Ch 35: Protozoal and Helminthic Infections

Question 1

What is meant by the phrase “anopheline mosquitoes”?

Answer 1

Any mosquitoes of the genus Anopheles; malaria is transmitted by female mosquitoes of this genus

Question 2

What complications are associated with falciparum malaria?

Answer 2

cerebral malaria
severe anemia
hypotension
pulmonary edema
acute kidney injury
hypoglycemia
acidosis
hemolysis

Question 3

Which genus is responsible for nearly all severe malarial disease?

Answer 3

Plasmodium falciparum

Question 4

Malaria is transmitted by the bite of…

Answer 4

….infected female anopheline mosquitoes.

Question 5

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.

Answer 5

sporozoites
liver
Merozoites
asexual erythrocytic

Question 6

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.

Answer 6

dormant liver hypnozoites

Question 7

____ and ________ are not typical in malaria, and thus suggestive of another cause of fever.

Answer 7

Rash

lymphadenopathy

Question 8

The risk for falciparum malaria is greatest within _ _____ of return from travel

Answer 8

2 months

Question 9

Four species of the genus Plasmodium classically cause human malaria. They are…

Answer 9

Plasmodium falciparum
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae

Question 10

Plasmodium _____ and Plasmodium _____ are much less common causes of disease, and generally do not cause severe illness.

Answer 10

ovale

malariae

Question 11

Plasmodium ________, a parasite of _______ monkeys, is now recognized to cause occasional illnesses, including some severe disease, in humans in Southeast Asia.

Answer 11

knowlesi

macaque

Question 12

Plasmodium falciparum is endemic in most malarious areas and is by far the predominant species in ______.

Answer 12

Africa

Question 13

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.

Answer 13

headache

fatigue

Question 14

Seizures may represent simple _____ _____ or evidence of severe neurologic disease.

Answer 14

febrile convulsions

Question 15

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 ______.

Answer 15

all ages
sequestration
spleen

Question 16

What uncommon disorder can result from immunologic responses to chronic infection with P. malariae?

Answer 16

Immune complex glomerulopathy with nephrotic syndrome

Question 17

_____-_____ blood smears remain the mainstay of diagnosis, although other routine stains (e.g., _____ stain) will also demonstrate parasites.

Answer 17

Giemsa-stained

Wright

Question 18

The severity of malaria correlates only ______ with the quantity of infecting parasites

Answer 18

loosely

Question 19

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.

Answer 19

10 - 20%
200,000 - 500,000
5% of neutrophils

Question 20

Serologic tests indicate history of disease but are not useful for diagnosis of _____ _______.

Answer 20

acute infection

Question 21

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.

Answer 21

erythrocytic

primaquine

Question 22

The first-line drug for NON-falciparum malaria from most areas remains ________.
(some falciparum malaria is sensitive to chloroquine.)

Answer 22

chloroquine

Question 23

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.

Answer 23

Indonesia
Oceania
South America

artemisinin-based

Question 24

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.

Answer 24

chloroquine

primaquine

Question 25

P falciparum is resistant to _________ and ______-______ in most areas

Answer 25

chloroquine

sulfadoxine-pyrimethamine

Question 26

Chloroquine is the drug of choice for the treatment of non-falciparum and sensitive falciparum malaria. It rapidly ______ _____ (in 24–48 hours) and clears _______ (in 48–72 hours) caused by sensitive parasites. Chloroquine is also the preferred chemoprophylactic agent in malarious regions without resistant falciparum malaria.

Answer 26

terminates fever

parasitemia

Question 27

What are the essential of diagnosis for toxoplasmosis (primary infection)?

Answer 27

Fever, malaise, headache, sore throat.
Lymphadenopathy.
Positive IgG and IgM serologic tests.

Question 28

What are the essentials of diagnosis for toxoplasmosis (congenital infection)?

Answer 28

Follows acute infection of seronegative mothers and leads to CNS abnormalities and retinochoroiditis.

Question 29

What are the essentials of diagnosis for toxoplasmosis in immunocompromised patients?

Answer 29

Reactivation leads to encephalitis, retinochoroiditis, pneumonitis, myocarditis.

Positive IgG but negative IgM serologic tests.

Question 30

Toxoplasma gondii, an obligate ______ ______, is found worldwide in humans and in many species of mammals and birds. The definitive hosts are cats.

Answer 30

intracellular protozoan