The human immunodeficiency virus (HIV) targets and weakens the body’s immune system. It specifically attacks CD4 cells, a type of white blood cell crucial for fighting infections. As HIV multiplies, it gradually destroys these immune cells, making the body more vulnerable to various illnesses. Understanding the progression of HIV and the timeline of symptom development is important for managing the condition.
Early Symptoms
Within two to four weeks after initial exposure, some individuals may experience acute HIV infection, often presenting with flu-like symptoms. These signs, sometimes called acute retroviral syndrome, can include fever, fatigue, muscle aches, headache, sore throat, rash, and swollen lymph nodes in the neck, armpits, or groin.
These symptoms usually last from a few days to several weeks, typically resolving within a month. It is important to note that these symptoms are not unique to HIV and can be caused by many common conditions, making early diagnosis challenging. Additionally, not everyone experiences these early symptoms, or they may be mild enough to go unnoticed. Even without noticeable symptoms, the virus level in the blood is very high during this acute stage, increasing the risk of transmission.
The Latent Phase
Following the acute phase, HIV typically enters clinical latency, or chronic HIV infection, where the virus is active but reproduces at low levels. During this stage, individuals often experience no noticeable symptoms. Despite the absence of overt symptoms, the virus remains present in the body and continues to damage the immune system over time.
Without medical intervention, this latent phase can extend for several years, commonly eight to ten years, or even longer. The duration varies significantly among individuals, with some progressing faster. Even without symptoms, the virus actively multiplies, slowly depleting CD4 cells, gradually weakening the body’s defenses, and can still be transmitted to others.
Advanced Symptom Development
When HIV infection progresses without treatment, it can advance to its most severe stage, acquired immunodeficiency syndrome (AIDS). This occurs when the immune system becomes severely compromised, making the body highly susceptible to opportunistic infections and certain cancers that a healthy immune system would normally fight off. An AIDS diagnosis is typically made when the CD4 cell count drops below a specific threshold, or when certain AIDS-defining illnesses appear.
Symptoms in this advanced stage often reflect the impact of these opportunistic infections on various bodily systems. These can include persistent fever, night sweats, chronic diarrhea, and significant and unexplained weight loss. Extreme fatigue is also frequently observed. Individuals may also develop skin rashes, mouth sores, or recurrent infections such as pneumonia or candidiasis. Without treatment, life expectancy after an AIDS diagnosis is generally about three years.
Factors Affecting Progression
Several factors influence the rate at which HIV infection progresses and symptoms develop. Early diagnosis and prompt initiation of antiretroviral therapy (ART) are crucial in slowing or halting disease progression. ART works by reducing the amount of HIV in the body, allowing the immune system to recover and preventing the virus from advancing to later stages. Individuals on effective ART can live long, healthy lives, often with a life expectancy comparable to those without HIV.
Beyond treatment, an individual’s overall health plays a part, as co-existing conditions can affect immune system resilience. Genetic factors also influence progression; for instance, certain genetic variations, such as in the CCR5 or HLA genes, have been linked to slower or faster disease progression. The age at which a person acquires HIV can also be a factor, with those over 40 potentially experiencing more rapid progression. The specific strain or subtype of HIV can also impact the rate of disease advancement.