Final answer:
HIV transmission can occur through unprotected sex, needle sharing, and from mother to child, but preventive measures like condom use, needle-exchange programs, and antiretroviral therapies are effective. Challenges include stigma and access to care, while opportunities lie in education and public health interventions that reduce incidence rates.
Step-by-step explanation:
HIV, or Human Immunodeficiency Virus, affects specific cells of the immune system, particularly CD4 cells, often referred to as T cells. There are several ways HIV can be transmitted, including unprotected sexual contact, sharing needles, and from mother to child during childbirth or breastfeeding. To combat the spread of HIV, major prevention strategies include the use of condoms to reduce transmission through sexual contact, needle-exchange programs for those who use intravenous drugs, and antiretroviral therapies to decrease the viral load in HIV-positive individuals.
Challenges in HIV prevention include combating social stigma, ensuring access to healthcare and prevention tools, and maintaining proper education about transmission and prevention methods. Opportunities in HIV prevention are reflected in the decreases of incidence rates through effective public health policies, comprehensive sex education, and early treatment initiatives with antiretroviral medications which have transformed HIV from a fatal disease to a chronic condition that individuals can manage.