2. Intro I:
• Malaria is a mosquito-borne, hemolytic, febrile disease.
• In humans, is caused by Plasmodium falciparum, P. vivax, P.
ovale and P. malariae.
• Vector is mosquito;
• in many infections there is an intermediary, which bridges the gap
between infected host (or the reservoir) and the uninfected host.
• Occurs throughout the tropics and subtropics at altitudes below
1500metres.
• P. falciparum has now become resistant to chloroquine &
sulfadoxine-pyrimethamine.
WinnerzKlub18
3. Intro II:
• One of the differential diagnosis of elevated core body
temperature.
• Intermediate incubation period (10-15 days).
• Continues to afflict people in tropical & subtropical areas, esp.
Africa, South & Central America, India & Southeast Asia.
• P. falciparum & P. vivax are the most common pathogens.
• P. vivax is rare is Africa, where majority of the blacks lack the
erythrocyte cell surface receptors (Duffy) required for
infection.
• P. falciparum & P. ovale are the predominant species in Africa.
• P. malariae is the least common & mildest form of malaria.
WinnerzKlub18
5. Pathology:
• RBCs infected with malaria are prone to haemolysis.
• Most severe with P.falciparum, which invades RBCs of all ages, esp.
young ones.
• P. vivax & P. ovale invade reticulocytes
• P. malariae normoblasts, so that infections remain lighter.
• P. falciparum causes malignant malaria, a much more aggressive form of
disease compared to other plasmodia
• P. falciparum distinguished from other parasites in 4 respects:
i. No secondary exoerythrocytic (hepatic) stage.
ii. It parasitizes erythrocytes of any age (high-level parasitemias & anemias).
iii. There may be several parasites on a single red-cell
iv. Alters the flow & adhesive properties of infected RBCs, increasing
adherence to blood vessels leading to obstruction & ischaemia.
• Obstruction of renal blood flow produces acute renal failure, whereas
intravascular hemolysis leads to hemoglobinuric nephrosis (blackwater
fever)
• In the lung, damage to alveolar capillaries produces pulmonary edema &
acute alveolar damage.
WinnerzKlub18
7. Clinical Features:
• Recurrent paroxysms of chills and high fever.
• Headaches, followed by high spiking fever
• Tachycardia
• N/V & abdominal pain.
• High fever produces marked vasodilation n& often
associated orthostatic hypotension.
WinnerzKlub18
8. Investigations:
• Giema-stained thick and thin blood films should be
examined wherever malaria is suspected.
• In thick film RBCs are lysed, releasing all blood stages of
parasite –
• also facilitates the diagnosis of low-level parasitemia.
• A thin film, essential to confirm the diagnosis,
• to identify the species of parasite, and in P. falciparum
infections, to quantify the parasite load.
• DNA detection (PCR) used mainly in research.
WinnerzKlub18
9. Complications of
falciparum malaria & mx:
• Coma (Cerebral malaria):
i. Maintain airway
ii. Nurse on side
iii. Exclude other treatable causes of coma
iv. Avoid harmful ancillary treatments such as corticosteroids, heparin &
adrenaline
v. Intubate if necessary
• Hyperpyrexia:
i. Tepid sponging, fanning, cooling blanket
ii. Antipyretic drug (PCT)
• Convulsions:
i. Maintain airway
ii. Treat promptly with diazepam & paraldehyde injection.
WinnerzKlub18
10. Complications of
falciparum malaria & mx:
• Hypoglycaemia:
i. Measure CBG
ii. Give 50% dextrose injection followed by 10% dextrose infusion (glucagon
may be ineffective)
• Severe anaemia:
i. Transfuse fresh whole blood or packed cells if pathogen screening of donor
blood is available.
• Acute pulmonary edema:
i. Nurse at 45°, give oxygen, venesect 250mL of blood, give diuretic, stop IV
fluids
ii. Intubate & add PEEP/CPAP in life-threatening hypoxaemia.
iii. Haemofilter.
