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Malaria is a very simple disease to diagnose and treat; yet it
claims more lives than any other infectious disease in the world. It is therefore very
essential that every case of malaria be assessed thoroughly.
Clinical examination:
General: Functional status,
prostration, breathlessness, level of consciousness, hydration, toxicity, puffiness of
face and lids, etc.
Vital signs: Pulse rate, blood
pressure (hypotension), temperature (hyperpyrexia), respiratory rate (tachypnoea, acidotic
breathing).
Other signs: Pallor, Jaundice,
Cyanosis, Edema, etc.
Abdomen: Liver, spleen, bowel
sounds - Tender hepato/ splenomegaly is more common in acute malaria.
Respiratory system: Basal
crackles, wheezes; sometimes, associated pneumonia and its bronchial breath sounds.
C.N.S.: Level of sensorium,
convulsions, neck stiffness, ocular fundii, any focal deficits.
Investigations:
Hemoglobin: Anemia is common in
malaria. Rapid reduction in level of hemoglobin is seen in falciparum malaria and less
than 7 g/ dl should be a warning.
Total leukocyte count: It can vary
from low to high, and neutrophilic leukocytosis is common in severe malaria with or
without associated bacterial infection. Leukopenia is seen in severe malaria with
septicemia, and chronic hypersplenism.
Platelet count: Thrombocytopenia
is common in P. falciparum and P. vivax malaria, but it does not correlate with the
severity of the infection.
Parasite
count: This is a simple yet very important and useful method of assessing the
severity of infection in falciparum malaria. It should be done routinely in all cases of
falciparum malaria.
How to do a parasite count?
Thick film: The density of malarial
parasites can be read against the leukocytes and an approximate parasite count can be
calculated.
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Count the number of asexual forms of the
parasite ( rings, trophozoites and schizonts) against 100 leukocytes and multiply by 75,
this gives an approximate total per micro liter (mm3).
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The average leukocyte count per
microscopic field is about ten. Therefore, multiply the average number of parasites per
field by 750, this also gives an approximate total per micro liter.
Thin film: Count the number of
parasites within 1000 red blood cells and divide this by 10. This gives the percentage of
parasitemia.
A parasite count of 100000 or more per mm3
(or 5% and more) is considered as severe infection.
See details
Blood Glucose: Hypoglycemia is a
common problem encountered in malaria and may remain undetected because the symptoms and
signs of hypoglycemia viz. sweating, tachycardia etc., are even otherwise seen in malaria.
It is very important to monitor the blood glucose levels once at least 6 hours in
falciparum malaria, particularly if the patient is pregnant or is receiving quinine.
Other investigations:
Moderate elevation in blood urea and
creatinine are common. Significant increase is suggestive of renal impairment.
Hyperbilirubinemia is common in malaria,
particularly due to hemolysis. Some patients with falciparum malaria may have very high
levels of conjugated bilirubin due to associated hepatocyte dysfunction.
Serum albumin levels may be reduced, some
times markedly.
Serum aminotransferases, 5' -
nucleotidase and lactic dehydrogenase are elevated.
Prothrombin time and partial
thromboplastin time are elevated in 20% of patients with cerebral malaria. Some may have
features of disseminated intravascular coagulation.
Hyponatremia is common and needs careful
management.
Lactic acidosis is seen in severely ill
patients, especially in patients with hypoglycemia and renal dysfunction. It can be
suspected if there is a wide anion gap.
Urine examination may show albuminuria,
microscopic hematuria, hemoglobinuria and red cell casts. With massive intravascular
hemolysis, urine may be black in colour.
SEE - Misjudgement of severity
Indications for
hospitalisation of malarial cases:
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Persistence of fever even after 48 hours
of initial treatment.
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Continuously worsening headache.
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Persistent vomiting.
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Any
complications of P. falciparum malaria- altered sensorium, convulsions, anemia,
jaundice, hyperpyrexia, bleeding and clotting disorders, breathlessness, high coloured
urine etc.
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Patients
who are at higher risk for development of complications of P. falciparum
malaria-extremes of age, pregnancy etc.
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Patients who appear sick and prostrated
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Significant dehydration
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