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• HIV history – originated from the SIV (simian immunodeficiency virus)
• HIV was possibly spread through bush meat butchering.

  It is an STD transmitted through bodily fluids – semen, blood and saliva.

  Geographically, HIV was traced back to african trucking routes and areas with mining activities.

  HIV can be spread from sexual contact, blood donation from IV drug users
• There are 2 types of viruses – HIV (Human immunodeficiency virus) and AIDS (Acquired immunodeficiency syndrome)

  There are 2 types of HIV – HIV -1 and HIV – 2

  HIV is a retrovirus – has RNA nucleic acid, invades and kills T cells, it is released by budding and has RNA-DNA-RNA replication.

  AIDS is a syndrome that is a collection of diseases thriving from an HIV weakened immune system.
• HIV structure – has 3 enzymes and RNA.

  Viral RNA, Reverse transcriptase, protease and integrase.

  It also has a docking glycoprotein GP120

  Reverse transcriptase is used to convert RNA into DNA. This is then incorporated into the DNA of host cell.
• 1)HIV attaches to host cell plasma membrane

  2)HIV enters host cytoplasm

  3)Uncoating occurs and Reverse transcriptase converts RNA to DNA.

  4)DNA strand is used as a template for DNA replication and viral proteins synthesis

  5)Enzyme integrase incorporates the viral DNA into host nucleus

  6)Upon activation viral DNA uses host enzymes to transcribe viral RNA

  7)Viral RNA leaves nucleus and proteins are assembled to form new viruses.

  8)Virus leaves from host cell through budding (exocytosis) using the hosts plasma membrane
• HIV host infection – when there is an exposure to HIV infected bodily fluids. Risk increases when there is a STD already present

  Early infection starts at lymph nodes. Within 2 weeks of infection, T cells are infected and killed.

  low viral replication during latent period.
• HIV is transmitted:sexual contact – anal, vaginal or oral. HIV can be transmitted into the bloodstream through small breaks in the lining of the vagina, vulva, penis or mouth.

  Pregnancy, childbirth and breastfeeding – infants can get HIV from infected breast milk. Fetus can get HIV from the amniotic fluid and mothers bloodstream.

  Infected needles

  Blood transfusion with infected blood or organ transplant from an infected donor.

  Occupational exposure – healthcare workers.
• HIV control – there are 2 ways of controlling HIV.

  Protease inhibitors – blocks viral protease which forms non-infective viruses.

  AZT – inhibits reverse transcriptase which prevents DNA formation from RNA. It crosses the blood brain barrier and is prone to evasion by mutated viral strains.
• AIDS symptoms (slims disease)

  neurological – encephalitis and meningitis.

  eyes - retinitis

  lungs – pneumocysts

  skin – kaposi disease and tumors

  gastrointestinal – chronic diarrhea, tumors and esophagitis.
• AIDS opportunistic infections – AIDS defining cancer and AIDS defining bacteria infections

  Cancers – cervical carcinoma, kaposis sarcoma, non-hodgkins lymphoma

  Bacteria infections – Mycoplasma Pneumoniae, strepococcus pneumoniae, candida albicans and treponima pallidum.