10 Malaria Flashcards by Hannah Frank

What species is the vector for malaria infections?

Anopheles mosquito (female)

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What are the five different malaria species we discussed?

Plasmodium vivax
P. falciparum
P. malariae
P. ovale
P. knowlesi

Varied clinical manifestations based on causative species

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The reproductive event for malaria species occurs in…

Mosquito saliva

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The malaria life cycle has a ____ phase and a ______ phase

Human phase

Mosquito phase

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The human phase of the malaria life cycle begins with…

Injection of Plasmodium sporozoites (motile forms) through transmission of mosquito saliva during blood meal

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After sporozoites enter the human host, they…

Migrate to liver and asexual division known as schizogony cycle begins

Rapid cell division at this point

Life cycle form released from this phase are called MEROZOITES

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______ can infect other liver cells or RBCs

MEROZOITES (the products of schizogony)

This is called the Erythrocytic cycle

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Once in RBC, the MEROZOITE enlarges and undergoes a differentiation into a _______ cell termed a ___________.

Uninucleate

Ring Trophozoite

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As trophozoites age, they can develop into …

Amoeboid trophozoites

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The single nucleus trophozoite can also divide to produce a multinucleated form called a _______.

Schizont

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______________ are multinucleated cells that produce ___________.

Erythrocytic schizonts

Erythrocytic merozoites

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After infected RBCs rupture (spilling merozoites to invade new cells) _______ begins again or ______ is initiated

Schizogony (asexual)

Gametogony (sexual cycle)

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Some merozoites in erythrocytes develop into _______ and do not cause erythrocyte to rupture

Gametocytes (male or female)

Mosquito feeds and takes in gamers that lead to sexual reproduction within the mosquito

Sporozoites produced in the mosquito travel to salivary glands of the mosquito

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The malaria organism consumes…

Hemoglobin

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Fever and chills of malaria correspond to…

Release of pyrogens waste following rupture of RBCs

Pyrogens travel to hypothalamus and causes an increased thermal set point

Episodes of 1-2 hours of severe shivering and high fever follows

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__________ release intensifies malarial symptoms

Tumor necrosis factor (TNF) —> inflammation

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What are the SSx of malaria?

Fever
Gastric manifestations (N/V/D)
Headache
Back pain
Increased sweating 
Myalgia
Cough
ANEMIA (result of RBC destruction)
Vasodilation —> hypotension

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Untreated malaria cases may progress to …

Coma
Renal failure
Respiratory distress
Death

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__________ produces resistance to falciparum malaria

Sickle cell anemia

Thought is that the parasite has difficulty utilizing the abnormal hemoglobin

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___________ is a receptor for P. vivax merozoites that many African Americans and most West African’s lack

Duffy antigen (glycoprotein)

Makes them resistant to vivax malaria

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In 2010, 1691 cases of malaria were reported in the US. Most were linked to …

Travel to Africa

60% were falciparum, 20% vivax

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Central and South America and Asia is mostly _____ malaria

Vivax

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Benign Tertian Malaria is caused by…

Plasmodium vivax

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Plasmodium vivax tends to infect ________ erythrocytes

Young

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Fever and chills in vivax malaria are due to

Rupture of RBC schizonts

Relapses occur with vivax malaria as a result of...

The activation of liver hypnozoites Can be 3-5 years after initial disease

P. vivax is most prevalent in ...

The tropics - Latin America and Caribbean Rare in US Rare in West Africa

Vivax malaria accounts for ____% of world wide malaria

43%

How is P. vivax identified

Giemsa stain Enlarged infected RBCs with SCHUFFNER’S DOTS

What species causes Malignant Tertian Malaria

Plasmodium falciparum

P. falciparum causes __________.

High grade parasitemia - large numbers of parasites in blood RBCs of any age are affected

P. falciparum is virulent because ...

It multiplies rapidly Fever is very high due to number of parasites

High parasite numbers with P. falciparum can lead to ...

Black water fever High levels of free hemoglobin in urine Leads to autoimmune reaction in which the host destroys kidney tissue Chills, fever, rigor, dark to black urine

Falciparum malaria can lead to ____________ obstruction as infected RBCs tend to stick to ________.

