Gert van der Hoek
In Memoriam - Editor, Senior Moderator
Edit: the full unedited report, courtesy of ELA : http://hobbydierhouder.nl/images/stories/pdf/conference_on_q-fever_25-26.2.2010.pdf
From ProMED
Q FEVER - NETHERLANDS (18): UPDATE AND REVIEW
*********************************************
Date: Wed, March 3 2010
From: Christine Bijl Christinebijl@gmail.com [edited]
[We are most grateful to Christine Bijl for the submission of her
following recorded minutes; an official report (proceedings) is not
(yet?) available. These recordings have been abridged and edited;
discussions omitted. - Mod. AS]
The conference was attended and the report made by Christine Bijl, as
ELA representative.
The conference, organised by the Ministry of Agriculture in
collaboration with Wageningen UR and the Animal Health Service,
started early on Thu 25 Feb 2010.
1st day: 25 Feb 2010
The 1st day was chaired by Jaap Wagenaar (Veterinary Faculty Utrecht)
with the opening words of welcome by Elske Smith (Ministry
LNV/Agriculture). Wagenaar emphasised that the conference had an
informative character.
1. Christianne Bruschke (Ministry-CVO) - Actual veterinary situation
and developments in the Netherlands
Christianne sketched the
development of the Dutch situation from the veterinary point of view.
The human side of the problems would be outlined in the next
presentation by Yvonne. No one in the Netherlands had ever expected
that after the 1st human cases (2007) this epidemic would grow to
such proportions. Nowhere in the world has such a development been
documented before. At this moment, 70 percent of all dairy goat farms
are still Q-fever free. Some contaminations were caused by
transporting animals from one farm to the other. Investigations into
an industrial way of killing the bacterium in manure are in process.
Much is still to be learned about the Dutch problem.
2. Yvonne van Duynhoven (RIVM) - The story of human Q-fever in the Netherlands
There have been retrospective investigations into previous clusters
of Q-fever patients in hospitals: 2 in 2005, 1 in 2006 and 4 in 2007.
In Herpen (1st village in Brabant reporting human Q-fever), 24
percent of the people became infected.
In Helmond, 30 percent of
abortions in a goat farm resulted in the 1st human cases 3 weeks
later, most of them in the 2-km-zone and decreasingly in the
5-km-zone. Research into the risks of an infection for pregnant women
showed no complications for partus or neonatals.
The Public Health
Council has been requested to advise on the possible use of a human
vaccine, answer expected in June 2010. Diagnostic delay has
decreased: more awareness made patients visit the doctors sooner, and
the doctors did not wait long before checking for Q-fever.
Why is it
that in all Q-fever literature, just 5 percent serious illness is
mentioned, when in the Netherlands 20 percent have been hospitalised?
An artefact? The hospitalisation rate has gone down from 20 to 16.8
percent. Occurring complications: hepatitis 3.5, and endocarditis 0.3 percent.
3. Francisco Reviriego Gordejo (DGSANCO) - Q-fever: the EU public and
animal health legislative context
Riviriego sketched Q-fever as an apparently underestimated and
under-listed disease not included in EU legislation for animal
diseases, in contrast to brucellosis and RVF, and as a zoonosis not
explicitly listed in zoonoses- monitoring, in contrast to brucellosis
and salmonella.
Q-fever is progressively covered by EU surveillance
for public health monitoring. In the basic OIE standards, Q-fever is
listed but not for international trade. Apparently, the EU wheels are
turning slowly; however, moves are being made now to include Q-fever
in future as a notifiable disease.
3. Pia Makela (EFSA) - Current reporting and monitoring of Q-fever in
animals in EU
EFSA collects yearly data on monitoring of zoonoses. MSs have to
submit these data on 8 zoonoses, among which Q-fever is not listed.
However, based on the epidemiological situation of the MSs, other
zoonoses may be included.
Currently, data of 7 other zoonoses,
including Q-fever, are reported. EFSA collaborates closely with ECDC
(European Centre for Disease prevention and Control) to analyse and
publish the yearly reports. Reporting list B diseases (like Q-fever)
or not is an MS decision.
Encouraged by EFSA, Q-fever reporting started in 2005. Since then,
more and more MSs are sending in their data. The reported data are
not harmonised: most reports are from clinical investigations
(abortions), some from monitoring, some from surveillance and some
from surveys.
Data do not show whether they are herd based or from
individual sampling, nor what diagnostic methods were used. So data
between MSs are not comparable. EFSA has given a grant to a
consortium of MSs institutes (AFSSA/France, CVI/Netherlands,
FLI/Germany and NVRI/Poland) led by AFSSA to produce a harmonised
monitoring and reporting scheme for Q-fever in animals. (See Richard
Thiery's presentation on 26 Feb 2010).
