Ask A Scientist© Veterinary Topics Archive

name         Joe A.
status       other
age          60s

Question -   A number of years ago, one of the major TV channels ran a
program that traced the bacteria from dog feces to the deaths of
children.  The process was the children playing in the area where a dog
defecated, collected the bacteria on their hands which were placed in the
child's mouth and an organism developed in the child's brain which
eventually killed the child.  Within the last month, one of the news
channels carried a similar story.  Do you know the name of the disease
and could you please direct me to additional information on the above
subject?
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Toxacara Larva Migrans

http://www.biosci.ohio-state.edu/~parasite/vlm.html

Phillip Raclyn, DVM CVA
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There are a number of disease causing agents that can be transmitted
from dogs to people through the feces.  From the description, this
sounds like roundworms.  

If a dog ingests the roundworm eggs, which are too tiny to see without
a microscope, the eggs hatch into tiny larvae that migrate through the
dog's intestinal wall, back to the intestine and develop into adult
worms.  

Since the human is not the right host for the parasite, the microscopic
larvae that hatch can migrate into other parts of the body.  Many people
have been exposed to small numbers of these parasites without showing
any disease signs.  But exposure to large numbers of eggs can cause
disease and in very rare cases of high exposure, many larva may migrate
into the brain causing severe problems.  Of even more concern than the
dog roundworm is the raccoon roundworm, which seems to have a greater
affinity for migrating to the brain. 


Fortunately, these cases can be largely prevented by 1) making sure
that children don't eat dirt or contaminated soil or wood chips, 2)
having good hand-washing after contact with soil, 3) making sure that
animals are unlikely to defecate in areas where children play and 4)
having regular veterinary care for pets so that they are treated to kill
and prevent worms.

Laura L. Hungerford, DVM, MPH, PhD
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