Parasitology: Midterm 3 (Malaria)

___________________ is one of the most severe neurological complications of malaria caused by P. falciparum involving sequestration with the brain and encephalopathy (accounts for approximately 1 million deaths of children in sub-saharan Africa annually)

cerebral malaria

What demographic has the highest malaria related mortality

children

the non-photosynthetic apicoplast organelle is derived via secondary endosymbiosis by a

cyanobacterium

Vectors of Haemosporidians are blood sucking _____________ insects

dipteran (Diptera is one of the major insect orders and of considerable ecological and human importance. )

Which Plasmodium species has a crescent shaped gametocyte?

falciparum

Which of the 3 main human plasmodium causes cerebral malaria?

falciparum

which of the main 3 human plasmodium are mainly in tropical and subtropical regions?

falciparum

which of the 3 main human plasmodium do not relapse?

falciparum and malariae

Which of the main 3 species of human plasmodium is most pathogenic?

falciprum

T/F Margination and knob adherence are 2 complications of P. vivax infection

false. Margination and knob adherence are complications with P. falciparum infection

Humans colonized Hawaii in the 13th century. At the time there were no mosquitos, thus no malaria. Mosquitos were introduced in ~ 1820 by non-native birds infected with Plasmodium relictum. House mosquitos distributed from the coast all the way up to 6,000 feet elevation. Lowland species of birds declined rapidly. What role do feral pigs play?

feral pigs make wallows while foraging in which water collects and mosquitos can lay eggs

Life Cycle of Plasmodium falciparum (MOSQUITO): An uninfected mosquito ingests __________________ when she feeds on infected Swedish blood

gametocytes

Life Cycle of Plasmodium falciparum (MOSQUITO): Once ingested, gametocytes undergo _______________ to form male gametes, and then fertilization takes place giving rise to the _________________. Where in the mosquito is this taking place?

gametocytes undergo exflagellation, fertilize, and give rise to the zygote. This is taking place in the gut of the mosquito.

Preliminary results suggest that SPECIALIST / GENERALIST parasites increase in prevalence with deforestation

generalist

_____________ is often called malaria pigment. Free heme is toxic to cells, so the malaria parasites convert it to an insoluble crystalline form that can be seen as dark spots within infected rbcs.

hemozoin

production of _______________ allow for malaria relapse to occur

hypnozoites

Plasmodium has an INDIRECT / DIRECT life cycle

indirect

Malaria causing parasites are EXTRACELLULAR / INTRACELLULAR

intracellular parasites

Why is it hard to create new malaria drugs?

malaria is difficult to isolate and grow in a lab

which of the 3 main human plasmodium are least pathogenic?

malariae

match each human plasmodium to its fever cycle: 1. malariae A. benign tertian 2. vivax B. malignant tertian 3. falciparum C. quartan malaria

malariae = quartan malaria (4 fevers within 72 hours) vivax = benign tertian (3 fevers every 48 hours) falciparum = malignant tertian (3 fevers every 48 hours)

Life Cycle of Plasmodium falciparum (HUMAN): Once released, merozoites penetrate ________________ and undergo further rounds of asexual reproduction (called the ____________________) giving rise to more merozoites. Some infected cells cease asexual reproduction and instead develop from _________________ into ______________________ and circulate in the blood.

merozoites penetrate red blood cells and undergo further asexual reproduction (called the erythrocytic cycle). Some infected cells cease asexual reproduction and instead differentiate from trophozoites into gametocytes and circulate in the blood to infect more mosquitos.

Life Cycle of Plasmodium falciparum (MOSQUITO): Once in the hemocoel of the mosquito, the ookinete gives rise to an ____________.

oocyst

The merozoite is enveloped by a ________________________ and brought into the RBC

parasitophorous vacuole

Life Cycle of Plasmodium falciparum (HUMAN): __________________ are released into the human during the mosquitos blood meal, which enter the blood and penetrate the _____________ cells. This begins the asexual propagative stage known as ____________________

sporozoites are released, enter the blood and penetrate the liver cells. This begins the asexual propagative stage known as the exo-erythrocytic cycle

Life Cycle of Plasmodium falciparum (HUMAN): Sporozoites penetrate the liver cells and undergo asexual reproduction within the cells. This gives rise to _________________.

sporozoites reproduce within the liver cells giving rise to schizonts.

