Malaria & Babesiosis

Front 1

Malaria:
Two main phases of the life cycle?

Back 1

– Sporogony - sexual multiplication in the mosquito to allow it to infect you

– Schizogony - asexual multiplication in you to allow it to infect a mosquito

Front 2

Steps of the malaria life cycle starting with the anopheles mosquito and ending in the blood? What is the name of this portion of the cycle?

Back 2

Exoerthrocytic schizogony:

1. anopheles mosquito bites human and injects sporozoites, which then travel to the liver

2. In the liver sporozoites develop asexually into schizonts

3. Schizonts rupture and release thousands of merozoites

4. merozoites enter circulation, bind to glycophorin on RBC and invade it

Front 3

In people who become infected with P. _____ or P. _____, a latent form of infection may develop in liver cells. These ‘dormant’ tissue schizonts are known as ________. These may reawaken weeks to months after the initial infection and lead to a relapse of malaria.

Back 3

In people who become infected with P. vivax or P. ovale, a latent form of infection may develop in liver cells. These ‘dormant’ tissue schizonts are known as hypnozoites. These may reawaken weeks to months after the initial infection and lead to a relapse of malaria.

Front 4

After the merozoites invade the RBC, what happens next and what is the name of this part of the cycle?

Back 4

Erythrocytic phase:

1. In the RBC merozoites develop into trophozoites

2. Trophozoites grow and enter the schizont phase.

3. The schizont ruptures and releases merozoites

Front 5

What occurs in the life cycle of plasmodium after the merozites are released from RBC? (Hint the bug bites again)

Back 5

1. Anopheles bites and ingests gametocytes

2. sexual reproduction occurs in the stomach of the mosquito and forms oocysts

3. Oocysts rupture into thousands of sporozites

Front 6

Malaria that repeats every other day is known as? What type(s) produce this cycle?

Malaria that repeats every third day is known as? What type(s) produce this cycle?

Back 6

Every other day = benign tertian malaria = P. vivax, P. Ovale, and P. falciparum

Every third day = benign quartan malaria = P. Malariae

Front 7

Where does P. Falciparum occur?

Back 7

In all areas of the world with malaria.

Intensity is highest in sub-Saharan Africa

Front 8

Where does P. vivax occur?

Where does P. ovale occur?

Where does P. Malariae occur?

Back 8

P. vivaX occurs everywhere eXcept West or Central Africa

P. ovale occurs only in West and Central Africa

P. malariae occurs in low levels everywhere malaria occurs

Front 9

Transmission requires the presence of four factors, what are they?

Modes of transmission?

Back 9

1. Human host
2. Malarial parasite
3. Female Anopheles mosquitoes
4. Appropriate environment

Transmission via female mosquito bite, transplacental, transfusions

Front 10

Host factors that influence incidence and severity of malaria? (4)

Back 10

1. Underlying immunity via IgA; complete immunity does not develop

2. Occupation, social behavior, migration

3. Heterozygotes for sickle cell

4. People who lack Duffy antigen are resistant to P. vivax

Front 11

Cerebral malaria, a frequently fatal complication of _______ infections, is due to the blockage of cerebral capillaries

Back 11

Cerebral malaria, a frequently fatal complication of falciparum infections, is due to the blockage of cerebral capillaries

Front 12

Severe intravascular hemolysis can result in ______ which may also precipitate acute renal failure.

Back 12

Severe intravascular hemolysis can result in hemoglobinuria (“blackwater fever”) which
may also precipitate acute renal failure.

Front 13

Prodromal symptoms of malaria

Back 13

malaise, myalgias, headache, anorexia, nausea, vomiting and low grade fever

Front 14

Symptoms of acute attack

Back 14

chills or rigors and then fever and sweating. Febrile stage lasts 2-6 hours and is followed by a period of intense sweating

Physical exam: fever, tachycardia, flushed skin, splenomegaly

Front 15

Severe complications of malaria (5)

Back 15

1. cerebral malaria = seizures and neurological deficits

2. Hypoglycemia

3. Severe anemia

4. jaundice

5. splenomegaly

Front 16

Definitive diagnosis of malaria depends on identification of the parasite on ?

______ have highest sensitivity for parasite detection.

______ are useful for species identification.

Back 16

Definitive diagnosis depends on identification of the parasite on Giemsa-stained blood smears.

Thick smears have highest sensitivity for parasite detection.

Thin smears are useful for species identification.

Front 17

What do you do when the initial smear is negative?

Back 17

If the initial smears are negative and there is a strong clinical suspicion of malaria, they
should be repeated in 12-24 hours for a total of three sets.

Front 18

Characteristics seen on smear to identify Plasmoidum species:

Back 18

1. Multiple ring forms within one cell
2. High-grade parasitemia (>10% of RBCs)
3. Appliqué forms: rings appearing on the periphery of the RBC
4. Schuffner dots

5. Enlarged RBCs
5. Schizonts: rarely seen

Front 19

RDTs?

Back 19

rapid diagnostic tests (RDTs) are immunochromatographic tests that utilize antibodies; high sensitivities

Front 20

Vector for Babesiosis? What is this also a vector for? reservoir?

Back 20

deer tick

also vector for Lyme and HGA

reservoir = many mammals (rodents, cattle, deer)

Front 21

Most cases of babesiosis in the US are caused by ?

Infections commonly occur where?

Back 21

Babesia microti

abesia microti infections are most common in the Northeast, (especially in Connecticut, Massachusetts, and New York) and upper Midwest.

In Massachusetts, about 85% of the cases are acquired on Nantucket, primarily between June and August.

Front 22

What is the pathogenesis of babesiosis

Back 22

protozoan parasite infects RBCs and causes hemolysis

Front 23

Clinical manifestations of babesiosis

Back 23

Mostly mild or subclinical.

malaise, rigors, fever, headache, myalgias, arthralgias, N, V, abdominal pain

Signs:f ever,petechiae/ecchymosis,jaundice, and mild hepatosplenomegaly

Front 24

Diagnosis of babesiosis is primarly made with?

Back 24

Giemsa- or Wright-smeared thin smears

Front 25

What is looked for on the blood smear? What rare formation is pathognomonic of babesiosis?

Back 25

Ring forms in RBCs

Tetra or maltese cross is pathognominic