HIV infection comes in three stages. The first stage is called acute infection or seroconversion, and it typically happens within two to six weeks after exposure or becoming infected. This is when the body's immune system puts up a fight against HIV. The symptoms of acute infection look similar to those of other viral illnesses and are often compared to those of the flu. The symptoms may last a week or two and then completely go away as the virus goes into a non-symptomatic stage.
The initial symptoms of acute HIV infection may include:
Pneumocystis pneumonia (PCP) is a serious infection that causes inflammation and fluid buildup in the lungs. It is caused by a fungus called Pneumocystis jiroveci. Likely spread through the air, this fungus is very common. Most people are exposed to it by age 3 or 4. A healthy immune system can easily control it. But it causes a type of pneumonia in people with weakened immune systems, such as those with HIV/AIDS. This is why it's called an opportunistic infection. Although it's rare, PCP can affect...
You think you have come in contact with HIV. Doctors can now prevent HIV from taking hold in the body if they act quickly after initial infection. Health care workers, police, and firefighters who are exposed to HIV-infected blood often use a process that involves taking anti-HIV drugs to protect themselves. These drugs must be taken within 72 hours of initial exposure.
You may be tested for HIV using highly sensitive tests that detect both HIV antigen, a protein produced by the virus immediately after infection, and HIV antibodies. This test can confirm a diagnosis within days of infection. (Regular HIV tests don't work this soon after infection; they can only detect antibodies.) You may be given anti-HIV drugs to take for a prescribed period of time. There may be unpleasant side effects to these drugs, but they may stop HIV from infecting you.
Most people don't know they've been infected with HIV, but weeks later they may experience the symptoms of seroconversion. These symptoms mean the body is trying to fight HIV.
The Period Without Symptoms of HIV - the Second Stage
After the first seroconversion period, the immune system loses the battle with HIV and symptoms go away. HIV infection goes into its second stage, which can be a long period without symptoms, called the asymptomatic (or latent ) period. This is when people may not know they are infected and can pass HIV on to others. This period can last 10 or more years.
During this period without symptoms, HIV is slowly killing the CD4 T-cells and destroying the immune system. Blood tests during this time can reveal the number of these CD4 T-cells. Normally, a person has a CD4 T-cell count between 450 and 1,400 cells per microliter. This number changes constantly, depending on a person's state of health. For an HIV-infected person, the number of CD4 T-cells steadily drops, making them vulnerable to other infections -- and in danger of developing AIDS.