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blood/tissue parasites

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What parasite in Phylum apicomplexa causes the disease we most concerned with?
PLASMODIUM, which causes MALARIA
What are the four species of Plasmodium?
1. vivax
2. falciparum
3. malariae
4. ovale
what are the diseases caused by malaria?
PICCMMART
Paludism, Intermittent fever
Chagres fever,Coastal fever
Malaria, Marsh fever,
Ague, Roman fever, Tropical fever
What is the definitive host of Plasmodium?
What is the intermediate host?
Definitive: Female anopheles mosquito

Intermediate: Humans, other animals
What is the Geographic distribution of malaria?
in the Malarial belt:
-Africa
-South/Central America
-Southeast Asia
what are the 2 main compoments of the Plasmodium life cycle?
-in which host does each take place?
-Sporogeny = sexual, in mosquitos.
-Schizony = asexal, in humans
What terms denote species with
-48 hr cycle
-72 hr cycle
-Which species belong to each?
48hr = Tertian Cycle; all species except Malariae.

72hr = Quatern cycle, P.malariae
In what order are the stages of malarial infections seen on a thin smear?
-Troph
-Schizont
-Gametocytes
Which species of Plasmodium have very similar morphologies?
What makes them similar?
Vivax and Ovale.
-makes RBCs Macrocytic
-species are v. motile
-Tertian (48 hr)
-Schuffner's dots are seen
-both can cause relapse
Which species don't cause relapse?
P. malariae
P. falciparum
Which species of Plasmodium causes normocytic RBCs?

What other notes make it unique?
P. malariae
-also low motility
-the only QUARTERN species
-Schizonts have ROSETTE look.
Which species has crescent shaped gametocytes?
P. falciparum
What characteristics and morphology are used to I.D. P. falciparum?
-36-48 hr cycle - works faster!
-VARIOUS sized RBCs
-More than 1 parasite/cell
-Most resistant, but doesn't show relapse.
Why is P. falciparum the worst species?
becasue it infects both young and old RBCs, over 50%.
The other species only infect 2-4% of the RBCs.
What 4 things are used to treat malaria?
QMCWAP
1. Quinine/Mefloquine
2. Chloroquine
3. Wormwood extract
4. Artemisinin + Piperaquine is the Chloroquine-resistant treatment.
What are the 4 possible forms of malaria pathology/symptomology?
1. Usual
2. Blackwater fever
3. Cerebral malaria
4. Congenital malaria
What are the USUAL COURSE symptoms?
1. Fever/chill cycle (allergic rxtn when schizonts rupture)
2. Anemia, splenomegaly
What is Blackwater fever? What species causes it?
Acute hemolytic syndrome causing hemoglobinuria - P. falciparum
What are symptoms of Cerebral malaria, what causes it?
Confusion/disorientation, caused by P. falciparum
What species causes Congenital Malaria?
ALL species
what are 3 resistance mechanisms to malaria?
1. Sickle cell anemia
2. Duffy blood group negative
3. others - HgF in infants, dietary deficiencies, G6PD defic., cell/humoral immunity, vaccines.
How is a thin smear prepared for malarial exam?
Normally, but stained with Giemsa.
How is a thick smear prepared?
1. Nickel drop of blood on slide
2. Dry.
3. Slide stained w/ Giemsa to lyse RBCs
4. Look at slide for parasites
Where does Quinine kill malarial organisms?

How is the drug commonly used?
In the BLOODstream - not the liver.

Often used as a prophylactic.
Which organism is Chloroquine resistant?
P. falciparum
What drug is used for cellular AND liver prophylaxis?
Malarone

also, Larium and Doxycycline
What parasite causes Babesiosis?
Babesia microti
In what geographical areas is Babesiosis seen, and how is it transmitted?
-Nantucket
-Cape Cod
-Midwest

-Transmitted via DEER TICK
-What is the Defin host of Babesia microti?
-What is the intermed. host?
Defin: deer tick

Intermed: humans
Morphologically, what does B. microti resemble?

What makes it unique?
Resembles P. falciparum, BUT:
-Only has rings, no granules or pigment.
-Rings form a MALTESE CROSS - a tetrad of rings.
What 5 symptoms are often seen in Babesiosis?
Fever and Chills
Splenomegaly
Hepatomegaly
Hemolysis causing Blckwtr fever
With what 3 lab techniques do I diagnose Babesiosis?
Thick smears, Thin smears, and ELISA.
What 2 medicines will I use to treat Babesiosis?
1. Azithromycin
2. Atovaquone in combo with Malarone.
How can patients prevent babesiosis?
Keeping away from
-ticks
-blood transfusions.
What are the 2 blood/tissue flagellates that we are concerned with?
What genus/phylum/order are they in?
What type of organism transmits all of these?
-Leishmania
-Trypanosoma

Protozoa, Mastigophora, Kinetoplastida

All transmitted via arthropod
What two subspecies of the Kinetoplastida cause African sleeping sickness, where?
-Tryp. brucei rhodesiense - East
-Tryp. brucei gambiense - West
what organism (specific subspecies too) transmits East/West african sleep sick?
Tsetse fly, Glossina species.
what parasite causes Chagas' disease?

