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Healthcare Communications

Malaria

 

Malaria

* Caused by parasitic protozoan-Plasmodium
* Disease characterised by fever with rigor, anaemia and splenomegaly
* 200 - 300 million cases globally anually
* 1 - 2 million deaths globally anually

 

 

Malarial Parasite - Types

* Plasmodium vivax
* Plasmodium falciparum
* Plasmodium ovale
* Plasmodium malariae

 

 

Clinical Features of Malaria

  P. vivax,
P. ovale
P. falciparum

P. malariae
Incubation period 8-24 days 8-24 days 15-30 days
Type of fever Tertian Aperiodic quotidian Quartan
Exo-erythrocytic cycle Yes No No
Relapse Common upto 1 year Recrudescence Recrudescence for many years

 

 

Clinical Syndromes

Uncomplicated acute malaria
- Commonest variety, usually due to P. vivax, P. falciparum
- Fever with chills & rigors every 48 hours
- Asymptomatic between paroxysms

Severe (complicated, pernicious) malaria
- Caused by P. falciparum
- Cerebral malaria is commonest; mortality rate 25-30%
- Other features - severe anaemia, renal failure, pulmonary oedema, hypoglycaemia, circulatory collapse, acidosis, jaundice, convulsions

 

 

Clinical Syndromes (Contd…)

Chronic malaria
- Persistent P. vivax infection may lead to partial immunity
- Asymptomatic low grade parasitaemia
- Splenomegaly may lead to rupture

Tropical Splenomegaly Syndrome
- Splenomegaly in absence of parasitaemia
- Occurs in endemic areas
- Excessive response to infection with any species of plasmodia
- Splenomegaly regresses with prolonged malarial chemoprophylaxis

 

Diagnosis

Demonstration of parasite in peripheral blood smear

 

Treatment of Malaria

Acute uncomplicated infection

1) P. vivax, P. ovale
- Oral chloroquine 10 mg / kg (max. 600 mg) followed by 5 mg / kg (max. 300 mg) after 6, 24 and 48 hours
- Oral primaquine 15 mg / kg / day x 14 days to prevent relapse

 

 

Treatment of Malaria (contd.)

Acute uncomplicated infection (Contd…)

2) P. falciparum
- Chloroquine sensitive - Chloroquine 10 mg / kg (max 600mg) followed by 5 mg / kg (max300 mg) after 6, 24 and 48 hours
- Chloroquine resistant - Pyrimethamine 25 mg + sulphadoxine 500 mg tablets - 3 tablets single dose for adults OR - Quinine sulphate 650 mg (10 mg / kg) salt orally T.D.S. X 7 days, plus Tetracycline 250 mg Q.D.S. x 7 days
- Multi drug resistant - Mefloquine 15-25 mg / kg (max 1.5 g) single dose orally OR - Artesunate 200 mg on first day followed by 100 mg daily x 4 days

 

Treatment of Malaria (contd.)

Severe falciparum malaria (including cerebral malaria)
- Quinine I . V . 10 mg / kg over 4 - 8 hours T. D . S x 7 days (oral therapy when possible)
- Quinine resistant cases - Artesunate 2 mg / kg IM followed by 10 mg / kg after 6 hours on first day, then daily x 4 days OR - Artemether 160 mg (3.2 mg / kg IM) on first day; 80 mg (1.6 mg / kg IM) on days 2 - 5
- Supportive Therapy : I. V. fluids, blood transfusion, etc.

 

Chemoprophylaxis

Usually chloroquine 300 mg base once weekly, starting 1 week before exposure

Alternatives
- Mefloquine, 250 mg base weekly, starting 1 week before exposure
- Doxycycline, 100 mg daily, starting 2 days before exposure
- Chloroquine, 300 mg base weekly, starting 1 week before exposure + proguanil 200 mg daily, starting 2 days before exposure

 

Anti-Malarial Drugs

Drug
Antimalarial
effect
Adverse
effect
Comment
Chloroquine
Blood trophozoite
of all species
Bitter taste nausea, vomiting extrapyramidal reaction psychosis, myopathy pruritus hypotension (parenteral use) retinopathy (chronic use)
Should not be given by IM injection in children
Quinine
Blood trophozoites; gametocytes of P. vivax, P. malariae and P. ovale
Bitter taste tinnitus, vertigo high-tone hearing loss, prolonged QT on ECG Ventricular tachycardia hypoglycaemia haemolysis, thrombocytopenia
Monitor QT interval on ECG,safe in pregnancy

 

 

 

Anti-Malarial Drugs (contd.)

Drug
Antimalarial
effect
Adverse
effect
Comment
Mefloquine
Blood trophozoite gametocytes of P. vivax, P. malariae and P. ovale
nausea, vomitting, Dysphoria, vertigo, Postural hypotension Convulsions, encephalopathy
Acts more slowly than Chloroquine or quinine
Pyrimethamine Sulphadoxine
Blood stages
Megaloblastic Pancytopenia Steven - Johnsons syndrome
Contraindicated in pregnancy
Proguanil Sporozites and primary tissue stages Megaloblastic anaemia Renal failure Mouth ulcer Hair loss Used for causal prophylaxis

 

 


 

 
 

Anti-Malarial Drugs (contd.)

Drug
Antimalarial
effect
Adverse
effect
Comment
Primaquine
Exoerythrocytic forms of P. vivax, P. ovale gametocytes of P. falciparum
Abdominal cramps Haemolysis in G6PD deficiency Methaemo- globinaemia Teratogenic
Contraindicated in pregnancy
Artemesinin derivatives : Artesunate Artemether Arteether
Exoerythrocytic forms of gametocytes of P. falciparum - fastest parasite clearance time
Neurological effects Embryo toxicity
Contraindicated in pregnant and lactating women