Up till today, Q-fever was
present in all 18 reporting MSs. Without harmonisation, it is
impossible to interpret the data.
4. Denis Coulombier (ECDC) - Implications for public health in the EU
ECDC is involved in an advisory role re Q-fever since 2007/08. With
the rise of cases in the Netherlands, there seems to be a new
dimension in the Q-fever situation. The EU Commission has requested
ECDC to assess the risks. The Bavarian problems in Germany appear not
to be related to the Dutch situation. His conclusion: Confirmed
circulation of _C. burnetii_ should start early warning for public health.
5. Jeannette van de Ven (ZLTO) - The meaning and consequences of
Q-fever for farmers in general and especially the situation of goat farming
Jeanette and her husband started the family farm in 1995 with 200
kids and have expanded that number to 2000 goats today. In 2008,
their farm is situated in the compulsory vaccination zone, and
therefore all animals were vaccinated twice (boost after 6 weeks); in
2009, the old animals were vaccinated once and the kids twice.
Then
in December 2009, the farm was declared contaminated based on bulk
milk monitoring. Out of 2000 animals, 524 pregnant animals were
killed in the 1st round and 101 in the 2nd. Not only did she tell her
own sad story, she also told us about a farm outside the compulsory
vaccination zone where all animals had been vaccinated voluntarily
and yet this farm too was declared contaminated. Again the pregnant
animals were culled based on bulk milk testing results.
Bulk milk
tests give no information about the number of infected animals at a
contaminated farm. It could be that the majority of culled animals
were healthy. At the moment, there is continuing uncertainty for the
farmers: the breeding ban is set till July 2010, but what is going to
happen afterwards? The culling policy undermined the vaccination
policy. The vaccination policy should have avoided unnecessary
killing as control policy.
Farmers are eager to do everything to
prevent people from getting sick (therefore, they did agree to the
drastic measures this time), but eradication of the bacterium is
impossible. There must be a risk-based balance in future and not a
policy based on sentiment and media impact.
6. Annie Rodolakis (France) - Q-fever in France - An elaborate
description of the Q-fever situation in France where most human cases
were due to infection in sheep herds.
To compare virulence of strains, a mouse model was developed. Sheep
strains appeared to be less virulent for mice than the ones from
bovines and goats. So possibly other factors could be responsible for
the route to humans. Sheep mostly shed in faeces and vaginal mucus.
Bovines hardly do.
Studies into the efficacy of the available
vaccines showed that the CEVA vaccine Coxevac is very efficient, not
only reduces the number of abortions in a herd, but also the amount
of shedding. Whereas the Merial vaccine Chlamyvax (combination
vaccination against Chlamydophila and Q-fever) did neither. The
French have developed a skin test for infected herds to determine
which ones are to be vaccinated. Then, one can suffice with
vaccinating the non-reacting animals.
Hygienic measures are in place
as well, like carefully destroying afterbirth material (so it will
not be taken-up by domestic or wild animals), birthing in confined
locations, disinfection of these locations afterwards and treating
the manure with lime or calcium cyanamide and refraining from its
spreading/dissemination in windy conditions. Still more research is
done regarding the best way to handle manure and the other hygienic measures.
7. Stephen Graves (Australia) - Epidemiology and the role of human vaccination
After giving us the history of _C. burnetii_, Graves told us that
Q-fever is widely spread in Australia, with concentrations in
Queensland and anywhere around localities with livestock and
abattoirs etc. Australia is a scarcely-populated country with widely
scattered farms (lots of space for all the Dutch goats).
The Coxiella
bacterium is found in all ruminants, kangaroos and the kangaroo tick,
not so much in domestic animals. Most human cases are due to aerosol
spread from dried animal waste. The Australians developed a vaccine
for humans, licensed in 1989. It is still the only approved human
vaccine in the world.
However, before vaccinating a person, one MUST
(obligatory) perform a skin test to prevent post-vaccination
reactions. Anyone with previous Q-fever history will test positive
and therefore be excluded from vaccination, unless the risk of
infection is higher than a possibly harmful reaction to the vaccine.
Immunity is supposed to last 10 years. Q-fever (for humans) is a
notifiable disease. It is often not diagnosed, therefore
under-diagnosed. The incidence is higher in dry years.
