Ch 35: Protozoal and Helminthic Infections Flashcards
What is meant by the phrase “anopheline mosquitoes”?
Any mosquitoes of the genus Anopheles; malaria is transmitted by female mosquitoes of this genus
What complications are associated with falciparum malaria?
cerebral malaria severe anemia hypotension pulmonary edema acute kidney injury hypoglycemia acidosis hemolysis
Which genus is responsible for nearly all severe malarial disease?
Plasmodium falciparum
Malaria is transmitted by the bite of…
….infected female anopheline mosquitoes.
During feeding, mosquitoes inject ________, which circulate to the _____, and rapidly infect hepatocytes, causing asymptomatic liver infection. _______ are subsequently released from the liver, and they rapidly infect erythrocytes to begin the ______ ______ stage of infection that is responsible for human disease. Multiple rounds of erythrocytic development, with production of merozoites that invade additional erythrocytes, lead to large numbers of circulating parasites and clinical illness.
sporozoites
liver
Merozoites
asexual erythrocytic
In P. vivax and P. ovale, parasites also form ______ _____ _______, which are not killed by most drugs, allowing subsequent relapses of illness after initial elimination of erythrocytic infections.
dormant liver hypnozoites
____ and ________ are not typical in malaria, and thus suggestive of another cause of fever.
Rash
lymphadenopathy
The risk for falciparum malaria is greatest within _ _____ of return from travel
2 months
Four species of the genus Plasmodium classically cause human malaria. They are…
Plasmodium falciparum
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae
Plasmodium _____ and Plasmodium _____ are much less common causes of disease, and generally do not cause severe illness.
ovale
malariae
Plasmodium ________, a parasite of _______ monkeys, is now recognized to cause occasional illnesses, including some severe disease, in humans in Southeast Asia.
knowlesi
macaque
Plasmodium falciparum is endemic in most malarious areas and is by far the predominant species in ______.
Africa
An acute attack of malaria typically begins with a prodrome of _____ and _____, followed by fever. A classic malarial paroxysm includes chills, high fever, and then sweats.
headache
fatigue
Seizures may represent simple _____ _____ or evidence of severe neurologic disease.
febrile convulsions
P falciparum infection uniquely infects erythrocytes of ___ ____ and mediates the ____________ of infected erythrocytes in small blood vessels, thereby evading clearance of infected erythrocytes by the ______.
all ages
sequestration
spleen
What uncommon disorder can result from immunologic responses to chronic infection with P. malariae?
Immune complex glomerulopathy with nephrotic syndrome
_____-_____ blood smears remain the mainstay of diagnosis, although other routine stains (e.g., _____ stain) will also demonstrate parasites.
Giemsa-stained
Wright
The severity of malaria correlates only ______ with the quantity of infecting parasites
loosely
High parasitemias (especially greater than \_\_ – \_\_% of erythrocytes infected or greater than \_\_\_\_\_\_ – \_\_\_\_\_\_ parasites/mcL) or the presence of malarial pigment (a breakdown product of hemoglobin) in more than _% of \_\_\_\_\_\_\_\_ is associated with a particularly poor prognosis.
10 - 20%
200,000 - 500,000
5% of neutrophils
Serologic tests indicate history of disease but are not useful for diagnosis of _____ _______.
acute infection
Symptomatic malaria is caused only by the ___________ stage of infection. Available antimalarial drugs act against this stage, except for _________, which acts principally against hepatic parasites.
erythrocytic
primaquine
The first-line drug for NON-falciparum malaria from most areas remains ________.
(some falciparum malaria is sensitive to chloroquine.)
chloroquine
Due to increasing resistance of P vivax to chloroquine, alternative therapies are recommended when resistance is suspected, particularly for infections acquired in ______, ______, and ______. These infections can be treated with _____-_____ combination therapies (ACTs) or other first-line regimens for P falciparum infections.
Indonesia
Oceania
South America
artemisinin-based
For P vivax or P ovale, eradication of erythrocytic parasites with ______ should be accompanied by treatment with ______ (after evaluating for glucose-6-phosphate dehydrogenase [G6PD] deficiency; see below) to eradicate dormant liver stages (hypnozoites), which may lead to relapses with recurrent erythrocytic infection and malaria symptoms after weeks to months if left untreated.
chloroquine
primaquine
