DDT 18- Human Immonodeficiency Virus Infection Flashcards
where does HIV originate from
SIV Simian immunodeficiency virus but mutated and infected humans
2 types of HIV
HIV 1 - most common worldwide
HIV 2 - West Africa, mozambique and Angola
HIV 1 strains are related to
SIVcpz/s, from the
Chimpanzee subspecies Pan troglodytes
HIV 2 strains are related to
SIVsmm, from Sooty Mangabey monkeys (Cercocebus atys)
how is it believed that HIV crossed species
possibly crossed species. through butchering bush meat trade
How is HIV transmitted
Blood
Semen
Saliva to a lesser degree
HIV
Human Immunodeficiency Virus
AIDS
Aacquired Immuno Deficiency Syndrome
HIV as a retrovirus
RNA nucleic acid
RNA-DNA-RNA replication
how does HIV attack immune system
Invades and destroys T helper cells
how is HIV released
Released by budding
what macromolecules, enzymes and nucleic acid does HIV contain
Viral RNA • Reverse trancriptase • Integrase • Protease • Docking glycoprotein GP120
what does HIV need to do once a host is infected with HIV
needs to convert its RNA using Reverse transcriptase into DNA
It then incorporates into the DNA of the host cell
HIV propagates in host cell
envelope protein binds to receptors of plasma membrane of host cell
envelope protein fuses with plasma membrane and HIV enters cytoplasm - capsid is removed
Reverse transcriptase converts RNA into single stranded DNA then double stranded DNA which enters the host’s nucleus and is integrated into the host’s chromosomes
Chromosome now transcribes viral RNA
Viral RNA leaves nucleus and synthsizes viral proteins on host ribosomes
These proteins will produce new viruses and virus leaves host cell using host plasma membrane as viral envelope
where does early infection of HIV begin in the body
lymph nodes
what cells are infected with HIV what is this event followed by
T helper cells are infected and destroyed
this is followed by a latent period - asymptomatic
HIV transmission
During sexual contact
During pregnancy, childbirth, breastfeeding
Injection substance use
Blood transfusion with infected blood or organ transplant
Occupational exposure
HIV drugs
drus that will mimic receptors of T helper cells and prevent virus from binding to T helper
Drugs that prevent integration
HIV control
protease inhibitors
AZT - azidothymidine
protease inhibitors
Block viral enzyme protease. Resulting in viral copies that cannot infect new cells
Azidothymidine
inhibits reverse transcriptase
crosses blood brain barrier
Blocks RNA conversion to DNA
Prone to evasion by mutated viral strains
HAART
Highly Active Antiretroviral Therapy - combination of several antiretroviral medicines to slow the rate at which HIV makes copies of itself
How did the prevalence of HIV in pregnant women in Uganda captial
increased at over 30%
HIV prevention programs
practice safe sex w/ condoms
sterile needles for people addicted to intravenous drugs
Screening and treatment for other STIs
Substance abuse screening
main symptoms of AIDS
Encephalitis meningitis retinitis pneumocystis kaposi's disease, tumours esophagitis
AIDS defining bacterial infections
Mycoplasma pneumoniae
• Streptococcus pneumoniae
• Treponema pallidum
• Candida albicans
AIDS defining cancers
Kaposi’s sarcoma from HHV-8 / KSV (20-30%, only in male homosexuals)
• cervical carcinoma from some HPV types
• non-Hodgkin’s lymphomas