Vaccination is
not government funded; however, meat-industry companies take
responsibility by offering their workers vaccination. The use of
vaccination in rural communities is common. His suggestions for the
Netherlands: "Buy our vaccine, try its efficacy for your local
strains and then develop your own vaccine. Good luck!"
8. Martin Ganter (Germany) - Q-fever in Germany
In Germany, there have been over the years (notifiable since 1947)
some outbreaks of human Q-fever, mainly in the south (Bavaria). But
there have been 2 outbreaks in Jena/Thuringia (2005) and in North
Rhine-Westphalia where in 2003 some 300 people became ill with
Q-fever after they had visited a country fair, where a single
aborting sheep had shed _C. burnetii_.
In the Jena valley, the source
of infection was found to be a small flock of lambing sheep. There
are no specific regulations for Q-fever; it is handled when necessary
usually by the veterinary officer, who can instate a transport ban,
hygienic measures regarding birthing and disposal of material, and
antibiotic treatments (tetracyclines) and vaccination.
But all this
depends on the available knowledge of Q-fever of the involved
persons. Due to some large outbreaks, a research network of
public-health and veterinary groups is working on diagnostics and
epidemiology of Q-fever. Ganter has performed his own trial (ongoing)
to investigate and evaluate the vaccination of a pregnant flock of
sheep. It looks like there is a decrease (in 2009) of _C. burnetii_
in the flock, but too soon for conclusions.
9. Paula Menzies (Canada) - Q-fever & Coxiellosis in Canada
Canada is a scarcely-populated country. However, in Ontario there are
high animal concentrations (sheep and goats). Reported human Q-fever
cases are low. Coxiellosis is not reportable for humans, but annually
notifiable. No actions are taken after diagnosis, no routine
surveillance. Outbreaks are always related to visiting barn shows and
fairs. No human cases have been reported as due to cattle source;
there are links with cats and trapped hares (wildlife).
After the cod
fishery collapsed, Newfoundland imported goats to start dairy goat
farming. In the virgin area, Coxiella found a receptive, susceptible
host. There have been several outbreaks on 6 of the 8 farms, a
situation of concern [Will this turn out to be the Dutch scenario?].
However, Coxiellosis is unlikely to become reportable in Canada and
is under-diagnosed in general.
Better communication to the public is
needed. More awareness with the authorities is needed. And Menzies is
looking for evidence in the Netherlands to support her efforts
towards the Canadian government. In May this year [2010], a study
starts on prevalence in Ontario.
2nd day: 26 Feb 2010
Chairman: Frits Pluimers (former Ministry CVO)
Edit:
----------------------------------------------------------------------
[Following the posting above of minutes taken from Paula Menzies'
presentation of 25 Feb 2010 at the Breda Q fever conference, the
original text of the presentation has been kindly submitted by the
author to replace previous versions. Dr Menzies is gratefully
acknowledged. - Mod.AS]
Paula Menzies (Canada): Q fever and coxiellosis in Canada
---------------------------------------------------------
Although small ruminant numbers are lower in Canada than in other
countries, in Ontario sheep and goats are often raised in confinement
situations with high stocking densities.
Reported human Q fever (notifiable) cases are low in Ontario.
Coxiellosis (Q fever) is not reportable in animals, but annually
notifiable. No action is taken by the federal or provincial
governments after diagnosis. No routine surveillance in animals is
currently performed.
Outbreaks of human Q fever are usually related to visiting farms and
fairs and outbreaks of abortion in sheep and goats due to _Coxiella_
-- but human disease has been associated with parturient cats with no
contact with livestock. No human cases have been linked to infection
in cattle; but there are links with wildlife, such as, snaring hares.
After the cod fishery collapsed, Newfoundland imported goats to start
a dairy goat industry. The outbreak of coxiellosis associated with
mixing of these introduced animals resulted in 80 cases of human Q
fever in the surrounding community.
Coxiellosis -- the disease in animals -- is unlikely to become
reportable in Canada. Q fever in humans is likely under-diagnosed in
general. Better communication of the risks of this infection to
medical health professionals and the public in general, is needed. A
sero-prevalence study in sheep and goat flocks and their caregivers
is commencing in May [2010] in Ontario. This will help to clarify the
importance of the infection in this province.
--
Dr Paula I Menzies
Assoc Professor Dip.ECSRHM
Small Ruminant Research Coordinator
Ruminant Health Management Group
Department of Population Medicine
Ontario Veterinary College, University of Guelph
Guelph, Ontario Canada N1G 2W1
pmenzies@uoguelph.ca
http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,81685
10. Benaouda Kadra (CEVA) - Q-fever: Vaccine production and control
As producer of the vaccine Coxevac, Kadra gave an overview of its
benefits and of the production process (purification of the bacterium
is a difficult technique). Coxevac is registered in France since 2004
and is used on a voluntary basis. The Netherlands have a temporary
registration since 2008. The Dutch have bought every possible
available dose for 2010. Because of the difficult production process,
not a single extra dose will be available this year [2010].
