Human Immunodeficiency Virus

HIV stands for human immunodeficiency virus.

HIV is transmitted by body fluids:

• Unprotected sex is responsible for the majority of HIV transmissions globally
• The second most frequent mode of HIV transmission is via contaminated blood and blood products. Blood-borne transmission can occur through needle sharing during intravenous drug use, needle-stick injury in health professionals, transfusion of contaminated blood or blood products, or medical injections with unsterilized equipment.
• The third most common way HIV is transmitted worldwide is from an untreated mother to her child during pregnancy, childbirth, or breastfeeding. If the mother is infected with HIV, there is about a 15% chance that the virus will be transmitted to her infant through her breast milk. 

Image: Waglione. CC BY SA 3.0

The virus infects the lymphocytes (T helper cells) of the body's immune system. Immediately after infection, people often suffer mild flu-like symptoms. During this time, the virus rapidly replicates causing a high viral load in the person’s blood and a drop in the number of lymphocyte cells. The body responds by producing more lymphocyte cells and they start killing HIV-infected cells. 

Consequently, the viral load starts to decline, and the number of lymphocyte cells recovers. However, the virus is not eliminated and remains in the body.

Without treatment, person may be infected for up to 20 years before they develop any symptoms of HIV.  Symptoms which may occur are shown in the diagram below:

Image: Mikael Häggström. CCO

Most infected individuals will eventually progress to AIDS if their HIV infection is not treated. AIDS is diagnosed when the lymphocyte cell count falls below 200 per microliter of blood or when the infected individual starts to develop opportunistic diseases. 

Patients with AIDS will eventually develop an illness which will kill them because they do not have an immune system which is strong enough to fight off an infection.  These common diseases include pneumonia, yeast infection and cancer. 

In addition, many AIDS patients develop HIV wasting syndrome, in which they lose weight and muscle mass and experience extreme fatigue and weakness. People with AIDS also frequently experience long fevers, night sweats, swollen lymph nodes, and diarrhea.

HIV is easily diagnosed with a blood test.  HIV/AIDS is an uncurable disease. Antiretroviral drugs are available which reduce the amount of virus in your body and slow down the progression but there is no known cure.  Trials into a vaccine to prevent HIV infections have begun with promising results. 

Credit: Stanford Center for Health Education. What to expect when beginning treatment for HIV/AIDS

Stop the Spread

To prevent the spread of the disease the use of condoms is recommended, and disposable gloves should be used where there is any danger of contact with contaminated blood. 

HIV transmission through intravenous drug use can be reduced through needle exchange programs or the substitution of prescription drugs for illegal drugs. 

Anti-retroviral drugs can be taken 2 - 3 days after you suspect you have been exposed to the virus and significantly reduce the chances of transmission. 

Rates of mother-to-child transmission can be reduced to about 1 percent by giving antiretroviral medications to the mother during pregnancy and to the infant after birth.  Bottle feeding a baby instead of breastfeeding takes away the risk of HIV transmission through breast milk.

HIV/AIDS is one of the world’s most fatal infectious diseases – particularly across Sub-Saharan Africa, where the disease has had a massive impact on health outcomes and life expectancy in recent decades.

Image: OurWorldinData.org. CC BY

Global HIV statistics:

• 38.4 million people globally were living with HIV in 2021.
• 1.5 million people became newly infected with HIV in 2021.
• 650 000 people died from AIDS-related illnesses in 2021.
• 28.7 million people were accessing antiretroviral therapy in 2021.
• 84.2 million people have become infected with HIV since the start of the epidemic.
• 40.1 million people have died from AIDS-related illnesses since the start of the epidemic.
• In 2021, there were 38.4 million people living with HIV.
  • 36.7 million adults (15 years or older).
  • 1.7 million children (0–14 years).
• 54% of all people living with HIV were women and girls.
• At the end of December 2021, 28.7 million people were accessing antiretroviral therapy, up from 7.8 million in 2010.
• In sub-Saharan Africa, six in seven new HIV infections among adolescents aged 15–19 years are among girls. Girls and young women aged 15–24 years are twice as likely to be living with HIV than young men

Source: UNaids.org

Image: WHO. CC BY-NC-SA 3.0 IGO