IFH
PARALLEL SESSION AT THE EUROPEAN PUBLIC HEALTH
ASSOCIATION CONFERENCE |
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 In
November, the IFH organised a parallel symposium
within the 11th Annual European Conference
of the European Public Health Association
(EUPHA). The conference, held in Rome at the
Università
Cattolica del Sacro Cuore, was attended by some
800 delegates. The IFH session on ‘Preventing
Infectious Disease in the Domestic Setting’
included presentations by Dr. John Barker, who
spoke about the infection potential in the home,
Prof. Bloomfield, who explained the IFH targeted
approach to hygiene, and Prof. Chris Griffith,
who talked about how to motivate hygiene behaviour
change using social marketing techniques. IFH
made contact with interested parties, during
the conference session and with those who visited
our exhibition stand, where IFH materials and
the newly released training resource were distributed. |
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THE
HYGIENE HYPOTHESIS AND ITS IMPLICATIONS
FOR HYGIENE
A NEW REPORT FROM IFH
COMING SOON |
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Over
the past 2 centuries, sanitation, clean water,
clean food and hygiene practice have played
crucial roles in reducing infectious disease.
Following the introduction of antibiotics and
vaccines in the 1930-1950s, it seemed possible
that infectious disease might someday become
a thing of the past. In the last 10 years however
a range of events have underlined the need for
renewed action; global data on the incidence
of infectious diseases combined with concerns
about emerging and re-emerging pathogens, antibiotic
resistance and so on mean that, after several
decades of complacency, infectious disease prevention
is most definitely back on the global health
agenda.
Now,
in the year 2003, the importance of hygiene
is again being challenged. The “Hygiene
Hypothesis” contends that if we are not
exposed to infectious agents the immune system
becomes imbalanced, thereby increasing susceptibility
to allergic diseases. Alongside this theory
a populist view that this key exposure no longer
occurs because of improved household amenities,
higher standards of personal cleanliness and
cleaner homes has emerged.
In
response to concerns that these concepts could
have a detrimental impact on the public’s
perception of infectious disease risks, IFH
has commissioned a literature review in order
to better understand the nature and extent of
the link between microbial exposure and the
development of the immune system, the implications
it might have for hygiene, and how the problems
presented by the hypothesis might be addressed.
This review is now complete and is currently
in press.
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| BIOCIDE
USE AND ANTIBIOTIC RESISTANCE – AN UPDATE |
| In
recent years a number of researchers have expressed
concern that use of antibacterials in consumer
products could be a contributory factor in the
emergence of antimicrobial resistance. IFH shares
everyone's concerns about "antibacterial
cleaners", but our evaluation of the clinical
and microbiological data suggests that in some
situations it is not possible to eliminate the
risk by detergent-based cleaning alone - and that
in these situations a disinfectant product is
needed to prevent the spread of infectious disease
agents. In
giving this advice we were however concerned
to assess whether there was any evidence to
show that use of antimicrobials in community
settings might be contributing to antibiotic
resistance. In view of this, in 1999, IFH undertook
a review of the scientific data [IFH
Consensus Statement on Microbial Resistance
and Biocides] and from this developed a
consensus view. One of our conclusions from
this work was that “It is important that
we continue to research and monitor these issues”.
In accordance with this we have recently made
a review of the new data published since the
first review.
Our
major concern regarding the possibility that
biocide use could contribute to the development
of antibiotic resistance is that, although laboratory
data indicates the potential for links between
biocide and antibiotic resistance, the key need
is to understand whether this might occur in
the environment and clinical situation. Of particular
relevance are the recently published studies
carried by Professor Peter Gilbert and co-workers
on the impact of biocides on naturally-occurring
kitchen sink and oral microbial microcosms,
which support the hypothesis that, rather than
selection of resistant mutants, exposure to
sublethal levels of biocides is more likely
to cause the emergence of pre-existing resistant
species.
Another
intriguing finding from Professor Gilbert’s
group, which confirms the need to interpret
laboratory findings with care, comes from studies
of the development of antimicrobial resistance
mediated by induction of efflux genes. A number
of workers have argued that in reality these
efflux pumps evolved as a defence against antimicrobial
agents occurring in the environment and that,
if this is so, it is to be expected that a wide
range of ‘natural’ antimicrobial
agents would produce these effects. In line
with this Gilbert and co-workers have shown
that a significant proportion of a range of
food household and personal products acted as
inducers of mar and acr when tested against
lacz fusions of E. coli. This included food
substances such as mustard, chilli and garlic,
and household products, none of which made hygiene
claims.
