2: malaria Flashcards
vector for malaria
anopheles freeborni mosquito
what areas of the world do you see malaria?
tropical climates
what map echoes the malaria map?
hemoglobinopathy - tells you selective pressures
describe the plasmodium species that cause disease in humans
5 species:
- falciparum (most severe disease)
- vivax
- ovale
- malariae
- knowlesi
key points of plasmodium lifecycle
- bite of infected mosquito
- plasmodium sporozoites have trophism for hepatocytes
- asexual reproduction in hepatocytes
- release into bloodstream
- hijacking of RBC and degradation of Hb, formation of ring forms
- lyse RBC and release merozoites to invade more RBC, or gametocytes to reinfect mosquitos [hemolytic anemia -> direct hyperbilirubinemia = jaundice]
- P vivax and P ovale can produce dormant hypnozoites in hepatocytes, can reactivate in 3-12 months
host response to malaria
splenic immune reaction and filtrative clearance -> leads to clinical appearance
clinical presentation of malaria:
- general
- what features suggest falciparum over others?
- what features suggest vivax or ovale over others?
- exposure to endemic area
- lack of prophylactic treatment used by travelers
- headache
- fatigue
- myalgias
- abdominal pain
- *fever!
falciparum: seizures
vivax/ovale: paroxysmal chills, fever, rigors (hepatic sequestration and re-release)
physical findings in malaria
- fever
- mild hepatomegaly
- palpable spleen
- mild icterus (jaundice)
-rash is very unusual
why can falciparum cause cerebral malaria?
can cause sequestration and agglutination in vasculature, including CNS capillaries
features of cerebral malaria
- seizures
- encephalopathy
- coma
what causes hypoglycemia in malaria? significance of this sign?
due to decreased hepatic gluconeogenesis and increased systemic glucose utilization - poor prognostic sign
what causes metabolic acidosis in malaria?
due to hypoperfusion, lactic acidemia
what does noncardiogenic pulmonary edema of malaria look like?
ARDS- adult respiratory distress syndrome
what causes renal impairment in malaria?
ATN (acute tubular necrosis)
what hematologic abnormalities do you see in malaria?
anemia