BIOCHEMISTRY OF HIV

This post covers the structure of HIV, how it infects a cell and how HIV spreads!

STRUCTURE:

• HIV are called Virions
• Virions is a virus particle consisting of:

1) an outer protein shell, (purple layer)                          
2) capsid (green dotted layer)

3) inner core of ribonucleic acid (yellow layer)

• The core confers infectivity& the capsid provides specificity to the virus!!

•  The virus is approx 100nm and has a icosahedral structure with 72 spikes found on the surface of the virus. The spikes are made up of 2 glycoproteins ( gp 120 & gp 41 )

WONDERING HOW HIV INFECTS OUR CELLS???????

Step 1: ENTRY

HIV can only replicate inside human cells! HIV attaches itself onto the surface protein CD4. The spikes on the surface of the virus sticks to CD4, causing the viral envelope to fuse with the cell membrane. The contents of the deadly virus are   then released into the                                                                         cell. 

Step 2: REVERSE TRANSCRIPTION & INTEGRATION

The primary host of HIV are white blood cells called T-helper cells. These cells are very important to our immune system as they activate responses of many other immune cells. When the T-helper cells are infected with HIV they die.

The body compensates for the loss of infected T cells by producing them in greater quantities. HIV enzyme, reverse transciptase converts RNA into DNA using the host cell's machinery to replicate itself.

The T4 is transformed into a biological factory producing new HIV. The T4 cell bursts releasing new virus into the blood stream. HIV then destroys the ability of the body to fight infection leading to illness and possible death

*** Protease Inhibitors can stop this process***

REFERENCES:

• http://www.britannica.com/EBchecked/topic/630143/virion
• http://www.avert.org/hiv-structure-and-life-cycle.htm
• http://health.howstuffworks.com/diseases-conditions/infectious/hiv-and-aids-dictionary2.htm

PREVENTION ????

Here are some methods to prevent HIV infection:


PREVENTION VIDEO



  1) PRACTICE SAFE SEX

- Use a condom when having sex
- Get tested and know if your partner has HIV before having sex
- Apply vaginal gel containing tenofovir

  2) SAFER SEX ACTIVITIES

Abstain from sex. Not having vaginal, anal or oral sex is the surest way to avoid HIV. If you do decide to have sex, you can reduce your risk of HIV by practicing safer sex.

These activities carry no risk of HIV infection:

- Non-sexual massage
- Casual or dry kissing
- Masturbation (without your partner's body fluids)
- Frottage- also known as "dry humping" or body-to-body rubbing

You can still contract other STIs, like herpes, HPV, or pubic lice ("crabs") if you have bare skin-to-skin contact with your partner.

3) USE A CLEAN NEEDLE 

-If you use a needle to inject drugs, never reuse or share needles,syringes, water or drug preparation equipment. 
- Make sure it's sterile and only use equipment obtained from a reliable source.

- Take advantage of needle-exchange programs in your community and consider seeking help for your drug use.
- Use a new, sterile needle or syringe each time to prepare and inject drugs.
- Throw away needles and syringes after one use.

REFERENCES:

http://www.mayoclinic.org/diseases-conditions/hiv-aids/basics/prevention/con-20013732

http://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/helping-someone-recently-diagnosed/how-to-protect-yourself/

http://www.aids.gov/hiv-aids-basics/prevention/reduce-your-risk/substance-abuse-use/
http://www.avert.org/hiv-prevention.htm

TREATMENT OF HIV

Sadly, there is NO cure for HIV, however on the brighter side there are a variety of drugs used to control the virus. 

The Classes of Anti-HIV Drugs include:

1) Non-nucleoside reverse transcriptase inhibitors (NNRTIs):

Drugs in this prevent HIV from making copies of itself 


E.g. efavirenz and nevirapine

2) Nucleoside reverse transcriptase inhibitors (NRTIs):

They are faulty versions of building blocks that HIV needs to make copies of itself. 

