Industry
experts Robert F. Whitcomb and Edwin
F. Goldstein reveal overlooked facility sources of deadly
bacteria.
In 1977, it
was discovered that Legionnaires’ disease (LD),
a respiratory illness, was caused by a new family of bacteria.
Although we now know how to identify and treat it, many still needlessly
die from LD—often in healthcare institutions, including nursing
homes. To illustrate, a recent LD outbreak at a Philadelphia nursing
home cost the lives of four residents before it was brought under
control. 1 In the summer of 2003 there was a dramatic increase
in reported cases all along the East Coast that has yet to be explained.
2 This disease can be prevented, if building operators, owners,
and managers follow sufficient preventive maintenance procedures.
They also should be aware that Legionnaires’ disease can
be detected and cured, with appropriate and timely procedures.
Background
In 1976, attendees of an American Legion convention in Philadelphia were stricken
with a pneumonia-like illness. The cause was traced to a newly discovered bacterium,
which soon became known as Legionella pneumophila. 3 This family of
bacteria has since been expanded. More than 15 known serogroups have been identified,
including LD’s less-threatening cousin, Pontiac fever. Fortunately, more
sophisticated tests have been developed to diagnose and identify each 4 (figure
1).
Incidents of LD are now commonly reported to disease control centers and in the
press, and it is one of the top three causes of community-acquired pneumonia.
An estimated 25,000 or more cases occur each year in the United States, with
more than 4,000 deaths attributed annually to Legionella pneumophila.
It poses such a significant health risk that OSHA has devoted an entire chapter
in its Technical Manual to recognizing, investigating, and controlling the disease.5
Untreated, LD can reach fatality rates as high as 40%, 6 yet
treatments are quite effective if Legionella testing and
diagnosis occur at an early stage, when pneumonia is first suspected.
LD is most often fatal among adults with lowered immune deficiencies,
such as the elderly and those who are hospitalized. Increasingly,
cases are being reported in which normally healthy adults contract
the disease and are not diagnosed properly until it is too late.
7 Therefore, it is especially important that staff who care for
senior citizens or the sick are aware of the need to test for LD
whenever pneumonia-like symptoms are evident.
Testing and Treatment Protocols
The initial screening for LD in patients can be done directly with a urine sample.
Lab workers should be instructed to conduct urine antigen tests for Legionella.
8 If the antigen test comes back positive, then further tests of respiratory
specimens are required to identify the exact strain of bacteria involved. These
testing procedures are described in more detail by advisories published by health
authorities, such as those distributed in July 2003 by the Philadelphia Department
of Public Health. 9
Once the disease is diagnosed as LD, several effective antibiotics are available
for treatment, such as erythromycin 8 and fluoroquinolone. 9 This article’s
intention is not to prescribe medicine or treatment. Please refer to the advisories
published by the referenced medical authorities and note that the research has
proven that LD can be fully cured when treated in its early stages. Our assertion,
and that of others in the water treatment industry, 10 is that LD fatalities
can be prevented if healthcare professionals are aware of the need for early
detection. This includes all personnel caring for those at high risk of contracting
pulmonary diseases, such as immunosuppressed residents in nursing homes, rehabilitation
centers, and life care facilities. 11
Identify the Facility’s Breeding Sites
LD is not contagious. It is contracted from the environment through inhalation
of mists carrying Legionella bacteria. Several well-known sources for
these mists include cooling towers, showerheads, fountains, and spas, as well
as other less-obvious sources such as the misting machines found in produce sections
of grocery stores. 12 The water temperatures in these potential sources allow
very small quantities of Legionella bacteria to grow rapidly and concentrate. Legionella lives
in the natural environment, travels through municipal water systems and, like
so many bacteria, surrounds us every day. Inhaling high concentrations of Legionella bacteria
easily can lead to infection. Failure to maintain these potential sources properly
gives Legionella a place to propagate, usually in still, warm water,
where exposure to air helps to carry a fine mist to unsuspecting victims.
The most publicized cases of LD were caused by mists emanating from cooling towers
13 (figure 2) that usually are located on building roofs or in out-of-the-way
areas where only the building engineer goes to inspect their condition. Cooling
towers are designed to circulate water through an air flow (to cool the water
from the building’s interior) and by their nature, mix warm water with
passing air. If some of the warm water is not circulating, it easily can create
stagnant breeding grounds for bacteria such as Legionella. When Legionella bacteria
counts reach elevated levels (such as when the cooling tower is improperly treated
or not cleaned often enough), the normal air flow around the building easily
can become saturated with a vapor mist containing Legionella and an
unsuspecting passerby can become infected. Under certain conditions, these contaminated
mists can carry great distances, even infiltrating other nearby towers (figure
3).
