Since the first cases of what became known as AIDS were reported in 1981, researchers have focused on understanding exactly what happens when the human immunodeficiency virus (HIV) infects the body.
Unlike cold or flu viruses that cause symptoms and make a welcome departure after a week or two, HIV infects your body permanently. The disease progresses in stages, with the most serious consequences and complications developing years after the initial infection. However, one of the most active and critical stages of HIV infection occurs in the first days and weeks after contracting the virus. This stage is called acute HIV infection. It begins when the viruses enter your body and lasts for several weeks to months.
Forty to 90 percent of people experience a flu-like illness during acute stage HIV. This illness, known as acute HIV syndrome, typically occurs two to four weeks after infection.
Common early symptoms of HIV infection include:
- Swollen glands
- Upper body rash
Regardless of whether symptoms occur, the infecting viruses and your immune system are engaged in an intense battle during the acute stage of HIV infection. Internal events occurring during this stage have important implications for HIV prevention, treatment and possibly the long-term course of the disease.
Early HIV Infection and Transmission
HIV has the upper hand against your immune system when it originally gains entry and spreads throughout your body. Viruses take up residence in immune system cells called CD4 cells, hijacking their cellular machinery to produce more HIV viral particles. As virus numbers increase, more CD4 cells are infected and become HIV production sites.
The amount of HIV in your bloodstream, body fluids and moist body surfaces — such as the vagina, rectum and mouth — skyrockets during the acute stage of the infection, with the number of viruses doubling roughly every 10 hours. Your HIV level, or viral load, reaches its highest point during the acute stage of the illness, peaking approximately three to four weeks after infection.
The risk of transmitting HIV to others is influenced by the amount of HIV in your body fluids and moist body surfaces. Therefore, the risk of HIV transmission is exceptionally high during the acute stage of the infection. Commonly used HIV screening tests can miss an infection during these early weeks, adding to the risk of unknowingly transmitting the virus to others.
Immune System Damage and Permanent Infection
Direct infection of your CD4 cells and your immune system’s response to acute HIV infection leads to the death of many CD4 cells — casualties of the early battle. These cells act as essential partners with other immune system cells, protecting you from a variety of infections and illnesses. Serious infections that are usually seen in people with fully developed AIDS can occur during the acute infection stage due to this initial loss of CD4 cells.
Although many CD4 cells are killed as your immune system engages in its initial fight against HIV, other HIV-infected CD4 cells survive in a resting state. These cells do not produce new HIV particles but rather become “reservoirs” of HIV in your body, thereby establishing the permanence of the infection.
Treatment with HIV medications (e.g., antiretroviral therapy) does not rid your body of these HIV reservoirs, which is why the illness is currently incurable. Because it is the time when the permanent viral reservoir is established, researchers increasingly view the acute stage HIV as crucially important in influencing the long-term course of the illness.
Potential Benefits and Risks of Early Treatment
Progression of HIV infection to AIDS occurs largely due to CD4 cell loss and the associated vulnerability to a broad array of serious illnesses. Therefore, preserving your CD4 cells and immune system function are the primary goals of HIV treatment.
Antiretroviral therapy (ART) medications suppress HIV by disrupting the multiplication process or interfering with the virus’ ability to infect CD4 cells.
Research studies show that beginning ART during acute stage HIV:
- Limits the extent of immune system infection,
- Preserves the number of CD4 cells in the body,
- Slows disease progression, and
- Reduces the size of the HIV reservoir.
Based on the strength of the research data, the International Antiviral Society – U.S.A. Panel and the U.S. Department of Health and Human Services recommend offering ART to anyone diagnosed with HIV regardless of their CD4 count, including people in the acute stage of the disease. Although medical researchers believe initiating ART earlier in the course of the illness will lead to improved long-term survival and fewer people with HIV developing AIDS, more research is need to confirm these potential benefits.
Additionally, it is unclear whether beginning treatment earlier in the course of HIV disease may increase the risk for harmful side effects from antiretroviral medications.
While being tested for HIV when you think you may have been exposed can be frightening, it is important to be tested as soon as possible.
Make an appointment with your regular health care provider or go to a local HIV testing site. The Centers for Disease Control and Prevention and the Department of Health and Human Services offer online locators for HIV testing sites in the U.S. If you live in Canada, call your provincial or territorial HIV/AIDS hotline to find a testing site.
When you go for testing, be honest about when and how you think you may have been exposed to HIV. This information is essential for choosing the appropriate HIV test to use, especially if your possible exposure was recent. If your test indicates you have HIV, your health care provider will explain your treatment options and the potential benefits and risks.
Learning you have HIV is a life-altering event for patients and their loved ones. Deciding whether to begin lifelong HIV treatment during this time can also be overwhelming. Offering your support and accompanying your loved one to medical appointments may ease the burden and make this emotional period less difficult.