INTE 398 Lecture Notes - Lecture 2: Viral Load, Cohort Study, Reverse Transcriptase
5 May 2018
School
Department
Course
Professor
Ffar 291/Inte 298 – Intro HIV Class
Lesson 2
2.1 Intro Lecture
-HIV understood in many ways by society
-its understood as a social prob, a risk or danger, as something that affects particular ppl,
is/isn't threatening, is/isn't a prob within certain communities
-focus on the science and biol
-understand how AIDS works, what's going on, what we mean when we say AIDS
2.2 Excerpts from HIV Transmission Reading
-notion of risk = qualitative so NO objective way to express degrees of likelihood of
transmission
-lvls of risk of various activities organized in 4 categories (no risk, negligible risk, low risk & high
risk)
Conditions for HIV Transmission
1.There must be a source of infection
-presence of hiv in certain body fluids (ex blood)
2.There must be a means of transmission
-sexual, subcutaneous/per cutaneous (sharing used, piercing), vertical/mom-to-child,
receiving transfusions of infected blood/blood products/donated sperm/transplanted
organs
3.There must be a host susceptible to infection
-susceptible cells within host's body
4.There must be an appropriate route of entry to the target cells of the body
-infected blood ,etc must reach hiv-susceptible cells thru break in skin, absorption thru
mucosal membranes (mucosa) or thru some disruption to the mucosa
-mucosa - moist surfaces of body which line most body cavities & hollow internal
organs
5.There must be a sufficient lvl of virus delivered to establish infection
-semen, vaginal fluid, blood and breast milk are of MOST concern in transmission
-viral load (amount of hiv present in diff body fluids & tissues) can also be factor in
transmission
-the HIGHER the vital load, the HIGHER the risk of transmission thru exchange of
fluids
Factors Used to Determine the Level of Risk
1.Potential for Transmission
-whether or not the 5 conditions for transmission are met
2.Evidence of Transmission
-case reports, abstracts and research reports
*greatest weight on reports from cohort studies
find more resources at oneclass.com
find more resources at oneclass.com
Categories for Assessing Risk
1.No risk
-none of practices demo to lead to infection; no potential for transmission bc conds not
present
2.Negligible risk
-all practices to this risk lvl present a potential for transmission bc body fluids exchange
-amounts greatly diminished tho
*potential for transmission - YES; evidence of transmission - NONE
3.Low risk
-all practices to this risk lvl present a potential for transmission bc body fluids exchange
-few reports of infection attributes to these activities
*potential for transmission - YES; evidence of transmission -YES (under certain
conds)
4.High risk
-all practices to this risk lvl present a potential for transmission bc body fluids exchange
-sig number of sci studies repeatedly associated the activities w HIV infection
*potential for transmission AND evidence of transmission - YES
2.3 Transmission Lecture
What does HIV mean?
Human Immunodeficiency Virus
-It’s a tiy irus, is't agified ultiple ties
How the Virus Enters the Host
-NO virus can get thru healthy intact skin
-skin is BEST defense vs any form of viral infection
-tend to think that we are all vulnerable to hiv and that its real easy to get it
-requires a lot of diff steps and factors so for someone to become vulnerable to hiv
infection
-Source of Infection
-semen, blood, vaginal fluid, rectal fluid, breast milk - MOST infectious bodily fluids
-tears, sweat, saliva - do’t hae NEARLY eough irus i the for the to e ifetious
-if touch something that someone w a cold touched - possibility of infection quite HIGH
bc pretty strong and it can survive being in the air and being in a variety of body fluids
and move from host to host
-HIV NOT nearly as tough (amount of virus in saliva is minimal so mixing is no risk
really)
-HIV does’t lie outside the host
-Means of transmission
-Situation where virus could move into the host (a person that is NOT HIV+ that is
vulnerable)
-Host (any human)
-Appropriate route of entry
-way for virus to enter
-Sufficient lvl of virus
-Unbroken skin is an absolute defense vs infection
find more resources at oneclass.com
find more resources at oneclass.com
-skin is a PRETTY solid defense mechanism
-needle prick, syringue - touched by HIV or cut and sore
*EVEN IF all conds are at play, infection is NOT guaranteed even in those circumstances
-sometimes not long enough exposure or other things happening
HIV Transmission: Guidelines for Assessing Risk
-way to help catalog whether or not infection is likely or even possible
-if NO potential for infection and no evidence - NO WAY it can occur
-kissing, spitting on someone
-diff btwn negligible risk and low risk - sometimes harder to understand, less clear for ppl
-whether or not there has been any concrete evidence that is occurring
-negligible - POTENTIAL for transmission (ex possibility for open skin)
-NEVER any evidence of that being the way someone became infected
-so possibility NEVER manifested of being an infection
-low risk - sometimes evidence of transmission, so might involve intercourse w a
condom but it was used incorrectly (ex broke, passed expiration date, lack of lubrication,
NOT a latex condom)
*lot of specific conds to get HIV
-high risk - ALL conds are in place and lots of evidence - will facilitate transmission of hiv
-circumstance of having needle in someone who is HIV + within their bloodstream and
then no rinsing or interruption putting that needle in another body = MOST effective
way of meeting ALL of those conds
2.4 Risk of transmission
-From most to least:
Injection of needle after used by someone HIV+; penetrative vaginal intercourse;
penetrative anal sex w a condom used correctly; blowjob; kissing
2.5 HIV - The Basics Link
-HIV - a virus that weakens your immune system, which is the internal system that defends
your body vs disease so the virus can infect cells of the immune system that are supposed to
fight off infections
-HIV can sneak past immune system & then attack your body from the inside
-infects cell including CD4+ cells
*that’s hat akes HIV dagerous
-AIDS - Acquired ImmunoDeficiency Syndrome
-if hiv not treated w anti-hiv drugs, immune system becomes weaker over time
-eventually, become sick w life-threatening infection, at that pt said to have AIDS
-Virus - very simplest and smallest of all living things - even SMALLER than bacteria/other
germs
-cant reproduce on their own
*when describing how viruses like HIV reproduce, use the term REPLICATE
-HIV infection happens when enough HIV from an HIV-posi person gets into an HIV-neg
person's body
-having a STI like herpes, syphillis or gonorrhea can make it easier to transmit HIV
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Its understood as a social prob, a risk or danger, as something that affects particular ppl, is/isn"t threatening, is/isn"t a prob within certain communities. Understand how aids works, what"s going on, what we mean when we say aids. Notion of risk = qualitative so no objective way to express degrees of likelihood of transmission. Lvls of risk of various activities organized in 4 categories (no risk, negligible risk, low risk & high risk) Presence of hiv in certain body fluids (ex blood) Sexual, subcutaneous/per cutaneous (sharing used, piercing), vertical/mom-to-child, receiving transfusions of infected blood/blood products/donated sperm/transplanted organs. 3. there must be a host susceptible to infection. 4. there must be an appropriate route of entry to the target cells of the body. Infected blood ,etc must reach hiv-susceptible cells thru break in skin, absorption thru mucosal membranes (mucosa) or thru some disruption to the mucosa. Mucosa - moist surfaces of body which line most body cavities & hollow internal organs.
