HIV and AIDS Human Immunodeficiency Virus HIV causes

HIV and AIDS Human Immunodeficiency Virus (HIV) causes Acquired Immune Deficiency Syndrome (AIDS)

HIV is a retrovirus • 2 kinds of virus: RNA or DNA, depending on what kind of genetic material the carry and use to replicate themselves inside a host. • RNA viruses: SARS, influenza, hepatitis C, HIV • DNA viruses: herpes, HPV, chicken pox, smallpox • Retroviruses carry RNA that is then transcribed back into DNA and the DNA is integrated into the host cell using reverse transcriptase • This is how retroviruses work.

How does HIV invade and take over cells? • HIV attacks immune cells, which weakens the immune system • Glycoproteins on the outside of the virus bind with helper T (TH) lymphocytes (sometimes called WBC or white blood cells) • Viral proteins and RNA are released into the host cell • Reverse transcriptase transcribes the RNA into DNA • The new viral DNA is incorporated into the host’s genome (called a provirus) – So…. what kind of replication method does HIV use? Lytic or lysogenic? • The new genome provides all instructions needed to make complete new viruses • Offspring viruses bud off from host cell and invade other cells

HIV is a retrovirus odd in that buds from the cell and doesn’t destroy it during lytic phase…. .

Good HIV simulation…. • http: //www. sumanasinc. com/webcontent/ani mations/content/lifecyclehiv. html

HIV and your immune system • HIV invades TH lymphocytes, cells which normally assist in the destruction of viruses • HIV mutates at a high rate during replication • Altered proteins on the surface of the virus can make it unrecognizable and allow it to evade destruction and mutate further • The viral DNA “hides” in the host DNA where antiviral drugs cannot destroy it • The invasion of TH cells weakens the immune system making the victim susceptible to infections and cancers

Transmission • • Blood to blood contact Unprotected sex Needle sharing, untested blood transfusions Pregnant or nursing mother to infant

Statistics • 0. 6% of the Worlds population is infected • Since 1981, the virus has killed over 25 million people (one third from sub-Saharan Africa) • 10. 8% of South Africans are HIV positive • On average about 22% of infected people get treatment worldwide • The U. S. spends about $6 billion/year on prevention (not treatment)

In 2010, 40 million people worldwide living with HIV/AIDS

In the U. S. : CDC HIV Surveillance Data for 2009

US Snapshot for 2012 from Kaiser Family Foundation

CDC Surveillance Data: 48, 000 new HIV diagnoses/year

Treatments • HAART (highly active antiretroviral therapy) – Inhibit reverse transcriptase – Inhibit protease (the proteins found on the outside of the virus) – Intregrase inhibitors (inhibit the binding of HIV to TH cells)