Life Cycle of Plasmodium falciparum (MOSQUITO): Within the hemocoel, the oocysts undergoes __________________. Once released, the __________________ migrate to the salivary glands of the mosquito. The mosquito will now go on to infect our human model via saliva while blood feeding.

the oocyst undergoes sporogony giving rise to sporozoites that migrate to the salivary glands of the mosquito.

P. falciparum ________________ produce proteins that are deposited in and on rbc membranes promoting adherence to endothelial cell receptors.

trophozoites

T/F Anemia in infants infected with P. vivax can be life-threatening.

true

T/F Effects of malaria on wildlife is not as well understood as the effects of malaria on humans

true

T/F P. falciparum also triggers extreme inflammatory responses and extreme rbc lysis

true

T/F Trophozoites, gametocytes, and schizonts/segmenters can all be seen in P. malariae and P. vivax infection

true

T/F when deciding on medications for treating malaria, you most consider erythrocytic and exoerythrocytic stages

true

T/F: P. malariae does not relapse, but can survive at low parasitemia for many years, causing disease many years later (aka recrudescence).

true

Which of the main 3 species of human plasmodium is most widely distributed?

vivax

which of the 3 human plasmodium is found in both tropical and temperate climates?

vivax

Life Cycle of Plasmodium falciparum (MOSQUITO): Still within the mosquitos gut, the zygote develops into an _______________ which then penetrates to gut epithelium and migrates into the hemocoel.

zygote develops into the ookinete and penetrates the gut epithelium

List the plasmodium species to its proper merozoite rbc invasion behavior: 1. merozoites invade mature/older rbcs 2. merozoites only invade young rbcs 3. merozoites can invade rbcs of any age

1 = P. malaria 2 = P. vivax 3 = P. falciparum

List the top 3 Haemosporidia diseases threatening birds (The Haemosporida (sometimes called Haemospororida) are an order of intraerythrocytic parasitic apicomlexans)

1. Haemoproteus spp 2. Plasmodium spp 3. Leucocytoprozoon

List the 3 main species of human plasmodium

1. P. falciparum 2. P. vivax 3. P. malariae

List 6 ways in which deforestation alters patterns of avian infectious disease

1. global climate change 2. altered microclimates 3. loss of biodiversity 4. loss of immune health 5. altered vector ecology 6. altered migration patterns

You dissect a mouse with chronic P. berghei infection. Its liver and spleen are enlarged and darkly discolored. 1. what is responsible for the enlargement, and 2. what is responsible for the discoloration?

1. growth of fixed macrophages cause heptospleenomegaly 2. hemozoin causes discoloration

List the 2 most effective means of malaria control ( in order of most to lesser effective)

1. insecticide mosquito nets 2. residual indoor insecticide spray

Exoerythrocytic cycle was discovered in what year?

1938

What is the incidence for human malaria?

200 million/year

What percent of tropical forests still remain in Africa?

23%

Approximately _______% of birds are infected with malaria parasites

30%

What is the prevalence of Plasmodium malariae infection?

4-40%

P. vivax is responsible for approx. ______% of all human cases of malaria

40%

How long is P. vivax erythrocytic cycle?

48 hours

P. falciparum is responsible for approx. _______% of all human malaria cases.

50%

Lack of Fya and Fab blood group receptors allow for ________% of West Africans to be refractive to infection of Plasmodium _____________.

50% of West Africans are refractive to infection of Plasmodium vivax

what is mortality for human malaria in 2013?

584,000

_________% of P. vivax cases occurs in Asia and Latin America (approx. _____ cases/year)

65% (approx. 75 million cases/year)

P. malaria is responsible for approx. ______% of all human cases of malaria

7%

How long is the P. malariae erythrocytic cycle?

72 hours

_____% of P. falciparum cases occur in Africa (approx. _____ million cases/year)

98% (approx. 100 million cases/year)

What is the annual rate of deforestation in subsaharan nations?

>5%

What is AMA-1?

Apical Membrane Antigen-1 (AMA-1) is on the surface of the apicomlexan merozoite that interacts with the RON2 RBC receptor allowing for the merozoite to invade the cell

What phylum do malaria causing parasites belong?

Apicomplexa

__________________ is a severe complication of malaria caused by P. falciparum in which hemoglobin is released directly into the blood vessels and into the urine, frequently leading to kidney failure.

