Volume 14
Hypervirulent Strains of Clostridium difï¬cile
Dr. Barry Cookson, Centre for Infections, Health Protection Agency, UK
The anaerobic, gram-positive, spore-forming several investigations were performed: rates of
bacterium Clostridium difï¬cile was ï¬rst isolated CDAD were, 28/1000 admissions (ï¬ve times
Also In This Issue: in 1935. The designated name related to how dif- the national average of 1997) with an extra 10.7
ï¬cult the original investigators found it to culture. days in hospital and 30-day attributed mortality
It has been isolated widely in the soil and the gut rates of 6.9%, these being 0.8�2% in 1997. Per-
A Safer Future .................2 of many animals and, although a known cause of forations, toxic megacolon and colectomy rates
colitis in animals such as cats, dogs, birds, rodents had also increased. Between 2004 and 2005 it
and neonatal pigs, it was not until 1978 that it was was estimated that over 14,000 patients had
Virox Update ....................3
found to also cause human disease (pseudomem- been affected in the province of Quebec, with
branous colitis). high mortality and relapse rates. By June 2006
Decreasing Clostridium
the problem had spread to seven provinces with
difï¬cile in the Newborn
CAUSES OF CDAD estimates of 13 cases per 1000 admissions.
Intensive Care Unit Risk factors for Clostridium difï¬cile associated
Through Institution of Risk factors compared with matched controls
diarrhoea (CDAD) comprise those that affect the
comprised, as in many previous studies, cepha-
gut microbial flora, the most common being ex-
Environmental Cleaning
losporins (odds ratio (OR) 3.8%, 95% con�-
posure to antibiotics. Almost all antibiotics have
Procedures ......................4
dence interval (CI) 2.2% to 6.6%) and for the
been associated with CDAD, although it is less
ï¬rst time fluoroquinolones (OR 3.9%, 95% CI
often associated with some—for example, met-
MRSA - More Common 2.3% to 6.6%). Interestingly it may be that the
ronidazole, aminoglycosides, trimethoprim and
Than Thought..................4 association is only with certain quinolones; me-
the quinolones. Clindamycin historically had
thoxyquinolones (gatifloxacin and moxifloxa-
a particularly infamous relationship to CDAD;
cin) had been introduced recently
animal work showed that following its use
Bacteria Can Hide Out in
in several of the affected
there was a particularly long pe-
Cells for Weeks................5 centres, these agents hav-
riod of gut susceptibility
ing greater anaerobic
to the disease when
activity. However,
challenged with
the situation with
C difficile spores.
antibiotics was
CDAD is a disease
not straightfor-
predominantly of
ward, as patients
the aged, but other
received more
factors include
antibiotics per
recent gastroin-
case (46%) than
testinal surgery
controls.
and immunosup-
pressive therapy,
Typing was per-
including cytotox-
formed and a new
ics. Other indepen-
strain (ribotype
dent risk factors
O27) was isolated
described more re-
from 82% of pa-
cently comprise pro-
tients. It was as-
ton pump inhibitors,
sumed that this was
which increase the risk
related to the increased
threefold. It is presumed
virulence and relapse
that increased gastric pH
rate. There were other
leads to decreased destruc-
relevant factors, however;
tion of spores, but colonic
hospitals agreed that their
receptors do exist for some
case mix had changed over the
proton pump inhibitors.
last few years with greater num-
“The secret of success is HYPERVIRULENT CDAD IN NORTH
AMERICA
constancy of purpose�
Continued on page 6
Increased numbers of patients requiring colec-
tomy alerted a hospital in Montreal in 2002 to the
Benjamin Disraeli
possibility of CDAD with a higher severity, mor-
tality and relapse rate. Over the next two years
©Virox Technologies 2007
A Safer Future?
