Infectious Disease 7

Question 1

Schistosomiasis features

Schistosomiasis comes from?

treatment?

Answer 1

features - blood eosinophilia, bladder cancer or hematuria

Aetiology - Snails = Flat tapeworm

Tx - Praziquantel

Question 2

Leishmaniasis features

treatment?

Answer 2

Chronic skin ulceration in nose/mouth
+ Hepatoslenomegaly

Tx - Amphotericin

Question 3

Amoebiasis transmission mechanism?

Answer 3

Water/food - cyst

Fecal oral - trophozoites

Question 4

Amoebiasis treatment?

Answer 4

Asymp. carriage = Paromomycin

Colitis, diarrhea = Metronidazole

Abscess ( trophozoites) = Drain it + Metronidazole + Ampicillin + Gentamicin

Question 5

Strongyloidiasis aetiology?

Infection pattern?

Worms goes into lungs?

Treatment

Answer 5

Roundworm

Auto-infection + Hyperinfection in intestine

Lungs = Loffler syndrome - pulmonary eosinophilia of upper lobes

Ivermectin/Albendazole

Question 6

Filariasis aetiology?

Treatment?

Answer 6

Roundworm

Tx - Ivermectin/Albendazole

Question 7

Neurocysticerosis aetiology?

Answer 7

Taenia tapeworm

Tx
GI taenia = Praziquantel
Neuro taenia = Albendazole + Steroids

Question 8

Hydatid disease aetiology?

Clinical presentation?

Tx?

Answer 8

Echinococcocis tapeworm

Clinical - large liver/alveolar cysts

Treatment
Albendazole + PAIR (Puncture,Aspirate,inject and reaspiration)
-if spilled in surgery
=Praziquantel

Question 9

Angiostrongylus cantonesis aetiology?

Tx?

Answer 9

Snails - roundworm
=Eosinophilic meningitis!

Tx Albendazole + Steroids

Question 10

Glutamate dehydrogenase sensitive in what infection?

Answer 10

C. difficile

Question 11

C. difficile most virulent strain?

Answer 11

PCR 027

Question 12

Staph aureus produces what?

MRSA produces what?

Answer 12

Protein A coagulase

PVL - panton-Valentine leucidin protein

Question 13

What is jarish-herxheimer reaction and treatment?

Answer 13

Release of toxins from treponemal destruction = give with prednisolone + Benzylpenicillin
(syphillis)

Question 14

Enterococcus usually treat with what abx?

Answer 14

Amoxicillin + Gentamicin

Question 15

Bartonella infection - treat with?

Cat scratch disease

Answer 15

systemic + persistent lymphadenopathy = Azithromycin (macrolide)

Endocarditis = Doxycycline + Gentamicin/Rifampicin

Question 16

Q fever treat with?

in pregnancy?

Answer 16

Doxycycline

Pregnancy = Bactrim + FOLIC ACID until 32 weeks no matter what!

Question 17

Brucellosis from pigs - treat with?

Answer 17

Doxycycline + Rifampicin ( reduce rate of failure/relapse)

Question 18

Which organism causes nitrates negative but leucocytes positive for UTI? ( don’t produce nitrate reductase)

Answer 18

Pseudomonas
Enterococcus fecalis
Acinebacter
Staphylococcus
Streptococcus

Question 19

Alemtuzumab famously cause what type of infection?

Answer 19

Listeria

Question 20

Primary prophylaxis in HIV - what organism and what’s the treatment?

Answer 20

Pneumocytic carinii
MAC
Toxoplasmosis

Bactrim - covers Toxoplasmosis and PJP
Azithromycin - covers MAC

Question 21

PJP but allergy to Bactrim or sulphur - what’s the alternative?

Answer 21

Clindamycin + Primaquine

Question 22

Toxoplasma but allergy to Bactrim - what’s the alternative?

Answer 22

Dapsone ( Need to include folic acid - calcium folinate) + Pyrimethamine

Question 23

Whipple disease pathogenesis and treatment?

Answer 23

Gram +ve Trop Whippelli

manifest as malabsorption syndrome

Tx - IV Ceftriaxone, then Bactrim as maintenance

Question 24

Trimethoprim mechanism of action?

Answer 24

Bacterial Dihydrofolate reductase inhibitor

Question 25

Rifampicin inhibits bacterial RNA polymerase | The analogue in mammals/humans is cytarabine - how it works?

Answer 25

Inhibit a-DNA polymerase

Question 26

sulfonamides - sulfamethazole mechanism of action?

Answer 26

Inhibit folate synthesis

Question 27

Tetracycline usually inhibit 30s Ribosomal unit - but it can also attack 50s - how?

Answer 27

Competitive binding site of A site for tRNA - inhibit protein synthesis

Question 28

4 main ways mechanism of antimicrobial resistance?

Answer 28

Modify anti-microbial molecule - destroy/chemical alteration Prevents molecule reaching target - efflux/permeability alteration Modify target site Resistance ( global adaptive effect)

Question 29

Prevents molecule from reaching target - efflux/permeability -porin - affects what antibiotics?

Answer 29

1. Efflux pumps - Tetracyclines - Fluoroquinolones - Chloramphenicol 2. Permeability - porins ( Pseudomonas/ Enterobacter) - Tetracyclines - fluoroquinolones - b-lactams

Question 30

Modify target site - affects what drug?

Answer 30

Target site mutation - Rifampicin/ Fluoroquinolones - main way of resistance Methylation of 50s - lincosamides/macrolides Replace antibiotics' target with smtg else, cell wall continue to strengthens (MRSA/VRE)

Question 31

Modify antibiotic molecules - what drugs affected?

Answer 31

B-lactam | aminoglycosides

Question 31

NRTI/NtRI - mechanism of action? Zidovudine - what analogues? Lamivudine/Emtricitabine - what analogues? Abacavir/entecavir - what analogues? Tenofovir/tAdefovir - what analogues?

Answer 31

Incorporate into Viral DNA growing chain but incomplete - so halting replication Zidovudine - Thymidine analogue Lami/Emtri = Cytosine analogue Aba/Ente = Guanosine NRTI ( nucleoside) Teno/Ade = Guanosine NtRTI ( nucleotide)

Question 32

Non-nucleotide RTI - mechanism and eg drugs?

Answer 32

Bind to reverse transcriptase enzyme, near catalytic side and deactivates enzyme Efavirenz Nevirapine

Question 33

Antivirals for herpes group - aciclovir/famiclovir -mechanism of action?

Answer 33

Inhibit DNA polymerase | phosphorylated by Triphosphate form to be active

Question 34

HIV lymphoma, Hodgkin lymphoma - what's the virus causing it?

Answer 34

EBV!!!

Question 35

Aciclovir and Herpes zoster opthalmicus?

Answer 35

Reduces pain and complications but NOT POST-HERPETIC NEURALGIA

Question 36

TB most resistant to which drugs worldwide?

Answer 36

Isoniazid

Question 37

Aflatoxins from Aspergillus fungi a/w?

Answer 37

P53 mutations = HCC

Question 38

Staphylococcal Toxic Shock syndrome divided into 2 categories? Pathogenesis?

Answer 38

Menstrual - tampon colonised by S. Aureus Non-menstrual - burns/surgery/ post-influenza pneumonia Superantigens bind to MHC II - interact with T cells - large amount of IL2, IL1, cytokines (TNF-a, IFy) release