hiv

History In 1981, the first cases of AIDS were identified in the US. However, scientists later found evidence that the disease existed in the world as early as 1959. The first documented case of HIV was traced back to 1959 in the Democratic Republic of the Congo. The HIV virus was identified in 1984. By the late 1990s, anti-retroviral were developed and the number of AIDS-related deaths were reduced by half in just one year

Human Immunodeficiency Virus Retrovirus – its genetic material is RNA The virus uses an enzyme called reverse transcriptase to build DNA from its RNA once it infects a cell Once it has made the DNA, it inserts it into the host cell’s DNA

The host cell then replicates and translates the DNA as it’s own, making more HIV RNA, reverse transcriptase, and viral proteins that are used to assemble new HIV viruses

HIV targets helper T cells of the immune system If 1,200 or higher, the individual has a normal immune system. If 800 or less, the immune system is weakened and individual is susceptible to infection. If 200 or less, AIDS is diagnosed. Once a person is diagnosed with AIDS, she or he is always categorized as having AIDS, even if her or his T-cell count increases.

HIV (arrows) Infecting a T-lymphocyte

Methods of transmission: Sexual transmission, presence of STD increases likelihood of transmission. Exposure to infected blood or blood products. Use of contaminated clotting factors by hemophiliacs. Sharing contaminated needles (IV drug users). Transplantation of infected tissues or organs. Mother to fetus, perinatal transmission variable, dependent on viral load and mother’s CD 4 count.

Natural History of HIV Infection DR. S.K CHATURVEDI

Natural History of HIV Infection Virus can be transmitted during each stage Seroconversion Infection with HIV, antibodies develop Asymptomatic No signs of HIV, immune system controls virus production Symptomatic Physical signs of HIV infection, some immune suppression AIDS Opportunistic infections, end-stage disease DR. S.K CHATURVEDI

Treatments ART – anti-retroviral therapy – idea is to block the production of viral proteins in cells Usually requires a combination of many as the virus mutates quickly and develops resistance to medications Have made HIV a chronic illness instead of a death sentence