Blood parasites Flashcards
How is Diphyllobothrium latum acquired?
By eating raw or undercooked freshwater fish infected with plerocercoid larvae.
Diphyllobothrium latum (Fish Tapeworm)
What unique clinical feature is associated with Diphyllobothrium latum infection?
Vitamin B12 deficiency, potentially causing megaloblastic anemia.
What is the treatment for Diphyllobothrium latum?
Praziquantel
Where is Diphyllobothrium latum most prevalent?
Scandinavia, Chile, Argentina, and occasionally the Great Lakes region of the US.
What are the clinical features of Babesia infection?
- Flu-like sxs
- Hemolytic anemia
- Juandice
- Fever
- Malaise
What are the histologic features of Babesia infection?
Babesia forms Maltese cross tetrads in red blood cells.
Tx for Babesiosis
Atovaquone and azithromycin
or
Clindamycin and quinine (severe cases)
What are the four species of Plasmodium that infect humans?
P. falciparum
P. vivax
P. ovale
P. malariae
What is the vector for malaria?
Female Anopheles mosquitoes
How do symptoms of malaria correlate with erythrocytic cycles?
Fever paroxysms align with RBC rupture and merozoite release (e.g., 48-hour tertian cycles for P. vivax).
What is the most severe complication of P. falciparum?
Cerebral malaria
Causing coma, convulsions, and high mortality
What distinguishes recrudescence from relapse in malaria?
Recrudescence occurs from latent RBC merozoites
Relapse originates from dormant liver hypnozoites.
What is the hallmark microscopic finding of P. falciparum?
Banana-shaped gametocytes in blood smears
What are the stages of malaria symptoms?
Cold stage (shivering, fever onset)
hot stage (high fever, nausea),
sweating stage (profuse sweating, exhaustion)
What complication is characterized by “blackwater fever”?
Acute intravascular hemolysis, leading to dark urine from free hemoglobin
Caused by P. falciparum
Why is malaria particularly dangerous during pregnancy?
It causes placental cytoadherence, leading to fetal growth restriction, low birth weight, and increased maternal mortality.
What is the gold standard for diagnosing malaria?
Giemsa-stained blood smears.
How is Babesia confirmed
Via PCR, serology, or detection of Maltese cross formations in RBCs
What unique feature allows P. falciparum to cause cerebral malaria?
Cytoadherence of infected RBCs to brain capillaries via ICAM-1 and other receptors.
What virulence factor allows Diphyllobothrium latum to cause vitamin B12 deficiency?
Its high affinity for absorbing vitamin B12 in the intestines
How does P. vivax cause relapses of malaria?
By reactivating dormant hypnozoites in the liver
Describe the life cycle of Diphyllobothrium latum
Humans ingest infected freshwater fish → larva attaches to the small intestine → matures into an adult worm → eggs released in feces → eggs develop in water → copepods ingest larva → fish consume copepods → humans eat fis
Vitamin B12 deficiency leading to megaloblastic anemia, with symptoms such as fatigue, mild diarrhea, and anemia.
Parasitic infection from hematology block
clinical manifestation of Diphyllobothrium latum infection
What is the treatment of choice for Diphyllobothrium latum
Praziquantel
What is a distinguishing complication of ingesting an intermediate larval stage of Diphyllobothrium latum?
Formation of nodules under the skin, mistaken for tumors, that may require surgical removal.
What is the life cycle of Babesia in humans?
Ticks introduce sporozoites into the bloodstream → sporozoites infect RBCs → transform into merozoites → rupture RBCs → infect new RBCs. Occasionally, gametocytes form in humans.
Name the four species of Plasmodium that infect humans and their associated periodicity.
Two main life cycles of Plasmodium
Sporogony - sexual reproduction in mosquitoes
Schizogony - asexual reproduction in humans (liver and erythrocytic stages)
What is cerebral malaria, and what causes it?
A severe complication of P. falciparum caused by cytoadherence of infected RBCs to brain capillaries, leading to oxygen deprivation
What is the treatment for chloroquine-resistant P. falciparum?
Artemisinin-based combination therapy (ACT)
Recrudescence vs. relapse in malaria
Recrudescence occurs from latent parasites in RBCs (P. falciparum, P. malariae), while
relapse originates from dormant hypnozoites in the liver (P. vivax, P. ovale).
What is the epidemiological significance of P. falciparum?
It causes the most severe disease and highest mortality among the Plasmodium species, particularly in sub-Saharan Africa.
Why is P. vivax associated with relapse?
Hypnozoites remain dormant in the liver and can reactivate months or years later.
What is blackwater fever?
A complication of P. falciparum involving massive hemolysis, leading to hemoglobinuria and kidney damage
What stage of Diphyllobothrium latum is infectious to humans?
Plerocercoid larvae.
What receptors are involved in placental malaria?
Chondroitin sulfate A and hyaluronic acid
What is the unique feature of Diphyllobothrium latum eggs?
Eggs must reach freshwater to continue the life cycle.
Plasmodial resistance to chloroquine
Due to decreased accumulation of drug in parasite food vacuole
What drug should be given to eradicate schizoites and latent hypnozoites in a patient’s liver?
Primaquine
Which drug used in malaria treatment is MOST likely to be associated with an
acute hemolytic reaction in patients with glucose-6-phosphate-dehydrogenase deficiency?
Primaquine
D. Nifurtimox
D. Interference w/ polymerization of heme into hemozoin
D. Decreased conversion of heme into hemozoin
D. G6PD deficiency
D. Atovaquone-proguanil
A. Primaquine
DOC for Tx of Leishmaniasis
Sodium stibogluconate
QT prolongation
Cinchonism
An entire constellation of
symptoms comprised of:
tinnitus
high-tone deafness
visual disturbances,
headache
dysphoria
vomiting
postural hypotension
QT prolongation
rashes
increased LFTs
blindness/blurred vision
optic neuritis
Associated w/ quinine Tx
How are Diphyllobothrium infections most commonly identified?
By finding proglottid segments in the stool
Severe cases of babesiosis primarily cause which disease type?
C) Hemolytic anemia
Diphyllobothrium is classified as which group of parasites?
Cestode
Tapeworm
What is a histologic finding that can be used to distinguish malarial infection from babesiosis?
The presence of four intracellular trophozoites w/i RBC
Which genus and species of malaria is most commonly the most severe?
Plasmodium falciparum
Babesiosis is transmitted by what vector?
Tick
Which peculiar characteristic is associated with Diphyllobothrium infections?
Vitamin deficiency
Paritcularly B12 - can cause megaloblastic anemia
E. Scandinavia
B. RBCs
A. Small mammals (mice)
Neccessary for reproduction (similar to Lyme)
D. Intermitten or constant fever
Characterizes the erythrocytic cycle of malarial infection
Which malarial causing organism has an irregular erythrocytic cycle
P. falciparum (irregular tertian cycle)
B. P. ovale and P. vivax
B. The invasion, development of new sporozoites, and release from RBCs
D. The extremely high parasitism
(increased number of parasites)
D. Cerebral malaria
