The condition that occurs after becoming infected with HIV is called HIV disease and it lasts until the death of the infected person. The disease is usually divided into several stages, but in practice there is usually no clear boundary between the individual stages of the disease.
After 3 to 6 weeks of infection, the first stage of HIV disease occurs, called acute HIV infection. Most patients develop fever and a disease similar to virus, influenza, or infectious mononucleosis. The main symptoms of the disease are: fever, swollen lymph nodes, sore throat, rash and pain in the muscles and joints. These symptoms disappear without treatment and are followed by a long period without more pronounced symptoms and signs of the disease. This is the stage when there are no symptoms of the disease. Then an increase in lymph nodes can be found, the number of CD4 lymphocytes is usually 350-750 / mm3. However, although the infected person has no more pronounced symptoms, the virus multiplies daily, destroys the attacked cells and gradually reduces the number of CD4 lymphocytes. This phase of the disease usually lasts 10 years.
After the stage of the disease when there are no symptoms (asymptomatic phase) there is a phase of the disease with symptoms which can be divided into early, middle and late symptoms / signs. In the early phase, the number of CD4 lymphocytes decreases to 200 500 / mm3. Painless enlargement of the lymph nodes is usually present. Common skin infections (eg herpes zoster, impetigo, folliculitis), various dermatitis or fungal infections of the oral cavity (candidiasis) or vagina may occur more frequently. Recurrent inflammation of the lungs and sinuses, reactivation of tuberculosis and Kaposi's sarcoma are possible. In untreated individuals this stage of the disease lasts 0-5. year.
In the middle (advanced) stage of HIV disease, which occurs in 50% of patients after 10 years of infection, more serious diseases such as pneumonia caused by the fungus Pneumocystis jiroveci or diarrhea caused by the parasite Cryptosporidium occur. The CD4 lymphocyte count is then below 200 / mm3. Toxoplasmosis of the brain, cryptococcal meningitis or atypical forms of tuberculosis appear.
Anemia and symptoms such as fever, general weakness and weight loss are often present at this stage of HIV disease. Symptoms of nervous system damage: lethargy, depression, forgetfulness, decreased concentration, dullness, unstable gait, and poor coordination of movements may also be present. It is important to emphasize that some patients with less than 200 / mm3 CD4 lymphocytes have no significant symptoms and that common infections in these patients can be cured with conventional therapy. In untreated individuals this stage of the disease lasts 0-3. year.
In the late stage of HIV disease, when the CD4 lymphocyte count is below 50 / mm3, retinal infection caused by cytomegalovirus, brain lymphoma, infection with atypical mycobacteria occurs, and Kaposi's sarcoma becomes widespread. Symptoms such as loss of appetite, nausea, vomiting, diarrhea, weight loss and general weakness may also be present. In untreated individuals this stage of the disease lasts 1-2. year.
Only 1% of those infected develop symptoms of advanced HIV disease in the first two years after infection, 10% have symptoms after 5 years, and 50% of those infected develop AIDS-specific diseases 10 years after infection. Only about 2% of those infected after 12 years have no symptoms of the disease and have more than 500 / mm3 CD4 lymphocytes.