Malaria

Malaria

MALARIA
It is caused by Plasmodium vivax, P. ovale, P. malariae and P. falciparum
It is transmitted by the bite of female anopheline mosquitoes

LIFE CYCLE:

The female anopheline becomes infected when it feed on human blood containing gametocytes which develop in the mosquito over 1 – 3 weeks into sporozoites

LIFE CYCLE:

sporozoites which are transmitted to another persons via mosquito bites and then enter the liver to form merozoites which leave the liver and invade RBC where multiplication occurs

forming schizont which rupture to release more merozoites into the blood and causes fever.

* The periodicity of the fever and rigor depend on the species of the parasite (( Tertian, Quartian, Aperiodic ))
* P. vivax and P. ovale may persist in the liver as dormant

PATHOGENESIS:

The pathology of Malaria is due to hemolysis of the infected red cells and there adherence to capillaries.
Anemia may developed and it worse by spleenomegaly
P. Falciparum cause wide spread organ damage.


CLINLCAL FEATURES:

P. vivax & P. ovale

Continuous fever for several days then classical boats of fever on alternated days (( cold phase and rigor for ½ - 1 hour, hot phase with flushing for several hours and gives a way to profuse sweating – wet phase- )) the cycle is repeated every 48 hr.

P. vivax & P. ovale

Hepatospleenomegaly
Anemia
Herpes simplex is common
Relapses are frequent in the first two years.

P. Malariae

It is usually associated with mild symptoms
boats of fever every third day
it may cause GN and nephrotic syndrome

P. Falciparum

insidious onset with malaise, headache and vomiting ( Flu – like )
cough and diarrhea are also common

P. Falciparum

The fever has no particular pattern
Jaundice is common
Hepatospleenomegaly and anemia developed rapidly


Cerebral Malaria
Cerebral Malaria is a grave complication manifested by coma or confusion, no localizing sign and death

Other complication

Hypoglycemia
pulmonary oedema
acute renal failure
severe anemia
metabolic acidosis
aspiration pneumonia
shock

DIAGNOSIS:

Thick blood film for diagnosis to show the blood stage of the parasite.
Thin blood film to identify the species of the parasite.

TREATMENT:

P. vivax, P. ovale and P. malarae:
Chloroquine 600 mg fallowed by 300 mg in 6 hours then 150 mg 12 hourly for 2 more days.


TREATMENT
In P. vivax and P. ovale, radical cure and prevention of relapses can be achieved with primaquine 15 mg daily for 14 days to destroy the hypnozoite phase in the liver.

P. falciparum:

Because of chloroquine resistance, Quinine is the drug of choice given 600 mg /8 hr. for 5 days fallowed by single dose of (( sulfadoxine 1.5 gm with pyrimethamin 75 mg )) 3 tab. Of fansidar.

P. falciparum:

In pregnancy, 7days course of quinine should be given alone
In quinine resistant area, Malarone , 4 tab. Once daily for 3 days

Severe malaria

Severe malaria is a medical emergency and cerebral malaria is the most common cause of death in malaria.

Severe malaria

Quinine should be given i.v until the patient can take orally, active treatment of complication with fluid and electrolyte correction.
Steroid has no role in treatment

PREVENTION:

1. Avoiding mosquito bites
Long sleeves and trousers should be worn
Use of mosquito nets
Repellent creams and sprays
Impregnation of bed nets with permethrin.


• Chloroquine 2 tab./ week & proguanil 1 tab. /day.
Moderate Chloroquine resistant areas:
Chloroquine 2 tab./ week & proguanil 2 tab. /day.

PREVENTION:

High chloroquine resistant areas:
Mefloquine I tab. Weekly or
Doxycycline 100 mg daily or
malarone 1 tab. Daily

3. Vaccination: still under trial.