_A female anopheles mosquito feeds on an infected person and ingests blood containing gametocytes.
_After 1-2 wk(s) gametocytes produce sporozoites sexually.
_Sporozoite-infected mosquito feeds on another person
_Sporozoites infect hepatocytes and mature into tissue schizonts
_Each schizont produces 10,000 to 30,000 merozoites
_The merozoite-infected hepatocyte rupture releasing merozoites into blood stream
_The released merozoites invade the Red Blood Cells
_They are transformed into trophozoites which grow and develop into erythrocyte schizonts that in turn produce more merozoites.
_The merozoites then rupture the RBC and are released in plasma after 48-72hrs.
_The released merozoites invade new RBCs, repeating the cycle.
_Some of the trophozoites develop into gametocytes.
_In the gut of the mosquito gametocytes which develop into oocysts and later released as sporozoites that migrate to the salivary glands.
**Do NOT assume absence of malaria in BS negative cases.
**Consider possibility of other diseases with similar presentations to severe malaria e.g.meningitis).
Therapeutics guided by Essential Drug List consideration
Antimalarials in the Essential Drug List:
*Adults: 4 tablets stat, then 4 after 8hrs, then 4BD x 2/7 [24 tablets].
*5-15kg: 1 tablet stat, then 1 after 8 hrs, then 1 BD x 2/7 [total = 6 tablets].
*15- 25kg: 2 tablet stat, then 2 after 8hrs, then 2 BD x 2/7 [to-tal = 12 tablets].
*5- 15kg: 3 tablet stat, then 3 after 8hrs, then 3 BD x 2/7 [total = 18 tablets].
In the event of vomiting within I hr of administration a repeat dose should be taken.
For the Artemether 80mg/Lumefantrine 480mg tablets:
*Adults: One tablet BD x 3/7.
Supportive Rx with NSAIDs.
Management of treatment failure (defined as deterioration of clinical conditions or symptoms persisting for more than 3-14 days).
Quinine tablets: 10mg/kg body weight TID x 1/52
Dihydroartemesinin 40mg / piperaquine 320mg [DHQ-PPQ].
Patient above 16yrs: day 1(3 tabs); day 2 (3 tabs); day 3 (2 tabs). 11-16yrs: day 1(2 tabs); day 2 (2 tabs); day 3 (2 tabs). 6-11yrs: day 1(1.5 tabs); day 2 (1.5 tabs); day 3 (1 tab)
Failure to complete 1st treatment: repeat full dose of AL.
Treatment of uncomplicated P.vivax infection: AL and primaquine 15mg daily for 14 - 21 days
Rx of severe malaria in patients who cannot tolerate oral Rx:
In situations where quinine IV infusion cannot be given
Quinine, loading dose of 20mg/kg IM followed by the maintenance dose of 10mg/kg 8hrly IM.
Artemether, loading dose of 3.2mg/kg IM followed by the maintenance dose of 1.2mg/kg OD IM until the patient can take oral therapy when a full dose of ALis given.
**Nasal Gastric tube can be used as well to administer oral doses of quinine.
In situations where quinine IV infusion can be given
Quinine, loading dose of 20mg/kg IV infusion in 500mL 5% dextrose for 4hrs followed by the maintenance dose of 10mg/kg 8hrly in 500mL 5% dextrose for 4hrs until the patient can take oral therapy when a full dose of ALis given or quinine tablets, 10mg/kg body weight TID, to complete the remaining days to ensure a total of 7 day treatment with quinine.
Management of conditions associated with severe malaria
Hypoglycemia: 50% dextrose (1mL/kg)
Oliguria: Monitor urinary output (it should be above 30mL/hr. Otherwise, give frusemide 40-80mg IV STAT.
Convulsion: diazepam 0.3mg/kg IM or IV or rectally 0.5mg/kg
Situations where chemoprophylaxis is required include:
Pregnancy: Intermittent preventive therapy (IPTp) using Sulfadoxine / pyrimethamine (SP): It is given during antenatal visits at curative dose of 3 tabs at least twice during pregnancy, once at the second trimester and once at least 1 month after the first treatment.
Non-immune visitors to malaria endemic areas: Mefloquine tablets 250mg (not in the Essential Drug List) weekly from 2 week before travelling and for at least 4 weeks after travelling.
Children with impaired immunity such as leukemia and HIV.
Sickle cell disease or Thalassemia. (Malaria is known to be the most common precipitating cause of crises in sickle cell disease in malaria-endemic areas): weekly pyrimethamine dose (not in the Essential Drug List).
Therapeutics using drugs that are NOT in the Essential Drug List
Antimalarials that are NOT in the Essential Drug List
HB (if below 5gm/dL and there are signs of cardiorespiratory distress transfuse blood)