Potable water systems and hot-water heaters have been shown statistically to
be the more frequent source of LD. 13 In healthcare facilities, the disease often
is spread via rarely used showerheads in bathrooms, water fountains, or other
outlets where a fine mist can be created. If a shower in a nursing home goes
unused for weeks or months, the warm-water residue left in the showerhead or
plumbing can become a breeding ground for Legionella bacteria. Hot-water
heating tanks (figure 4) are another breeding ground, although the danger is
present only when bacteria-laden water mixes with air to form an aerosol mist.
Regular maintenance programs, such as superheating and flushing the hot-water
tanks, super chlorinating domestic water systems, and bleaching the inside of
showerheads, can prevent the contamination of potable water. Other advanced systemic
methods available include ultraviolet sterilizers, ozonation systems, and copper-silver
ionization units. 10
Other sources can be found in some of the more upscale long-term care facilities—public
spas and decorative fountains can be growth points, for example, as can hot tubs
that are allowed to run for lengthy times without proper cleaning. Slow-circulating
fountains where water is exposed to a heat source also could provide a place
for Legionella bacteria to grow. Facility managers should identify any potential
growth source and adopt appropriate maintenance procedures to it, with regular
tests to detect Legionella bacteria.
The time and effort required go beyond protecting lives and health—another
consideration is protecting the facility from potential lawsuits. In today’s
litigious environment, losing one patient to suspected LD could result in a costly
legal settlement, unless it is shown that due diligence and good preventive maintenance
practices are in place.
Protecting Healthcare Environments From LD
Nursing homes and senior care environments have the two most common sources of Legionella bacteria:
cooling towers and domestic hot-water holding tanks. These are primary systems
that need attention from building operating and maintenance personnel.
Because the water circulating in the cooling tower is segregated completely from
other water systems, it can be treated with chemicals to prevent biologic buildup.
13
To treat the cooling tower properly, a professional water-treatment service might
be the best resource for supplying the proper chemicals and conducting regular
maintenance tests. These professionals know how to test the recirculating water
to ensure that the system is protected against corrosion, biologic buildup, and
accumulating dirt, which is a constant threat to efficient cooling tower operation.
Like elevator testing, this testing should be performed regularly, especially
during warmer months of the year. Some states and localities already have established
guidelines for hospitals, 14 and we believe that every building with immunosuppressed
occupants should do likewise.
The other frequent source, the hot-water system, uses municipal or other potable
water as a source, and is always subject to waterborne bacteria introduced from
outside the facility. Therefore, each system requires different preventive maintenance
procedures and each system should be tested regularly. A preventive maintenance
program for domestic hot-water systems should be developed based upon the type
of facility and residents. We recommend that maintenance managers be proactive
and regularly test hot-water tanks and seldom-used showerheads.
The Testing Debate
It must be acknowledged that the question of the type of testing program needed
has long been debated among industry experts. Although the Centers for Disease
Control issues guidelines for the testing of various disease-causing bacteria,
it has yet to issue guidance on Legionella testing. 8 OSHA requires
thorough investigation of any outbreaks and continued monitoring of the suspected
source. 5 Some state health authorities have adopted Legionella testing
procedures for hospitals, including New York and Maryland. 15 The 2003 position
paper by the Association of Water Technologies (AWT), 13 which represents regional
water-treatment companies nationwide and has examined this issue in depth, reinforces
the recommendation that building managers assess their facilities for the need
of a program. In essence, the AWT suggests that facilities with higher-risk residents
take a more proactive approach to Legionella detection and prevention.
Conclusion
Having been involved with the initial 1976 LD outbreak and after 40 years in
the industry, we strongly recommend that all healthcare facilities adopt a proactive
approach. For years, we’ve urged all facility managers to take the prudent
steps to ensure their occupants are not exposed to Legionella bacteria
from cooling towers or other potential breeding grounds. At the very minimum,
cooling tower waters and domestic hot-water heaters of public buildings should
be tested quarterly. In facilities housing sick or aged occupants, testing for Legionella
pneumophila should be done even more frequently.
A proactive water treatment and Legionella testing program should be
an integral part of every building’s preventive management program. With
such a program, and with the healthcare industry’s increasing awareness
and diligence towards detecting and treating outbreaks of LD, we should no longer
have to read about tragic deaths caused by Legionella bacteria.