Prof. Peter Curson Professor of Population & Security, The University of Sydney, Australia
years ago we thought that DDT spraying
The recently released WHO World placing its old smallpox vaccine stocks
would remove the threat of a wide range
Health Report 2007 A Safer Future holds with a new generation vaccine.
of mosquito-borne diseases such as ma-
some chilling messages for all of us
laria, and dengue. As it turns out noth-
facing life in the 21st century. Accord- The problem of growing antibiotic resis-
ing could have been further from the
ing to the WHO the world faces a new tance and the use and misuse of antibi-
truth. These and other mosquito- borne
era of infectious disease and as usual otics particularly in animals raises other
diseases have re-emerged, often in more
the culprit is us. Human behaviour and questions. Like food borne disease, an-
virulent forms. Dengue in particular has
agency lies at the heart of all the disease tibiotic resistant infections are a growth
surged in recent years with millions af-
threats we face � whether it be how we industry, particularly in our hospitals.
fected, and globally the number of cases
interact with and transform our natural
reported to the WHO has doubled in
environment, the growing world trade So what needs to be done to secure a saf-
each of the last four decades.
in wildlife, factory farming of poultry er world? The WHO places emphasis on
in South Asia, poor food preparation, international cooperation and collabora-
Finally, the threat of another pandemic
poor hygiene in our hospitals, or the fact tion, effective systems of surveillance,
of influenza has preoccupied most gov-
that roughly 2 billion of us now travel alert and response, of strengthening
ernments over the last few years. Based
by air all over the globe, often passively local health systems and encouraging
on past experience, some experts predict
transporting new infections around the cross-sector collaborations within gov-
that in the advent of a new pandemic, 1.5
world. ernment. More reactive than proactive
billion people around the world would perhaps, but in an uncertain, insecure
be affected. In the words of the WHO, it
The WHO Report argues that new infec- world, certainly essential.
is naïve and complacent to assume that
tions are emerging and spreading faster
the world will not see another disease
than at any other time in human history, www.who.int/whr/2007/en/index.html
like AIDS or SARS over the next few
while older infections, once thought un-
years.
der control and destined for the global
scrapheap, are reappearing, redistribut-
The global health tally
ing and continuing to wreck havoc. Over
THE WORLD HEALTH REPORT 2007
A SAFER
sheet does not stop there.
the last three decades so called ‘new�
Food borne diseases are
infections have appeared at the rate of
having a heyday as global-
at least one per year and we now face
isation affects production,
more than 40 infectious diseases, which
FUTURE
storage, distribution and
were unknown or thought controlled a
preparation. The trade of
generation ago. In addition, epidemic
contaminated foodstuffs
outbreaks are becoming more common.
between countries is on
Since 2002 the WHO has identiï¬ed at
the rise, as is the incidence
least 1100 such epidemic events world-
of contamination from
wide. SARS and Bird Flu remain in the
sloppy institutional and GLOBAL PUBLIC HEALTH SECURITY IN THE 21ST CENTURY
collective memory not only because they
home food preparation.
caused substantial human suffering and
resulted in considerable economic dam-
New threats have also ap-
age, but also because as psycho-social
peared in the 21st century.
events they captured the public imagi-
Among these the threat of
nation, triggered international concern,
bioterrorism looms large.
and produced a ï¬eld day for the media
The anthrax episode in
... subsequently producing considerable
the USA, when potentially
panic and hysteria worldwide. But they
lethal anthrax spores were
were not alone. Outbreaks of other viral
sent through the postal
diseases have become common. Ebola,
system, placed bioterror-
Marburg Virus, Nipah Virus, West Nile
ism ï¬rmly on the 21st cen-
Virus all pose threats to world security
tury security agenda. The
and raise critical issues about global co-
use of smallpox as a bio-
operation, surveillance and response.
terror weapon continues
to worry authorities here
But it is not simply new emerging infec-
and abroad and it is not
tions which should concern us. Older
without note that the US
infections, once thought under con-
Government has been re-
trol have come back to haunt us. Fifty
Page 2
Volume 14 ©Virox Technologies 2007
Virox Update
a new Certiï¬cation Criteria Document invitations to all Virox’s FREE education
CCD 166 for Disinfectants and Disinfec- seminars? Log on to www.virox.com
tant Cleaners was ï¬nalized. and click the Member’s Sign-Up icon to
enrol!
