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32 Cards in this Set
- Front
- Back
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Does transmission of HIV-1 drug resistance mutation within clusters impact viral transmission?
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No
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What are the examples of treatment as prevention? (5)
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1) Discordant couples
2) Pregnant women 3) Microbicidal trial 4) PREP 5) Circumsision |
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Describe the discordant couple prevention
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Treat infected person in the couple and get decreased viral load
Person can't transmit anymore |
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Describe the prevention method for pregnant women
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Prevent transmission to offspring
Just need to treat mother during pregnancy -->If treated, kids won't be infected Need to IT HIB in mothers Most HIV transmission to kids now in women who don't see a doctor duringn pregnancy (Aboriginals, Dev'p countries) |
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Describe hte microbicidal trial
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38% effective
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Describe PREP
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44% effective
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Describe the circumcision prevention strategy
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Impractical unless done when young
But some tribes in Africa do it after the age of 18 Circumsized ppl are less likely to be infected because the foreskin is very susceptible to HIV infection, can harbour the virus ->This is where there are langerhan's epithelial cells, which are very efficient portals of entry for HIV |
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What is the % of new infections in developed countries that have at least one drug-resistance related mutation?
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5-10%
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Why are some mutations for some drug classes more prevalent than for others?
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Long term treated end up with a lot of mutations if there have been a lot of failed treatments
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What are the most common mutations?
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To NNRTIs
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What is the least common mutations early in treatment?
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M184V
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Why is the K103N mutation the most common mutation EARLY in infection?
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Impact viral fitness
Makes the virus more fit (affects reverse T, common in clusters) -->Fittest virus is the one that can replicate the best |
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What is the most common mutation LATE in infection?
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M184V
-->Makes virus fit after patient has been treated |
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Are all HIV viruses equally transmitted?
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Yes
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What is TAM?
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Thymidine analogue (Zidonivine/d4T)
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What drug resistance does M184V offer?
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To 3TC and FTC
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What does allele specific PCR show?
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Look for specific mutations using primers
-->Found that M184V mutation is in more than double the amount seen by allele-spot PCR |
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What test is used to find a resistant virus?
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PCR test --> find genotype
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What can happen in a newly infected person who has the M184V mutation?
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Can get a spontaneous mutation back to 184M
The WT revertant will out compete the M184V |
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What happens if a newly infected person has the K103N mutation?
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Mutation will persist (will still get reversion)
The K103N mutation will compete well vs the WT |
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Is the M184V mutation found alone or linked in cases of transmitted resistance, as determined by bulk sequencing?
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More likely to be linked
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What will eventually happen to the M184V mutation in new infections/untreated ppl?
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Will eventually disappear because it is not fit
->By 40 weeks, nothing left |
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What is essential to treatment?
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Use good drugs in combo
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Why do drugs need to be used in combo?
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Totally suppress viral replication
If virus can replicate, will mutate and develop resistance |
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Why isn't there a cure for HIV yet?
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Don't kno how to get it out of the body yet
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In which subtype is the K65R mutation important?
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Subtype C
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What is the importance of this mutation?
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May affect prevention research strategies and treatment options over time, in areas where subtype C is the predominant virus
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How is HIV transmitted?
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Mostly sexually
also through blood |
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Whens the best time to transmit the virus?
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Early on, when the viral load is very high
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What does clustering lead to?
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More transmission of drug resistant subepidemics
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What is the most dangerous mutation right now?
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K103N
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What drives transmission drug resistance?
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Clustering and viral fitness
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