Incubation stage (1) – can range from 3 weeks to 3 months, rarely lasting up to a year. During this time, the virus is actively reproducing, but there is no immune response to it yet. The incubation period of HIV ends either with the clinic of acute HIV infection or with the appearance of HIV antibodies in the blood. At this stage, the basis for the diagnosis of HIV infection is the detection of the virus (antigens or DNA particles) in the blood serum.
The stage of primary manifestations (2) is characterized by the manifestation of the body’s reaction to the active replication of the virus in the form of acute infection clinic and immune reaction (production of specific antibodies). The second stage may be asymptomatic, the only sign of developing HIV infection will be a positive serologic diagnosis for antibodies to the virus.
The clinical manifestations of the second stage run along the lines of acute HIV infection. The onset is acute, occurring in 50-90% of patients three months after infection, often preceding the formation of HIV antibodies. Acute infection without secondary pathologies has a rather diverse course: fever, various polymorphic rashes on the skin and visible mucous membranes, polylymphadenitis, pharyngitis, lienal syndrome, diarrhea may be noted.
In 10-15% of patients acute HIV infection proceeds with the accession of secondary diseases, which is associated with a decrease in immunity. These can be sore throats, pneumonias of various genesis, fungal infections, herpes and others.
Acute HIV infection usually lasts from a few days to a few months, on average 2-3 weeks, after which in the vast majority of cases it progresses to the latent stage.
The latent stage (3) is characterized by a gradual increase in immunodeficiency. The death of immune cells at this stage is compensated by their increased production. At this time, HIV can be diagnosed by serologic reactions (antibodies to HIV are present in the blood). A clinical sign may be an increase in several lymph nodes from different, unrelated groups, excluding inguinal lymph nodes. There are no other pathologic changes in the enlarged lymph nodes (soreness, changes in surrounding tissues). Latent stage can last from 2-3 years, up to 20 and more. On average, it lasts 6-7 years.
The stage of secondary diseases (4) is characterized by the emergence of concomitant (opportunistic) infections of viral, bacterial, fungal, protozoal genesis, malignancies against the background of marked immunodeficiency. Depending on the severity of secondary diseases, 3 periods of course are distinguished.
4A – loss of body weight does not exceed 10%, infectious (bacterial, viral and fungal) lesions of covering tissues (skin and mucous membranes) are noted. Work capacity is reduced.
4B – weight loss of more than 10% of the total body weight, prolonged temperature reaction, prolonged diarrhea without organic cause is possible, pulmonary tuberculosis may be attached, infectious diseases recur and progress, localized Kaposi’s sarcoma, hairy leukoplakia is detected.
4B – general cachexia is noted, secondary infections acquire generalized forms, esophageal and respiratory candidiasis, pneumocystis pneumonia, extrapulmonary tuberculosis, disseminated Kaposi’s sarcoma, neurological disorders are noted.
Substages of secondary diseases undergo phases of progression and remission, which differ depending on the available antiretroviral therapy or its absence. In the terminal stage of HIV infection, the secondary diseases developed in the patient become irreversible, treatment measures lose their effectiveness, and the lethal outcome occurs several months later.
The course of HIV infection is quite diverse, not always have all stages, certain clinical signs may be absent. Depending on the individual clinical course, the duration of the disease can be either a few months or 15-20 years.