The only sources of AIDS infection are AIDS patients (pair A) and HIV-infected patients (pair B). Monkeys, orangutans, and baboons (CDE wrong), there is currently no evidence that they can cause transmission, so they are not the source of AIDS infection.

HIV belongs to the genus Lentivirus in the family Retroviridae. For retro-transcribing RNA viruses. The shape is round or rod-shaped, with a diameter of 100~140nm. There are three structural genes: (1) Gag gene (group antigen gene), encoding core protein p24. (2) pol gene (polymerase gene) and coding core polymerase are collected and compiled on the Medical Education Network. (3) env gene (outer membrane protein gene), encoding outer membrane proteins gpl20 and gp41. Structural genes mainly encode core proteins, polymerases and outer membrane proteins. 3 regulatory genes: (1) Tat gene (transactivator) plays a positive regulatory role in HIV genes. (2) rev gene (viral protein expression regulator), increases the expression of structural proteins by gag and env genes. (3) nef gene (negative factor) has the effect of inhibiting HIV proliferation. Regulatory genes mainly act on a certain sequence of the viral genome or its mRNA through regulatory proteins. There are 4 more genes: (1) The vif gene (viral infection factor), in cooperation with some cytokines, promotes HIV replication in cells. (2) The vpr gene (R protein) can enable HIV to proliferate in macrophages. (3) vpu gene (u protein), promotes the release of HIV-1 from the cell membrane, only in HIV-l. (4) The vpx gene (X protein) is necessary for the proliferation of HIV-2 in lymphocytes and macrophages and can promote