WinnerzKlub18
11. Complications of
falciparum malaria & mx:
• Acute renal failure:
i. Exclude pre-renal causes.
ii. Fluid resuscitation if appropriate
iii. Peritoneal dialysis
• Spontaneous bleeding & coagulopathy:
i. Transfuse screened fresh whole blood
ii. Vitamin K injection.
• Metabolic acidosis:
i. Exclude or treat hypoglycaemia, hypovolaemia, & Gram-negative
septicaemia
ii. Fluid resuscitation
iii. Give oxygen
WinnerzKlub18
12. Complications of
falciparum malaria & mx:
• Shock (‘algid malaria’)
i. Suspect Gram-negative septicaemia
ii. Take blood cultures
iii. Give parenteral antimicrobials
iv. Correct haemodynamic disturbances
• Aspiration pneumonia:
i. Give parenteral antimicrobials
ii. Change position
iii. Physiotherapy
iv. Give oxygen
• Specific therapy:
i. IV artesunate
ii. Mefloquine should be avoided due to increased risk of post-malaria
neurological syndrome.
WinnerzKlub18
13. Management:
A. Mild P. falciparum malaria
B. Complicated P. falciparum malaria
C. Non-falciparum malaria
WinnerzKlub18
14. Mild P. falciparum
malaria:
• Artemisinin-based treatment recommended.
• Co- artemether (artemether + lumefantrine)=4 tablets at 0,
8, 24, 36, 48 & 60 hrs.
• Alternative; quinine by mouth (600mg every 8hrs for 5-7
days)
• With; doxycycline (200mg once daily for 7 days) or
clindamycin (450mg every 8hrs for 7 days)
• NB: Doxycycline & artemether should be avoided in
pregnancy.
WinnerzKlub18
15. Complicated P.
falciparum malaria:
• Mx includes:
early & appropriate antimalarial chemotherapy
Active treatment of complications
Correction of fluid, electrolyte & acid-base balance
Avoidance of harmful ancillary treatments.
• Treatment of choice: IV artesunate (2.4 mg/kg at 0, 12 & 24 hrs &
then once daily for 7 days)
• Oral artesunate once feasible (2 mg/kg once daily)
• Quinine salt (20 mg/kg over 4hrs, max. of 1.4g)
• Pts monitored by ECG, with special attention to QRS duration & QT
interval.
• Mefloquine should not be used in severe malaria since no parenteral
form is available.
WinnerzKlub18
16. Non-falciparum malaria
mx:
• P. vivax, P. ovale & P. malariae: oral chloroquine.
• 600 mg chloroquine followed by 300 mg base in 6hrs, then
150 mg base 12 hourly for 2 more days.
• Primaquine (15 mg daily for 14 days) – destroys the
hypnozoite phase in the liver.
• Cyanosis due to the formation of methaemoglobin in the
red cells is more common but not dangerous.
WinnerzKlub18
17. Malaria
Chemoprophylaxis:
Antimalarial tablets Adult prophylactic dose Regimen
Chloroquine resistant high
Mefloquine 250 mg weekly Started 2-3wks before travel &
continued 4wks after
Doxycycline 100 mg daily Started 1wk before & continued
until 4wks after travel
Malarone 1 tablet daily From 1-2days before travel &
1wk after return.
Chloroquine resistant absent
Chloroquine 300 mg base weekly Started 1wk before & continued
until 4wks after travel
Proguanil 100-200 mg daily
WinnerzKlub18
18. Malaria Prevention:
1. Insecticide-treated bed nets
(ITNs)
3. Intermittent preventive tx in
pregnancy
For women in 1st & 2nd pregnancy, this
reduces instances of severe antenatal
anaemia, antenatal parasitaemia &
perinatal deaths, & increases birth
weight.
2. Intermittent preventive tx in
children
4. Electronic mosquito repellents
(EMRs)
Antimalarial drugs reduce clinical
malaria, severe anaemia & hospital
admissions.
WinnerzKlub18
19. The 3nd:
• References:
• Davidson’s Principles & Practice of Medicine, 21st Ed.
• Rubin’s Pathology, Clinicopathological Foundations of
Medicine, 6th Ed.
• Emed.com
• Nccbi.net
WinnerzKlub18