11. Hendrik-Jan Roest (CVI) - Diagnosis, genotyping, virulence and
culture of _C. burnetii_ in the Netherlands
In the Netherlands, bulk milk testing is used since October 2009;
beforehand, the abortion rate of more than 5 percent was the
indicator for notification. A lot of discussion has been going on
about the efficiency and credibility of bulk milk testing as a
criterion for culling.
However, according to Roest, the detection of
_C. burnetii_ in a milk sample provides an absolute positive result,
even if another test should be negative. And the fact that at culled
farms the last test results were negative after positive initial
results does not mean there is no infection on the farm, just that
the shedding went below the detection threshold. 30 percent of the
animals will not be detected. In genotying, 13 types were found in
the Netherlands using Multi Locus variable number tandem repeat
Analysis (MLVA). MLVA-type 11 is predominant on all Brabant farms and
on all dairy goat farms. Harmonising of the typing methods is
essential for interpretation (see EFSA-grant).
Whether the
predominant type 11 is more virulent than the others is still a
question not answered. However in cooperation with France, several
Dutch and French strains will be compared to find the answer,
expectedly this year [2010]. It may be assumed that the Dutch goats
and people are relatively more susceptible ("virgin") regarding
Q-fever, this possibly leading to more severe effect.
12. Richard Thiery (AFSSA) - Results of EFSA's grant on improving
harmonised Q-fever monitoring in the EU
As we heard from Pia Makela (EFSA), the reports from MSs are not
harmonised and therefore cannot be properly interpreted or compared.
The EFSA-grant to AFSSA (in collaboration with CVI, FLI and NVRI)
aims to create a harmonising-system. So harmonisation is the key
word. In 14 of 18 reporting MSs, the disease is notifiable for
animals. Some MSs are reporting at level of animals (individual)
others at herd level.
There are no definitions or specificity of
clinical signs. Harmonisation will start with central reporting of
clinically affected herds (of domestic ruminants only) after serial
abortions and presence of the bacterium is confirmed by PCR, and
positive serology by ELISA. RT-PCR is most effective when performed
within 8 days after abortion, and ELISA is very effective in
vaccinated herds. For active surveillance, bulk milk testing is very
effective. The final report is expected this spring [2010].
13. Dimitrios Frangoulidis (Germany) - _Coxiella burnetii_ -
stability in the environment and molecular typing
There are 55 strains and 17 genotypes. Despite the fact that _C.
burnetii_ is spread all over the world and is found in many species,
it is rarely reported. _C. burnetii_ is known as large cell variants
(LCV) and small cell variants (SCV). The small variant is more stable
and can survive in soil or dust for many years, in various
circumstances like in acid environments and high temperatures
(resistance up to 70 C for 15 minutes). Diagnostic capabilities have
improved over the years, but there is still a lot to be learned about
the epidemiology of the disease.
14. Piet Vellema (Animal Health Service Deventer) - Research in
relation to the approach of Q-fever
Bulk milk testing was initially (October 2009) aiming at accrediting
repeatedly test negative dairy farms. However in December 2009, this
testing was used to identify positive farms and consequently kill all
pregnant animals at such farms. Efficacy of vaccination was tested on
15 dairy farms. There was some elevation of temperature, some skin
effects, and a few cases of a drop in milk production.
However, the
shedding of bacteria was considerable after some time. At the request
of the audience, Vellema elaborated on research into the relation
between temperature in the manure heap and survival of the bacterium.
It became apparent that the temperature in manure rose to over 70 C
within 2 days, but only in the upper layer.
The core never rose above
40 C. The more oxygen could be induced (like in the top layer), the
higher the temperature rose. As up-turning a contaminated heap
produces the risk of freeing bacteria, one believes that airing the
heap with pipes would be the best way to raise the temperature in the core.
It was a very interesting and well organised conference with a wide
range of speakers and enough time for questions and discussion. In
the afternoon, the speakers and invited experts and stakeholders
remained to discuss several angles in smaller groups. This session
was open only to selected people.
