MALARIA Flashcards
Organism Type
protozoan parasites of the genus Plasmodium
Scientific name:
plasmodium
Subtypes:
P. falciparum, P. vivax, P. ovale, or P. malariae
Common Name(s):
Malaria is common name in Spanish; (Mal = Bad)
& (aira = Air)
Prevalence
Very Common; ~228 million cases annually and ~500,000
deaths. Estimated that Malaria has killed 1 out every 5 humans who
have ever lived.
Predisposing Factors
mosquito exposure, operating in endemic areas,
lack of PPE, lack of chemoprophylaxis, lack of bed nets
Transmitted Via
female anopheles mosquito
Vector
Yes
Incubation Period:
7 to 30 days, depending on the species of malaria
infection
Vaccine
No
Reportable
Yes
Lethal
p. falciparum (Yes); P. vivax, P. ovale, P. malariae (maybe)
exual cycle in (F) Anopheles Mosquito:
(a) Begins when a female anopheles mosquito takes a blood meal
from an infected human
(b) Ends when the mosquito salivary glands are filled with
malaria parasites
Sporogony Phase
asexual cycle in human liver
Exoerythrocytic Phase
Patient is asymptomatic in this stage
Exoerythrocytic
Patient is symptomatic in this stage
Erythrocytic Phase
Symptoms
(1) Symptoms can develop as early as 7 days mosquito bite and as late as
several months or more after exposure.
(2) The presentation of Malaria can be broken down into 2 broad
categories: uncomplicated Malaria & Severe Malaria.
Uncomplicated Malaria is characterized by:
(a) paroxysmal (cyclical) fever
(b) influenza-like symptoms including chills, headache,
myalgias, and malaise
(c) Jaundice & mild anemia secondary to hemolysis
Severe malaria is characterized by:
(a) small blood vessels infarction, capillary leakage and organ dysfunction (b) Altered consciousness (c) Hepatic failure & renal failure (d) Acute respiratory distress syndrome (e) Severe anemia
Presentation
(1) Paroxysmal fevers are typical of Malaria and considered a clinical
hallmark of the infection
(a) Cold stage – lasts approximately 1 hour
(b) Febrile stage – lasts 2-6 hours
(c) Diaphoretic stage where fever drops – lasts 2-4 hours
(d) Patient then returns to normal
(e) Cycle repeats itself in 48 – 72 hours depending species
infection
(2) Pathogenesis of paroxysmal fever is 2/2 RBC infection and life cycle
of the parasites
(a) When RBC lyse and schizonts are released, the patient’s
immune system mounts an immune response and develops a
fever
(b) Life cycles of Malaria ranges from 48-72 hours depending on
species
Diagnosis is based on
(a) Clinical findings consistent with Malaria infection
(b) Rapid diagnostic testing or laboratory confirmation via blood
smear.
Rapid Malaria testing (AMAL)
) Rapid Malaria testing (AMAL):
(a) Detect antigens associated with different malarial species
(b) Gives qualitative result but no quantitative information
regarding parasite density
(c) Both positive and negative RDT results must always be
confirmed by microscopy
Treatment options are dependent on:
(a) Species of malaria
(b) Severity of infection
(c) Likelihood of drug resistance (where infection was acquired)
(d) Patient’s age & Pregnancy status
Two reliable-supply treatment regimens available in the U.S.
(a) Atovaquone-proguanil (Malarone)
b) Artemether-lumefantrine (Coartem
(a) Complete course of approved treatment regimen obtained in
the U.S.
(b) Is not counterfeit or substandard
(c) No adverse interactions with the patient’s other medicines,
including prophylaxis
(d) Will not deplete local resources in the destination country
Reliable Supply
Do not use the same or related drug to treat Malaria as was used for
____
chemoprophylaxis
Treatment of uncomplicated Malaria
(a) Chloroquine phosphate 1g (600mg base) PO
(b) THEN 0.5g in 6 hours
(c) THEN 0.5g daily for 2 days
Treatment of malaria in areas with chloroquine resistance
Malarone (Atovaquone 250mg/Proguanil 100mg) 4 tabs PO
QD for 3 days
Treatment of severe Malaria
(a) Artesunate 2.4mg/kg IV at 0, 12, 24, 48 hours
(b) Followed by Doxycycline 100mg BID x 7 days after
parenteral therapy
Treatment of P.ovale
(a) ADD primaquine 52.6mg (30mg base = 2 tablets) PO QD x
14 days
(b) Added to regiment for hypnozoites
Prevention
(1) The most important protective measures are proper clothing and
awareness.
(2) Long sleeve shirts, long pants, insect repellant, and head nets, will
keep mosquitoes from biting.
(3) Addition precautions include closed sleeping quarters, insecticides,
and prophylaxis.
Resistance
(1) Resistance to many drugs in constantly changing and the most up-todate information should be sought from the CDC at www.CDC.gov, or
the cognizant EPMU prior to travel to an endemic area.
(2) Administration of prophylactic medication should begin 1-2 weeks
prior (except for Malarone, Primaquine, & Doxycyline) to the
expected embarkation to an endemic area and continued for 4 weeks
after leaving the endemic area
Disposition
(1) Even patients presenting with signs and symptoms of the mild form of
the disease should be evacuated to definitive medical care facility as
soon as possible.
(2) Complications can include neurologic abnormalities, acute renal
failure, anemia, metabolic acidosis, hypovolemia, and Acute
Respiratory Distress Syndrome.
