Infectious disease.

• Health - a state of physical, mental and social well being that includes the absence of disease and infirmity.
• Disease - the condition that impairs the normal functioning of an organism.
• Pathogen - an organism that can cause damage to the host.
• Parasite - an organism that lives on and in the host and causes damage to the host.
• Genetic defects/Nutritional deficiencies/Environmental factors are also causes of disease.

Malaria:

• Parasite - Plasmodium.
• Transmitted by mosquitoes.
• Vector transmission.
• Plasmodium infects the liver and red blood cells by disrupting the blood flow to the vital organs.

AIDS:

• Caused by…