The time from HIV infection to the development of AIDS varies. Rarely, some individuals develop complications of HIV that define AIDS within one year, while others remain completely asymptomatic after as many as 20 years from the time of infection. However, in the absence of antiretroviral therapy, the time for progression from initial infection to AIDS is approximately eight to 10 years. The reason why people experience clinical progression of HIV at different rates remains an area of active research.
Within weeks of infection, many people will develop the varied symptoms of primary or acute infection, which typically has been described as a mononucleosis– or influenza-like illness but can range from minimal or low-grade fever, aches, and pains to very severe symptoms. The most common symptoms of primary HIV infection are
It is not known, however, why only some HIV-positive people develop these symptoms. It also is also not completely known whether or not having the symptoms is related in any way to the future course of HIV disease.
Regardless, infected people will become symptom-free (asymptomatic) after this phase of primary infection. During the first weeks of infection when a patient may have symptoms of primary HIV infection, antibody testing may still be negative (the so-called window period). If there is suspicion of early infection based upon the types of symptoms present and a potential recent exposure, consideration should be given to having a test performed that specifically looks for the virus circulating in the blood, such as a viral load test or the use of an assay that identifies HIV p24 antigen, for example, the new fourth-generation antibody/antigen combination test.
Identifying and diagnosing individuals with primary infection is important to assure early access into care and to counsel them regarding the risk of transmitting to others. The latter is particularly important since patients with primary HIV infection have very high levels of virus throughout their body and are likely to be highly infectious. There is no definitive data showing that initiation of antiretroviral therapy during this early stage of infection results in clinical benefits. Nevertheless, it is generally thought that the benefits of reducing the amount of the HIV virus in the body, preserving select immune responses, and reducing transmissibility favors early treatment. Once the patient enters the asymptomatic phase, infected individuals will know whether or not they are infected if a test for HIV antibodies is done.
Shortly after primary infection, most HIV-positive individuals enter a period of many years where they have no symptoms at all. During this time, CD4 cells may gradually decline, and with this decline in the immune system, patients may develop the mild HIV symptoms and signs such as
Any of these symptoms should prompt HIV testing for at risk individuals. With a further decline in function of the immune system, patients are at increasing risk of developing more severe complications of HIV, including more serious infections (opportunistic infections), malignancies, severe weight loss, and decline in mental function.
From a practical perspective, most physicians think about patients with HIV diseases as having no symptoms, mild symptoms, or being severely symptomatic. In addition, many would characterize a patient’s level of immunosuppression by the degree and type of symptoms they have as well as the CD4 cell count. The Centers for Disease Control and Prevention have defined the presence of a long list of specific diseases, or the presence of less than 200 CD4 cells per mm3 as meeting the definition of AIDS.
It is important to note that with compliance to an effective antiretroviral therapy, many of the signs and symptoms of HIV as well as severity of immunosuppression can be completely reversed, restoring even the most symptomatic patients to a state of excellent health.