Malaria is an acute febrile illness caused by the Plasmodium parasite; it is transmitted to humans through the bites of infected female Anopheles mosquitoes.
Tuberculosis is an infectious disease caused by tuberculosis bacilli or bacteria called My-cobacterium tuberculosis.
The abbreviation HIV stands for human immunodeficiency virus. It is a retrovirus that infects cells of the human immune system (in particular CD4+ T cells and macrophage cells essential to the cell immune system). It destroys or disrupts their functioning.