How is the parasite transmitted?
Trypanosoma cruzi, found in C. and S. America, and Mexico.

-carried by the Reduviid bug, which poops while eating.
What are the four pathogenic species of Leishmania?

What vector is common to all?
L. donovani,
L. tropica and L. mexicana
L. braziliensis

Transmitted by SANDFLY
What are the 2 developmental forms of the blood/tissue flagellates?
-Which species is each in?
-Trypomastigotes - seen in Trypanosoma infections

-Amastigotes - seen in Leishmaniasis.
What two Tryp species cause AFrican sleeping sickness?
-Trypanosoma gambiense
-Trypanosoma rhodesiense
What is the infectious stage that causes african sleeping sickness?
-Metacyclic trypomastigote.
What are the hosts of tryp gambiense and rhodesiense?
-vertebrate
-invertebrate
-Vertebrate is human/animals
-Invert is Glossina tsetse fly
What are possible stages of Afr. sleeping sickness?
-Acute stage
-Chronic stage
What are the symptoms of African sleeping sickness, the Acute stage?
-Fly bites cause Chancres
-Trypomastigotes in blood invade lymph nodes
-Fever/night sweats
-Nodules on the neck (aka Winterbot. sign)
What is Winterbottom's sign?
-the presence of neck nodules in acute sleeping sickness.
What is the diagnostic stage of trypanosoma gambiense and rhodesiense?
-Trypomastigotes in the blood.
What are 3 chronic stage symptoms?
1. Trypomastigotes in the CNS
2. Coma
3. Death
What are 4 methods for diagnosis of African sleeping sickness?
-Clinical symptoms (fever/sweat)
-Trypomastigotes in blood
-IgM levels (high - frequently change surf antigens)
-ELISA for Ag in blood/CSF
what are 3 drugs for treating african sleeping sickness?
1. Suramin via IV
2. Pentamidine isothionate via intramuscular injection
3. Melarsoprol can cross BBB
What are two ways to prevent african sleeping sickness?
-Control the vector (tsetse fly) population

-Reduce the human reservoir.
what does T. cruzi cause?

what vector transmits it?
Chagas disease

vector: reduviid bug
wat are the hosts of T. cruzi?
-vertebrate
-invertebrate
Vert: humans/animals

Invert: Reduviid bug
what are symptoms of Acute and Chronic Chagas disease?
Acute: chagoma (inflmtn), fever, rash, hepato/splenomegaly, acute myocarditis, swollen liver, spleen, and heart.

Chronic: severe cardiomyopathy and megacolonopathy.
How is Chagas disease diagnosed?

What are 3 other methods?
Primarily Clinical symptoms

Also
Trypomastigotes in blood
Amastigotes in tissue
Serological tests
What is one additional, slightly weird method of diagnosing Chagas disease?
Xenodiagnosis
What is Xenodiagnosis?
Raising pure reduviid bugs, allowing them to eat blood of patient, test feces for metacyclic trypomastigotes
What 2 drugs may treat Chagas disease?
What other treatment may be necessary?
1. Bayer 250Z, Radamil

2. May surgiclly remove megaesophagus and megacolon.
How can Chagas disease be prevented?
-Controlling vector breeding by painting or using plastic boards
-Protect humans from the flies
What is the developmental form present in Leishmaniasis?
-Amastigote
What are 3 types of hosts of Leishmania?
-Vertebrate - Man
-Invertebrate - Sandfly
-Reservoir - Dogs/rodents
how is leishmania prevented?
(two normal, common things)
-Control vector breeding ground
-Protect humans
what are the 4 leishmania species?
-Donovani
-Mexicana and tropica
-Braziliensis
What are 3 names for Leishmania donovani infection?
Kala-azar
Visceral leishmaniasis
Dumdum fever
What does Kala-azar mean?
Black poisoning
Where is L. donovani found?
-South/Central America
-Africa
-Middle East
What are 3 ways an L. donovani infection can present?
1. Asymptomatic
2. general fever/chills
3. Hepato and Splenomegalic
How is an infection of L. donovani diagnosed?
(2 things seen in general, 2 specific tests)
-Clinical manifestations
-Amastigotes in tissues like liver/spleen, bone marrow
-DNA probe
-Montenegro test
what is the montenegro test?
a test for l. donovani, by mixing a mL of serum and formaldehyde - positive if mixture turns gelatinous.
L. donovani causes visceral inf; what causes a cutaneous inf?
L. tropica and mexicana
what is the main symptom of cutaneous leishmaniasis?


other names?
a sore on the forehead/face

-Oriental sore, dehli ulcer, aleppo.
whatcauses American leishmaniasis?

what is the most commonly used name for it?
Leishmania braziliensis --> brazil is in south america.