--
Communicated by:
Christine Bijl
European Livestock Association (ELA) Secretary
Kootwijkerbroek, The Netherlands
http://www.ela-europe.org/
Christinebijl@gmail.com
[Should the presentations or official abstracts become available, we
shall be happy to include them in future posting(s). - Mod.AS]
http://www.promedmail.org/pls/otn/f...,F2400_P1001_USE_ARCHIVE:1001,20100303.0703,Y
From ProMED
Q FEVER - NETHERLANDS (18): UPDATE AND REVIEW
*********************************************
Date: Wed, March 3 2010
From: Christine Bijl Christinebijl@gmail.com [edited]
[We are most grateful to Christine Bijl for the submission of her
following recorded minutes; an official report (proceedings) is not
(yet?) available. These recordings have been abridged and edited;
discussions omitted. - Mod. AS]
The conference was attended and the report made by Christine Bijl, as
ELA representative.
The conference, organised by the Ministry of Agriculture in
collaboration with Wageningen UR and the Animal Health Service,
started early on Thu 25 Feb 2010.
1st day: 25 Feb 2010
The 1st day was chaired by Jaap Wagenaar (Veterinary Faculty Utrecht)
with the opening words of welcome by Elske Smith (Ministry
LNV/Agriculture). Wagenaar emphasised that the conference had an
informative character.
1. Christianne Bruschke (Ministry-CVO) - Actual veterinary situation
and developments in the Netherlands
Christianne sketched the
development of the Dutch situation from the veterinary point of view.
The human side of the problems would be outlined in the next
presentation by Yvonne. No one in the Netherlands had ever expected
that after the 1st human cases (2007) this epidemic would grow to
such proportions. Nowhere in the world has such a development been
documented before. At this moment, 70 percent of all dairy goat farms
are still Q-fever free. Some contaminations were caused by
transporting animals from one farm to the other. Investigations into
an industrial way of killing the bacterium in manure are in process.
Much is still to be learned about the Dutch problem.
2. Yvonne van Duynhoven (RIVM) - The story of human Q-fever in the Netherlands
There have been retrospective investigations into previous clusters
of Q-fever patients in hospitals: 2 in 2005, 1 in 2006 and 4 in 2007.
In Herpen (1st village in Brabant reporting human Q-fever), 24
percent of the people became infected.
In Helmond, 30 percent of
abortions in a goat farm resulted in the 1st human cases 3 weeks
later, most of them in the 2-km-zone and decreasingly in the
5-km-zone. Research into the risks of an infection for pregnant women
showed no complications for partus or neonatals.
The Public Health
Council has been requested to advise on the possible use of a human
vaccine, answer expected in June 2010. Diagnostic delay has
decreased: more awareness made patients visit the doctors sooner, and
the doctors did not wait long before checking for Q-fever.
Why is it
that in all Q-fever literature, just 5 percent serious illness is
mentioned, when in the Netherlands 20 percent have been hospitalised?
An artefact? The hospitalisation rate has gone down from 20 to 16.8
percent. Occurring complications: hepatitis 3.5, and endocarditis 0.3 percent.
3. Francisco Reviriego Gordejo (DGSANCO) - Q-fever: the EU public and
animal health legislative context
Riviriego sketched Q-fever as an apparently underestimated and
under-listed disease not included in EU legislation for animal
diseases, in contrast to brucellosis and RVF, and as a zoonosis not
explicitly listed in zoonoses- monitoring, in contrast to brucellosis
and salmonella.
Q-fever is progressively covered by EU surveillance
for public health monitoring. In the basic OIE standards, Q-fever is
listed but not for international trade. Apparently, the EU wheels are
turning slowly; however, moves are being made now to include Q-fever
in future as a notifiable disease.
3. Pia Makela (EFSA) - Current reporting and monitoring of Q-fever in
animals in EU
EFSA collects yearly data on monitoring of zoonoses. MSs have to
submit these data on 8 zoonoses, among which Q-fever is not listed.
However, based on the epidemiological situation of the MSs, other
zoonoses may be included.
Currently, data of 7 other zoonoses,
including Q-fever, are reported. EFSA collaborates closely with ECDC
(European Centre for Disease prevention and Control) to analyse and
publish the yearly reports. Reporting list B diseases (like Q-fever)
or not is an MS decision.
Encouraged by EFSA, Q-fever reporting started in 2005. Since then,
more and more MSs are sending in their data. The reported data are
not harmonised: most reports are from clinical investigations
(abortions), some from monitoring, some from surveillance and some
from surveys.
Data do not show whether they are herd based or from
individual sampling, nor what diagnostic methods were used. So data
between MSs are not comparable. EFSA has given a grant to a
consortium of MSs institutes (AFSSA/France, CVI/Netherlands,
FLI/Germany and NVRI/Poland) led by AFSSA to produce a harmonised
monitoring and reporting scheme for Q-fever in animals. (See Richard
Thiery's presentation on 26 Feb 2010).
