HIV and Viruses

• What are viruses classified as in terms of living status?

  Viruses aren't living things
• What is the organism that viruses infect called?

  The host
• What does HIV stand for?

  Human immunodeficiency virus
• What condition does HIV eventually lead to?

  Acquired immune deficiency syndrome (AIDS)
• What happens to the immune system in AIDS?

  It deteriorates and eventually fails
• What makes someone with AIDS more vulnerable?

  They are more vulnerable to other infections
• Which cells does HIV infect and kill?

  Helper T-cells
• What role do helper T-cells play in the immune response?

  They send signals to activate other immune cells
• What happens when helper T-cell numbers drop critically low?

  The immune system can't mount an effective response
• What are the initial symptoms of HIV infection?

  Severe flu-like symptoms
• What is the latency period in HIV infection?

  Time when HIV replication drops and symptoms are absent
• How long can the latency period last?

  It can last for years
• When are people with HIV classified as having AIDS?

  When symptoms appear or helper T-cell count drops
• What is the typical time frame for HIV to develop into AIDS without treatment?

  Around 10 years
• What types of infections do people with AIDS develop?

  Diseases that wouldn't affect healthy individuals
• What are some initial symptoms of AIDS?

  Minor infections of mucous membranes
• What serious infections can develop as AIDS progresses?

  Chronic diarrhoea, severe bacterial infections, tuberculosis
• What infections can occur during late stages of AIDS?

  Toxoplasmosis of the brain and candidiasis
• What ultimately causes death in AIDS patients?

  Serious infections, not HIV itself
• What factors affect the progression of HIV to AIDS?

  Existing infections, HIV strain, age, healthcare access
• What is the basic structure of HIV?

  Spherical structure with RNA and proteins
• What is the role of reverse transcriptase in HIV?

  It is needed for virus replication
• What is the function of the capsid in HIV?

  It is an outer coating of protein
• How does HIV attach to host cells?

  Using attachment proteins on its envelope
• What happens during the replication of HIV?

  It uses host cell machinery to replicate
• What are the steps of HIV replication inside a host cell?

  1. Attachment protein binds to host cell receptor
  2. Capsid enters and releases RNA
  3. Reverse transcriptase makes complementary DNA
  4. Double-stranded DNA integrates into human DNA
  5. Host enzymes create viral proteins
  6. New viruses bud from the host cell
• Why can't antibiotics be used to treat viral infections?

  Viruses use host's enzymes and ribosomes
• What do most antiviral drugs target?

  Virus-specific enzymes
• What is the best way to control HIV infection in a population?

  Reducing its spread
• How can HIV be transmitted from mother to child?

  Through infected bodily fluids during pregnancy
• How can antiviral drugs affect HIV-positive mothers during pregnancy?

  They can reduce the chance of baby being infected