EXAM 3 Malaria Flashcards
what is the clinical classification of malignant malaria?
pl. falciparum
what is the clinical classification of benign malaria?
- pl. vivax
- pl. ovale
- pl. malariae
describe the epidemiology of malaria in the USA
- 1727 cases reporded in 2013
- increasing trend since the 1970s
in the USA, ___% of reported malaria cases in 2013 were pl. falciparum
61%
in the USA, ___% of reported malaria cases in 2013 were in people from African countries
72%
in the USA, ___% of reported malaria cases in 2013 were classified as severe
16%
in the USA, ___ deaths as a result of malaria were reported in 2013
10 (1%)
who is at risk for death as a result of malaria?
- children 6mo to 6yrs
- non-immune adults
- pregnancy - especially primigravida
- emigrants returning form home visits
severe malaria rarely occurs in what populations?
- sickle cell trait in children
- denizens of endemic areas - immune adults
what is cerebral malaria
a form of malaria where the patient becomes comotose and is unresponsive; often leads to death
what is cerebral malaria with acidosis?
- form of malaria where the patient becomes comatose
- nasal flare and intercostal retractions characteristic of metabolic acidosis
what is cerebral malaria with focal seizures and acidosis?
- a form of malaria where the patient becomes comatose
- focal seizures - eyes will flutter
- desperately ill
describe a patient who has cerebral malaria and anemia
- severe anemia and coma with eyes open
- severe anemia may lead to heart failure
- blood transfusion needed, but frequently is not available
describe the 3 stages of malaria infection transmission
- mosquito stage
- mosquito bites human, infecting with sporozoites (inoculation/infection)
- liver stage
- sporogony
- sporotoites invade the liver, become merozoites then enter the blood stream
- blood stage
- shizogony
- asexual cycle and sexual cycle
- sexual cycle produces gametocytes, which are taken up by new mosquitos that bite the human (transmission to mosquito)
- asexual cycle produces illness when parasite numbers reach 100 million
___ has no latent stage in the liver (hypnozoites)
pl. falciparum
why are only early stage (ring form) parasites seen in vivo?
because mature forms adhere to the walls of the microvessels in the brain
which stages of sporogany are seen in vitro?
all stages
what is a thick smear?
- one drop of blood
- RBCs lysed
- fixed and stained with Giemsa
what are the benefits (to the parasite) of sequestration?
- evade splenic clearance - free intravascular replication
- post-capillary venule blood pH is low (~7.1) - favors parasite replication
- post-capillary venule pCO2 is high - favors parasite replication
- pl. falciparum infects RBCs of any age
- multiple PfEMP-1 genotypes evade host IR
- all lead to enourmous parasite mass in severe malaria
describe the concerns of fever in returning travelers.
- life threatening (immediate) vs. non-emergent diseases
- malaria
- typhoid fever
- tuberculosis
- meningococcol/meningitis (or other serious bacterial infections)
- viral hemorrhagic fevers
how is malaria managed?
- hospital vs. out-patient treatment
- sequestration comes and goes and is a dynamic process
- oral vs. IV prescriptions
- GI absorption, level of consciousness, emesis
- WHO recommended prescription not available in pharmacy
- artemisinin derivatives
- request through the CDC&P
describe the prevention of malaria
- malaria prophylaxis with anti-malarials
- weekly, daily
- toxicity, side effects
- mosquito repellant - DEET
- permethrin - impregnated bed nets
- permethrin - treated clothing
what is the three pronged approach to combating malaria in the world?
- insecticide impregnated bed nets
- residual insecticide spraying
- pre-emptive treatment with ACT
what is the cost of combating malaria in the world?
- sustained funding from philanthropic sources
- lack of acquired immunity in increasingly older individuals
what stage of pl. falciparum maturation is shown?
ring trophozoites (early)
what stage of pl. falciparum maturation is shown?
maturing trophozoites
what stage of pl. falciparum maturation is shown?
shizont - early and mature
what stage of pl. falciparum maturation is shown?
gametocyte
what is the function of knob proteins?
cytoadherence of pl. falciparum to red blood cell membranes
