hey everyone and this is where I’m
talking about toxoplasmosis toxoplasmosis is caused by an infection
with the protozoa species known as Toxoplasma gondii what i want you to
take from this is it is a protozoa species that’s causing the infection and
it is an obligate intracellular parasite here is a picture of that protozoa
species now Toxoplasma gondii has a worldwide distribution. cats
and livestock act as hosts for this protozoa and mice act as intermediate
hosts now there are several different sources by which a person can be
infected with this protozoa one is through cat feces so in this
source or in this transmission the person gets exposed to the Toxoplasma
oocysts the second source is through undercooked meat and in that source is
the tissue cysts there’s also horizontal transmission
this can include through organ transplant or a blood transfusion from
an infected person in the fourth source is vertical transmission from mother to
child and this leads to something known as congenital toxoplasmosis we’ll talk
more about this in the next few slides but what I want you to take from these
sources is that the first three sources lead to what is known as acquired
toxoplasmosis and the fourth leads to congenital toxoplasmosis and we’re going
to talk about the differences between acquired and congenital a little later
on so as we mentioned before the hosts include cats and livestock and humans
can be infected from cats through fecal oases and humans can be infected from
livestock through undercooked meat ingesting tissue cysts
so again the sources are cat feces with fecal oases and undercooked meat with
tissue cysts so when someone ingests either fecal oocysts
and or tissue cysts they transform into what is known as tacky so White’s
shortly after ingestion these tackies all whites then enter the muscle and
neural tissues of the individual and become a bright as a white cyst
now what is most concerning is that in a pregnant woman who is exposed to cysts
these tackies all whites can pass through the placenta and infect the
developing fetus leading to what we call congenital toxoplasmosis so what is the
clinical presentation of toxoplasmosis we’re gonna first talk about congenital
toxoplasmosis and congenital toxoplasmosis has a classic triad of
three signs and symptoms we’re going to use a mnemonic device c-h-i or Chi like
the energy force Chi or you can use hick HIC as in hiccup which ever helps you
remember these three signs and symptoms the first one is chorioretinitis, the
second one is hydrocephalus and the third one is intracranial calcifications
so the classic triad again is chorioretinitis , hydrocephalus and intracranial
calcifications congenital toxoplasmosis can also lead to microcephaly and in
Toxoplasma or toxoplasmosis is actually one of the TORCH infections that you
might have learned about before the T in torch is actually toxoplasmosis and this
is one of the infections that leads to an intrauterine growth restriction
generally during pregnancy the woman will actually be infected with
Toxoplasma in the third trimester however can happen at any trimester and
being in fact in the first trimester leads to worse
outcomes for the infant and when we mean or when we talk about infection during
pregnancy we actually mean primary infection if a woman has actually been
infected prior to pregnancy they have already either clear the
infection or have suppressed the infection and it is not a concern it is
more of a concern when this is the first time a woman has been infected with
Toxoplasma so if the first time a woman is infected with Toxoplasma is during
their pregnancy with their child that is when we get concerned so the primary
infection is actually what we worry about now this is all in contrast to
acquired toxoplasmosis acquired toxoplasmosis is generally asymptomatic
it can be latent so it can basically be in a suppressed form and have no
symptoms at all but the person is still infected with Toxoplasma it can persist
for the life of the person and generally immunosuppression can lead to
reactivation so when a person is severely immunosuppressed as in aids
this can lead to in reactivation of Toxoplasma leading to toxoplasmosis and
it can lead to an acute systemic infection we’re going to talk about more
about these symptoms of acquired toxoplasmosis in the next slide with
acquired toxoplasmosis there are a wide variety of signs and symptoms that we
can see with an individual that is infected with Toxoplasma one is again
this acute systemic infection this acute systemic infection generally occurs at
five to 23 days after an infection it can occur in immunocompetent
individuals most of the time it’s asymptomatic but some individuals can
have symptoms those who do develop symptoms have a benign and generally
self-limited course that lasts for a few weeks to months cervical lymph
adenopathy is the most common symptom in acquired toxoplasmosis it is a bilateral
and symmetrical non tender lymph adenopathy of the neck this usually
happens within weeks of infection a subset of individuals about 20 to 30
percent will have generalized lymphadenopathy
and there can also be constitutional symptoms such as fever chills and sweats
and this usually occurs for two to three days other symptoms of acquired
toxoplasmosis can include headaches myalgias, pharyngitis, hepatosplenomegaly
so an enlargement of the liver and spleen and in rare cases toxoplasmosis
can lead to pneumonitis myocarditis and pericarditis
so myocarditis is the inflammation of the cardiac muscle and pericarditis is
an inflammation of the pericardium that surrounds the heart you can also lead to
polymyositis hepatitis and sefa lightest or a posterior uveitis
and having said all of this again majority of immunocompetent individuals
are asymptomatic for toxoplasmosis but in some individuals we can see some of
these symptoms and especially in those with a reactivation due to
immunosuppression so how do we diagnose and what do we use to treat
toxoplasmosis for diagnosis we use serology looking for antibodies to
Toxoplasma gondii with CSF we can do a Wright-Giemsa sustain and we can use PCR to
look for genetic evidence of Toxoplasma gondii i an immune compromised patients
the patients we worry about the most for either symptomatic toxoplasmosis or a
reactivation of toxoplasmosis we can do a head CT scan and we can do up to Lyme
up thermo logical examinations and how do we treat it what do we use to treat
toxoplasmosis again because oftentimes this is a benign self-limited infection
and a lot of times individuals are asymptomatic we often do not require a
treatment for toxoplasmosis however there are special considerations during
pregnancy we would like to use Spira Meissen or para methylene in
sulfadiazine for HIV patients we can also use pure methylene and sulfadiazine
as well in 4i disease related to toxoplasmosis we can use cortical
steroids so anyways guys I hope you found this lesson helpful that was a
lesson on toxoplasmosis and looking at the differences between acquired and
congenital toxoplasmosis I hope you found this lesson helpful if you did
please like and subscribe for more lessons like this one and it’s always
think is much for watching and I’ll see you next time

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