MICRO 460 parasitology lectures_exam 1

Which Plasmodium causes periodicity of attacks Q72h?

"quartan" malaria P. malariae

Which Plasmodium causes periodicity of attacks Q48h?

"tertian" malaria P. falciparum P. vivax P. ovale

Apicomplexa: definition

A protist taxonomic grouping that shares a structural feature: "apical complex of microtubules within the cell" Structure allows the parasite to enter a host cell

A patient diagnosed with relapsing malaria presents with a fever of 100.8 F (38 C). The healthcare provider understands that the fever in this patient is caused by which of the following mechanisms? A. Release of inflammatory cytokines B. Dysfunction of the hypothalamus C. Presence of malarial endotoxins D. High concentration of viral particles

A. Release of inflammatory cytokines

Plasmodium falciparum attack what stages of RBC?

All stages

malaria is associated with what vector?

Anopheles mosquito sting insert like "syringe"

The healthcare provider is caring for a patient diagnosed with malaria. Before administering primaquine (Aminoquinoline), which of these laboratory data should the healthcare provider obtain? A. Erythrocyte sedimentation rate (ESR) B. Glucose-6-phosphate dehydrogenase (G6PD) screen C. Activated partial thromboplastin time (aPTT) D. Complete blood count (CBC) with differential

B. Glucose-6-phosphate dehydrogenase (G6PD) screen

Which of these measures should be included in the plan of care of a patient who is diagnosed with complicated malaria? A. Prepare the patient for an exchange transfusion B. Monitor pedal pulses closely C. Monitor the patient's blood glucose levels D. Adhere to strict contact precautions

B. Monitor pedal pulses closely

Babesia species that causes disease?

B. microti B. divergens B. duncani

The healthcare provider is teaching a student about malaria and its mode of transmission. Which of the following statements made by the student would indicate a *need for additional teaching*? A. "Sometimes a patient can contract malaria from a transfusion of contaminated blood products." B. "If a patient receives an organ transplant from infected donor, the patient may contract malaria." C. "A bite from the deer tick is the most common mode of transmission." D. "It's possible for malaria parasites to get into the placenta and infect the developing fetus."

C. "A bite from the deer tick is the most common mode of transmission."

Assessment findings for a patient include: temperature 101.4 F (38.7 C), chills, and muscle aches. The patient states that the fever began during a return trip from Central America. Which additional assessment finding would be consistent with a diagnosis of uncomplicated malaria? A. Altered level of consciousness (LOC) B. Decreased urine specific gravity C. Enlarged spleen D. Petechiae

C. Enlarged spleen

Toxoplasmosis definitive host

Cat (carnivore) → eats meat with tissue cysts→sporozoites excyst→ enter cat intestinal endothelium → short asexual cycle (10 d) →sexual cycle → excrete non-infectious oocysts maturation in soil → infective oocysts!

A patient diagnosed with malaria has developed anemia. When reviewing the patient's laboratory report, which of these red blood cell characteristics should the healthcare provider anticipate? A. Large and pale B. Small and pale C. Large and varying in shape D. Normal size and color

D. Normal size and color

P. vivax requires ______ blood group to penetrate RBC?

Duffy blood group rare in West Africa, thus fewer P.vivax infections

Pre-patent period

From infection to first laboratory appearance of a disease. In malaria, the time until the first appearance of parasites in the blood

merogony (schizogony) in lifecycle of protozoa

Intermediate host = asexual cycle

Babesia vector

Ixodes scapularis (ticks)

Babesia spp. are transmitted to humans by hard ticks that also transmit ________.

Lyme disease

Toxoplasmosis life cycle

Obligatory intracellular parasite.

Cerebral malaria, due to ________, can result in coma and death if not treated

P falciparum

Which plasmodium is ALWAYS present in *circulating blood* or can be *sequater along endothelial cells*?

P. FALCIPARUM

Gametocytes of ________exhibit a delayed appearance of at least 10 days after the onset of the disease.

P. falciparum

Which Plasmodium causes jaundice, hepatosplenomegaly, tachypnea?

P. falciparum

Which Plasmodium species is most aggressive?

P. falciparum Fearsome: infects all erythrocytes

Which Plasmodium infection causes the most severe pathology?

P. falciparum - severe hemolysis, multi-organ failure, brain involvement (encephalopathy) -> coma -> death. Also still birth, low birth weight

Plasmodium brasilianum resembles _______

P. knowlesi

Which Plasmodium causes periodicity of attacks Q24h?

P. knowlesi

Plasmodium knowles resembles _______

P. malariae

Which Plasmodium species only infects old RBC?

P. malariae

Plasmodium cynomolgi resembles _______

P. vivax

Which Plasmodium species can hide in the hepatocyte as a hypnozoite?

P. vivax

Which Plasmodium species cause relapses (hint: hypnozoites in liver)?

P. vivax P. ovale

Which Plasmodium can have LONG incubation period?

P. vivax P. ovale P. malariae in liver-stage infeciton

Relapse malaria?

P. vivax P. ovale reappearance of erythrocytic parasite forms by release of exo-erythrocytic forms (hypnozoites) from the liver

Which Plasmodium species only infects young RBC?

