Infectious disease 3 Flashcards
Chikungunya virus initially replicated where?
Fibroblast of dermis then disseminates
Zika virus most infectious when?
first 30 days from symptoms
Congenital Zika syndrome features?
Microcephaly + Thin cerebral cortices
Macular scarring
Contractures + hypotonia
Dengue virus if infected - immunity last for how long?
2 years
Dengue in tropical areas vs cooler areas?
Aegpyti in tropical
Albopictus in cooler climate
How Dengue hemorrhagic shock and fever occurs?
Viral protein NS1 - disrupt endothelial glycocalyx so more vascular permeability
When to do NS1 antigen to detect dengue?
< day 4
day 5 = dengue serology
Platelet transfusion in dengue?
No role - cause more harm - increase length of hospitalization and recovery of platelet counts
When to give Dengvaxia vaccine?
Past hx of dengue infection if not - in naive patient - more severe dengue infection and higher rate of hospitalisation
How does dengue virus gain entry?
Fc receptor of target cells - macrophage
Chronic carrier of thyphoid - tx?
Ciprofloxacin for 4 weeks
MDR thyphoid definition?
Resistance to first 3 line abx drugs
- Chlorampenicol
- Ampicillin
- Cotriomaxole
XDR thyphoid definition?
Resistance to at least 5 abx
Thyphoid from india or SEA - treatment?
Ceftriaxone or Azithromycin
Thyphoid from pakistan - treatment?
Carbapenem - bcoz resistant to ceftriaxone
Thick screening in Malaria purpose?
Thin screening in malaria purpose?
Thick - screening
Thin - species identification and quantification
Why artesunate cause hemolytic anemia?
Produces ROS that kills parasite but in the process cause hemolysis
When use Tefanoquine?
P. vivax/ovale but G6PD assay must be > 70%
Commonest malaria species ?
P. Falciparum
Why glandular fever - sero-conversion period in HIV?
CD8 kills infected CD4 cells
What is associated with slower progression to AIDS?
HLAB57
Why overtime immune system can’t beat HIV virus?
HIV mutant clones bind poorly to MHC I thus CD8 can’t regconise it
Bnabs - broadly neutralizing antibodies not effective in HIV?
Bnabs targets glycoprotein 41/ 120 on virus
virus learns to evade by 20 weeks
Why TAF (tenofovir) better than TDF (tenofovir)?
TDF rapidly absorbed in gut and excreted by kidney - so need higher dose but then causes renal toxicity
Nevirapine causes what side effect?
Fatal hepatitis
PREP : High risk factors for Transgender and MSM?
Last 3 months
- Condomless anal intercourse - partner HIV +ve
- Methamphetamine use
- Rectal chlamydia/gonorrhea/syphilis
PREP regimen and test?
Tenofovir/Emtricitabine Test UEC+ ACR - every 3 months Syphilis/HIV serology - every 3 months Hep C every 12 months
PoEP : Non-occupational exposure = Known HIV
Lowest risk activity for contracting HIV
Highest risk activity for contracting HIV
-When to give PoEP and not to give PoEP?
- Receptive/insertive oral intercourse - lowest
- RAI - receptive anal intercourse - highest
- KNOWN HIV :unknown/detectable viral load or not on treatment = oral intercourse - no need give PoEP
- KNOWN HIV : viral load NOT DETECTABLE - no need give PoEP
- Everything else give PoEP ( 3 drugs)
PoEP : non-occupational exposure = Dunno if got HIV
lowest risk activity for contracting HIV?
highest risk activity for contracting HIV?
-When to give PoEP?
- Needlestick injury/Receptive or oral insertive oral intercourse/ mucous membrane contact but no skin breakage = lowest
- NO NEED PoEP
- RAI + ejaculation
- everything give PoEP ( 2 drugs) except mentioned above
PoEP : occupational exposure = HIV source
when to give PoEP?
Give in all scenarios
Viral load KNOWN to be undetectable : 2 drugs
Unknown/high viral load/not on treatment : 3 drugs
What is PoEP regimen?
start within 72 hours from exposure and therapy for 1 month
2 drugs : 2 NRTI - tenofovir + emtricitabine/Lamivudine
3 drugs : 2 NRTI + 1 INSTI drug