Capillary obstruction | Capillary linings

Occlusion of capillaries with parasitized RBCs —> necrosis hemorrhages, extreme fever, mania, convulsions, and death

Cerebral malaria

Frequent vomiting in addition to other malaria symptoms

Gastric falciparum malaria

What is Algid malaria?

Skin is cold but internal temp is high (b/c of lack of BP)

How do you identify P. falciparum?

Erythrocytes with double or multiple ring stages, crescent shaped gametocyte, MAURER’S CLEFTS (not as obvious as Schuffner’s dots) Young trophozoites and gametocytes (but not schizonts) are observed in periphery

Untreated P. falciparum infections are often...

Fatal

Quartan malaria

Plasmodium malariae

Plasmodium malariae infects _______ erythrocytes

Older

How do you identify P. malariae?

Basket and band shaped trophozoites Rosette shaped schizonts

Species of plasmodium similar to vivax but common to west Africa

Plasmodium ovale

Zoonotic plasmodium species found in Southeast Asia

Plasmodium knowlesi May be life-threatening if a heavy parasite burden occurs

How is climate change affecting the fight against malaria?

Thought to change distribution pattern of malaria in the next 50 years New areas exposed to plasmodium No host resistance in these areas

Low incidence of vivax malaria in West Africa is due to many _________ persons, but organism is increasingly independent of binding to _______

Duffy negative Duffy antigen This is a research topic - potential target for new chemotherapy research

The main mechanism of resistance to malaria treatments is...

Efflux pumps Leading to multi-drug resistant parasites Now more expensive to treat and priced out of reach in many countries

Causative agent of Nantucket Island Fever

Babesia microti NIF aka Babesiosis

What is Babesiosis?

Infects RBCs, presents with malaria-like manifestation Prevalent in New England in warm months Vector - deer tick

Babesiosis has no significant rash but does have...

Small pinpoint lesions

Babesiosis is more problematic in what population?

Immunocompromised or asplenic patients

Babesiosis is often a co-infection with...

Lymph disease (because same type of vector)

How do you identify Babesiosis?

Morphology and clinical manifestations similar to P. falciparum (less severe) Form “CROSS-LIKE” RBCs******

What is the treatment for Babesiosis?

Clindamycin and quinine Control vectors with insect repellents

What are the three Trypanosomatid diseases?

African sleeping sickness: Trypanosoma brucei Chagas’ disease: Trypanosoma cruzi Leishmaniasis: Leishmania spp

Chaga’s disease is also known as...

American trypanosomiasis or American sleeping sickness

Chagas is prevalent in...

Mexico Central America South America In the US, it’s considered a Neglected Parasitic Infection by the CDC

What is the vector for Chagas?

Triatomine bugs (“kissing bugs”) They like to bite you in the face at night

Causative agent for Chagas’ disease

Trypanosoma cruzi Parasitic protozoan

What is the life cycle of T. cruzi?

Trypomastigotes passed in feces of triatomine bug (primarily at night) Trypomastigotes enter cells near inoculation site and differentiate in AMASTIGOTES Amastigotes replicate by binary fission in cells, different into trypomastigmotes and are released into circulation —> rupture host cells

What are the two stages of Chagas’ disease?

Acute | Chronic

Acute chagas ranges from ______ to ______

Asymptomatic to mild manifestation Non-specific SSx May see a CHAGOMA (bite on face)

Most characteristic sign of acute chagas is ...

Romaña’s sign (about 1/2 of cases) Swelling of the eyelid near the parasite entry site or where the organism was rubbed into eye

Chronic chagas may be asymptomatic for years, even for life , but complications include...

Cardiac complications (cardiomyopathy, HF, arrhythmias, sudden death) Intestinal complications, especially ORGANOMEGALY Usually have to remove spleen because of intense splenomegaly Heart complications more common than intestinal complications

How is chagas diagnoses?

Observation of parasite under microscopy Blood smear in acute phase will show TRYPOMASTIGOTES Biopsy in chronic cases will show AMASTIGOTES There are also serological tests and PCR test

How do you treat Chagas?

Antiparasitic Benznidazole - extremely toxic and not FDA approved; only available through CDC and must monitor kidney and liver functions

10 Malaria Flashcards

(66 cards)