HIV.docx - HIV/AIDS Serology Viruses considered to be...

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HIV/AIDS: Serology Viruses considered to be acellular microorganism o not considered as true cells composed either DNA or RNA cannot contain both of these nucleic acid (labeled A in the photo) no organelles 3 basic parts of virus: a) Nucleic acid (DNA or RNA) b) Capsid – directly covering Nucleic acid. - Rich in protein - Capsomeres – make up the capsid c) Viral Envelop – attach to it is the Glycoproteins Nucleocapsid – we have a capsid covering the nucleic acid component of the virus Note: some viruses do not have envelop so they only have NA and Capsid, they are called naked viruses. But if they contain envelope they refer to as enveloped viruses Retrovirus – causative agent of HIV Retroviridae Single stranded RNA virus Enveloped with glycoproteins o Use to infect human cells With cone-shaped capsid Has reverse transcriptase enzyme o Convert RNA of retrovirus to DNA, so that the virus can insert its nucleic acid into the nucleus of the human cell o Because retroviruses multiply inside the nucleus, which contain high amount of DNA Mode of transmission Sex without a condom (1) direct inoculation of the virus in the blood vessel breached by trauma blood vessel breached doesn’t have to be there for the sexual transmission of the HIV to happen, because even if the mucosa is intact and there is no presence of breach BV or minor break in the skin. Once the virus is deposited in the mucosa the virus will penetrate the lining epithelium (w/ or w/o breaks) these viruses will be sampled by the dendritic cells, that will carry the virus into the lymph node (rich in T cells) (2) infection of the dendritic cells within the mucosa Most popular mode of transmission Parenteral transmision (1) IV drug users (sharing of needles) (2) Hemophiliacs who received factor VIII or IX concentrate (1985) a. Born with deficiency among with the coagulation factors b. Factor VIII = Hemophilia A c. Factor IX = Hemophilia b (3) Transfusion – 1 in 2 million of units of blood transfused (4) Can be transmitted between heterosexual couples Vertical transmission (Mother to infant transmission) (1) in utero by transplacental spread (most common), baby is still inside the mother’s womb (2) during delivery through an infected birth canal (3) after birth through ingestion of breastmilk Sharing injecting equipment Contaminated blood transfusions and organ transplant According to DOH - 2015: 21 new cases of HIV everyday - 2018: 32 new cases of HIV everyday - 1984: first case of HIV in the Philippines Target Cells CD4+ cells o T cells (helper cells) Primary age group: 25-34 y/o
o Once there is retrovirus in the CD4, it will be targeted by CD8 (T cytotoxic T cells, that will kill T helper cells) o Monocytes and macrophages: serves major reservoirs for HIV o Can also infect endothelial cells HIV uses CD4 molecule and some chemokine receptors as co-receptors HIV -1 is common worldwide; HIV-2 is less common and is largely confined to Africa.

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