.
Isolation of Legionella pneumophila from the cold water of hospital ice machines:
A previously unrecognized reservoir for L. pneumophila within the hospital
environment, ie, the cold water dispensers of hospital ice machines. The cold
water dispensers of 14 ice machines were cultured monthly over a 1-year period.
Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300
CFU/plate. We were able to link the positivity of these cold water sites to the
incoming cold water supply by recovering
L. pneumophila from the cold water
storage tank, which is directly supplied by the incoming municipal water
line.
This was accomplished by a novel enrichment experiment designed to
duplicate the conditions (temperature, sediment, stagnation, and continuous
seeding) of the hot water system. Our data indicate that significant
contamination of cold water outlets with L. pneumophila can occur. Although no
epidemiologic link to disease was made, the fact that the primary source of a
patient's drinking water is from the ice machines warrants further investigation
of these water sources as possible reservoirs.
(Stout JE;
Yu VL; Muraca P Source Infect Control, 1985 Apr, 6:4, 141-6
)
Risk factors for domestic acquisition of
legionnaire`s disease.
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. METHODS: 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. RESULTS: 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.
CONCLUSIONS: 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.
(Straus WL; Plouffe JF; File TM Jr; Lipman HB;
Hackman BH; Salstrom SJ; Benson RF; Breiman RF Address Division of Bacterial and
Mycotic Infections, Centers for Disease Control and Prevention, Atlanta, Ga,
USA. Source Arch Intern Med, 1996 Aug 12-26, 156:15, 1685-92
)
Potable water as a source of Legionnaires`
disease.
A three-year epidemic of legionnaires` disease in a
hospital was dramatically curtailed following hyperchlorination of the potable
water supply. The hypothesis that potable water was the source for the outbreak
was further supported by isolation of Legionella pneumophila (the agent of
legionnaires' disease) from the hospital water supply, observation that a sudden
upsurge had occurred in the number of cases following a peculiar manipulation of
the hospital water system, and documentation of a 30-fold increase in
concentration of organisms in the water when this manipulation was artificially
recreated. Thus, potable water may be an important source of epidemic
legionnaires' disease and continuous hyperchlorination a method of control.
(Shands KN; Ho JL; Meyer RD; Gorman GW; Edelstein PH;
Mallison GF; Finegold SM; Fraser DW Source JAMA, 1985 Mar 8, 253:10,
1412-6)
Investigating a single case of Legionnaires`
disease:
Guidance for consultants in communicable disease
control.
When a single case of legionnaires' disease is reported, it should
be investigated to check whether or not it is linked to other cases or part of
an outbreak. The investigation includes confirmation of the diagnosis, tracing
the patient's movements during the incubation period, and reporting the case to
the National Surveillance Scheme for Legionnaires' Disease at the PHLS
Communicable Disease Surveillance Centre. If no common factors are identified
between the cases and other cases reported previously, no further action is
usually required, unless it is suspected that the infection was acquired in
hospital. In these circumstances, the individual case and the hospital's water
maintenance programme should be reviewed, and a search made for associated
cases, because hospital patients are particularly susceptible to infection.
Further steps may be necessary if the link with the hospital is confirmed.
(Saunders CJ; Joseph CA; Watson JM Source Commun Dis Rep
CDR Rev, 1994 Sep 16, 4:10, R112-4)
Fifty-two patients were thought to have been infected outside a hospital in Denmark; of these, 18 were previously well, while the remainder had chronic illnesses. The cases were evenly distributed throughout the country, with an age range of 18-84 years. In 4 cases a probable source of infection was stated: a hot water tank with stagnant water over an extended period (2), cleaning an old hot water system (1), and a spa-pool (1). In addition, there was an outbreak of Pontiac fever which affected 13 patients. The source of infection was probably a whirlpool. Pontiac fever is an influenza-like illness without pneumonia and is not notifiable in Denmark.
(PRoMED-mail 28 FEBUARY 1997)
TAIWAN 1997
The Taiwanese health department last wednesday (11June) issued a warning on th esurge of Legionnaires` disease that had produced almost twice as many cases in the first five months of 1997 as the total number of cases in 1996, 81 cases January to May as 44 cases in 1996.also this year`s outbreak is affecting persons under the age of 25. One patient was only four years old,
The health department is urging people to keep their living
space clean and also their Airconditoining systems.