Espundia
what kind of infection does L. braziliensis cause? What occurs in the pathology?
Mucocutaneous - the parasite erodes the cartilage of the lips and nose.
what are the 5 organisms of blood and tissue NEMATODES?
1. Wuchereria bancrofti
2. Wuchereria malayi
3. Loa loa
4. Onchocerca volvulus
5. Dracunculus medinensis
what forms are present in the nematode cycles - what type of a parasite is it?
Forms: filariae (adult worm) and microfilariae (larval form)
Type: a worm the size of coarse sewing thread.
What is interesting about the blood/tissue nematode adult females?
they are ovoviparous - eggs develop within, but they give birth to living larva.
what is the diagnostic stage of all the nematodes here?
-microfilariae - it migrates in the blood and tissues, in a periodic pattern.
What 3 methods are used to prevent all of the nematode infections?
1. controlling the vector populn
2. Treating people to reduce microfilariae
3. Protecting humans from bites.
What are 3 names for infections of Wuchereria bancrofti?
Elephantiasis
Wuchereriasis
Bancroftian filariasis
in what geographic places are Wuchereria bancrofti and malayi found?
Afria
Southeast Asia
South America
what are hosts of w. bancrofi?
-definitive
-intermediate
Defin: people
Intermediate: mosquitos - this is the vector that transmits it.
What 3 things morphologically set W. bancrofti apart?
-Sheath
-Acellular tip
-Nocturnal periodicity
When does W. bancrofti collect blood?
at night
What are three variations of Bancroftian filariasis, aka elephantiasis?
1. Asymptomatic
2. Inflammatory
3. Obstructive - result of lymphatics draining to low legs.
How is Elephantiasis due to W. bancrofti diagnosed?
by the presence of microfilariae in the blood.
How is elephantiasis treated?

Drug used to kill microfilariae:
-Unfortunately only by amputation.
-Hetrazan kills microfilariae.
What disease does W. malayi cause?
Malayan filariasis
What is the only difference btwn Wuchereria bancrofti and malayi?
The tip of tail - 2 cells are seen in the malayi tail, none in bancrofti.

-Also obstructive stage is not as severe.
What are 3 names of diseases caused by LOA LOA?
-Loasis
-Fugitive swellings
-Calabar swellings
what is the common name of Loa loa infection?
AFRICAN EYEWORM
where is african eyeworm found?
in Central and West african rainforests.
what symptoms does loa loa cause?
Swelling of tissues around eyes
Pain in conjunctival space
what transmits loa loa?
Deerfly vector
which nematodes cause eye disease? which causes blindness?
Loa loa and Onchocerca volvulus.

only O. volvulus causes blinding.
what are 3 names for Onchocerca volvulus infections?
-River blindness
-Onchocerosis
-Onchocerciasis
where is river blindness found?
Africa
Central and South America
what are hosts of O. volvulus?
-Definitive
-Intermediate
Defin: people

Intermed: Simulium (black fly)
what are the 2 symptoms of river blindness?
-Inflammation causing skin/eye nodules and lesions.

-Blindness- leading worldwide cause of blindness.
how is Onchocerca volvulus diagnosed?
By the presence of microfilariae in a skin snip.
what drug treats river blindness?

How else can it be treated?
-Ivermictin

Prophylactic treatment is surgical removal of nodules.
which of the blood/tissue nematodes is the largest?
Dracunculus medinensis.
what is the common name of D. medinensis infection?
Fiery serpent infection.
Also:
Dracontiasis, dracunculosis, dracunculiasis, guinea worm.
What 3 places is fiery serpent found?
Central Africa
Middle East
India
what are the hosts of D. medinensis?
Defin: humans
Intermed: Water flea or cyclops
How is Fiery Serpent disease transmitted?
via ingestion of water flea or cyclops - NOT a bite!!
what is the major symptom of infection by d. medinensis?
Worm under the skin - crawls in when washing clothes, out when wading in water.
how is Dracunculosis diagnosed?
treated?
prevented?
by finding adult worms under the skin.
Treatment: pull it out on stick.
Prevent: use clean water.

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