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Conference Summary
Third Congress for the European
Society for Emerging Infections
Maria Mavris*
and Lénaïg Halos*
*Ecole Nationale Veterinair d'Alfort, Maisons-Alfort, France
Suggested
citation for this article
Third Congress for the European Society for Emerging Infections
Ecole Nationale Vétérinaire d'Alfort in Maisons-Alfort, France
October 2004
The Third Congress for the European Society for Emerging Infections brought
together an impressive list of scientists, clinicians, and veterinarians
from different fields, including Nobel Prize winner Professor Carlton
Gadjusek, and encouraged a dialogue related to emerging infections. The
theme of this meeting was that, because many infectious diseases have
a zoonotic origin, disease processes in animals should be examined, not
just considered as models for humans.
Various strategies used by viruses and bacteria to infect their hosts
and subsequently persist were discussed. Deaths attributable to infectious
diseases are ≈25% of the total number of human deaths worldwide
annually. Changes in demographics and behavior are the main influences
on the emergence of new diseases. Many existing and emerging diseases
arose from animals: 75% of new human diseases are zoonotic in origin.
Changes that affect the pathogen spectrum include climatic factors, such
as global warming, increased volume and speed of international travel,
increased trade, deforestation, urbanization, and adaptation of microbes
to new environments.
An example of microbe environmental adaptation is the discovery of an
African mosquito-borne flavivirus in central Europe. Large numbers of
blackbirds and owls in the zoological gardens and around Vienna, Austria,
had been found dead in the summer of 2001. Upon further investigation,
they were found to have swollen livers and spleens as well as other characteristics
of West Nile virus. Reverse transcription–polymerase chain reaction (RT-PCR)
determined that the flavivirus was Usutu virus from South Africa, which
had been carried to Europe by migratory swallows. Some spread has occurred
to the 4 countries bordering Austria; however, no human clinical cases
have occurred to date.
On a global scale, the most important vector-borne infections are mosquito-transmitted,
whereas in Europe tick-transmitted infections are a major concern. An
example of a tickborne infection is ehrlichiosis. This disease was first
described in the United States in 1994 but was described in animals in
Europe in the 1960s. At least 20 cases in humans have now been reported
in Europe. Anaplasma phagocytophilum, the causative agent, can
be detected by PCR in 2% to 45% of Ixodes ricinus ticks. Animals
can act as good sentinels for human infection. Erhlichiosis due to A.
phagocytophilum may also be associated with a high risk of co-infection
by Coxiella, Babesia, and Theileria. Therefore, information
and education for both veterinarians and general practitioners are important
for managing and identifying this widespread zoonosis. The combined broad-range
PCR-TTGE (temporal temperature gradient gel electrophoresis) technique
can detect several bacterial pathogens in ticks in a single step.
Transmissible spongiform encephalopathies, in particular variant Creutzfeldt-Jakob
disease (vCJD), are caused by prions, which are able to cross species
barriers. Relatively little is known about their routes of transmission.
Recent experiments for vCJD have shown that the intravenous route for
infecting Macaque monkeys is as efficient as the previously used intracerebral
route, which implies a risk for transmission through blood transfusion.
Indeed, 2 cases due to blood transfusions have been identified in humans.
Risk factors for vCJD include dietary exposure to the infectious agent
of bovine spongiform encephalopathy and may be related to the low mean
age (29 years) for death due to this disease. In addition, many patients
with this disease live relatively close to each other; however, the implications
of this finding are unclear.
The meeting concluded with the topical subject of emerging respiratory
diseases, in particular those caused by coronaviruses and influenza viruses.
The host range of coronaviruses is greater than initially thought. Feline
and canine coronaviruses are closely related to porcine gastroenteritis
virus and are also able to replicate and cause enteric disease in swine.
Coronavirus relatedness is well demonstrated by the coronavirus associated
with severe acute respiratory syndrome (SARS). Like many of the new emergent
diseases, SARS has a zoonotic origin that is as yet unknown. A total of
8,098 cases of SARS and 774 deaths (case-fatality rate of 9.6%) have occurred
worldwide; the incidence is higher among healthcare workers (case-fatality
rate 17%). The spread of SARS was due to global travel and was also attributed
to illegal wildlife trade. Delays in identifying symptoms or clusters
of case-patients increased the risk of contracting SARS, especially in
healthcare workers, and inadequate personal protective equipment played
a large role in its spread.
The need for global medical and veterinary information systems was emphasized.
Strict adherence to protective measures for avoiding bird-to-human transmission,
in the context of avian influenza viruses, was also underscored, particularly
since the Asian outbreak, which began in December 2003, is still ongoing.
In general, the conference encouraged participants to exchange ideas
and to consider future collaborations. One suggestion for coordinating
such efforts could be a European version of the Centers for Disease Control
and Prevention.
In 1969, then-Surgeon General William H. Stewart stated that "the
time has come to close the book on infectious diseases," demonstrating
a misinformed and rather optimistic opinion. By contrast, the third congress
ended with a warning "to expect the unexpected."
Suggested citation
for this article:
Mavris M, Halos L.
Third Congress for the European Society for Emerging Infections [conference
summary]. Emerg Infect Dis [serial on the Internet]. 2005 Apr [date
cited]. Available from http://www.cdc.gov/ncidod/EID/vol11no04/04-1297.htm
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