Infectious diseases are caused by microorganisms like bacteria, viruses, or parasites. How these diseases are transferred are through direct contact from human to human. For example, HIV is transmitted from person to person via bodily fluids. It cannot just be spread by touch or close proximity but require body fluids to enter the person. Ways it can be transferred is through sexual intercourse as unprotected sex allows an infected person to spread the virus directly through the transfer of sexual fluids. Those who already have STI (Sexually Transmitted Infection) are at a higher risk of contracting HIV. Another method on how this virus could be spread is through blood transfusion. For instance, a child of an HIV positive mother can contract the virus during the pregnancy, labour or through breastfeeding.