EQUINE | Equine Disease Quarterly
Equine Disease Quarterly –
October 2018 & January 2019
Vector or arthropod-borne diseases represent some
of the most significant threats to human and animal
health in certain regions/countries of the world.
An ever-increasing number have spread beyond
historically defined boundaries, in no small part as a
result of continued expansion in international trade of
live animals or animal products and because of global
climate change. The worldwide spread of two human
pathogens, Chikungunya and Zika viruses, from the
African continent in recent years illustrates the major
difficulties confronting the global community in
containing these and other arthropod-borne diseases.
Within the realm of infectious diseases, it is more
relevant in today’s world to consider populations
of humans and animals in different countries as co-
existing in a global context, blurring the boundaries
and reach of national political interests. We have in
essence become an international community in which
social media play a major role in communicating
information across a spectrum of issues, including
disease events.
Aside from what is known of the diversity and range of
particular disease vectors in the USA, there is a need to
be mindful of the possible introduction of a particular
arthropod, e.g. tick or mosquito, that has never been
recorded previously in the country—in other words,
an invasive species. The article in this issue of the
Quarterly on the discovery of the Asian longhorned
tick (Haemaphysalis longicornis) for the first time in the
USA highlights the challenges that can be presented
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by an invasive tick species. Although shown to be a
competent vector of various diseases in a number of
Pacific Rim countries, the potential competency of this
particular tick to transmit animal or human diseases in
the country remains to be established. Within recent
months there have also been reports of the introduction
of invasive species of mosquito (Ochlerotatus japonicus)
into Spain and of ticks (Hyalomma marginatum and H.
rufipes) into Germany.
Although the discovery of H. longicornis was reported
for the first time in 2018, subsequent investigations
have shown that the tick had been in the USA at least
since 2013. The lesson to be learned from this latest
experience is that much greater surveillance and
monitoring of tick and insect populations in general is
needed to establish the range and distribution of the
various species with potential to serve as competent
vectors of known mosquito and tick-borne diseases of
equids.
To better prepare ourselves for dealing with future
disease threats, resources need to be made available
to support the infrastructure for more comprehensive
vector and disease surveillance programs in conjunction
with improved capacity to respond to major disease
events. The risk of such threats will increase inevitably
with continued growth in the globalization of trade and
the influence of climate change on our environment
and the spread of vectors and vector-borne diseases.
An integral element to better prepare ourselves for the
• Equine Health Update •