Showing posts with label AIDS. Show all posts
Showing posts with label AIDS. Show all posts

Human Immunodeficiency Virus – AIDS


            The emergence and pandemic spread of the AIDS- Acquired Immunodeficiency Syndrome- have posed the greatest challenge to public health in modern times. It was first recognized in the United States in 1981, as a sudden outbreak of two very rare diseases – Kaposi’s sarcoma and Pneumocystis carinii pneumonia in young adults who were homosexuals or addicted to injected narcotics. They appeared to have lost their immune competence, rendering them vulnerable to fatal infections with relatively avirulent microorganisms, this condition was given the name acquired immunodeficiency syndrome. Isolation of the etiological agent was first reported in 1983 by Luc Montagnier and colleagues from Pasteur Institute, Paris. They isolated a retrovirus from a West African patient with persistent generalized lymphadenopathy and called it lymphadenopathy associated virus (LAV). In 1984 Robert Gallo and colleagues isolated a retrovirus called HTLV-3. two antigenic types of HIV– HIV-1 & HIV-2.
            Virions of the family Retroviridae possess reverse transcriptase enzyme, hence the name. This family has been divided into 3 genera - Retrovirus (HTLV-1 & HTLV-2, oncogenic viruses), Lentivirus (HIV-1 & HIV-2 causes AIDS) and Spumavirus (Human foamy virus).

Rhabdoviruses

The family Rhabdoviridae comprises more than 200 viruses which infect mammals, reptiles, birds, fishes, insects and plants. It has two ge...