Virox Introduces RESCUE Accelerated Hydrogen Peroxide has
Sporocidal Gel proven its superiority with respect to Virox prides itself on being a resource
cleaning and disinfection properties and tool to the infection control community
Virox Technologies Inc. of Oakville,
can now proudly display the EcoLogo so please check out our website frequent-
Ontario has received a Drug Identiï¬ca-
as Canada’s ï¬rst registered disinfectant- ly as new links will be posted regularly.
tion Number (D.I.N) registration from
cleaner.
Health Canada for Accel RESCUE Spo-
What exactly does the Virox
ricidal Gel, a 4.5% Accelerated Hydro-
Accel TB Soft Packs Launched! Professional & Technical Services
gen Peroxide formulation that achieves
Team do?
At Virox, we are very aware of the in-
sporicidal disinfection in 10 minutes.
creasing importance of pandemic plan-
The intended use is for toilet bowls and
ning and the development of effective The Professional & Technical Services
commodes as well as inside sinks and
pandemic kits within health care facili- (PTS) department’s mission is to pro-
basins in the washrooms of C. difï¬cile
ties as well as within industry. Healthcare vide education opportunities to Virox
patients where the spore count has been
and industry are trying to take a proactive partners, distributors, and end users in
shown to be the highest. The introduc-
role in protecting their staff and clients. all areas pertaining to infection control.
tion of RESCUE Sporicidal Gel along
The Accel TB Soft Pack maintains the The PTS team is a consulting resource
with Accelerated Hydrogen Peroxide
current 30-second sanitizing, 5-minute that infection control professionals,
0.5% TB disinfecting and cleaning solu-
bactericidal, 5-minute general virucidal public health inspectors and nurses, en-
tions allows facilities to have an alterna-
(non-enveloped viruses such as norovi- vironmental services personnel and dis-
tive protocol to bleach when C.diff exists
ruses), 5-minute fungicidal and 5-minute tributor sales reps can use for questions
or is suspected. The use of bleach is not
tuberculocidal claims. The Accel TB pertaining to microbiology, disinfectant
without disadvantages such as workplace
Soft Packs offers the ability for employ- chemistries, protocol creation and in-
safety concerns. RESCUE Sporicidal
ees, physicians and nurses to carry per- service product training. The PTS group
Gel maintains the excellent safety proï¬le
sonal wipes to clean and disinfect those provides services free of charge - con-
of the patented Accelerated Hydrogen
non-critical devices and surfaces, such as ducts training seminars at infection con-
Peroxide technology.
stethoscopes, countertops, light switches, trol and public health conferences, spon-
door knobs, elevator buttons etc., that sors other educational opportunities to
For more information on the RESCUE
may not be included in regular cleaning the infection control community such as
product please visit
and disinfection practices. sponsoring Webber Training Teleclasses,
www.virox.com/medical/acute_care.asp
and Infection Control Today webinars.
or call 800-387-7578.
Further information on the Accel TB Soft Professional and Technical Services
Virox receives Canada’s ï¬rst regis- Packs product can be found on the Virox has resposibility for the annual CHICA-
tered EcoLogo disinfectant-cleaner website (www.virox.com) including the Canada Virox Patron Member Scholar-
efï¬cacy study, MSDS, and product bro- ship Fund, and works with facilities to
From its inception in 1998, Virox Tech-
chure. conduct clinical trials and research stud-
nologies has been a ï¬rm believer in de-
ies with the objective of minimizing
veloping and manufacturing disinfectants
New Claims for Accel hospital acquired infections.
that not only provide superior cleaning
Hydrotherapy Tub Product!
