Human Immunodeficiency Virus

& AIDS

Robin Russell &Daniela Kane

Basics

Human Immunodeficiency Virus (HIV) is a retrovirus that results in infections that are hard for the body to fight.

Acquired Immune Deficiency Syndrome is the fatal disease caused by HIV.

History

Scientists identified a type of chimpanzee in West Africa as the source of HIV infection in humans. The virus most likely jumped to humans when humans hunted these chimpanzees for meat and came into contact with their infected blood. Over several years, the virus slowly spread across Africa and later into other parts of the world.

History1983 – Luc Montagnier of the Pasteur

Institute in Paris, France, discovers HIV.

1984 – Robert Gallo of the National

Cancer Institute in Washington, DC, US co-discovered HIV.

A look at AIDSYear Activity1985 -The first HIV test is licensed by the US Food and Drug Administration

(FDA)-US blood banks are screened for the virus-US President Ronald Reagan mentions the word "AIDS" in public for

1986 - The first panel of the AIDS quilt is created1987 - Princess Diana gets involved with AIDS victims1988 - FDA begins a “Fast-track-policy” allowing public access to life saving

drugs still in clinical trials1989- Scientist find that even before aids symptoms develop, Hiv replicates

widely in the blood.1991-1992

Aids becomes the leading cause of death in the U.S I men 25-44

1993 CDC launches its first condom advertisement on TV

1996-1997

Researcher David Ho claims that HAART (highly active anti-retrovial therapy) can cut hiv to undeletable levels. Later to be proven wrong because hiv hides in dormant cells

A look at AIDS Year Activity1998-2000

Awareness grows of HARRT has serious side effects

2001-2002

AIDS becomes the leading cause of death world-wide for people 15-59

2003-2005

President Bush announces the 15 billion dollar Presidents Emergency Plan for aids relief

2006-2007

HIV treatment is shown to extend life by 24 yerts at a cost of $618,9000.

2008 The CDC says improved surveillance shows Aids in America is worst than we thought 33million are infected .

HIV-Related Opportunistic Infections

Most common:

- Kaposi’s Sarcoma

- Pneumocystis carinii pneumonia (PCP)

Kaposi’s Sarcoma

Grows into reddish-purple patches on skin Considered AIDS related because it is seen in people

with weakened immune systems. Most likely to occur with low CD4 counts – typically below 350 cells/ml

Pneumocystis carinii pneumoniacarinii pneumonia (PCP)

A parasite transitional between a fungus and protozoan, frequently occurring as aggregate forms existing within rounded cystlike structures.

BIOLOGY OF DISEASE

HIV is a retrovirus Almost all organisms, including most viruses,

store their genetic material on long strands of DNA. Retroviruses are the exception because their genes are composed of RNA (Ribonucleic Acid).

Retroviruses allow for a reversal of genetic transcription, from RNA to DNA rather than the usual DNA to RNA.

Biology of Disease Outside of a human cell, HIV exists as roughly

spherical particles (sometimes called virions). The surface of each particle is studded with lots of little spikes.

An HIV particle is around 100-150 billionths of a metre in diameter. That's about the same as:

-one seventieth of the diameter of a human CD4+ white blood cell.

Biology of Disease HIV particles surround themselves with a coat of fatty

material known as the viral envelope (or membrane). Projecting from this are around 72 little spikes, which are formed from the proteins gp120 and gp41. Just below the viral envelope is a layer called the matrix, which is made from the protein p17.

The viral core is usually bullet-shaped and is made from the protein p-24. Inside the core are three enzymes required for HIV replication.

- reverse transciptase - integrase - protease

Biology of Disease

PathophysiologyEntry

HIV can only replicate (make new copies of itself) inside human cells.

Infections begins when - a virus particle bumps into a cell that carries

on its surface a special protein called CD4. - the spikes on the surface of the virus particle

stick to the CD4 and allow the viral envelope to fuse with the cell membrane.

- The contents of the HIV particle are then released into the cell, leaving the envelope behind.

PathophysiologyReverse Transcription and Integration

Once inside the cell, the HIV enzyme reverse transciptase converts the viral RNA into DNA, which is compatible with human genetic material. This DNA is transported to the cell's nucleus, where it is spliced into the human DNA by the HIV enzyme integrase. Once integrated, the HIV DNA is known as provirus.

PathophysiologyTranscription and Translation HIV provirus may lie dormant within

a cell for a long time. But when the cell becomes activated, it treats HIV genes in much the same way as human genes. First it converts them into messenger RNA (using human enzymes). Then the messenger RNA is transported outside the nucleus, and is used as a blueprint for producing new HIV proteins and enzymes.

PathophysiologyAssembly, Budding and Maturation

Among the strands of messenger RNA produced by the cell are complete copies of HIV genetic material. These gather together with newly made HIV proteins and enzymes to form new viral particles, which are then released from the cell. The enzyme protease plays a vital role at this stage of the HIV life cycle by chopping up long strands of protein into smaller pieces, which are used to construct mature viral cores.

The newly matured HIV particles are ready to infect another cell and begin the replication process all over again. In this way the virus quickly spreads through the human body. And once a person is infected, they can pass HIV on to others in their bodily fluids.

Federal recommendations for first line anti-HIV therapy NNRTI-BASED REGIMENTS

Preferred regimens

efavirenz + 3TC + (AZT or tenofovir or d4t): except for pregnant women or women who whish to become pregnant. (3 to 5 pills a day)

Alternative Regimens

efavirenz + (3TC or (FTC) +ddl; except for pregnant women or women who wish to become pregnant (3 to 5 pills a day)

nevirapine + (3TC or FTC) + (AZT or tenofovir or d4t) (4 to 6 pills a day)

PI – based regimens Preferred regimens

Kaletra + 3TC + (AZT or d4t) (8 to 10 pills a day)

Diagnostic testing for HIV Diagnostic Testing For HIV

EISA/Western Blot Blood TestsThe OraQuick Rapid HIV-1 Antibody TestViral Load TestsCD4/CD8 ratio Tests

Diagnostic Testing Diagnostic Testing on When to start your medication:

Blood CountBlood Chemistry profile (including testing for your kidney and liver)Hepatitis B testHepatitis C testViral load test (amount of HIV in your blood) CD4 cell count (number of cells in your blood that fight infection, also called “T cells”)Syphilis Test TB skin TestToxoplasma antibody testGynecologic exam (with pap test and pregnancy test)-for women

Interesting Facts

Worldwide, AIDS kills more than 8,000 people every day; 1 person every 10 seconds

HIV accounts for the highest number of deaths by any single infectious agent.

Since the beginning of the epidemic, AIDS has claimed nearly 30 million lives; more than 14 million children have lost one or bother parents to AIDS

Aids wasting syndromeAIDS wasting is the involuntary lose of more than 10% of body weight, plus more than 30 days of either diarhhea, or weakness and fever. Wasting is linked to disease progression and death. Losing just 5% percent of body weight can have the same negative effects. There is no standard threatment for AIDS wasting.

Aids wasting syndrome

Aids wasting syndrome

Protection

To protect yourself, remember these ABCs:

A=Abstinence B=Be Faithful C=Condoms

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