On Fri, 24 Feb 1995, Alfred Sancho <sancho at hsc.usc.edu> wrote:
> To my understanding the incidence and the degree of infection has
> deminissed greatly, mainly due to more control growth environments of the
> sows. This also means that an infection would spread rapidly through out
> an entire farm...
I imagine you are refering to the tendency to raise pigs in a
confinment environment as opposed to a free-ranging type of managment
where they gestate and farrow on pastures. I suppose this could impact on
Trichinella by limiting access to infected rodents and other hosts with
infective tissue stages. I think the lower prevalence also has to do
with the relative numbers of sows that make it into the food chain.
Because the trend is toward large grow-finisher operations with young pigs,
it seems reasonable that older sows make up only a small part of our total
pork consumption. Folks in the pork industry tell me that most sows end up
as sausage so I would suspect that the likelyhood of obtaining a Trichinella
infection would be higher for sausage, than other commerical cuts. The
reasoning behind the increased prevalence in sows is only speculation, but
it seems sensible that animals which live longer are more likely to acquire
infections than animals with a 150 to 200 day lifespan.
>the question then becomes, is the goverment going to
> enforce the law and prohibit the selling of the meat? Or will the meat
> inspector even find the infection.
I think the latter is the real issue. If Katherine's work is
indicative of the magnintude of the problem, identifying and condemming
every infected pig is too costly. This problem will have to be addressed
if the pork industry wants access to overseas markets.
> In relation to the clinical symptomology, it has also lessened, again due
> to goverment inspections and "cleaner" sow gorwth practices. This could
> also mean that humans will die of other diseases, more acutely and more
> "pronounced" than this parasitic disease. Therefore, the physicians
> would neglect to search for these parasites - or any other - and any
> symptoms would be classified as ""complications"" or ... For instance,
> trichenela prefers actively moving muscles, how many "cardiac" incidents
> in humans are said to be due to stress, fatigue, cholesterol,
> electrophysiology, chemistry, etc and how many are said to be due to
> trichenela? Most likely the physician would never think of the parasite
> as a possible cause or at least as a contributor to the patients' illness
> and symptoms.
> Good points. I'm reminded of a incident involving one of my
wife's nursing students. She was complaining of chronic heart problems,
and her physician attributed them to fatigue, stress etc. Nevermind that
she was in her late 20's and a native Brazillian. I don't know the final
outcome of the case, but I wonder how long it was until Chagas was
considered in the differential diagnosis. I suppose this is not
suprizing given the brief attention to parasitiology in med school curricula.
Perhaps the public should seek out veterinarians for advice on parasite
related illnessses, and take their pets to physicians for attention to
chronic, degenerative illnesses.
more food for thought .......
* Charles T. Faulkner * When you don't know where you're
* Univ of Tennessee, Knoxville * going any road will take you there.
* (ctfaulkn at utkvx.utk.edu) * Alice