Up till today, Q-fever was
present in all 18 reporting MSs. Without harmonisation, it is
impossible to interpret the data.
4. Denis Coulombier (ECDC) - Implications for public health in the EU
ECDC is involved in an advisory role re Q-fever since 2007/08. With
the rise of cases in the Netherlands, there seems to be a new
dimension in the Q-fever situation. The EU Commission has requested
ECDC to assess the risks. The Bavarian problems in Germany appear not
to be related to the Dutch situation. His conclusion: Confirmed
circulation of _C. burnetii_ should start early warning for public health.
5. Jeannette van de Ven (ZLTO) - The meaning and consequences of
Q-fever for farmers in general and especially the situation of goat farming
Jeanette and her husband started the family farm in 1995 with 200
kids and have expanded that number to 2000 goats today. In 2008,
their farm is situated in the compulsory vaccination zone, and
therefore all animals were vaccinated twice (boost after 6 weeks); in
2009, the old animals were vaccinated once and the kids twice.
Then
in December 2009, the farm was declared contaminated based on bulk
milk monitoring. Out of 2000 animals, 524 pregnant animals were
killed in the 1st round and 101 in the 2nd. Not only did she tell her
own sad story, she also told us about a farm outside the compulsory
vaccination zone where all animals had been vaccinated voluntarily
and yet this farm too was declared contaminated. Again the pregnant
animals were culled based on bulk milk testing results.
Bulk milk
tests give no information about the number of infected animals at a
contaminated farm. It could be that the majority of culled animals
were healthy. At the moment, there is continuing uncertainty for the
farmers: the breeding ban is set till July 2010, but what is going to
happen afterwards? The culling policy undermined the vaccination
policy. The vaccination policy should have avoided unnecessary
killing as control policy.
Farmers are eager to do everything to
prevent people from getting sick (therefore, they did agree to the
drastic measures this time), but eradication of the bacterium is
impossible. There must be a risk-based balance in future and not a
policy based on sentiment and media impact.
6. Annie Rodolakis (France) - Q-fever in France - An elaborate
description of the Q-fever situation in France where most human cases
were due to infection in sheep herds.
To compare virulence of strains, a mouse model was developed. Sheep
strains appeared to be less virulent for mice than the ones from
bovines and goats. So possibly other factors could be responsible for
the route to humans. Sheep mostly shed in faeces and vaginal mucus.
Bovines hardly do.
Studies into the efficacy of the available
vaccines showed that the CEVA vaccine Coxevac is very efficient, not
only reduces the number of abortions in a herd, but also the amount
of shedding. Whereas the Merial vaccine Chlamyvax (combination
vaccination against Chlamydophila and Q-fever) did neither. The
French have developed a skin test for infected herds to determine
which ones are to be vaccinated. Then, one can suffice with
vaccinating the non-reacting animals.
Hygienic measures are in place
as well, like carefully destroying afterbirth material (so it will
not be taken-up by domestic or wild animals), birthing in confined
locations, disinfection of these locations afterwards and treating
the manure with lime or calcium cyanamide and refraining from its
spreading/dissemination in windy conditions. Still more research is
done regarding the best way to handle manure and the other hygienic measures.
7. Stephen Graves (Australia) - Epidemiology and the role of human vaccination
After giving us the history of _C. burnetii_, Graves told us that
Q-fever is widely spread in Australia, with concentrations in
Queensland and anywhere around localities with livestock and
abattoirs etc. Australia is a scarcely-populated country with widely
scattered farms (lots of space for all the Dutch goats).
The Coxiella
bacterium is found in all ruminants, kangaroos and the kangaroo tick,
not so much in domestic animals. Most human cases are due to aerosol
spread from dried animal waste. The Australians developed a vaccine
for humans, licensed in 1989. It is still the only approved human
vaccine in the world.
However, before vaccinating a person, one MUST
(obligatory) perform a skin test to prevent post-vaccination
reactions. Anyone with previous Q-fever history will test positive
and therefore be excluded from vaccination, unless the risk of
infection is higher than a possibly harmful reaction to the vaccine.
Immunity is supposed to last 10 years. Q-fever (for humans) is a
notifiable disease. It is often not diagnosed, therefore
under-diagnosed. The incidence is higher in dry years.
Vaccination is
not government funded; however, meat-industry companies take
responsibility by offering their workers vaccination. The use of
vaccination in rural communities is common. His suggestions for the
Netherlands: "Buy our vaccine, try its efficacy for your local
strains and then develop your own vaccine. Good luck!"