Of
particular relevance also to the home are recent
studies which investigated whether antibiotic
resistant bacterial strains are more likely
to be found in domestic homes where antibacterial
products are used compared with homes where
they are not. Samples were collected from houses
in the USA and UK of 30 users and nonusers of
antibacterials. Susceptibility tests against
antibiotics and antibacterial agents were carried
out on the bacteria isolated. The authors conclude
that their data showed no evidence that antibiotic
resistant strains occurred more frequently in
user homes compared with non-user homes.
Details
of studies addressing the issue of lab vs clinical
situation can be found in our “update”
review.
The
ongoing assessment of the IFH is that, although
we must continue to research and monitor the
findings carefully, there are still no indications
that biocide usage is a significant factor in
the development of antibiotic resistance in
clinical practice – overprescribing of
antibiotics is the most important factor.
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HYGIENE
CENTRE AT LSHTM NOW ONLINE |
 The
“Hygiene Centre” at the London School
of Hygiene and Tropical Medicine has recently
published its own website:
www.lshtm.ac.uk/dcvbu/
hygienecentre
with up-to-date information on projects, activities
and publications. A very useful section in this
site is the recommended “Hygiene top 10”.
These are 10 materials selected as the most relevant
“tools and resources” for use by researchers
and field workers involved in promotion of hygiene
behaviour and advocacy for hygiene promotion.
The materials include:
-
Theoretical and academic evidence for advocacy
including evidence for effectiveness
and hygiene approaches and techniques
-
Guidelines on how to plan manage, implement
and evaluate a hygiene promotion programme
- Materials
that can be used in a hygiene promotion
programme
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WORKSHOP: “BIOCIDES
IN CONSUMERS HANDS ARE
THERE RISKS”
OPPORTUNITY OR THREAT ? |
On
6th November a workshop
entitled "Disinfectants
in consumer hands -
are there risks?" was
organised by the German
Bundesinstitut für
Risikobewertung (BfR)
and the Austrian Federal
Environmental Agency
in Vienna.
There
were 11 presentations on
topics such as which the
risk of developing resistant
microbes by uncontrolled
use of disinfectants, the
potential health risks from
misuse of disinfectants and
the potential effects on
the environment. Professor
Exner, IFH board member from
the Hygiene Institute in
Bonn, presented some of the
data in support of the IFH
approach to home hygiene
which recommends the use
of disinfectant products
within a clearly defined
risk based approach. His
position was also supported
by Dr Assadian a representative
of the Austrian Hygiene-Institute,
Vienna, for whom "clean
is not always enough".
During
the final session three specific
questions were discussed:
- Is
it necessary to draw
up a list which specifies
the situations where
disinfectant product
should be used in the
home setting ?
It
was agreed that the Austrian
Ministry and the German BfR
will initiate a working group
to review the risks and benefits
related to using disinfectant
products in the home, and
to prepare a list of indications
of when to use them.
- Is
it necessary to draw
up a list to specify
the risks of using disinfectants?
Although
the hygiene experts agree
that there are no real risks,
the environmentalists continue
to express concerns.
- Is
there a need for further
studies ?
Professor
Exner argued the need for
further studies to confirm
or refute assumptions which
are currently being made
about environmental contamination
from biocide usage.
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| THE
NATIONAL HYGIENE DAY IN THE NETHERLANDS |
 After
inspiring discussions with the Advisory
Board of IFH and members of the Dutch
Hygiene Platform, it was decided to
have a ‘National Hygiene’
day in the Netherlands.
Dr Rijkelt Beumer and his co-workers,
who organized this day, can be proud
that a well-visited symposium (125 participants),
including a hygiene market with stands
of the IFH and other organisations active
in (home) hygiene, took place on the
9th of October 2003.
Invited speakers presented various aspects
in the field of home hygiene. Els van
Gurp (Netherlands Nutrition Centre,
The Hague) presented the Dutch
hygiene code for households and
the information campaigns for consumers
based on this code.
The
‘targeted hygiene approach’,
mentioned first by IFH, was discussed
by Frank Pieterman (Unilever Research).
Professor van Schayk (University of
Maastricht) made some critical remarks
about the Hygiene hypothesis, and showed
some results of his research work on
this topic. Washing at low temperatures
inactivates not all microorganisms.
However, Professor Terpstra (Wageningen
University) reassured us that only people
involved in washing laundry might be
at higher risk. After drying (and, if
appropriate, ironing) microorganisms
will be largely reduced.
