HIV/AIDS

HIV/AIDS is acquired immunodeficiency syndrome caused by the Human immunodeficiency virus HIV.The virus infects T helper cells, a type of white blood cell that is part of the specific immune system. As the virus gradually destroys the immune system infected individuals will be unable to fight off opportunistic infections such as pneumonia and TB and some may develop some forms of cancer.HIV is a retrovirus that affects humans and primates. It consists of two strands of RNA and a few enzymes including reverse transcriptase, integrase and a protease enclosed in a protein coat or capsid and covered in a lipid envelope.It gains entry into the cell by using its attachment glycoprotein to bind to CD4 cell surface receptors resulting in the lipid envelope and the cell surface membrane fusing to deliver the capsid into the cell.The capsid is digested and the RNA and enzymes are released into the cell. Reverse transcriptase copies the RNA into a strand of DNA and DNA polymerase synthesises a second strand using the first strand as a template.The virus is passed from one person to another in bodily fluids by unprotected sex, shared needles, contaminated blood and blood products, from mothers to babies during pregnancy or while breastfeeding.There is no vaccine and there is no cure but anti-retroviral drugs slow down the progression of the disease. 70% of the cases are in Sub-Saharan Africa with the disease having a huge social and economic impact.