Infectious Disease Flashcards

Question

Syphilis stages

Answer 1

Primary - Painless chancre and lymphadenopathy Secondary - condyloma lata, contagious genital ulcers, mouth ulcers, uveitis Tertitary - Neurosyphilis, aortitis, gumma.

Answer 2

Emperic - Ceftriaxone + Benpen + Dex Strep - Benpen or Ceftriaxone, add Vancomycin if Cef MIC > 1 Meningicoccus - Ceftriaxone Listeria - Benpen Dex only has benefit in Strep & H.Influenzae

Answer 3

Coxiella (Q fever) Bortenella (Cat scratch) Legionella Chlamydia

Answer 4

- Malaria - cyclical fevers without rash, myalgia, GI upset - Dengue - saddleback fevers and back pain, with macular rash - Zika Virus - mild illness with teratogenicity - Yellow Fever - acute hepatitis - Chikungunya - Severe joint pain - Typhoid/Paratyphoid - enteric fever- stepwise fevers with relative bradycardia and abdominal pain, rose spots - Enterotoxigenic E.Coli - acute diarrhoea illness - Giardia - delayed diarrhoea illness - Bacillus cereus bacteria - reheated rice within 6 hours (very early!)

Answer 5

Haemophilis, Aggregatibacter, Cardiobacterium, Eikenella, Kingella Small gram negative bacteria that cause IE

Answer 6

- Microbiology - 'typical' bugs in 2 separate blood cultures OR persistently positive culture of unusual organism - Echocardiogram - oscillating mass, abscess, new partial dehiscence of prosthetic valve OR new valvular regurgitation - Serology - for Coxiella (Q fever)

Answer 7

- Predisposition - IVDU or heart condition - Fever 38°C - Vascular phenomena - arterial embolism, septic pulmonary infarct, Janeway lesion, mycotic aneurysm, intracranial haemorrhage - Immunological phenomena - glomerulonephritis, Oslers nodes, Roth spots - Suggestive microbiology

Answer 8

Nucleotide reverse transcriptase inhibitors - stop RNA to DNA transcriptase via binding at deoxynucleotide binding site Non-nucleotide reverse transcriptase inhibitors - stop RNA to DNA transcriptase by binding at an alternative site to the deoxynucleotide Integrase inhibitors - stop viral replicated DNA being integrated with host DNA Protease inhihbitors - stop budding and maturation of virus from host cells, main role is to inhibit CYP3A4 to increase efficiency of other HIV drugs

Answer 9

Bone Marrow suppression with thrombocytopenia Neuropathy Serotonin syndrome

Answer 10

GI symptoms, dry cough, hyper infection decades after infection due to immunosuppression, larvae rash & organ failure due to infiltration or overlying bacterial infection Worse with co-infection human T-lymphocytic virus 1 (HTLV1) Ix - Serology or Rhabditiform larvae in stool Rx Ivermectin

Answer 11

Conjugated (Ag bound to protein) - will induce a T cell response and long-term immunity - 13PCV pneumococcal - single dose to be given before non-conjugated - monovalent Menigicoccal - Against serotype C - Quadravalant Meningicoccal - Against serotypes A, C, W, Y - Meningococcal B Unconjucated (Ag not bound to protein)- will only induce a B cell response, and no long term immunity - 23PPV pneumococcal - for 2 further doses to make up total 3 doses over 5 years - Haemophilus

Answer 12

Amoxicillin for 3 years if otherwise healthy Lifelong if Hx opportunistic infection

Answer 13

Mild - 3 day course chloroquine followed by 14 day course Primaquine OR Artemether + lumefantrine Latent - 14 days primaquine Severe - IV Artesunate - resistance due to KELCH 13 gene in SE Asia

Answer 14

Mutation in malaria strains of SE asia which cause IV artesunate resistance

Answer 15

If G6PD deficient, will cause haemolysis

Answer 16

Anopheles - Malaria Aedes - Flavivirus

Answer 17

Teratogenic Gullian Barre Dx PCR < 7 days, serology > 7 days

Answer 18

1-3 weeks incubation Enteric fever due to Salmonella. - Stepwise fevers - diarrhoea or constipation w abdominal pain, - Relative bradycardia - Salmon coloured papule on skin (rose spots) - Rx with Ceftriaxone.

