L2 Biology

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AIDS

• L2 Biology

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What is AIDS?

• AIDS Acquired Immunodeficiency Syndrome
• Deadly disease caused by
• HIV Human Immunodeficiency virus

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Structure of HIV
gp 120
gp 41
RNA
p24
p17
Enzyme

• Enzyme

Enzymes reverse transcriptase, integrase and
protease Gp glycoprotein p protein (number
is how big it is)
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How does HIV attack a cell?
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2
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Steps of an HIV infection

1. Virus attaches to Helper T cell (one of the white
   blood cells in the immune system).
2. Virus sends its RNA into cell.
3. RNA codes back to DNA needs reverse
   transcriptase (enzyme).
4. DNA becomes part of the cells DNA needs
   integrase.
5. Cell starts to make parts for new HIV particles.
6. New HIV parts come together in cell (needs
   protease) and bud out of cell membrane takes
   a part of cell membrane to become the virus
   envelope.

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Click here for an HIV animation
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Helper T cells

• These are the cells that start the immune
  response by alerting the other cells that there
  is a foreign protein (like a virus or bacteria
  cell) in the body.
• When a lot of them die because they are making
  HIV instead of the proteins they need, then the
  person cant fight infections.
• If the Helper T cell count gets below 500
  cells/ml, the person gets opportunistic
  infections. Below 200 cells/ml, the person has
  AIDS and gets life-threatening infections.

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How do you get HIV?

• Sexual activity unprotected sex passes infected
  fluids from a person with HIV to a person without
  it.
• Contaminated needles IV drug users share
  needles if the person who just used it has HIV,
  then the next person to use it can get HIV.
• Mother to baby during the birth
• process or breastfeeding

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HIV cannot be caught by

• Coughing and sneezing droplets in the air
• Kissing, touching or shaking hands
• Sharing eating utensils or glasses
• Contact with toilet seats
• Insect or animal bites
• Swimming pools
• Eating food prepared by someone with HIV

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How do you prevent HIV?

• ABSTINENCE !!!!!!!!
• Never have unprotected sex
• Have only one sex partner who is free of the
  disease
• Dont use iv drugs
• Stay away from unknown blood fights and rough
  sports can expose you.
• Pregnant mothers who are HIV should get
  treatment to prevent the baby from getting it.

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What happens during the disease?

1. Asymptomatic May last years.
2. Eventually swollen glands, slight infections
   may seem like the flu, may recover, then symptoms
   return and stay. During this time, T-cells are
   being destroyed. The infections are those that a
   person with a normal immune system would not get.
   AIDS-related complex.
3. When T-cell count is too low, then the person
   gets life-threatening infections - AIDS

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Symptoms

• Fever
• Swollen glands
• Night sweats
• Unexplained weight loss
• Kaposi sarcoma reddish/brown
• cancer on skin
• Many others

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Diagnosis

• Blood test can tell if your body has made
  antibodies against HIV if theyre in your blood
  you have been exposed to HIV
• Be careful the test might be given too soon
  after infection you may not have made enough
  antibodies to give a positive test, even though
  you have HIV.
• Test results are private and confidential.

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Treatment

• Enzyme inhibitors
• Reverse transcriptase inhibitor
• Integrase inhibitor
• Protease inhibitor
• Many kinds of drug combinations are in use today
  expensive and have many bad side effects.

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Click here for an HIV animation including drug
treatments
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• AIDS statistics - People living with AIDS in the
  US
• At the end of 2003, the CDC estimates that
  405,926 persons were living with AIDS, of these
• 36 were white
• 42 were black
• 20 were Hispanic
• 2 were of other race/ethnicity.

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• Of the adults and adolescents in the US with
  AIDS, 77 were men. Of these men
• 58 had sex with men (MSM)
• 22 were injection drug users (IDU) 11 were
  exposed through heterosexual contact
• 8 were both MSM and IDU.

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• Of the 88,815 adult and adolescent women in the
  US with AIDS
• 63 were exposed through heterosexual contact
• 35 were exposed through injection drug use.
• An estimated 1,998 children were living
  with AIDS in the US at the
• end of 2003.

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• Persons with AIDS are surviving longer and are
  contributing to a steady increase in the number
  of people living with AIDS. This trend will
  continue as long as the number of people with a
  new AIDS diagnosis exceeds the number of people
  dying each year.

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How can you avoid getting AIDS?
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The End

• The End

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