AIDS Transmission and Stages

AIDS is primarily transmitted through sexual intercourse, blood transmission, and mother-to-child transmission. It is crucial to prevent these three modes of transmission and cut off the routes of infection to achieve effective prevention. Once infected with HIV, individuals initially enter the acute infection phase, which is the most contagious stage and typically manifests as symptoms such as fever, dizziness, and skin rashes. Nucleic acid testing is required to confirm the diagnosis. During the asymptomatic stage, HIV antibodies can be detected. In the third stage, patients experience a rapid decline in physical health and are at constant risk of death.

Acute Infection Phase

The acute infection phase typically occurs 2-6 weeks after infection and is characterized by flu-like symptoms such as fever, headache, muscle and joint pain, sore throat, skin rashes, and generalized lymphadenopathy. Some cases may resemble mononucleosis. About 10% of patients may develop meningitis with increased monocytes and moderately elevated protein levels in cerebrospinal fluid. Some patients may experience mild symptoms during this phase, which are often overlooked. The acute phase typically lasts 3-14 days, followed by a transition to the asymptomatic stage for most patients. However, some patients may continue to have fever, lymphadenopathy, and weight loss. During this time, blood tests may show normal or mildly elevated white blood cell counts with decreased lymphocytes. HIV antigens may be detectable in the blood, but the appearance of seropositive HIV antibodies is delayed, typically occurring 2-8 weeks after blood transfusion or 2-3 months after sexual transmission. This period allows for the detection of HIV antigens but not HIV antibodies.

Asymptomatic Infection Phase (Latency)

The period from HIV infection to the development of AIDS is known as the latency phase. The duration of the latency phase varies widely among individuals, ranging from less than a year to over 15 years, with an average of 5-7 years.

AIDS Progression Phase

When the immune system of an HIV-infected individual is severely compromised and unable to maintain even a minimal level of resistance to disease, various difficult-to-treat symptoms emerge, indicating the progression to full-blown AIDS. Once an individual reaches this stage, the prognosis is generally poor, with a typical lifespan of half to two years.