Answer 19

Azoles - inhibit D-14 alpha demethylase at CP450 to stop ergosterol synthesis at cell walls Echinocandins - inhibit beta 1,3 D glucan to inhibit cell wall synthesis Amphotericin (polyenes) - binds ergosterol to stop membrane function and create pores

Answer 20

Via Glycoprotein 120 and glycoprotein 41 with co-receptors CCR5 (mild disease) and CXCR4 (late infection, more aggressive) A lack of CCR5 causes a slower progression of disease

Answer 21

CCR5 - early CXCR4 - late Lack of CCR5 in populations causes slower and milder disease

Answer 22

CCR5 - early CXCR4 - late Lack of CCR5 in populations causes slower and milder disease

Answer 23

Patients with HLAB57.01 MHC type receptors on CD4 cells bind strongly to T killer cells and & are more likely to be able to control viral load/slower progression of disease. These patients cannot be treated with Abacavir. CCR5 co-receptor mutations - less ability of HIV to bind co-receptors causing slower progression of disease

Answer 24

within 72 hours (best within 24 hours) - High risk - 2 x NRTI + integrase inhibitor (Known HIV not on treatment with detectable viral load or high risk exposure to unknown patient) - Low risk - 2 x NRTI (unknown HIV or on treatment with undetectable viral load)

Answer 25

CD4 count > 50 - wait 8 weeks CD4 count < 50 - wait 2 weeks

Answer 26

Aminoglycosides (Gentamicin) Tetracyclines (doxycycline)

Answer 27

I.e. Ciprofloxacin Bind DNA gyrase

Answer 28

Block RNA polymerase

Answer 29

Block folate synthesis

Answer 30

Via mecA (mobile genetic element), which encodes for extra penicillin binding protein (PBP2a) that cross-links PBP and gives beta-lactams a lesser affinity

Answer 31

Inducible beta-lactamase via AmpC Enterobacter Serratia Citrobacter Acinetobacter Proteus Vulgaris (but not mirabilis) Providencia Morganella Morgani

Answer 32

New Delhi Metallo Beta Lactamase (NDM1) transferred by plasmids making enterobacter resistant to carbepenams

Answer 33

MRSA - genetic mobile unit MecA VRE - plasmid Van A, B, C ESBL - plasmid CTX-M ESCAPPM - inducible betalactamase AmpC CRE - plasmid New Delhi Metallo (NDM1) beta lactamase

Answer 34

Meropenum, Vancomycin and Clindamycin (for toxins)

Answer 35

CYP inducer (particularly important in HIV meds) Hepatotoxicity Orange sercretions

Answer 36

Hepatotoxicity, Peripheral neuropathy

Answer 37

Optic neuropathy - require baseline eye tests

Answer 38

Gout, Hepatotoxicity

Answer 39

Rifampicin - CYP inducers, orange secretions Isoniazid - Peripheral Neuropathy (give w B6 Pyridoxine) Ethambutol - Optic neuropathy Pyrazinamide - Gout, Worst risk of hepatitis!

Answer 40

Healthcare workers < 35 years old Immunosuppressed Recent infection

Answer 41

- Mononucleosis- type illness with Fever and Lymphadenopathy "CMV-effect" - Can affect many end organs "CMV disease" ( Pneumonia, hepatitis, GBS, Meningoencephalitis, myocarditis, thrombocytopenia, haemolytic anaemia) - Owl eyes on blood film - Risk of maternal -> fatal transmission 40%

Answer 42

Solid organ - Donar +, recipient - Haematological - Donar -, recipient +

Answer 43

Staph Aereus Or Staph Epi if within 2 months of prosthetic heart valve

Answer 44

MRSA - MecA gene causing change in penicillin binding protein 2 VRE - Van A or B causing change in cell wall to reduce affinity for Vancomycin ESBL - Plasma mediated genes which code for enzyme that hydrolyses bea-lactam, most commonly CTX-M gene. Causes resistance to penicillins & 3rd generation cephalosporins (Ceftr, Ceftaz) ESCAPPM - ESBL with inducible beta-lactamase on Chromosomal AmpC (not plasmid) CRE - Carbapenem resistant beta-lactamase - New Delhi Metallo-beta-lactamase-1 (NDM1) on plasmids

Answer 45

Candida albicans - fluconazole (most common) Candida glabrata - Echinocandin Candida Krusei - Voriconazole (fluconazole resistance) Candida Auris - Echnocandin (known multi-drug resistance)