HIV( human immunodeficiency virus) is a virus that targets the immune cells of the body. It is an infection that damages your immune system over time and causes AIDS. AIDS is the final stage of an HIV infection. As a person gets older his immune system becomes weak called immunodeficiency. As a result, this increases the risk of infections and tumors.
So, there are two distinct types of HIV.
- HIV-1
- HIV-2
HIV virus:
HIV is a single-stranded, enveloped, positive-sense, RNA retrovirus. So, it injects a single strand of RNA into the T-helper cell. When the immune cells become activated by infection or viruses then they start transcribing and translating new HIV viruses. They bud off from the cell membrane to infect more immune cells. HIV enters the body through sexual intercourse. So, it typically spreads from person to person.
When foreign bacteria and viruses enter the body then they can cause infections. In response, the immune system creates a counterattack and starts to control the viral replication. So, the amount of virus in the blood declines to lower but is still detectable.
After this point there are no clinical signs or symptoms of the virus, So, the number of viruses in the blood slowly increases and the patient enters the chronic or clinically-latent phase which lasts 2 to 10 years. Because of the weakness of the immune system person is losing about 1-2 billion T cells every day.
Mechanism of action for HIV virus:
HIV targets CD4+ cells. It means that these are the cells that have a specific molecule called CD4 on their membrane. Dendritic cells, Macrophages, and T-helper cells are all helpful in the immune response and they have CD4 molecules. That’s the reason they can be affect by HIV. The CD4 molecule helps the HIV attach to immune cells.
HIV attaches to the CD4 molecule and co-receptor by a protein name gp120. So, HIV binds to both the CD4 molecule and a co-receptor to enter the cell. The most common co-receptors for HIV name as CXCR4 co-receptor. These are present in T-cells, monocytes, macrophages, and dendritic cells.
What is the important role of CXCR4 in HIV?
Because some people with homogeneous genetic mutations in their CCR5 have immunity to HIV. So, HIV can’t attach and enter the cell. In fact, if someone has heterozygous mutations means it has fewer co-receptors than has fewer chances for the progression of the disease. Because it makes it harder for the virus to spread. Those people without this mutation have a higher chance of getting this disease because once HIV binds to CD4, CCR5, or CXCR4, it enters the cell.
Which type of HIV is most common?
HIV-1 is the more common link with AIDS worldwide. HIV-2 is rare and mostly present in southern Asia and western Africa. So, HIV-2 is so uncommon that “HIV” is always known as HIV-1.
What are the Symptoms of HIV/AIDS?
During the acute infection, Patients typically experience flu-like or mononucleosis-like symptoms. When the T cells level falls below 200 cells / mm3 low then patients start experiencing symptoms like:
- Swollen lymph nodes or lymphadenopathy
- Minor infections like oral hairy leukoplakia
- A hairy-looking white patch on the side of the tongue
- Oral candidiasis, a yeast infection in the mouth
- Persistent fever
- Fatigue
- Weight loss
- Bacterial pneumonia
- Pneumocystis pneumonia
- Candidiasis of the esophagus
- certain tumors and malignancies like Kaposi sarcoma which causes lesions on the skin and other soft tissues
- Respiratory illnesses, such as tuberculosis
- Intestinal illnesses, such as chronic diarrhea
- Non-Hodgkin lymphoma
How HIV/AIDS is transmitted?
The common mode of transmission in US is Male-to-male transmission and male-to-female is the most common mode in resource-limited settings. The less common mode of transmission is from female to male. That is due to HIV is present in the cervical fluids and vagina of infected women.
Causes of HIV/AIDS transmission:
- About 75% of HIV is contracted from sexual intercourse.
- The next most common means are intravenous drug abuse and mother-to-child transmission via the placenta or via breast milk.
- Other common modes of transmission are accidental needle sticks and blood transfusions.
How do we diagnose HIV/AIDS?
There are a few types of HIV tests that can be done for diagnosis such as
- Antibody tests
- Antibody/antigen tests
- RNA/DNA tests
Antibody tests detect the antibodies that the body’s made against HIV. Antigen tests detect the virus directly. RNA tests check viral RNA. So. it also detects the virus directly. For identifying early infection the recommended test is the antibody/antigen test.
Treatment for HIV/ AIDS:
There’s currently no cure for AIDS. However, treatment can help somebody with AIDS to live longer and healthier lives.So for this purpose antiretroviral therapy or ART I used.
ART is a combination of medicines that is known as an HIV regimen. One class of antiretroviral medication name as entry or fusion inhibitors. It disrupts the HIV infection by stopping the virus from attaching to your cells. Other classes of antiretroviral medications retain integrase inhibitors, protease inhibitors, and reverse transcriptase inhibitors.
These drugs slow down the HIV replication, creation, and assembly of new viruses. They also recover the immunity and immune system and help to fight off infections more effectively.
How to cure HIV permanently?
The most effective way to avoid the infection is to prevent vaginal and anal sex. Stay with only one uninfected partner and use latex condoms for protection. Also, avoid using injectable illegal drugs. Take care while using drug needles because the needles have viruses on them. Lastly, prevent intoxication from drugs or alcohol.