AIDS: Epidemiology, Causes, Pathology and Symptoms

Generally, the interactions of HIV with the host immune system can be divided into 3 phase. The early ,acute phase, is characterized by the presenceof viremia(virus in the blood), a fall in CD4+ Cells and a rise of CD8+ cells. Clinically, patient may have self-limited acute illnesses with sore throat, nonspecific muscle pain and aseptic meningitis . Recovery occur within 6-12 weeks. Then the middle, chronic phase, characterized by clinical latency with low-level viral replication and a gradual decline of CD4+ counts, may last from 7 to 10 years. Patients may develop persistent generalized lymph node enlargement with no constitutional symptoms. Toward the end of this phase, fever, rash, fatigue, and viremia appear. The final, crisis phase, characterized by a rapid decline in host defenses manifested by low CD4+ counts, is also recognized as full brown AIDS which include features of loss of weight, diarrhea, opportunistic infections, spectrum of bacterial infections, secondary neoplasm and neurologic involvement. With AIDS, the 5-year mortality rate is 85% and with longer intervals the rate approaches 100%. Anyone with HIV infections and CD4+ t-cell count less than 200 cells/ ul may also consider having AIDS even if no clinical features are present.…