E.g. Abacavir and tenofovir 

3) Protease inhibitors (PIs):

It disables protease, another protein that HIV needs to make copies of itself and infect healthy cells

E.g. atazanavir and ritonavir

4) Entry or fusion inhibitors:

These drugs block HIV's entry into CD4 cells

E.g. enfuvirtide and maraviroc

5)Integrase inhibitors:

It works by disabling integrase, a protein that HIV uses to insert its genetic material into CD4 cells.

E.g  Raltegravir

Each class of anti-HIV drugs blocks the virus in different ways. Because each HIV drug can't work by itself, it is best to combine at least three drugs from two classes to avoid creating strains of HIV that are immune to single drugs. When this combination of drugs is taken it is called '' highly active antiretroviral therapy'', or HAART.  

When taken properly, HAART helps people with HIV live way longer and have lesser infections. It works by lowering the amount of HIV in the blood thus improving your body's ability to fight infections.

Some side effects of these drugs include:

• Nausea, vomiting or diarrhea
• Heart disease
• Weakened bones
• Shortness of breath
• Skin rash
• Bone death, particularly in the hip join

Your doctor will monitor your viral load and CD4 counts to determine your response to treatment. Viral load should be tested at the start of treatment and then every three to four months during therapy. CD4 counts should be checked every three to six months.

HIV treatment should reduce your viral load to the point that it's undetectable. That doesn't mean your HIV is gone!!!! It just means that the test isn't sensitive enough to detect it. You can still transmit HIV to others when your viral load is undetectable.

Once you start treatment, you need to continue taking HIV medicines for the rest of your life!!!!!! You will have to think about:

1) Readiness to stick with treatment
You will need to take all of the drugs exactly how its prescribed. Missing doses can result in the virus becoming resistant to the medications. Once this happens, the drugs will not work as well or at all. Whether you must take multiple pills or just one pill a day, you must be ready to take all your medicines as directed and stick with it.                                                                                                                                                          

2) Managing side effects
You will likely have some side effects from the drugs. Some of these are harder to live with than others. Be sure to tell your doctor about any side effects you are having. Only stop taking your HIV medicine because of side effects if your doctor tells you to stop.

Treatment for your HIV disease is most likely to be successful when you know what to expect and are committed to following the plan that you and your healthcare provider work out together.

REFERENCES:

http://www.mayoclinic.org/diseases-conditions/hiv-aids/basics/treatment/con-20013732
http://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/treatment-options/side-effects/index.html
http://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/treatment-options/overview-of-hiv-treatments/

RISKS/DANGERS OF HIV

HIV infection weakens your immune system, making you highly susceptible to numerous infections and even certain types of cancer!

Infections common to HIV/AIDS:

• Tuberculosis (TB) which may cause death.

• Salmonellosis is a bacterial infection from contaminated food or water. Anyone can be exposed to salmonella bacteria and become sick, but it is more common in HIV-positive people.

• Candidiasis is a common HIV-related infection which causes inflammation and a thick, white coating on the mucous membranes of your mouth, tongue, esophagus or vagina. It makes eating painful.

Cancers common to HIV/AIDS:

• Kaposi's sarcoma
  A tumor of the blood vessel walls, this cancer is rare in people not infected with HIV, but common in HIV-positive people.

    It usually appears pink, red or purple lesions on the skin and    

    mouth. In people with darker skin, the lesions may look dark    

    brown or black. 

    Also affect the internal organs, including the digestive tract and       lungs.

• Lymphomas

    This cancer originates in your white blood cells and usually    

    appears in your lymph nodes. 

  

    The most common early sign is painless swelling of the lymph    

    nodes in your neck, armpit or groin.

Other complications:

• Neurological complications like confusion, forgetfulness, depression, anxiety and difficulty walking. It leads to behavioral changes and diminished mental functioning.

• Kidney disease. HIV-associated nephropathy (HIVAN) is an inflammation of the tiny filters in your kidneys that remove excess fluid and wastes from your bloodstream and pass them to your urine. Because of a genetic predisposition, the risk of developing HIVAN is much higher in blacks.

• Have other STI's. HIV produces open sores on your genitals. These sores act as doorways for sexually transmitted infections (STIs) to enter your body.