and efï¬cacy claims, but that are also
If you are interested in learning more
environmentally sustainable. The use of We are very excited to announce that we
about how the Professional and Techni-
disinfectant-cleaners is a marketplace have received the DIN approvals for new
cal Services team at Virox can provide
reality and these products are commonly claims for the Accel Hydrotherapy Tub
educational or consulting opportunities
used in the institutional and healthcare Product. The new claims include the
at your facility please contact Nicole
sectors. However, until February 2007 addition of a 5-minute Fungicidal Claim,
Kenny at 1-800-387-7578 x118 or via
the Environmental Choice a 5-minute General Virucide Claim and
email at nkenny@virox.com.
Program did not have a a 30-second Broad-Spectrum Sanitizing
certiï¬cation criterion that claim. The product will maintain its cur-
allowed for the registration rent 5-minute Bactericidal Claim. The
of disinfectant-cleaners. additional claims allow the Accel Hydro-
Never discourage
therapy product to be used in both non-
Recognizing the changing needs of the critical and semi-critical hydrotherapy
anyone...who continually
healthcare system and the reliance on
tub, birthing tubs and foot spa baths etc.
disinfectant-cleaners by both Canadian
makes progress, no
and American infection control guide-
Website Update: www.virox.com
lines, TerraChoice felt there was a need matter how slow.
to review the existing Certiï¬cation Cri-
MEMBER SECTION! Do you want to
- Plato
teria Document CCD 146 for Hard Sur-
be sure you get all the updates on Virox?
face cleaners and subsection H for Dis-
Interested in being included on all of the
infectants. As a result, in February 2007
Page 3
Volume 14 ©Virox Technologies 2007
MRSA - More
Decreasing Clostridium difï¬cile
Common Than
in the Newborn Intensive Care
Thought
Unit Through Institution of
Environmental Cleaning Procedures If the estimates are correct, the number
of deaths associated with methicillin-
Edited from an Article by LM Harper, Intermountain Healthcare, Provo, UT
resistant Staphylococcus aureus (MRSA)
- nearly 19,000 in the United States in
2005 - would exceed those attributed
to HIV-AIDS, Parkinson’s disease,
emphysema, or homicide.
A recent study, published in the October,
2007 issue of the Journal of the American
Medical Association, suggests that such
infections may be twice as common as
previously thought. By extrapolating data
collected in nine places, the researchers
estimated that 94,360 patients developed
an invasive infection from the pathogen
in 2005, and that nearly one of every
ï¬ve, or 18,650 of them, died. The study
points out that it is not always possible to
determine whether a death is caused by
MRSA or merely accelerated by it.
A major difference between the new study
Clostridium difï¬cile is a gram positive was referred to and a call was placed to and its predecessors is that it compiled
spore-forming rod that has been the CDC to conï¬rm the efï¬cacy of our conï¬rmed cases of MRSA infection,
historically associated with antibiotic proposed cleaning. Our environmental rather than relying on coded patient
related diarrheas. This is the most services cleaned the affected corner records that sometimes lack precision.
common cause of hospital associated from top to bottom with a disinfectant The study found higher prevalence rates
diarrhea � 3 million cases per year in solution. All moveable items, rockers, and death rates for the elderly, African-
the United States, adding up to $10,000 screens, scales, etc., were also cleaned. Americans and men. The ï¬gures also
per case with an expected two week We launched extensive staff education varied by geography, with Baltimore’s
hospitalization stay. related to C. difï¬cile and its ability to incidence rates far exceeding those of the
be found on environmental surfaces, in eight other locations.
