Sexually Transmitted Infections (Cambridge (CIE) IGCSE Co-ordinated Sciences (Double Award)): Revision Note

Unprotected sexual intercourse can lead to the transfer of pathogens via exchange of body fluids

Infections passed on in this way are known as sexually transmitted infections (STIs)

HIV (Human Immunodeficiency Virus) is an example of an STI

HIV is a viral pathogen

The virus infects the body's immune system and decreases the body’s ability to fight infection, eventually leading to AIDS (Acquired Immunodeficiency Syndrome)

HIV can be spread by infected body fluids, e.g.

• Sharing needles with an infected person

• Blood transfusions with infected blood

• From mother to fetus across the placenta during pregnancy

• Mother to baby via breastfeeding

• Having unprotected sexual intercourse with a person infected with HIV

The spread of STIs such as HIV is best controlled by:

• Not having unprotected sex, but making sure to always use a condom

• Getting tested if unprotected sex or sex with multiple partners has occurred

• Raising awareness through education programmes

• Never sharing needles and ensuring medical equipment is sterile

• Screening for HIV during pregnancy