1. HIV/AIDS
Biology 342

2. HIV Genus Lentivirus, Family Retroviridae
Single stranded, enveloped RNA virus
Long incubation period with long duration illness

3. HIV The HIV enters the host cell as a single stranded RNA
Viral RNA is converted via a viral protein- reverse transcriptase into double-stranded DNA
Next, this viral DNA is imported into the host cell nucleus and integrated into the cellular DNA
Virus goes “latent” avoiding detection from host’s immune system. It can remain integrated for months to years – being replicated with the host cell’s DNA
Eventually, the virus DNA cleaves from host DNA and is transcribed back into new viral RNA and viral proteins – then is packaged for released from the cell…

4. HIV Replication Cycle

5. Origin of HIV
HIV originated from non-human primates from West-central Africa.
The virus was transferred to humans sometime in the early 20th century
HIV is most closely related to SIV which is endemic in chimpanzees and sooty mangabeys.
(SIV smm) -> HIV – 2
(SIV cz) -> HIV - 1

6. History
AIDS was first clinically observed in the US in – then called gay-related immunodeficiency disease – associated with Kaposi’s Sarcoma. The name was changed to AIDS – “Acquired Immunodeficiency Syndrome in 1982.
It was initially thought to be caused by two viruses: LAV = Lymphadenopathy Associated Virus which caused severe swelling of lymph nodes and physical weakness, and HTLV = Human T- Lymphotropic Virus.
In 1986 it was found that the two viruses were the same and given the name HIV = Human Immunodeficiency Virus.

7. Transmission of HIV
Person to person within mucus membranes in specific body fluids including blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk.
HIV can be transmitted as both fee virus particles and/or virus within infected immune cells.
HIV can not be transmitted in body fluids such as saliva, tears, or sweat.
HIV is not transmitted through air, water, insects or ticks as vectors, skin contact, social kissing, or toilet seats.

8. Transmission Risk Hierarchy
Anal sex
Vaginal sex
Multiple sex partners
Sharing needles and syringes
Birth and/or breast milk
Blood transfusion
Oral sex
Broken skin contact
Kissing with open wounds

9. HIV Infection Prevention
Ask sex partners about test results
Correct and consistent condom use
Do not share needles, syringes, or other associated equipment
Pre-exposure and post-exposure prophylaxis
PrEP
PEP

10. HIV Infection Symptoms
1st stage (acute wks. post exposure): flu-like fever, headache, diarrhea, nausea, vomiting, sore throat, aching muscles, fatigue, night sweats, and a red rash on torso that doesn’t itch.
2nd stage (Latent): asymptomatic for 10 + years – people are infective, their immune system is being destroyed (T-cell count slowly drops).
3rd stage (AIDS): dramatic weight loss, recurrent opportunistic infections, yeast infections in mouth, throat, vagina, easy bruising and bleeding, Kaposi sarcoma (skin cancer) and pneumocystis (Pneumonia), coma, and death.

11. AIDS Mortality
HIV causes a slow but progressive failure of the host immune system which allows life- threatening infections by multiple opportunistic pathogens and also allows cancer to thrive.

12. HIV World Wide 2.1 million new infections per year
35 million people living with HIV infections
1.5 million people die each year
Overall death toll from HIV = 39 million
Sub-Saharan Africa with 70% of new HIV infections annually
Followed by Asia, Pacific, Latin America, Caribbean, and Eastern Europe

13. HIV in United States New infections in the US: 47,500 per year.
Living with infections in US: 1.2 million
Percent who don’t know, est. ~ 13% up to 20%

14. Logistic Growth of AIDS in US

15. New Infections
MSM = men who have sex with men

16. Infections by Ethnicity

17. World Wide Infections

18. AIDS today
In 2014, reports estimate that 36.9 million people are living with the virus, some 70% of them in sub-Saharan Africa, and that number continues to increase because 15 million of them now are taking life prolonging antiretroviral drugs. South Africa alone has 6.8 million HIV-infected people—more than any other country.

19. Hidden HIV
Researchers have developed a sophisticated new probe (DNA scope) that can find HIV in its hiding places.
The new probe shows viral DNA to aid in the assessment of infection.

20. Longevity with HIV
There is no cure for HIV infection and one is always a carrier of the virus, but…
A healthy 20 year old infected today can expect to live an additional 40 years.
Early detection today means a near normal life span.
Antiretroviral Therapy (ART) must begin before the decline in function of the immune system.

21. ART: Antiretroviral Therapy
ART stop/slows the progression of AIDS through a combination of at least 3 drugs.
Each drug attacks HIV in a different way.
A cocktail of drugs can block the virus from making DNA from its RNA, can inhibit assembly of viral proteins, prevent HIV from entering the host cell, and prevent HIV DNA insertion into the host DNA.

22. HIV Life Cycle and Inhibiting Drugs
HIV starts as a free virus circulating in the blood stream until it attaches to an immune cell (usually a T- helper cell that destroys other infected cells) (2 drugs interfere here).
HIV may enter other cells too, including brain cells.
HIV RNA uses reverse transcriptase to build HIV DNA (16 drugs slow this) which it inserts (2 drugs block this) into the host cell chromosome – infection is established
When the infected cell replicates so does HIV DNA.
Eventually new viral proteins and RNA are assembled (10 drugs slow or inhibit this process) and new virus exits the cell through a process called “budding”.

23. cART: Combination Therapy
A carefully monitored drug program is established early after diagnosis and lasts throughout the rest of life.
3 to 4 of the above drugs must be taken without interruption on a precise schedule.
The drugs must be changed or rotated periodically to prevent drug resistance.
The drugs reduce viral load – sometimes below detectable levels – but the virus is not gone and eventually will destroy the immune system.

24. Test & Treat Strategy
There is no cure or vaccine for HIV infection but early detection and treatment can change HIV infection from a fatal disease to a manageable chronic disease.
Education and treatment reduces transmission and slows the spread of HIV
Problems
Up to 20 % of infected people do not know -
Rising health care costs inhibits treatments -
New drugs are needed to fight drug resistance -
Legislative battles over budget of health care coverage and HIV drug research continue -