Our hospital had been tracking the C. tandem with educating to the importance
difï¬cile cases since October of 2003, of washing hands with soap and water MRSA, which was ï¬rst isolated in the
averaging from 6-8 cases per month for when you are caring for a patient with United States in 1968, causes 10% to
our entire hospital, and the Newborn C. difï¬cile. 20% of all infections acquired in health
Intensive Care Unit (NICU) averaging care settings, according to the CDC. The
one case every other month. Between The occurrences of C. difï¬cile in our prevalence of invasive MRSA â€? when
July and August of 2005 our NICU NICU have been drastically reduced. the bacteria has not merely colonized
reported 8 conï¬rmed cases of C. diff. The cleaning was done in August of on the skin, but has attacked a normally
All infants were symptomatic and had 2005, since that time there has not been sterile part of the body � is greater than
positive toxin assays. one positive toxin assay for C. difï¬cile the combined rates for other conditions
in the NICU. caused by invasive bacteria, including
An investigation was launched to bloodstream infections, meningitis and
determine any possible commonalities An incidence of C. difï¬cile can cost flesh-eating disease.
among the infected infants. We found $10,000 for the extended hospital stay;
that all of the 8 infected infants had therefore by cleaning of environmental The JAMA study also concluded that
shared one of three beds in a corner of surfaces of known C. difï¬cile patients, 85% of invasive MRSA infections are
the NICU. Our objective was to decrease you can prevent transference of this associated with health care treatment.
the incidence of C. difï¬cile in the NICU organism to other patients, thus saving Previous research had indicated that
through implementation of cleaning money, freeing up hospital space and many hospitals and long-term care centers
measures with an oxidizing disinfectant. decreasing cross-contamination.
Continued on page 6
A literature search was launched to ï¬nd
any related studies. The CDC website
Page 4
Volume 14 ©Virox Technologies 2007
Bacteria Can Hide Out in Cells for Weeks
Nicole Kenny, Virox Technologies Inc.
Another interesting study was released the Institute of Food Research, Norwich, most of the bacteria had died by about
recently that revealed a fascinating sur- UK set out to uncover what S. aureus did four days as a result of antibiotic treat-
vival strategy used by Staphylococcus inside human lung epithelial cells using ment, the team still found viable bacteria
aureus. The paper, “A global view of an in vitro model. They found that short- in their model system two weeks after
Staphylococcus aureus whole genome ly after S. aureus entered the lung cells, infection.
expression upon internalization in human the bacteria’s gene expression proï¬le
epithelial cellsâ€?, was published earlier dramatically changed: gene expression The ï¬ndings may help in understanding
this year in BMC Genomics and proï¬led for bacterial metabolic functions and relapsing infections (even years after the
in ScienceDaily. It explained that Staph. transport shut down, putting the bacteria ï¬rst episode was apparently cured), and
bacteria may evade the immune system’s in a dormant state. in designing new antibacterial drugs. S.
defenses and dodge antibiotics by climb- aureus has not traditionally been consid-
ing into our cells and then lying low to Simultaneously, production of toxins ered an intracellular pathogen, but the
avoid detection. The research shows how potentially lethal for the epithelial cells molecular details that govern its extend-
S. aureus makes itself at home in human becomes strictly controlled to limit cel- ed persistence remain largely unknown.
lung cells for up to two weeks. lular damage. Mechanisms that helped
the bacteria to survive and/or multiply,
A team of 12 researchers from Univer- including metabolic and energy produc-
sity Hospital of Geneva, Switzerland and tion functions, then resumed. Although
Page 5
Volume 14 ©Virox Technologies 2007
Hypervirulent Strains this may just produce secretion of fluid and France, and between hospitals in
by colonic cells but does not result in cell the Netherlands. The O27 strain is now
of Clostridium difï¬cile death. Many other factors may also be found in many parts of the UK, and it is
implicated, including ï¬mbriae and sub- interesting to speculate whether this may
Continued from page 1 groups of adhesions. O27 and O1 may be caused by increased inter-city patient
produce higher sporulation levels than transfers due to patient choice? We de-
other strains and these were even higher scribed inter-city spread of epidemic
bers of debilitated, immunocompro-
when non-chlorinated (ie, non-oxidat- methicillin resistant Staphylococcus
mised and elderly patients. Another in-
ing) disinfectants were used. aureus (MRSA) in the 1990s, perhaps
teresting point is that the study of Pepin
encouraged by this process.