8. Martin Ganter (Germany) - Q-fever in Germany
In Germany, there have been over the years (notifiable since 1947)
some outbreaks of human Q-fever, mainly in the south (Bavaria). But
there have been 2 outbreaks in Jena/Thuringia (2005) and in North
Rhine-Westphalia where in 2003 some 300 people became ill with
Q-fever after they had visited a country fair, where a single
aborting sheep had shed _C. burnetii_.
In the Jena valley, the source
of infection was found to be a small flock of lambing sheep. There
are no specific regulations for Q-fever; it is handled when necessary
usually by the veterinary officer, who can instate a transport ban,
hygienic measures regarding birthing and disposal of material, and
antibiotic treatments (tetracyclines) and vaccination.
But all this
depends on the available knowledge of Q-fever of the involved
persons. Due to some large outbreaks, a research network of
public-health and veterinary groups is working on diagnostics and
epidemiology of Q-fever. Ganter has performed his own trial (ongoing)
to investigate and evaluate the vaccination of a pregnant flock of
sheep. It looks like there is a decrease (in 2009) of _C. burnetii_
in the flock, but too soon for conclusions.
9. Paula Menzies (Canada) - Q-fever & Coxiellosis in Canada
Canada is a scarcely-populated country. However, in Ontario there are
high animal concentrations (sheep and goats). Reported human Q-fever
cases are low. Coxiellosis is not reportable for humans, but annually
notifiable. No actions are taken after diagnosis, no routine
surveillance. Outbreaks are always related to visiting barn shows and
fairs. No human cases have been reported as due to cattle source;
there are links with cats and trapped hares (wildlife).
After the cod
fishery collapsed, Newfoundland imported goats to start dairy goat
farming. In the virgin area, Coxiella found a receptive, susceptible
host. There have been several outbreaks on 6 of the 8 farms, a
situation of concern [Will this turn out to be the Dutch scenario?].
However, Coxiellosis is unlikely to become reportable in Canada and
is under-diagnosed in general.
Better communication to the public is
needed. More awareness with the authorities is needed. And Menzies is
looking for evidence in the Netherlands to support her efforts
towards the Canadian government. In May this year [2010], a study
starts on prevalence in Ontario.
2nd day: 26 Feb 2010
Chairman: Frits Pluimers (former Ministry CVO)
Edit:
----------------------------------------------------------------------
[Following the posting above of minutes taken from Paula Menzies'
presentation of 25 Feb 2010 at the Breda Q fever conference, the
original text of the presentation has been kindly submitted by the
author to replace previous versions. Dr Menzies is gratefully
acknowledged. - Mod.AS]
Paula Menzies (Canada): Q fever and coxiellosis in Canada
---------------------------------------------------------
Although small ruminant numbers are lower in Canada than in other
countries, in Ontario sheep and goats are often raised in confinement
situations with high stocking densities.
Reported human Q fever (notifiable) cases are low in Ontario.
Coxiellosis (Q fever) is not reportable in animals, but annually
notifiable. No action is taken by the federal or provincial
governments after diagnosis. No routine surveillance in animals is
currently performed.
Outbreaks of human Q fever are usually related to visiting farms and
fairs and outbreaks of abortion in sheep and goats due to _Coxiella_
-- but human disease has been associated with parturient cats with no
contact with livestock. No human cases have been linked to infection
in cattle; but there are links with wildlife, such as, snaring hares.
After the cod fishery collapsed, Newfoundland imported goats to start
a dairy goat industry. The outbreak of coxiellosis associated with
mixing of these introduced animals resulted in 80 cases of human Q
fever in the surrounding community.
Coxiellosis -- the disease in animals -- is unlikely to become
reportable in Canada. Q fever in humans is likely under-diagnosed in
general. Better communication of the risks of this infection to
medical health professionals and the public in general, is needed. A
sero-prevalence study in sheep and goat flocks and their caregivers
is commencing in May [2010] in Ontario. This will help to clarify the
importance of the infection in this province.
--
Dr Paula I Menzies
Assoc Professor Dip.ECSRHM
Small Ruminant Research Coordinator
Ruminant Health Management Group
Department of Population Medicine
Ontario Veterinary College, University of Guelph
Guelph, Ontario Canada N1G 2W1
pmenzies@uoguelph.ca
http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,81685
10. Benaouda Kadra (CEVA) - Q-fever: Vaccine production and control
As producer of the vaccine Coxevac, Kadra gave an overview of its
benefits and of the production process (purification of the bacterium
is a difficult technique). Coxevac is registered in France since 2004
and is used on a voluntary basis. The Netherlands have a temporary
registration since 2008. The Dutch have bought every possible
available dose for 2010. Because of the difficult production process,
not a single extra dose will be available this year [2010].
