With HIV, [its evolution has] been a long, drawn-out process because the virus is poorly transmissible. It takes, on average, 100 sexual contacts for a man to give it to a woman and 200 contacts HIV infection and AIDS: Summary. Human immunodeficiency virus (HIV) is a retrovirus that preferentially infects and destroys cells of the immune system, in particular the CD4 cells (a class of T lymphocyte). Through sexual activity. Vertically from mother to child — during pregnancy, childbirth, or through breastfeeding. Bovine immunodeficiency virus. Bovine immunodeficiency virus ( BIV) is a retrovirus belonging to the genus Lentivirus. It is similar to the human immunodeficiency virus (HIV) and infects cattle. The cells primarily infected are lymphocytes and monocytes / macrophages. [1] A long terminal repeat ( LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or a retroviral provirus. All retroviral genomes are flanked by LTRs, while there are some .

is hiv a retrovirus