ZIMSEC O Level Combined Science Notes: Diseases: Cholera
- Malaria is deadly disease
- It is caused by (the pathogen) a group of protozoa (single-celled animal) called Plasmodium
- The protozoa lives in the female Anopheles mosquito and in humans
NB Mosquitos do not cause malaria!
The Lifecycle of the anopheles
- The lifecycle lasts 10-21 days
The Lifecycle of Plasmodium
- The pathogen infects red blood cells and multiplies in the blood stream
- This happens every 48 hours causing a fever
- A female anopheles mosquito bites and feeds on an infected person
- The pathogen multiplies in the stomach of the mosquito
- The pathogens move from the stomach to the salivary gland
- When the mosquito bites again the infected saliva is injected into the victim
- The diseases has to be properly treated otherwise it will lie dormant only to resurge later
Methods of controlling malaria
- Prevent the breeding of mosquitos by:
- spraying their favourite breeding areas,
- draining/emptying stagnant water
- Spraying oil/paraffin into the stagnant water
- Killing adult mosquitoes using insecticides such as DDT
- Preventing mosquitos from biting people using:
- Treated/Untreated mosquito nets
- Covering windows and air vents using wire mesh
- Wearing thick long sleeved shirts/tops and trousers
- Use of mosquito repellant jelly
- Using antimalaria drugs to kill the parasite:
- Quinine-is effective but cannot kill the parasite in the liver
- Chloroquine-effective against acute malaria cases and red blood attacks
- Fancida-useful against chloroquine resistant cases
- Using prophylactic drugs to prevent and as a precaution against the malaria parasite
To access more topics go to the Combined Science Notes page