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wildlife and zoo assay data sheet
Baylisascaris procyonis
Test code:
X0019 - Ultrasensitive qualitative detection of
Baylisascaris procyonis
by real time PCR
Baylisascaris
procyonis
infection has recently been recognized as an important and
widespread emerging helminthic infection of both animals and
humans. Raccoons are thought to be the most favorable host for
this roundworm; reported infection rates are as high as 70% in
adult raccoons and can exceed 90% in juvenile raccoons. Due to
the close interaction of raccoons with human populations and
pets, this parasite has increasingly been recognized as a cause
of severe human disease.
When raccoons
ingest the eggs of this parasite the larvae hatch, enter the
wall of the small intestine and subsequently develop into adult
worms in the small bowel. These adult worms shed eggs into the
raccoon’s bowel. Although raccoons are not significantly
affected by these parasites, ingestion of the eggs by other
suboptimal host mammals (including rodents, birds, dogs and
other domestic mammals) results in extraintestinal migration of
larvae, and notably invasion of the brain. The migration of
helminth larvae through tissue in suboptimal hosts is termed
larva migrans and may affect the viscera (visceral larva migrans
[VLM]), the eye (ocular larva migrans [OLM]), or the nervous
system (neural larva migrans [NLM].
B.
procyonis
larvae have been found in more than 90 species of wild and
domestic mammals and birds, including dogs, chickens, pheasants,
quail, guinea pigs, domestic rabbits, rodents, porcupines,
chinchillas, prairie dogs, woodchucks, emus, foxes, weasels and
primates. Outbreaks of B. procyonis infestation have been
reported on farms, in zoos, among pets and in research animal
colonies.
The risk of
human infestation by this parasite has risen alarmingly due to
pets’ contact with raccoon feces. Studies have shown that a
single adult female worm can produce hundreds of thousands of
eggs per day, and an infected raccoon may shed as many as 45
million eggs daily (Jacobson et al., 1982; Kazacos and Boyce,
1989). These eggs can remain viable in the environment for
years. Accidental ingestion of the eggs by humans via contact
with infected domestic animals can lead to severe human
infection and death.
In the past,
B. procyonis infection was diagnosed by morphologic
identification of larvae in tissue sections. However,
morphologic identification is often difficult and unreliable
because a number of possible larval nematodes share very similar
morphology, including Toxocara canis, T. cati,
Ascaris lumbricoides, and species of Gnathastoma,
Angiostrongylus and Ancylostoma, as well as larval
cestode infections such as cysticercosis and echinococcosis.
While serologic testing has been used in some cases as
supportive diagnostic evidence, commercial serologic tests are
not available. Presumptive diagnosis has often been made on the
basis of clinical data (meningoencephalitis, diffuse unilateral
subacute neuroretinitis [DUSN], pseudotumor), epidemiologic data
(raccoon exposure), radiologic data (white matter disease), and
blood and CNS eosinophilia.
However,
molecular detection techniques are now available to rapidly,
sensitively and specifically detect B. procyonis.
With this more advanced approach, preventive screening and
environmental surveys are possible, enabling identification of
animal carriers and even contaminated soils.
Utilities:
-
Help confirm the
disease causing agent
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Shorten the
time required to confirm a clinical diagnosis of
Baylisascaris infection
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Help ensure that
animal groups are free of
Baylisascaris
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Early
prevention of spread of
Baylisascaris between animals
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Minimize
human exposure to
Baylisascaris
References:
Jacobson, J.E., Kazacos, K.R., and Montague, F.H. (1982)
Prevalence of eggs of
Baylisascaris procyonis (Nematoda:Ascaroidea) in
raccoon scats from an urban and a rural community. J Wildl. Dis.
18:461-464.
Kazacos, K.R. and Boyce, W.M. (1989)
Baylisascaris larva migrans. J. Am. Vet. Med. Assoc.
195:894-903.
Specimen requirement: 0.2 ml feces, or rectal swab, or 0.2 ml
soil, or 0.2 ml tissue.
Contact Zoologix
if advice is needed to determine an appropriate specimen type
for a specific diagnostic application. For specimen
types not listed here, please contact Zoologix to confirm
specimen acceptability and shipping instructions.
For all
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
Turnaround time:
2 business days
Methodology:
Qualitative real time PCR
Normal range:
Nondetected
Baylisascaris procyonis PCR test
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