REFERENCES:

http://www.avert.org/antiretroviral-drugs-side-effects.htm
http://aidsinfonet.org/fact_sheets/view/152?lang=eng

http://www.mayoclinic.org/diseases-conditions/hiv-aids/basics/complications/con-20013732

SIGNS AND SYMPTOMS OF HIV

The symptoms of HIV vary, depending on the individual and what stage of the disease you are in.

Within 2-4 weeks after HIV infection, some people experience flu-like symptoms which is the primary HIV Infection.


Symptoms can include:

• Fever (most common symptom)
• Swollen glands
• Sore Throat
• Rash
• Headaches
• Fatigue
• Muscle/Joint aches and pain

These symptoms can last from a few days to several weeks. However these are also common symptoms of other less serious illnesses, thus, it doesn't necessarily mean the person has been infected with HIV !!!!
You should not rely on symptoms to know if you have HIV.
Often infected people do not have symptoms at all. It isn't possible to tell just by one look that someone is infected by HIV. The only way to know for sure if you're infected is to get tested.

SO, HEAD DOWN TO THE NEAREST CLINIC/HOSPITAL IF YOU SUSPECT THAT YOU HAVE BEEN INFECTED WITH HIV :(

REFERENCES:

http://www.cdc.gov/hiv/basics/whatishiv.html
http://www.aids.gov/hiv-aids-basics/hiv-aids-101/signs-and-symptoms/
http://www.avert.org/hiv-aids-symptoms.htm

Transmission of HIV

HIV is found in the blood, body fluids of an infected person, and in the breast milk of an infected woman.

Transmission occurs when there is sufficient quantity of these fluids getting into someone else's bloodstream, mucous membrane, damaged tissue.
Mucous Membranes can be found inside the rectum, vagina, opening of the penis and mouth



                                  


3 WAYS:

1) Sexually

- Most frequent way of transmission
- Unprotected sexual intercourse with an infected person 
  (Anal, Vaginal Sex)
- Multiple Sex partners increases transmission of HIV

2) Body Fluids

- Contact with an infected person's blood
- Needle-sharing during drug use, transfusion of contaminated     
   blood, medical injections with unsterilised equipment
- E.g Blood, Semen(cum), Rectal and Vaginal Fluid

3) Mother-to-child

- Transmitted from mother to child during pregnancy, delivery or        through breast milk.
- If blood contaminates food during pre-chewing, it may pose a risk   of transmission
- If a woman knows she is infected there are drugs that can be         
  taken to reduce chances of the child being infected.


** Ranked in order from most common to least common **

NOT POSSIBLE:

- Mosquito Infections
- Air
- Saliva, Tears, Sweat
- Toilet Seats
- Casual Contact







REFERENCES:

http://www.aids.gov/hiv-aids-basics/hiv-aids-101/how-you-get-hiv-aids/index.html
http://www.avert.org/can-you-get-hiv.htm
http://www.cdc.gov/hiv/basics/transmission.html

WHAT IS HIV ???

Human Immunodeficiency Virus (HIV) is a virus that infects the human immune system.

•   H – Human (Virus can only infect human beings)
•    I  – Immunodeficiency (Weakens immune system by destroying cells which fight disease and infection. An immune system which is "deficient" is not able to protect one's body)
•   V – Virus (Reproduces by taking over cells in the body of its host)

HIV virus type is known as retroviruses, which infect cells in the body, incorporating their viral genetic material into the cell’s own DNA. The body’s cells produce the virus but in the process, end up being killed. In the case of HIV, this virus infects only selected cells in the body which are required for infection-fighting. (E.g white blood cells specifically those which can be identified because they carry a marker, "CD4" and some cells in the nervous system)

HIV destroys many CD4 cells till your body cannot fight infections and diseases anymore. When that occurs, HIV infection may lead to AIDS, which is the final stage of HIV infection.

REFERENCES:

http://www.aids.gov/hiv-aids-basics/hiv-aids-101/what-is-hiv-aids/
http://www.avert.org/hiv.htm
https://www.iaff.org/et/JobAid/InfDis/What_is_HIV_AIDS_.htm
http://www.cdc.gov/hiv/basics/whatishiv.html