Sexually Transmitted Infections | Biology for GCSE/IGCSE - Year 11 PDF Download

STIs & HIV/AIDS

• Unprotected sexual intercourse can result in the transmission of pathogens through the exchange of body fluids.
• Infections that are transmitted in this manner are referred to as sexually transmitted infections (STIs).
• An illustration of an STI is HIV (Human Immunodeficiency Virus), the virus which typically leads to the progression of acquired immunodeficiency disease (AIDS).
• HIV has the potential to spread through activities such as sharing needles with an infected individual, receiving blood transfusions containing infected blood, and from a mother to her fetus through the placenta and from mother to baby through breastfeeding.

How HIV Affects the Immune System

• Immediately after contracting HIV, individuals may experience mild flu-like symptoms.
• These initial symptoms subside, and infected individuals might remain unaware of their infection for a period.
• HIV targets a specific type of white blood cell called lymphocytes, which are crucial for the immune system's functioning.
• Ordinarily, lymphocytes identify and eliminate invading pathogens, generating antibodies that aid in pathogen destruction and enhance immune response.
• HIV evades detection and destruction by lymphocytes through frequent mutations in its outer protein coat.
• Upon infecting lymphocytes, HIV hijacks the cells' machinery to replicate itself.
• This replication process diminishes the count of lymphocytes and reduces the production of antibodies.
• As a result, the body's capacity to combat infections diminishes over time, eventually progressing to AIDS (Acquired Immunodeficiency Syndrome).

Controlling the Spread of STIs

Sexually transmitted infections (STIs) like HIV can be managed by implementing the following strategies:

• Limiting Sexual Partners: Encouraging individuals to have a smaller number of sexual partners reduces the risk of STI transmission.
• Practicing Safe Sex: Using condoms during sexual activity helps prevent the spread of STIs, including HIV.
• Regular Testing: Individuals engaging in unprotected sex or having multiple partners should undergo regular STI testing to detect infections early.
• Educational Programs: Increasing awareness through educational initiatives helps promote safe sexual practices and STI prevention.