HIV and AIDS — Definition

Definition

HIV and AIDS are terms often used interchangeably, but they represent distinct stages of a single disease process. HIV stands for Human Immunodeficiency Virus, which is the virus itself. AIDS stands for Acquired Immunodeficiency Syndrome, which is the most advanced stage of HIV infection.

Think of it this way: you can be infected with HIV, meaning the virus is present in your body, but you might not have AIDS yet. AIDS develops when the HIV infection has severely damaged your immune system, making you highly vulnerable to various infections and certain types of cancers that a healthy immune system would normally fight off.

The Human Immunodeficiency Virus is a tiny, microscopic organism that specifically attacks a crucial type of white blood cell in your body called CD4+ T-lymphocytes, also known as helper T-cells. These cells are like the 'generals' of your immune system, coordinating the attack against invading pathogens.

When HIV enters your body, it seeks out these CD4+ T-cells, infects them, and uses their machinery to make more copies of itself. In this process, it eventually destroys the infected T-cells. Over time, as more and more CD4+ T-cells are destroyed, your immune system weakens progressively.

Initially, after getting infected with HIV, a person might experience flu-like symptoms for a short period, or no symptoms at all. This is the acute phase. Following this, there's often a long period, sometimes many years, where the virus is active in the body, slowly destroying CD4+ T-cells, but the person might still feel relatively healthy.

This is the chronic or latent phase. However, without treatment, the number of CD4+ T-cells continues to drop, and the immune system becomes so compromised that the body can no longer defend itself effectively.

This is when AIDS is diagnosed. People with AIDS become susceptible to 'opportunistic infections' – infections that typically wouldn't cause serious illness in someone with a healthy immune system, but can be life-threatening for an individual with AIDS.

Examples include certain types of pneumonia, tuberculosis, and fungal infections. Early diagnosis and consistent treatment with antiretroviral therapy (ART) can effectively manage HIV, prevent its progression to AIDS, and allow people with HIV to live long, healthy lives.