Amebiasis (Amoebic Dysentery) | Entamoeba histolytica, Pathogenesis, Signs & Symptoms, Treatment

Amebiasis (Amoebic Dysentery) | Entamoeba histolytica, Pathogenesis, Signs & Symptoms, Treatment


Hey everyone, this lesson is on amebiasis,
otherwise known as intestinal amebiasis (amoebic dysentery) so in this lesson, we’re going to talk about
specifically an infection with entamoeba histolytica we’re also going to talk
about how we can get infected with this type of amoeba what is the pathogenesis how this amoeba can cause the signs and symptoms that it does. We’re
also going to talk about those signs and symptoms and we’re also going to talk
about how we can treat it so intestinal amebiasis is an invasive intestinal
infection with amoeba of the genus entamoeba so entamoeba you can remember
the word entamoeba by it’s the suffix amoeba so that’s easy and then we can
think of Ent so “Ent”, “Int”, “INTestinal” so that’s how we can remember this type of
genus of amoeba now it’s a estimated that about 50 million individuals are
infected worldwide annually with this type of infection and there are actually
four different types of amoeba species that can cause intestinal neaby aces
these include entamoeba histolytica entamoeba dispar and entamoeba moshkovskii
and entamoeba Bangladeshi and again we’re gonna specifically talk about
entamoeba histolytica because this is the most common cause of intestinal
amebiasis so how do we get infected with this amoeba? Well there’s a cyst
stage of infection that’s the infective stage, and then there’s also the trophozoite stage which is the stage of the amoeba that actually causes the invasive
disease so we get an infection from ingestion of the amoebic cysts so the
amoeba during their cyst stage that is the infective stage we can get this from
contaminated water or food we can also get it from fecal oral route as well so
if an individual has an infection with entamoeba histolytica they will actually
release mature cysts in their feces and then if another individual comes along
and actually ingests contaminated food or water that has been contaminated with
these cysts they’re going to get infected themselves so surprisingly cysts
can actually survive in the environment for weeks to months so they’re very
resilient and there are several stages of infection so again
the cysts are the infective stage they are what we ingest from the environment
and when these cysts pass through the stomach they will transform into
trophozoites in the small intestine this is what is the cause of
the invasive disease so the trophozoites themselves will invade into the
mucosa of large intestine so they pass through all the in small intestine they
make it to the large intestine and then they start to wreak havoc so they start
to cause damage to the tissue causing increased secretions and eventual bloody
diarrhea so they basically burrow into the mucosa of the large intestine this
causes damage to those tissues the tissues begin to become inflamed and
ademma tiss causing increased secretions and you’re gonna get blood as a result
of all that damage so what does the entamoeba histolytica specifically do to
cause this pathogenic scenario well entamoeba histolytica for one they
secrete proteinases that destroy protein so they will secrete these enzymes
proteinases that destroy proteins of the host so they can go in release these
proteinases and can actually destroy proteins in the
large intestinal mucosa another thing they can do is they can destroy
intestinal cells through a direct contact mechanism so they can get
against the cells and they can actually destroy the cells through direct contact
they can also form what we call an amoeba pore which forms pores in lipid
bilayers of infected cells this will basically lyse the cells and to cause
them to become injured and destroyed and another pathogenic mechanism by which
entamoeba histolytica can cause tissue damage is through disrupting tight
Junction proteins eventually result in increased intestinal permeability so
with all these mechanisms they can lead to destruction of intestinal tissue
leading to a bloody diarrhea and also increased secretions increased
intestinal permeability so they can do a lot of damage so what are some of the
clinical features of intestinal amebiasis we already talked about several so
some of the other ones include the following you can actually
have an asymptomatic pitcher so if you have a very good immune system if you’re
exposed to these amoeba you might not even have these symptoms if you’re able
to clear the infection the other one is amoebic dysentery so
we’ve talked about this in length the de century again involves abdominal pain
and colitis they can get bloody diarrhea from this and again the bloody diarrhea
is due to local tissue damage and destruction and in addition to amoebic
dysentery you may also get amoebic abscesses and these abscesses will
commonly occur in the liver so here’s an image a CT scan of amoebic abscesses
within the liver and these are due to hematologic spread so if you get an
infection in your GI system they can actually spread hematological e to the
liver and set up shop there and you’re gonna get hepatomegaly, right upper
quadrant pain, weight loss, and fever and these abscesses can also occur in other
sites less commonly than the liver but you can also get them in the lungs in
the brain so this is can be very significant so again these abscesses are
most common in the liver but can also call occur in the lungs in the brain so
these are the three clinical scenarios with an infection of entamoeba
histolytica one you may be completely asymptomatic if you have a very good
immune system you may be that clear this infection with no issues the second you
may have amoebic dysentery so you might have abdominal pain colitis you
may have bloody diarrhea due to that tissue damage we talked about before and
the third you may get these amoebic abscesses and these abscesses most
commonly occur in the liver but can also occur in the lungs in the brain so how
do the clinical features of intestinal amebiasis well we can think about the
species entamoeba histolytica so int entamoeba you can think of nth for
intestinal so that might clue you into the de century and you can think of
histo lytic lytic that component of the word lytic lytic means destruction so
you can think of lytic as destroying abdominal tissue so that’s you can think
of that in relation to the bloody diarrhea or another way to remember
these clinical features is the mnemonic “Ame” ordered BLOOD LABS so Amy spelled ame so that will clue you into amoeba ordered blood labs
blood this will help you remember bloody diarrhea and labs L for liver and abs for
abscess so you can just think of a maybe a physician whose name is Amy she’s
ordering blood labs and that may help you remember that amoeba or entamoeba
histolytica cause bloody diarrhea and L for liver and abs for abscess
so they cause bloody diarrhea and liver abscess so hopefully that helps you
remember some of the clinical features of Amebiasis so how do we make the
diagnosis and how do we treat intestinal amebiasis so investigations and
diagnosis include the following so we can do serology we can look for
antibodies against entamoeba histolytica we can do antigen testing we can do
stool sampling looking for those trophozoites always we talked about before
and we may need to do a biopsy of the colon because these amoeba can burrow
into the intestinal mucosa you might have to actually take a piece of the
colon to actually look at it under microscope to see these organisms so
once you’ve made the diagnosis how do you treat it so treatment involves a use
of metronidazole so if we got intestinal maybe aces just the GI symptoms of
amoeba amoeba infection we can use metronidazole to help clear that
infection if we have you know more an invasive picture more systemic illness
perhaps cysts perhaps more an invasive disease we might have to use Iodoquinol
or paramycin so again these are for cysts and for invasive disease so this
can be effective treatments for amebiasis so if you want to learn more about
infectious diseases please check out my infectious disease playlist and if you
haven’t already please consider liking subscribing and clicking the
notification bell to help support the channel and as always thank you so much
for watching and I hope to see you next time

