Malaria Flashcards
Define malaria
Malaria is a protozoa infection of the genius PLASMODIUM.
There are five many species of Plasmodium namely:
- Plasmodium falciparum
- Plasmodium Vivax
- Plasmodium Malariae
- Plasmodium Ovale
- Plasmodium Knowlesi
Malaria transmitted through the bite of an infected female mosquito belonging to the
genus ____________.
Anopheles
Symptoms of uncomplicated malaria are ?
• Symptoms of malaria are generally non-specific
• Fever/sweats/chills
• Malaise
• Weakness
• Gastrointestinal complaints (nausea, vomiting, diarrhea) • Headache
• Back pain
• Myalgia
• Cough
Major features of severe or complicated falciparum malaria in adults:
Cerebral malaria (coma not attributed to any identifiable cause in a patient with P. falciparum malaria)
• Impaired consciousness or seizures ( > 2 episodes/24 h)
• Drowsiness/lethargy
• Pulmonary oedema or acute respiratory distress syndrome (ARDS)
Shock (algid malaria: BP < 90/60 mmHg) Persistent/excessive vomiting Spontaneous bleeding/disseminated intravascular coagulation Anaemia (haemoglobin ≤ 8 g/dL)
Acute kidney injury (oliguria: urine output < 400ml/24 h in adults) Jaundice
Severe or complicated malaria in children:
Impaired consciousness or seizures Respiratory distress or acidosis (pH < 7.3) Hypoglycaemia (2.2 mmol/l) Severeanaemia(<8g/dL)
Prostration (inability to sit or stand without support) Parasitaemia > 2% red blood cells parasitized
Laboratory indicators of severe malaria
• Hyperparasitaemia ( proportion of parasitized red blood cells > 5% in the non-immune and 10% in semi-immune population)
• Metabolic acidosis (pH < 7.3, serum bicarbonate < 15mmol/L)
• Severe normocytic anaemia (Hb < 5g/dL or PCV < 15%)
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• Hyperlactataemia (serum lactate > 5 mmol/L)
• Renal impairment (serum creatinine > 265μmol/L)
• Haemoglobinuria (without G6PD deficiency)
• Hypoglycaemia (blood glucose < 2.2mmol/L)
Diagnosis of malaria
• Most important test is examination of thick and thin blood slides by microscopy (highly sensitive and specific in expert hands)
• Gold standard for laboratory confirmation of malaria
• Rapid diagnostic tests (RDTs) based upon detection of parasite antigens ( HRP ǀ or ǀǀ ) or enzymes (lactate dehydrogenase)
• Slightly less sensitive than good quality blood films
• Commonly used in addition to blood slides
• Easier for the non expert to use to detect falciparum infections
• Not as specific and sensitive for the detection of non falciparum infections
• If falciparum malaria is diagnosed, the percentage of red blood cells that are parasitized should be estimated.
Monitoring of malaria
• Assessment of the patient should include careful clinical evaluation and review of investigations for the features of severe malaria
Investigations (should be done routinely)
• Full blood count (FBC)
• Blood glucose level
• Liver function tests (LFTs)
• Urea and electrolytes (U/Es)
• In ill patients, arterial blood gases, blood culture, lactate and clotting studies (prothrombin time) should also be performed.
• Urine dipstick and culture, stool culture and chest X-ray may be appropriate.
• Lumbar puncture to exclude meningitis should be considered in febrile patients with impaired consciousness or repeated seizures.
Malaria treatment can be classified into three (3) namely:
- Uncomplicated Malaria.
- Severe Malaria
- Malaria in Pregnancy
First Line Treatment of uncomplicated malaria :
• Artemether – Lumefantrine (AL), an Artemisinin Based Combination Therapy (ACT) children below 5kg of weight should be treated under medical supervision.
• Sulphadoxine – Pyrimethamine (SP) for children below 5kg of weight.
Severe Malaria first line treatment:
a. Injectable Artesunate is the drug of choice in adults and children with severe malaria.
b. If injectable (IV) artesunate is unavailable, artemether (intramuscular (IM) ) or quinine (IV/IM) are suggested alternatives.
C. following initial parenteral treatment for a minimum of 24 hours, once the patient can tolerate oral therapy, it is essential to continue and complete treatment with an effective oral antimalarial using a full course of an effective ACT.
Intermittent Preventive Treatment during pregnancy (IPTp).
Sulphadoxine – Pyrimethamine should be usedfor for IPTp during the second and third trimesters of pregnancy on a monthly basis at all scheduled antenatal care visits.
ARTESUNATE
This is the medicine of choice for the treatment of severe malaria in all categories of patients.
Artesunate is dispensed as a powder of Artesunic acid. This must be dissolved in sodium
Bicarbonate (5%) of 5% Dextrose and given by IV injection or IM injection to the arterior thigh.
•The solution should be freshly prepared prior to administration and should never be stored.
DOSE
2.4mg/kg body weight IV or IM given on admission (time=0) then at 12 Hours and 24 Hours, then
once a day.
ADVERSE EFFECTS
Anorexia
Dizziness
Mild blood abnormalities
QUININE
•Altenative treatment of severe and complicated Malaria in all population group.
•First-line treatment for uncomplicated malaria during first trimester of pregnancy.
•Second line treatment in case of treatment failure with the first-line treatment.
DOSE
•By IV injection : loading dose of 20mg/kg body weight (Max. 1200mg) diluted in 10ml/kg of 5% or 10% Dextrose ( or isotonic fluid if hypoglycaemia is excluded) per kg body weight by infusion over 4 hours.
•Then give a maintenance dose of 10mg/kg over 4 hours.
ADVERSE EFFECTS
• Tinnitus
• Headache
•Hot and flushed skin
•Abdominal pain
•Visual disturbances, confusion, hypoglycaemia and cardiovascular effects.
