00:01
Let's move on to another helminth or worm
infection, this one Trichinella spiralis.
00:09
Trichinella spiralis is acquired by eating
undercooked meat containing the cysts of trichinella,
and a common theme, if you've listened to
many of the videos that I have prepared for
you, is that you have to be careful what you
eat and how you cook it for sure. The kinds
of meat that typically will harbor trichinella
include pork, and of course pork is raised
on farms and prepared for us, but also wild
meat, wild pigs and bears, many people around
the world like to catch these animals and
eat them. Even polar bears, the Inuit's like
to eat polar bears and there have been outbreaks
of trichinella associated with eating polar
bears in those populations. How do you acquire
this infection? You eat undercooked meat,
the meat contains larvae. We will see how
those larvae get there in a moment. If you
cook the meat really well, you will get rid
of the larvae, alternatively, if you freeze
your meat before cooking it, you kill larvae,
so you can have rare-ish pork now, as long
as the meat was frozen before you cook it.
You eat the meat containing the larvae, the
larvae go to your stomach, there your digestive
juices release the larvae from the shell that
they are in called the nurse cell and they
moved through your stomach into your small
intestines. There the adults mature and they
live in your small intestine and there they
mate and the female sheds newborn larvae that
then enter your lymph circulation or your
blood circulation and these worms can move
to other tissues like the CNS, and the heart,
and they can cause problems there, problems
to your CNS and heart failure as well. The
larvae are circulating through you and among
the other places they like to go are muscle
cells. The larvae penetrate the muscle cell
and they curl up in a structure called a nurse
cell. And there the larvae matures, and there
it is forever. So if you eat trichinella contaminated
meat and you survive the infection, you will
have larvae in nurse cells in your muscle
for the rest of your life. And as long as
no one eats you, you won’t transmit the
infection. But if this is a pig in which this
cycle is occurring, of course the pig will
be eaten and that is how the infection is
transmitted. So the nurse cell complexes that
remain viable in muscle specifically and if
that is eaten, then it's transmitted to the
next host. But as I've said humans don't eat
each other, so we don't transmit it to other
humans, but we certainly acquire this from
animals. So there you go that's the lifecycle,
again transmitted by undercooked meat. Now these
Trichinella go through a cycle that involves
intestinal passage into the blood and the
formation of a cyst in the muscle. So if you
reach again the cyst stage in the muscle,
you've survived infection, but you can be
killed earlier if worms get into other tissues.
03:31
Some of the symptoms include diarrhea, abdominal
pain, as these worms are moving about in your
abdomen, muscle pain when the worms penetrate
your muscle but once they form a nurse cell
that goes away, and headache if they happen
to enter your brain. As I said the worms can
involve the heart and central nervous system,
especially in cases where you've ingested
more larvae, some meat can be more contaminated
than other meats, and if you get a big dose
of nurse cells, you can have more serious
disease. How do you treat trichinella? So
if you catch it early, you can treat it with
albendazole, mebendazole and this will kill
the adults that are in the intestine, but
if you've passed that phase and now you have
cysts, it will not kill the cysts. So you
can get rid of the adults, so you can stop
shedding eggs, but you won't get rid of the
cysts in your muscle, you will live with those
for the rest of your days.