Blackwater fever

Who, in 1880 first described blood states of Plasmodium falciprum?

Charles Laveran

Synthetic drugs for malaria treatment trace their history to WWII and Japanese control of ______________ tree plantations (the source of _____________)

Cinchona trees, the source for quinine

_______________ refers to a population increase or population explosion that occurs when a species is freed from limiting factors in its environment.

Ecological release

What causes fevers in malarial infections?

Fever is the immune response to lysing RBC's releasing merozoites

Plasmodium sexual cycle ONLY takes place in VERTEBRATES / INVERTEBRATES

INVERTEBRATES

What life stage of plasmodium invades the red blood cells

Merozoite

Life Cycle of Plasmodium falciparum (HUMAN): Eventually the schizont ruptures releasing ____________________.

Merozoites

How is malaria in birds diagnosed?

Microscopy PCR Sequencing

P. falciparum and P. vivax both have tertian fever periodicity, both having fevers on day 1 and day 3. Which has a longer fever and why?

P. falciparum has a longer fever than P. viva due to the sequestered infected cells lining the endothelium of the blood vessels.

What industry is responsible for a major amount of deforestation?

Palm Oil Industry

What is the most important infectious disease agent in tropical countries?

Plasmodium falciparum

Which species malaria is adherence and blockage of capillaries leading to anoxia (ie. cerebral malaria) an important aspect?

Plasmodium falciparum

Which human plasmodium species has multiple ring stages

Plasmodium falciprum

Plasmodium lucens is a generalist parasite. Plasmodium megablogularis is a specialist parasite. If their habitat is "disrupted" (ie deforested), which Plasmodium will thrive?

Plasmodium lucens

You view a schizont under a microscope and count 8 nuclei within the infected rbc. what species Plasmodium is it?

Plasmodium malariae (8-12 nuclei)

Which human plasmodium species has only 1 ring stage?

Plasmodium vivax

Which species of human Plasmodium has hypnozoites?

Plasmodium vivax

You look at a blood smear and see a trophozoite that is much larger than the surrounding rbcs. what species is the Plasmodium?

Plasmodium vivax

You view a schizont under a microscope and count more than 12 nuclei within the infected rbc. what species Plasmodium is it?

Plasmodium vivax (>12 nuclei)

Apicomplexan Structures: The ____________ and ________________ structurally reinforce the anterior (penetration) and of the Apicomplexan.

Polar ring conoid

Apicomplexan Structures:" _________________ and ___________________ are secretory structures whose contents discharge to the outside and aid in penetration of the cell.

Rhoptries micronemes

Who, in 1897 discovered a stage of the parasite in Anopheles mosquitoes, providing an hypothesis for transmission?

Ronald Ross

Where in humans and in what cycle are hypnozoites made?

The exoeurythrocytic cycle within the liver

T/F A high percentage of the population that is infected with malaria is asymptomatic

True

T/F About half of all humans who have ever lived have died from malaria

True

T/F Epidemic malaria in agricultural areas around Rome contributed to population declines and fall of the Roman Empire

True

T/F Experimental transmission of human malaria by mosquito by Amigo Bignami and Giovanni Grassi

True

T/F Malria symptoms are very similar to the flu. For instance, headache, fever, fatigue, muscle/back pain, chills, sweating, dry cough, nausea, vomiting

True

T/F Most malaria causing species have both asexual and sexual reproduction

True

T/F Non-human primates can be infected by falciprum, vivax, and malariae but the role in epidemiology of human infections is less certain

True

T/F Plasmodium are blood parasites of mammals, birds, and reptiles

True

T/F only 1 infected red blood cell out of 20,000 red blood cells in P. malariae

True, very low parasitemia and very slow to develop and detect

T/F It is rare to find a schizont or segmenter in a typical P. falciparum infection.

True. One will typically only see the ring stage trophozoite and/or gametocyte

Asexual division and precursors of gametes occur in the VERTEBRATE / INVERTEBRATE host

VERTEBRATE

Why is it important to know what species Plasmodium infection has occurred when deciding treatment?

Vivax has the hypnozoites within the liver that require a different medication

What is the exoerythrocytic cycle?

another asexual life cycle within the liver

TEM reveals that malaria causing species all have ___________________________ involved in host cell recognition, attachment, and penetration

apical complex

What does malaria literally mean?

bad air (people thought swamp vapors led to the disease)