P. vivax P. ovale vivacious infect young RBC

Which plasmodium is ALWAYS present in *circulating blood*?

P.VIVAX P. OVALE P. MALARIAE P. KNOWLESI

Recrudescence malaria?

P.falciparum, P.malariae, P.knowlesi Sub-patent parasitemia that becomes patent again

malaria is caused by 4 hemoprotozoa

PLASMODIUM FALCIPARUM P.VIVAX P. OVALE PL. MALARIAE P. KNOWLESI

Which of phylum Apicomplexa species would infect humans?

Plasmodium Babesia Cryptosporidium Cystoisospora Cyclospora Sarcocystis Toxoplasma

Which Plasmodium species only has erythrocytic forms (ring form only) in the peripheral blood? Why?

Plasmodium falciparum Other forms are attached to vessel walls or in tissues

Toxoplasmosis etiology

Toxoplasma gondii (apicomplexan)

Can transfusion cause malaria?

YES, only in red cell forms do NOT cause liver form

What is bebesiosis?

a disease caused by an apicomplexan parasite that infects red blood cells and is *tickborne*. Humans are an accidental, dead-end host. "malaria in New England area"

Vector (mosquito) control is one way to control and eliminate malaria. Which of these is NOT a vector control technique? a. Leaving out old tyres b. Spraying insecticidal compounds inside homes c. Introduction of larvae-eating fish to lakes and ponds d Use of bednets impregnated with insecticides

a. Leaving out old tyres

Black water fever is a special manifestation of malaria caused by; a. P. falciparum b. P. malariae c. P. ovale d. P. vivax

a. P. falciparum Blackwater fever (BWF) is a severe clinical syndrome, characterized by intravascular hemolysis, hemoglobinuria, and acute renal failure caused by a variety of factors in patients with P. falciparum infestation

Trophozoites, Schizonts and gametocytes of all the malarial parasites are seen in the peripheral blood smear EXCEPT; a. P. falciparum b. P. malariae c. P. ovale d. P. vivax

a. P. falciparum Schizogony occurs inside the capillaries of the internal organs (spleen, liver and Bone marrow) hence only the ring form (but not the growing trophozoites and schizonts) are found in the peripheral blood

The infectious agent that causes malaria is known as which of the following? a. Protozoan parasite b. Bacterial parasite c. Viral parasite d. Fungal parasite

a. Protozoan parasite

Which of the following statement(s) regarding Plasmodium falciparum are true? a. causes more severe disease in pregnancy b. is associated with recurrent relapses after initial treatment because of liver hypnozoites c. is the only malarial parasite causing greater than 20% parasitaemia d. infection is typically associated with thrombocytopenia e. is the only cause of cerebral malaria

a. causes more severe disease in pregnancy c. is the only malarial parasite causing greater than 20% parasitaemia d. infection is typically associated with thrombocytopenia - Hypnozoite is responsible for relapse of malaria in P. vivax and P. ovale infections. - Plasmodium falciparum and Plasmodium malariae do not have a dormant liver stage. Usually cerebral malaria is caused by P. falciparum, and rarely, cerebral malaria occurs during the course of P. vivax infection.

P. malariae: attacks what stages of RBCs?

aged (senescent) RBCs

Apicomplexan structure

apical polar ring

Which mosquito genus is associated with spreading the human malaria parasite? a. Culex b. Anopheles c. Aedes d. Lutzia

b. Anopheles

The malaria parasite is spread by which of the following? a. Male mosquitoes b. Female mosquitoes c. Both male and female mosquitoes

b. Female mosquitoes

Which of these statements is incorrect? a. Malaria was once endemic in Europe b. Only humans can suffer from malaria c. Tonic water was used as a prophylactic against malaria d. The sickle cell gene mutation offers some protection against malaria

b. Only humans can suffer from malaria many different animals including birds, bats and monkeys.

After sporozoite gain entrance to human body it undergoes developmental cycle first in liver than in RBC, only after which fever is seen. This incubation period varies between plasmodium species, and .............. species has longest incubation period. a. P. falciparum b. P. malariae c. P. ovale d. P. vivax

b. P. malariae *Benign quartan* (with a fever every 3rd day) malaria is caused P malariae whereas *Benign tertian* (with a fever every 2nd day) is caused by P vivax and P ovale and *Malignant tertian* is caused by P falciparum.

Gold standard of detecting malaria?

blood smears X3

Which of these statements is correct? a. Malaria is a neglected tropical disease b. If you get malaria once, you won't get it again c. Malaria is quite often endemic in poorer regions of the world

c. Malaria is quite often endemic in poorer regions of the world

Patients usually respond well to treatment with quinine and ________ (hint: antibiotic)

clindamycin

Mosquitoes is/are the vector in the following disorder(s) a. Onchocerciasis b. Visceral leishmaniasis c. African trypanosomiasis d. Bancroftian filariasis

d. Bancroftian filaria Vector of Onchocerciasis is blackfly (Simulium damnosum) whereas that of Visceral leishmaniasis is Sand Fly (Phlebotomus argentipus). Trypanosomiasis is transmitted by a blood sucking insect, tsetse fly.

