Infectious Diseases Flashcards
Most common presentation of S. aureus with Panton-Valentine leucocidin (PVL)
Soft tissue infections (ie. pyogenic skin infections)
Necrotizing pneumonia
Common/typical infective endocarditis (IE) organisms
Viridans streptococci (mutans, sanguis, salivarus, mitis, bovis)
Enterococcus faecalis
Staphylococcus aureus
HACEK group (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella)
Major Duke Criteria for IE
- 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 burnetti
Minor Duke Criteria for IE
- 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
Common UTI organisms
E. coli Enterobacteriaceae Proteus mirabilis Klebsiella pneumoniae Staphylococcus saprophyticus
Common liver abscess organisms
Entamoeba histolytica Streptococcus milleri Klebsiella pneumoniae Burkholderia pseudomallei Candida
Common periodontic disease organisms
Streptococcus Peptostreptococcus Veillonella Corynebacterium Lactobacillus
Protease inhibitor (eg. ritonavir, cobicstat) function in HIV treatment
Reduce CYP3A4 metabolism of other anti-retrovirals, improving pharmacokinetic profile
Vaccines contraindicated for immunosuppressed
Measles, mumps, rubella (MMR) Live attenuated influenzae vaccine Varicella - live Zoster - live Rotavirus - live BCG Oral typhoid Yellow fever
Common chronic granulomatous disease (CGD) infections
Catalase producing organisms: S. aureus Aspergillus Pseudomonas Serratia Nocardia
Linezolid - adverse reactions
Myelosuppression Peripheral neuropathy GIT upset Bad taste Rash
Most associated antibiotics with C. difficile colitis
Clindamycin Fluoroquinolones (eg. ciprofloxacin) Cephalosporins Macrolides (eg. azithromycin) Penicillins - due to common prescribing
Most effective strategy to prevent recurrence of rheumatic fever
Secondary prophylaxis with benzathine penicillin G
Common traveller’s diarrhoea organisms
Enterotoxigenic E. coli (ETEC) Campylobacter Shigella Giardia Salmonella
Common persistent traveller’s diarrhoea organisms
Giardia Campylobacter Entamoeba Shigella Strongyloides
Treatment of traveller’s diarrhoea
Azithromycin
Ciprofloxacin
Norfloxacin
Tinidazole / metronidazole - in Giardia
Treatment of diabetic foot ulcers
Tazocin (piperacillin+tazobactam)
Timentin (ticarcillin+clavulanate)
Treatment of infective endocarditis
Penicillin + gentamicin - Viridans strep, enterococcal,
Flucloxacillin - Staphylococcal
Ceftriaxone - E. faecalis, or alternative to penicillin
Vancomycin - MRSA or MRSE
Dengue fever - presentation
Onset - 3-10 day incubation Fever (2-3 days) Rash (maculopapular) Aches / pains - breakbone fever Nausea / vomiting Tourniquet test - positive
Malaria relapse - presentation
Onset - 21-30 days (up to years) Fever Flu-like illness Splenomegaly Jaundice Great immitator - diarrhoea, cough etc.
Acute tuberculosis - presentation
Onset - 3-10 weeks
Fever (gradual, low grade, 2-3 weeks)
Pleuritic chest pain
Amoebic liver abscess - presentation
Onset - 12 weeks post-return Fever RUQ pain Weight loss Liver abscess
Travel-related infections - short incubation (less than 10 days)
Influenza Dengue Yellow fever Plague Paratyphoid fever Mediterranean spotted fever African tick-bite fever Rocky Mountain spotted fever
Travel-related infections - intermediate incubation (from 10-21 days)
Malaria Viral haemorrhagic fever Typhoid fever Scrub typhus Q fever Relapsing fever (Borrelia spp.) African trypanosomiasis
Travel-related infections - long incubation (more than 21 days)
Malaria Hepatitis A, B, C, E Rabies Schistosomiasis Leishmaniasis Amoebic liver abscess Tuberculosis Filariasis Brucellosis
Treatment of tuberculosis (TB)
2 months (initial phase): Isoniazid Rifampicin Pyrazinamide Ethambutol
4 months (continuation phase):
Isoniazid
Rifampicin
Most common cause of Mollaret’s recurrent meningitis
HSV-2
Characterised by 3 episodes of at least 2-5 days
Most common cause of infective endocarditis in IVDU
Staphylococcus aureus
Treatment of extended spectrum beta lactamase (ESBL)
Meropenem
Cotrimoxazole
Treatment of latent tuberculosis infection (LTBI)
Isoniazid 300mg daily for 6-9 months
(Pyridoxine 25mg daily - to reduce risk peripheral neuropathy)
(Alternatively - rifampicin for 4 months)
Risk factors for reactivation of latent tuberculosis infection (LTBI)
Recent acquisition within 2 years (household contact or healthcare worker)
T cell immunocompromise (HIV, post-transplant immunosuppression, lymphoma, leukemia)
Renal failure on dialysis
Treatment with biologics
Common prosthetic valve infective endocarditis organisms
Early (1st 6 months):
Staphylococcus aureus
Coagulase negative staphylococcus
Late (after 6 months):
Similar to non-valvular endocarditis - Streptococcus
Strongyloidiasis - presentation
Eosinophilia
Intermittent GI symptoms - abdo pain, diarrhoea, anorexia, nausea, vomiting
Cutaneous - oedema, petechiae, pruritis
Pulmonary - dry cough, dyspnoea, wheeze, haemoptysis
Pyrexia of unknown origin (PUO) - definition
Fever 38.3 on several occasions
Duration of fever more than 3 weeks
Uncertain diagnosis despite 1 week study in-hospital
Pyrexia of unknown origin (PUO) - minimum investigations
Blood cultures x3 ESR, CRP LDH Tuberculin skin test or Quantiferon Gold HIV Ab RF, ANA, SPEP CT CAP
Multi-drug resistant tuberculosis (MDR-TB) - definition
Resistance to isoniazid + rifampicin
isoniazid resistance most common - 13%
Common intravascular catheter related infection organisms
Coagulase negative Staph
Staphylococcus aureus
Enterococcus
Candida
Most common cause septic arthritis
Staphylococcus aureus
AIDS defining malignancies
Non-Hodgkin’s lymphoma
Kaposi sarcoma
Cervical cancer
Dengue haemorrhagic fever - criteria
- Increased vascular permeability - haematocrit 20% above base, pleural effusion, ascites
- Thrombocytopenia - less than 100
- Fever - 2 to 7 days
- Haemorrhage - spontaneous bleed, positive Tourniquet test
Asymptomatic bacteriuria - indications to treat
Pregnancy
Prior to urological intervention with mucosal bleeding