Other
speakers informed us about the introduction
of a National Centre for Hygiene
and Safety (Monique Leijen, GGD,
Haarlem), the role of the government
with regards to hygiene (Drs Toorop,
Ministry of Health, The Hague).
Last but not least, Professor Frewer
presented her view on ‘Food
safety and consumer behaviour’.
She posed that if food safety objectives
are adopted at point of consumption,
effective risk communication with
consumers will be explicitly required
in order to get them to adopt appropriate
food preparation practices.
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| CROSS
CONTAMINATION OF PATHOGENIC BACTERIA IN
HOUSEHOLD KITCHEN |
Dr
Harsi Kusumaningrum has recently completed
her thesis at the University of Wageningen
under the direction of Dr Rijkelt Beumer.
Copies of the thesis are available by
applying to the IFH Secretariat. Here
is a short abstract:
Based
on the understanding that a significant
proportion of foodborne disease
is attributable to improper preparation
practices in the home, including
cross-contamination, the thesis
set out to study the survival and
transfer of food-borne pathogens
via stainless steel surfaces and
cleaning sponges. Quantitative analysis
of the transfer of Salmonella and
Campylobacter from contaminated
chicken pieces to salad via kitchen
surfaces showed that it is realistic
to expect that a proportion of the
human exposure to, particularly,
Campylobacter in private homes originates
from cross-contamination in the
kitchen during food handling. The
probability that salads become contaminated
with Campylobacter is higher than
for Salmonella since the prevalence
and the levels of Campylobacter
on chicken carcass are higher. The
study also showed that whereas wiping
countertops and other kitchen surfaces
can significantly reduce microbial
counts when a clean cloth or an
antibacterial-impregnated napkin
is used, when the cloths are damp
and contain high numbers of micro-organisms,
they readily spread bacteria to
the surface instead of removing
them.
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| THE
IMPACT OF HYGIENE BEHAVIOUR ON CHILDHOOD
DIARRHOEA IN SALVADOR, BRAZIL |
 Based
on the growing acceptance that water
supply and sanitation are not sufficient
for the prevention of diarrhoeal diseases
in young children unless accompanied
by changes in domestic hygiene behaviour,
Strina and co-workers have carried out
a study of the impact of hygiene behaviour
(American Journal of Epidemiology 2003,
157, p.1032 - 1038). The team avoided
the use of questionnaire surveys and
used structured observations to monitor
hygiene behaviour. On bi-weekly visits
to homes, field-workers checked a list
of 23 forms of behaviour which were
scored as either hygienic (likely to
prevent faecal oral disease transmission)
or unhygienic (likely to favour transmission)
by the child or the child’s caretaker.
The children were then grouped according
to whether mainly unhygienic or hygienic
behaviour had been recorded. Among children
for whom mainly positive hygiene behaviour
was recorded the prevalence of diarrhoea
was 6.4 days per child year, compared
with 14.2 days per child year for children
with mainly negative scores. The difference
between the positive and negative groups
was highly significant.
A
remarkable finding was the significant
association between a positive hygiene
score and the presence of adequate
excreta disposal facilitates in
the household. It seems unlikely
that the presence of toilets per
se was the cause of the change in
hygiene score, since many of the
studied hygiene behaviours were
not related to excreta disposal.
The authors concluded that in fact
families predisposed to acquire
adequate sanitation in their homes
have a measurably better awareness
of hygiene which is expressed in
their behaviour. No association was
found between behaviour and the
presence of open sewerage channels
near the household, suggesting that
the difference is associated with
the families’ individual
predisposition to install and use a
toilet rather than the characteristics
of the neighbourhood in which they
live. Whereas previous studies of
the neighbourhood as a whole showed
that that sanitation offers important
health benefits, the data obtained
in this study is indicative of the
important role of hygiene behaviour,
in addition to water supply and
sanitation facilities in the house.
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NEW
PUBLICATIONS
A SELECTION
OF NEW ENTRIES IN THE IFH READING
ROOMS |
Survival
of foodborne pathogens on stainless
steel surfaces and cross-contamination
to foods.
The survival of Salmonella enteritidis,
Staphylococcus aureus and Campylobacter
jejuni at room temperature on stainless
steel surfaces was determined. The transfer
rates of bacteria from kitchen sponges
to stainless steel surfaces and from
the surfaces to foods was also investigated.
Bacterial levels decreased rapidly,
particularly when initial levels were
low. For example Staph. aureus
was recovered from the surfaces for
at least 96hr when the level was high
(105 cfu/cm2) or moderate (103 cfu/cm2).