JUNE 20 1997
Communicable Disease Report
Legionella and the European Council for Package
Travel
The recently implemented European Council Directive for Package
Travel makes tour operators responsible for the acts and omissions of their
suppliers. Tour operators can be held 1iable if they knowingly place clients In
hotels that may be associated with legionella lnfection. New procedures have
agreed with the Association of British Travel Agents (ABTA) and the Federation
of Tour Operators (FTO) for the PHLS to report to them anonymised summary
Information on single cases of travel associated legionnaires' disease ln
residents of England and Wales. ABTA and FTO will identify tour operators using
the hotels at which cases have stayed. The tour operators will then remind
managers of the hotels - on the understanding, however, that a single case does
not mean the hotel was necessarily the source of infection - to check that their
water and cooling systems are being maintained to appropriate standards to
mimimise any risk of legionella infection. The European Surveillance Scheme for
Travel Associated Legionnaires' Disease (EWGLl) , which is coordinated by the
PHLS Communicable Disease United Kingdom: Surveillance Centre (CDSC) , wlll
lnform ABTA and FTO when they detect travel associated clusters (two or more
cases linked to the same accommodatlon arising within a six month period). The
information will enable tour operators to make informed decisions on whether
they wish to continue using hotels that might present a health risk to their
clients.
Two clusters of travel assoclated legionnaires' disease recently
reported to CDSC have provided the first opportunity to use the new
procedures.
In the first cluster, two people who stayed at a hotel in
Marmaris, Turkey in May 1996 acquired legionnaires' disease. The same hotel was
associated with another two cases ln September 1995. EVVGLI collaborators, the
World Health Organisatlon in the United Kingdom: (WHO) , and the Department of
Health who were alerted to the cluster and ABTA monthly report and FTO were sent
summary lnformation. Tour operators from the United Kingdom have withdrawn
cilents from the hotel whlle public health officials investigate possible
sources of lnfection.
The second eluster was associated with an
apartment block In Cala Galdana, Minorca where three cases of legionnaires'
disease had stayed in the ten days before becoming ill ln May. Within 24 hours
of being sent summary informatlon, the tour operator with sole use of the
apartment block had withdrawn all its clients to alternative accommodation.
Investigations by local public health officials have shown that the outbreak may
have been caused by the installation of a new hot water system at the hotel
during the first three weeks of May.
Prompt communications from EWGLI, swift
withdrawal of clients from implicated hotels, and the rapid launch of
lnvestigations by local public health officials should contribute to improved
control and prevention of cases and outbreaks of legionnaires' disease linked to
package travel.
Association of Legionnaires' disease with
construction:
Two cases of nosocomial legionellosis and discuss the
epidemiology of this infection. DESIGN: Potable water was collected from
multiple sites. Patient and environmcntal isolates were characterized by the
Legionella slide agglutination test and monoclonal anlibody subtyping.
Concordance among isolates was conlirmed by pulsed-field get electrophoresis
(PFGC). SETTlNG: A 713-bed universily-affliated hospital.
RESULTS:
There
was widespread contamination of potable water with Legionella pneumophila during
a period of major construction; cooling towers were without growth of
Legionella. One patient's isolate was the same by PFGC as the environmental
isolate collected trom thc water laucet in his room. Control measures included
superheating water used in all paticnt carc areas to 75 degrecs C for 72 hours
and flushing super heated water through faucets and showers; cleaning shower
heads with a sonicator washer; and raising the hot water storage tank
temperature from 43 degrees C to 52 degrees C. Afier these interventions, repeat
environmental cultures over the next 6 months were without growth of Legionella,
and no further cases of nosocomial legionnaires' disease were documented. An
association between legionnaires' disease and construction is postulated.
Heightened surveillance and preventive measures may be warranted during periods
of excavation on hospital grounds or when potable water supplies are otherwise
shut down and later repressurized.
Mermel LA;
Josephson SL; Giorgio CH; Dempsey J; Parenteau S Department of Medicine, Rhode
Island Hospital, Providcnce 02903, USA. Infect Control Hosp Epidemrol, 16: 2,
1995 Feb, 76-81
Legionnaires` disease in
Missouri
a review of five sporadic cases.
(Misra DP, Maltby JD, Hurst DJ Mo Med 77 (10): 607-613 (Oct 1980)

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