Cats are the only _______ host for Toxoplasma. All other infected animals are __________ hosts

definitive intermediate

sporogony in lifecycle of protozoa

definitive host = sexual cycle

Which one of the following are NOT antimalarial compounds? a. Quinine b. Artemisinin c. Chloroquine d. Mefloquine e. Penicillin

e. Penicillin

Sexual reproduction of T gondii occurs only in the intestinal tract of _________, most commonly in the domestic cat

felines the only definitive host

Humans are infected by many zoonotic spp. of Cryptosporidium and Cryptosporidium hominis, which only infects _______.

humans

Severe cases of malaria can have what symptoms?

hypoglycemia anemia resp distress cerebral malaria

Babesiosis etiology

intra-erythrocytic protozoan Babesia microti (USA), B. divergens (Europe)

Un- or undertreated P. vivax and P. ovale infections exhibit RELAPSES from the ________

liver hypnozoites

A marine soldier returns from Africa feeling ill with flu-like symptoms and 10 days later has bouts of fevers, chills, and heavy sweating every other day. His urine is darker than usual and he has jaundice and splenomegaly. What disease?

malaria trigger words: paroxysms of fever and chills ring form cyclic disease

Apicomplexa: causes what diseases

malaria toxoplasmosis coccidioses

Babesia spp

maltese cross

Apicomplexan lifecycle

merogony (asexual) amplify ↓ gametogony (sexual) ↓ Zygote ↓ sporogony (asexual)

malaria life cycle

mosquito delivers sporozoites, merozoites develop in liver and infect RBC, become trophozoites and then schizont before releasing merozoites - infected RBC also develop gametocytes that infect mosquito during blood meal.

malaria is transmitted by _______ (insect) to man

mosquitoes (definitive host for sexual cycle) men (intermediate host for axesual cycle)

How is Babesie differ from Plasmodium infection?

no liver stage straight into RBC no parasitophorous vacuoles no pigment no travel history

Toxoplasma gondii is an ________ parasite transmitted to humans from felines.

obligate intracellular

sub-patent parasitemia

parasitemia below the microscopic threshold.

hemoprotozoa

protozoa found in blood

Un- or undertreated P. FALCIPARUM, P. malariae and P. knowlesi exhibit _________

recrudescences

Relapse

recurrence of asex. para. from hypnozoite(s) after earlier elimination of iRBC stages

Recrudescence

recurrence of asex. para. which (for any reason) originates from the same parasites responsible for the initial illness.

Recurrence

renewed asex. para., which is easily recognized if blood stages appear following drug treatment (can be due to new infection, relapse or recrudescence)

Babesiosis life cycle

rodent -> tick -> rodent (B. microti), cattle -> tick -> cattle (B. divergens) NO EXO-ERYTHROCYTIC FORMS like liver forms in malaria - Sexual cycle (sporogony) in tick. - Asexual cycle (merogony) in mammalian host. - Gametocytes of Babesia in mammalian host cannot be differentiated from ring forms.

Babesiosis reservoir

rodents (B. microti) cattle (B. divergens)

Intervals of fever and chill cycles are related to the types of RBC infected by the Plasmodium spp and induced by the __________ of the infected RBC and _______ of inducers of inflammation

synchronous lysis release

Babesiosis diagnosis

thin and thick blood smears

How is malaria diagnosed?

thin and thick blood smears

Cryptosporidium oocysts are highly resistant to most commonly used disinfectants (chlorine), accounting for numerous _______outbreaks.

waterborne

Toxoplasmosis distribution

world wide

Babesiosis distribution

world wide zoonotic disease. In U.S. - NE and upper midwest

P. vivax and P.ovale infect _____ RBC, paroxysms at ____ hour intervals

young 48 hour

P. vivax: attacks what stages of RBC?

young RBC "voracious to youngs"

P. ovale: attacks what stages of RBC?

young RBC West Africa

Plasmodium knowlesi is a _______ (zoonite/anthro) malarial species

zoonotic

What are best ways to prevent malaria?

• 35% DEET (ankle, wrist) • long sleeves • Insecticide-treated bed nets combined with indoor spraying dramatically reduces morbidity and mortality'

What is the vector for malaria?

• female Anopheles mosquito (sexual cycle) • [blood transfusion]

P. falciparum infects all RBC - paroxysms at _____ hours or continual symptoms.

36 - 48 hours also called *tertian malaria*

Approximately ______ % of the world's population is serologically positive for this infection

50%

Babesiosis prevention/control

- Prompt removal of tick (infection occurs late in blood-meal (24-36 hrs)) - Minimize amount of exposed skin. - Apply repellents - Screening of blood donors

Vector and transmission of babesiosis

- hard bodied ticks (Ixodes) - no transmission from man to man by tick bites - blood transfusion

What is the diagnosis for malaria?

- thin and thick blood smear If clinical suspicious but smear negative, *REPEAT thick/thin smears Q4-6 hrs for 48 hr* (of particular importance for P. falciparum infections)

Where do you find P. knowlesi? Which plasmodium does it *resemble*?

South East Asia P. malariae