At low levels (10 cfu/cm2), the numbers
decreased below the detection limit
(4 cfu/100cm2) within 2 days. All bacteria
were readily transferred from wet sponges
to stainless steel surfaces and then
to food, with transfer rates between
20-100%. The results highlight that
bacteria may remain viable on dry surfaces
and present a hazard for several days,
depending on the numbers and type of
bacteria.
Kusumaningrum, H.D., Riboldi, G.,
Hazeleger, W.C. and Beumer, R.R. Int
J Food Microbiol 2003; 85:227-236.
Microbial
contamination in home laundry operations
in Japan.
The home-laundering situation in Japan
is unique among many countries as leftover
bath water is used for laundering the
next day. However, such a unique custom
may cause household microbial transmission.
A bacteriological investigation of various
articles was carried out to clarify
the link between the microbial transmission
and the home laundering operation. Staphylococcus
spp. were isolated from every sample
of children's underwear, bath towels,
kitchen rags, washing machine and leftover
bath water. Although pathogenic bacteria
were not detected, some opportunistic
pathogens were detected. Since many
bacteria were isolated from bath water,
home-laundering with used bath water
may cause microbial contamination of
the laundry.
Tabata, A., Zhang, D., Maeda, T.,
Nagamune, H. and Kourai, H. Biocontrol
Science (Japan) 2003; 8(1):9-18.
Study
of cleaning standards and practices
in food premises in the UK.
The UK Public Health Laboratory Service
(PHLS) examined the bacterial status
of surfaces used to prepare ready-to-eat
foods in over 1500 UK food premises,
and also assessed the cleaning standards
and practices at the premises. Surfaces
examined included chopping/cutting boards,
worktops, food containers and cleaning
cloths. Cleaning cloths were more heavily
contaminated with bacteria compared
to other surfaces sampled. Bacteria
isolated from cloths included Staph.
aureus, Listeria, Salmonella and
Campylobacter. Chopping boards
used to prepare both raw and ready-to-eat
food were more heavily contaminated
compared to those used for ready-to-eat
food only. Some premises used the same
implements to clean raw and ready-to-eat
preparation areas.
Sagoo, S.K., Little, C.L., Griffith,
C.J. and Mitchell, R.T. Commun Disease
Publ Health 2003; 6:6-17.
Spread
of methicillin-resistant Staphylococcus
aureus (MRSA) among household contacts
of individuals with nosocomially acquired
MRSA.
The colonisation status of the household
and community contacts of patients undergoing
MRSA eradication at a university hospital
was reviewed. MRSA was isolated from
14.5% of 172 personal contacts of 88
index patients colonised with MRSA.
An analysis of antimicrobial susceptibility
and DNA fingerprint patterns suggested
person-to-person spread. The results
imply that failure to control MRSA within
the healthcare system is likely to lead
to further dissemination of MRSA into
the community.
Calfee, D.P., Durbin, L.J., Germanson,
T.P., et al. Infection Control and Hospital
Epidemiology 2003; 24:422-426.
Investigation
of antibiotic and antibacterial agent
cross-resistance in target bacteria
from homes of antibacterial product
users and nonusers.
This study looked for differences in
antibiotic resistance of bacteria in
homes where antibacterial products were
used compared with homes of non-users.
Evidence of resistance to antibacterial
agents was also investigated. Samples
were collected from homes in the USA
and UK of 30 users and 30 nonusers of
antibacterials. Susceptibility tests
against antibiotics and antibacterial
agents (triclosan, pine oil, BAC and
PCMX) were carried out on the bacteria
isolated. The authors conclude that
their data shows no evidence that antibiotic
resistant bacteria occurred more frequently
in user homes compared with non-user
homes. In addition there was no evidence
that bacteria from user homes showed
any increase in resistance to the antibacterials
compared with bacteria from non-user
homes.
Cole, E.C., Addison, R.M., Rubino,
J.R., et al. J Appl Microbiol 2003;
95:664-676
Antibacterial
cleaning and hygiene products as an
emerging risk factor for antibiotic
resistance in the community.
Aiello and Larson review the burden
of antibiotic resistance and known risk
factors within the community setting.
Their concerns stem from observations
that patients are increasingly being
admitted to hospital with antibiotic
resistant infections, for whom there
is no obvious explanation as to why
or how they acquired it (e.g. no previous
hospitalisation). They examine the proposition
that this trend may relate to increased
use of antibacterial cleaning and hygiene
products in the home, which could be
encouraging the emergence of antibiotic
resistant strains.
Aiello, A.E. and Larson, E. Lancet
Infect Dis 2003; 3:501-6.
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