HIV and Viruses

• What does HIV cause?


  AIDS
• What does HIV stand for?


  human immunodeficiency virus
• what is HIV?


  A virus that affects the immune system
• what does HIV eventually lead to\?


  AIDS
• Whart does AIDS stand for?


  Acquired immune deficiency syndrome
• what is AIDS?


  A condition where the immune system deteriorates and eventually fails

  This makes someone with AIDS more vulnerable to other infections, for example pneumonia
• How does HIV affect the immune system?


  • HIV infects and eventually kills helper T-cells, which act as host cells for the virus
  • Without enough helper T-cells , the immune system is unable to mount an effective response to infections because other immune system cells don't behave how they should
• When do people infected with HIV develop AIDS?


  When the helper T-cell numbers in their body reach a critically LOW level
• What structure does HIV have?

  HIV has a spherical structure
• what happesn during the inital infection period?


  replicates rapidly & the person may experience severe flu-like symptoms

  • after this period, HIV replication drops to a lower level . this is the LATENCY PERIOD
  • during the latency period which can last for years, the infected person wont experience any symptoms
• what are people with AIDS susceptible to?


  a range of illnesses
• when are people with HIV classed as having AIDS?

  when symptoms of their failing immune system start to appear or their helper T-cell count drops below a certain level.
• what do people with AIDS generally develop?


  diseases that would not cause serious problems in people with a healthy immune system
• The length of time between infection with HIV and the development of AIDS varies between individuals but without treatment it is usually 10 yeaers
• AIDS - the infections become more and more serious as there are fewer and fewer immune system cells to fight them