11 thoughts on “Amebiasis (Amoebic Dysentery) | Entamoeba histolytica, Pathogenesis, Signs & Symptoms, Treatment

  1. great video, as always. The mnemotechnic tricks you mention are not really useful (and I notice that from many English-speaking videos) because mnemotechnicity is individual. The way YOU remember a name or whatever may not be the way another person does. Otherwise, your videos are fantastic, thank you so much

  2. Wow, You shared very good information. My uncle had suffered from this problem. He was total upset during this. He went to many hospitals. But the result was not good. Then, Someone told him about planet Ayurveda. He went to Planet Ayurveda & got his treatment started. Now he is fine. If you have this type of problem or any other type of health problem. you should go to Planet Ayurveda.

  3. Idk if anybody can help me out in the comment section but I just was diagnosed with dysentery Entamoeba Hystolytica and received antibiotic for treatment in July or August. However, since treatment I have been unable to gain any of the weight back and in fact lost even more weight. I was 125 pounds prior to invasion and now down to 112 pounds. My doctor said it’s probably because it caused damage to my intestines and it will take about a year for those tissues to recover which for now could be causing me malabsorption thus my weight issues. My question is, how else can I speed up this recovery process? Is there anything I can do to help recover my intestines? I’m just tired of being tired all the time and eating 2,500-3,000 calories a day to just stay underweight.

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