Malaria Flashcards
Malaria parasite infects liver cells and _____ cells
Red blood
The asexual life cycle of malarial parasite occurs in _____
Humans
The sexual life cycle and the definitive host of the malaria parasite is the _____
Mosquito
90% of cases of malaria infection occur in Africa and the main population that dies are _______
Children
The females anopheles sp. of mosquito takes what what kind of meals?
Blood
- the major vector is female!
Where in the body of a human is the first place that the malaria parasite travels?
Liver
When the malaria parasite is in the liver, does the host show symptoms of infection?
No
______ (life stage) travel to the liver through the lymphatics and blood
Sporozoites
When the malaria parasite erupts from the liver, it enters into what cell type next and undergoes asexual stage of replication. This stage is then symptomatic and associated with the disease state.
Red blood cells
Malaria merozoites enter _____ cells
Red blood
In the red blood cells the malaria merozoites matures into the ring structure —> trophozoite–> _____ and then that ruptures and forms gametocytes that are infectious
Schizont
Plasmodium ____ is the most deadly cause of malaria
Falciparum
Plasmodium ____ and ____ infects reticulocytes only
all causes of malaria
Vivax; Ovale
- falciparum
- vivax
- ovale
- malariae
- knowlesi
Plasmodium _____ infects all RBC and this is likely the reason that is is most deadly
Falciparum
Plasmodium vivax and ____ have dormant stages (hyponozoites)
ovale
Plasmodium malariae infects [new/old] RBCs
Old
Plasmodium ____ has the longest asexual period inside of a human host (72 hrs)
Malariae
Where does the prepatent period of malaria infection occur and is it symptomatic or asymptomatic?
Liver; asymptomatic (7-14 days)
Periodic fever, nausea, vomiting, chills, malaise, etc. may be seen in what stage of infection with malaria?
Paroxysm
Paroxysm occurs when merozoites burst from _____ cells
Red blood
Acute febrile illness is seen in malaria after the ____ burst from red blood cells
Merozoites
Severe malaria is almost always due to Plasmodium _____
Falciparum
Symptoms of severe malaria include cerebral malaria (coma, seizures, etc.), severe ____, and multi organ failure
Anemia
Plasmodium falciparum protein PfEMP1 binds to ___ on the surface of red blood cells and platelets
CR1
Plasmodium falciparum protein PfEMP1 binds ____ on the cerebral microvascular endothelium
ICAM-1
Plasmodium falciparum protein PfEMP1 binds ____ on placental microvascular endothelium leading to [low/high] birth weight and premature death
CSA; low
Plasmodium falciparum protein PfEMP1 binds ____ on tissue microvascular endothelium leading to mild malaria
CD36
Plasmodium falciparum causes clogging of the ______
Microvasculature
Humans host immune response is what causes more of the symptoms of malaria. Plasmodium falciparum is unique in that it actually ____ red blood cells
Restructures
Women pregnant for the first time (primigravida) are at a [higher/lower] risk of infections with Plasmodium falciparum
higher; they do not have immunity
Plasmodium falciparum turn on the genes VAR2CSA to promote cytoadherance to the placenta by binding to ____ and that leads to ___ birth weights
CSA; low
In a woman who has Plasmodium falciparum expressing VAR2CSA and is pregnant for the third time may be immune bc she can produce _____ to the VAR2CSA protein
Antibodies
Malaria kills children in 3 ways:
- Infection in pregnancy (low birth wt, premature)2. Acute febrile illness (cerebral malaria, respiratory distress, hypoglycemia)3. Chronic repeated infections (severe anemia)
In places with low immunity to malaria, who is at risk of having serious disease?
Children and adults due to them not having a lot of continual infectious bites
In areas of high immunity (Sub-Saharan Africa, Papua New Guinea), people may be bit more than 100 times per year. Infections in adults are usually[symptomatic/asymptomatic]
Asymptomatic
Children under the age of ___ may become seriously ill from malaria in places of high immunity
5
In areas of [high/low] immunity, adults must be continually exposed to infectious bites to be semi-immune
high
What are some mechanisms that humans have evolved to have to protect from severe malaria infection?
Sickle cell trait and G6PD deficiency, thalassemia
Loss of this receptor in people in Africa means that infection with Plasmodium vivax is less severe and there is increased resistance to infection
Duffy antigen receptor for chemokines (DARC)
Ovalocytosis causes a rigid membrane in the ____ cells and that inhibits invasion of malaria parasites
Red blood
What are the 3 main genetic resistance mechanisms that people in Africa have developed over time to create an inhospitable red blood cell for malaria to grow in?
- Sickle cell trait- G6PD deficiency- Thalassemia
Relapse of infection with Plasmodium vivax (and ovale) occurs due to the dormant stage in the _____
Liver
Liver stages can only be treated with ______
Primaquine
Primaquine causes hemolytic anemia in people with ____ deficiency
G6PD
What are 2 ways to diagnose malaria?
- Blood smear- Rapid diagnostic tests (RDTs)
Rapid Diagnostic Tests are the gold standard to diagnosing malaria. In ____ there is resistance occurring that may be detrimental
Eritrea
Insecticide treated bed nets (ITNs) have an average decrease in child mortality of __%
20
Indoor residual spraying (IRS) is effective only if there is an infrastructure to spray. What is the main chemical that is sprayed that targets female anopheles mosquitoes when the land on a surface?
DDT
Bark of cinchona tree =
quinine
Treatment of malaria began with Quinine –> Chloroquinine and Mefloquinine —> _____ –> Artemisinin combo therapies (Coartem)
Fansidar
What is the treatment for Falciparum?
Artemisinin combo therapy (ACT)
What are the treatments for Vivax?
Chloroquine, Artemisinin combo therapy (ACT) if there is chloroquine resistance; have to watch the people with G6PD deficiency bc they cannot be treated with primaquine
Artemisinin combo therapy (ACT) is derived from ________ and is fast acting so need to use in combo with long acting drug such as mefloquine to treat malaria
Chinese herbal remedy
RTS,S vaccine has an efficacy of __% against malaria and is in stage 3
30
“Money is the best anti_______”
malarial
