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0:00
Hello.
My name is Jamie Stevens and I'm
based in the School of Biosciences
at the University of Exeter.
This talk forms part of the
series on vector-borne diseases
and will focus on myiasis
in humans and other animals,
and will include brief
reviews of the applied topics
of larval therapy and
forensic entomology.
This work, and indeed
my research generally,
have benefited from collaboration
with many colleagues in the UK,
Europe, Africa, North and South
America, Australia, and New
Zealand, many of whom have also
been kind enough to provide some
of the photographs used
in the presentation.
Full acknowledgements are
given at the end of the talk.
Additionally, however,
I would particularly
like to thank one of my recent
PhD graduates, Dr. Laura McDonagh,
for excellent work in
this field, and in helping
to prepare this presentation.
0:49
This talk will cover six main topic
areas, as outlined on the slide.
Firstly, we will define myiasis, and
we will look at types of myiasis.
And specifically, we will look at
what is and what is not myiasis.
Secondly, we will review the
various agents of myiasis,
including their biology
and life histories.
Thirdly, we will look at
the evolution of parasitism,
and in particular,
the myiasis habit.
Fourthly, we will look at control
and intervention strategies.
And finally, parts five and
six, we will look briefly
at the applied topics of larval
therapy and forensic entomology.
1:26
So before we go any further with
the main talk, what is myiasis?
Well, I'm not going to say
too much at this stage.
We will look at formal definitions
of myiasis in the next few slides.
For the moment, I
just want to show you
a couple of typical larval
infestations of a living vertebrate
host so you're familiar with
the type of disease condition
that constitutes myiasis.
On the left, we can see two
cases of obligate myiasis
in the hooves of goats.
The top picture is an
infestation with Old World
screwworm fly, Chrysomya bezziana.
In this case, it was from Malaysia.
The lower picture is an infestation
with Wohlfahrtia magnifica.
This is a common
parasite of livestock
throughout the
southern Mediterranean,
the Middle East, and parts of Asia.
On the right, we see two
non-obligate, or facultative,
myiases, and I'll say more
about these terms in a minute.
The lower right picture
is of a typical case
of sheep blowfy strike.
As you can see, the larvae of
the green bottle fly, Lucilia
sericarta, thrive in the humid,
soiled wool of the sheep.
The upper right picture is a
secondary infestation with larvae
of the corn bluebottle,
Calliphora vicina.
In this case, the host
animal was already dead.
Typically, bluebottles are
carrion flies and will only
feed at the site of
the pre-existing wound
and when the host is
already close to death.
One final point to
remember with myiasis
is that, unlike with many
other vector-borne diseases,
in myiases the vector-- the
adult fly and the parasite,
the larvae-- are, in fact,
one in the same thing.