11. Hendrik-Jan Roest (CVI) - Diagnosis, genotyping, virulence and
culture of _C. burnetii_ in the Netherlands
In the Netherlands, bulk milk testing is used since October 2009;
beforehand, the abortion rate of more than 5 percent was the
indicator for notification. A lot of discussion has been going on
about the efficiency and credibility of bulk milk testing as a
criterion for culling.
However, according to Roest, the detection of
_C. burnetii_ in a milk sample provides an absolute positive result,
even if another test should be negative. And the fact that at culled
farms the last test results were negative after positive initial
results does not mean there is no infection on the farm, just that
the shedding went below the detection threshold. 30 percent of the
animals will not be detected. In genotying, 13 types were found in
the Netherlands using Multi Locus variable number tandem repeat
Analysis (MLVA). MLVA-type 11 is predominant on all Brabant farms and
on all dairy goat farms. Harmonising of the typing methods is
essential for interpretation (see EFSA-grant).
Whether the
predominant type 11 is more virulent than the others is still a
question not answered. However in cooperation with France, several
Dutch and French strains will be compared to find the answer,
expectedly this year [2010]. It may be assumed that the Dutch goats
and people are relatively more susceptible ("virgin") regarding
Q-fever, this possibly leading to more severe effect.
12. Richard Thiery (AFSSA) - Results of EFSA's grant on improving
harmonised Q-fever monitoring in the EU
As we heard from Pia Makela (EFSA), the reports from MSs are not
harmonised and therefore cannot be properly interpreted or compared.
The EFSA-grant to AFSSA (in collaboration with CVI, FLI and NVRI)
aims to create a harmonising-system. So harmonisation is the key
word. In 14 of 18 reporting MSs, the disease is notifiable for
animals. Some MSs are reporting at level of animals (individual)
others at herd level.
There are no definitions or specificity of
clinical signs. Harmonisation will start with central reporting of
clinically affected herds (of domestic ruminants only) after serial
abortions and presence of the bacterium is confirmed by PCR, and
positive serology by ELISA. RT-PCR is most effective when performed
within 8 days after abortion, and ELISA is very effective in
vaccinated herds. For active surveillance, bulk milk testing is very
effective. The final report is expected this spring [2010].
13. Dimitrios Frangoulidis (Germany) - _Coxiella burnetii_ -
stability in the environment and molecular typing
There are 55 strains and 17 genotypes. Despite the fact that _C.
burnetii_ is spread all over the world and is found in many species,
it is rarely reported. _C. burnetii_ is known as large cell variants
(LCV) and small cell variants (SCV). The small variant is more stable
and can survive in soil or dust for many years, in various
circumstances like in acid environments and high temperatures
(resistance up to 70 C for 15 minutes). Diagnostic capabilities have
improved over the years, but there is still a lot to be learned about
the epidemiology of the disease.
14. Piet Vellema (Animal Health Service Deventer) - Research in
relation to the approach of Q-fever
Bulk milk testing was initially (October 2009) aiming at accrediting
repeatedly test negative dairy farms. However in December 2009, this
testing was used to identify positive farms and consequently kill all
pregnant animals at such farms. Efficacy of vaccination was tested on
15 dairy farms. There was some elevation of temperature, some skin
effects, and a few cases of a drop in milk production.
However, the
shedding of bacteria was considerable after some time. At the request
of the audience, Vellema elaborated on research into the relation
between temperature in the manure heap and survival of the bacterium.
It became apparent that the temperature in manure rose to over 70 C
within 2 days, but only in the upper layer.
The core never rose above
40 C. The more oxygen could be induced (like in the top layer), the
higher the temperature rose. As up-turning a contaminated heap
produces the risk of freeing bacteria, one believes that airing the
heap with pipes would be the best way to raise the temperature in the core.
It was a very interesting and well organised conference with a wide
range of speakers and enough time for questions and discussion. In
the afternoon, the speakers and invited experts and stakeholders
remained to discuss several angles in smaller groups. This session
was open only to selected people.
--
Communicated by:
Christine Bijl
European Livestock Association (ELA) Secretary
Kootwijkerbroek, The Netherlands
http://www.ela-europe.org/
Christinebijl@gmail.com
[Should the presentations or official abstracts become available, we
shall be happy to include them in future posting(s). - Mod.AS]
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