ID Flashcards
What mosquito spreads malaria
Anopheles - night time biter
What do positive thick and thin films show?
Rings of parasites within RBC
What does the malaria rapid antigen test detect?
HRP2
Detects 95% low parasitemia
What are indications for IV arterunate in malaria?
Can’t take tabs
End organ disease
Severe disease
What malaria species can be dormant in the liver for years?
P.vivax, P ovale
How do you treat relapsing malaria (p.vivax)
Primaquine
Tafenoquine
What needs to be checked before starting primaquine?
G6PD deficiency
What blood cultures are found with malaria?
Gram negative bacteraemia
Onset of illness and fevers in returned traveller <10 days?
Dengue
Influ
Zika
Chikungunya
Enteric
Rickettsia
Yellow fever
What illness in returned traveller happen 10-21 days
Malaria
VHF
Typhoid
Brucellosis
Leptospirosis
What illnesses occur >21 days in returned traveller?
Malaria
Hepatitis
TB
Returned from subsaharah Africa ass with what infection?
Malaria
Returned from East Asia + Latin America?
Dengue
Returned south central Asia?
Enteric fever
What is NS1 antigen panel for?
Dengue fever
What are the love vaccines?
MMR
Yellow fever
BCG
Varicella/zoster
Oral polio
IMOJEV
Orocol Berna
Oral typhoid
What is long duration of high fevers and relative Bradycardia a feature of?
Typhoid
Multi drug resistant typhoid is resistant to what?
Amoxi, quinoline, trimethoprim
Sens ceftri, azithro
How.do you treat typhoid from Pakistan?
Carbapenem (as resistant++)
What is NS1?
Viral protein (Dengue) that disrupts the endothelial gycoxalyx increasing vascular permeability leading to shock
For Dengue what test are done <5 days of infection, and what >5 days of infection
< 5 - PCR/NS1
>5 Serology/IgM
Do platelet infusion help with dengue thrombocytopenia?
No
What are the guidelines for unprotected sex after travel to Zika endemic country?
Men - condom for 3 months (NZ guidelines say 6)
Women - condom 2 months
Chikungunya is associated with what symptom?
Arthritis/arthralgia - some develop chronic inflammatory synovitis following infection
How do you treat strongyloides?
Ivermectin
What are side effects of rifampicin?
Hepatotoxicity, nausea, abdominal pain.
CYP3A4 Inducer, P-gly-p inducer
What are side effects of isoniazid?
Hepatotoxicity, peripheral neuropathy (treated by pyridoxine), inhibits cyp450 enzymes
What are the 4 drugs for TB?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
What are side effects of ethambutol?
Optic neuropathy - get eyes tested before starting
What is multi drug resistant TB?
Resistant to rifampicin AND isoniazid
What gene gives TB resistance to rifampicin?
ROPV (don’t usually have isolated rifampicin resistance, usually indicates Isoniazid resistance)
What are the treatment regimens for active tb?
RIPE - 2 months, followed by isoniazid+ rifampicin for 4 months
Extend to 9 months total I’d cavitatary disease, meningitis or bone/joint disease
When do you give steroids in TB?
TB meningitis + TB pericarditis
What is used in MRD TB?
Bedaquilline, pretomanid, linezolid, moxifloxacin
What is the MoA of isoniazid?
Inhibits the synthesis of mycolic acid through the NADPH-dependent enoyl-acyl carrier protein ACP reductase
What is the mechanism of drug resistance to isoniazid?
It requires mycobacterium catalase peroxidase to be activated - mutations in this confer resistance
What cytokines/chemokines are important in the immune response to TB?
T-cell mediated
INF-Y, TNF-A, IL12
How long after exposure to TB will the IGRA, TSPOT, TST tests be helpful?
8 weeks - need to have been able to mount a t cell response to have a positive test
Pyrazinamide, isoniazid, rifampicin causw hepatotoxicity, when do you stop treatment?
When ALT 3 X ULN with symptoms or ALT>5ULN asymptomatic
Restart when ALT near baseline
What defines XDR-TB? (Extensively resistant)
R to isoniy, rifampicin and fluoroquinolones and at least 1 injectable treatment (kanamycin, calreomycin, amikacin)
Can you culture PJP?
No, need microscopy/ immunofluorescence for visualisation
What is in maviret?
Glecaprevir and pibrentasavir
What is the MoA of Glecaprevir?
Inhibits HCV serine protease NS3/4A required for viral maturation
What is the MoA of pibrentasavir?
Inhibitor of HCV NS5A which is essential for RNA replication and vision assembly
Can you use glecaprevir+ pibrentasavir in pregnancy?
No data, Recommend deferring treatment until post-partum, risk of transmission is low.
Shouldn’t be used in BF either
How do you know treatment has cured HCV infection?
Negative HCV core antigen assay at 12 weeks
What surface molecule give HIV entry to cells?
GP120 attachedk to GP40 on the virus surface
What do GP120/GP40 attach to
CD4 and co-receptor CCR5, or CXCR4
What HLA type leads to more effective clearance of HIV virus?
HLAB*57.01 - binds HIV core protein that is essential for HIV replication, and therefore mutants are not able to replicate. Associated with slower progression ( same HLA ass with abacavir hypersens)
What is the MoA of Tenofovir?
Reverse transcriptase inhibitor
What is the MoA of Emtricitabine?
NRTI - Nucleoside reverse transcriptase inhibitor
What drugs are INSTIs? Intergrase inhibitor
Dolutegravir, raltegravir, bictegravid, elitegravir
What drugs are NNRTI? Non-nucleoside reverse transcriptase inhibitor
Efavirens, rilpivarine, nevirapine
What HIV med can’t be used in renal failure?
Tenofovir TDF - avoid eGFR <60, associated with renal tubulopathy
Tenofovir TAF - less nephrotoxic
What are side effects of zidovudine?
Lipodystrophy, central obesity, GI side effects
Side effects of tenofovir?
Nephrotoxic, reduced bone mineral density, phosphate wasting in urine. Need to monitor urine P{;Cr
What are the side effects of efaverens?
Eff you up - CNS side effects in first few weeks, sedation, insomnia, vivid dresms, neuropsych
What is ritonavir?
Protease inhibitor, but usually only used to inhibit CYP3A4 to improve function of/boost other ARTs
What are side effects of raltegravir?
can cause rhabdo, increase CK
What are side effects of dolutegravir?
Headache, depression/anxiety, raises serum creatinine without renal toxicity, vivid dreams, mood disturbance.