and colleagues did not show that proton
It should be noted that there has been no
pump inhibitors were an independent
consistent relationship between sever- Clearly a holistic approach to prevention
risk factor for CDAD, unlike the study
ity of disease and toxin concentration and control will be required if we are to
quoted above. There are several possible
in stool. It is clear that, despite years of make any impact on the increasing num-
explanations for this—for example, the
research, the organism has many hidden bers of CDAD cases described in many
patients may have been sicker or have
secrets and poses many interesting ques- parts of the world.
some other missed risk factor. Such a
tions. Interestingly, several of the infec-
risk factor might include patients admit-
Reversing Natural
tion control teams in Quebec comment
ted from the community.
that they no longer see as many cases of
Selection
serious CDAD and think this may be re-
A similar situation to that in Canada
lated to their aggressive early treatment
had emerged in the USA, with the Cen-
Continued from page 4
of infection as soon as the diarrhoea.
tres for Disease Control and Preven-
tion (CDC) showing rates had doubled
PREVENTION AND CONTROL OF
between 1996 and 2003 from of 31 to had become breeding grounds for
CDAD
61 cases per 100,000. Isolates from six MRSA because bacteria could be
The number of CDAD cases is increas-
recent outbreaks in the USA revealed transported from patient to patient
ing throughout the world. This may be
emergence of the same epidemic O27 by doctors, nurses and unsanitized
related to new factors including the emer-
strain. Higher morbidity and mortality equipment.
gence of certain strains, their increasing
were described in at least 17 states. A
antimicrobial resistance, the changing
nursing home outbreak of CDAD could Among other things, the ï¬ndings
case mix, and aspects of healthcare de-
be related to the switching from leva- in the JAMA study are likely to
livery. Prevention and control measures
floxacin to gatifloxacin. stimulate further an already active
are being reviewed in many countries.
debate about whether hospitals and
PATHOGENESIS OF CDAD other medical centers should test all
Control will be informed by improved
When considering the pathogenesis of patients for MRSA upon admission.
surveillance and typing information.
CDAD it is important to consider the
The guidelines point to reinforcement
interactions of the organism (the seed),
of all of the following: the use of hand
the affected patients (soil) and the en-
washing for soiled hands or close contact
vironment (climate). We have already
“Many of life’s
with CDAD cases, isolation of patients
mentioned various aspects of the patient
with diarrhoea, effective stewardship of
failures are people
case mix for the Canadian outbreaks and
antibiotics, and proper decontamination
similarly alluded to the some of the cli-
of the environment.
who did not realize
matic factors—for example, antibiotic
and other drug usage. Although CDAD
how close they were
A new factor in the rubric of prevention
is under long and continuing study,
and control are various aspects of clini-
much is still not known. The inoculum,
to success when they
cal governance. These are apparent in
for example, may be very low.
reports from the Quebec and other out-
gave up.�
breaks. Stafï¬ng shortages, high bed oc-
Several pathogenicity factors are de-
cupancy, poorly cleaned and maintained
scribed: there are two large exotoxins
premises, old buildings that need to be
- Thomas Edison
(TcdA&B). However, TcdA2/B+ strains
replaced, and low priority of infection
are recognized with increasing frequen-
control resonated. There are other inter-
cy and truncated A/B strains can cause
esting aspects about healthcare delivery.
disease. In 10% of selected strains there
Patient transfers have resulted in the
is a cdtA-B binary toxin encoding an
spread of the O27 strain between Belgian
actin-speciï¬c ADP-ribosyltransferase;
TM
2815 Bristol Circle,Unit 4,Oakville,Ontario L6H 6X5
Tel:(905) 813-0110 � Toll Free:1-800-387-7578 � Fax:(905) 813-0220
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Page 6
Volume 14 ©Virox Technologies 2007
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