ID Flashcards
HIV - Opportunistic infection
- CD4 Count 200-500; shingles, pneumococcal, oral candidiasis, TB
- CD4 50-200; PJP, CNS toxo, crytococcus, capos sarcoma, CNS EBV, NHL –> primary prophylaxis with COTRIMOXAZOLE (PJP + toxo)
- CD4 <100; Fluconazole prophylaxis for crytococcus
- CD4 <50; Disseminated MAC, CMV Retinitis, cryptosporidiosis –> primary prophylaxis with AZITHROMYCIN 1g weekly
- Continue prophylaxis until CD4 >200 for 3-6 mths (depending on the organism)
mantoux
A mantoux test would be considered as positive if the skin induration is:
- More than 5mm in HIV infected person, immunosuppressed, close contact of infectious TB and presence of old TB on CXR.
- More than 10mm if medical risk factors, foreign born endemic TB area, healthcare worker, nursing home, prisoners.
- More than 15 mm for all other persons, BCG vaccinated.
highest risk of developing invasive fungal infection
- Acute myeloid leukaemia
- Allogenic HSCT (particularly with cord blood source) and
- Heart, lung, liver transplantation
Live vaccines are contraindicated in immunosuppressed patients
- BCG
- Oral polio vaccine
- Measles
- Rotavirus
- Yellow Fever
syphillis
screening test - T. pallidum EIA (test both IgM and IgG)
confirmation test - TPHA/TPPA and VDRL/RPR tests
All serological investigations may be negative in early primary syphilis; the EIA IgM and the FTA-abs being the earliest tests to be positive.
Antibiotic prophylaxis
indicated in high risk group for dev IE;
– A prosthetic heart valve
– Valve repair with prosthetic material
– A prior history of infective endocarditis
– Many congenital (from birth) heart abnormalities, such as single ventricle states, transposition of the great arteries, and tetralogy of Fallot, even if the abnormality has been repaired. Patent foramen ovale, the most common congenital heart defect, does not require prophylaxis
High risk GI procedures:
- Dilatation of esophageal stricture
- Treatment of esophageal varies
- ERCP with obstruction
- Endoscopic ultrasound with FNA
- PEG
High risk respiratory procedures:
- procedures that involve incision or biopsy of the respiratory mucosa.
- tonsillectomy
- adenoidectomy
- bronchoscopy with biopsy.
Other high risk procedures:
- Procedures in patients with ongoing GI or GU tract infection.
- Procedures on infected skin, skin structure, or musculoskeletal tissue.
- Surgery to place prosthetic heart valves or prosthetic intravascular or intracardiac materials.
- All dental procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa.
NOT Recommended:
- Colonoscopy
- Gastroscopy
- C-section
aspiration pneumonia
According to the Australian Therapeutic guidelines, updated November 2014, the recommended empirical antibiotic treatment for community or nursing home acquired aspiration pneumonia are as follow:
1) Mild disease- oral amoxycillin.
2) Moderate disease- benzylpenicillin IV +/- metronidazole if the add. features are present.
3) Severe disease- Ceftriaxone IV or cefotaxime IV PLUS metronidazole. Use piperacillin + tazobactam IV if increased risk for resistant gram negative pathogens, or if staphylococcal pneumonia is suspected.
addition of metronidazole is recommended in the following patient group with:
- putrid sputum
- severe periodontal disease
- history of chronic hazardous alcohol consumption
- development of lung abscess, empyema or necrotising pneumonia.
- do not respond to initial empirical therapy.
daptomycin
inhibited by surfactant
-CANNOT use in lung infection
indications for surgery in native valve infective endocarditis
- Heart failure due to valvular regurgitation
- Paravalvular extension which signifies uncontrolled infection/difficult organism.
- Recurrent emboli and vegetations despite appropriate antibiotics therapy.
- Large mobile vegetations irrespective of embolisation (mobile vegetations >10mm)
bacterial meningitis
For empirical therapy:
Use dexamethasone 10mg IV PLUS EITHER ceftriaxone or cefotaxime.
ADD benzylpenicillin to cover Listeria in the following patient group: – immunocompromised – adults more than 50 years of age – history of alcohol abuse – pregnant – debilitated
For directed therapy:
1. Strep pneumoniae:
Use benzylpenicillin for susceptible strains with MIC
Use ceftriaxone or cefotaxime for susceptible strains with MIC <1.0mg/L.
For strains of penicillin MIC 0.125mg/L or greater and ceftriaxone or cefotaxime MIC 1.0 to 2.0 mg/L, use either ceftriaxone or cefotaxime PLUS vancomycin.
- Neisseria meningitidis:
Use benzylpenicillin.
For patient who is hypersensitive to penicillin, use
IV ceftriaxone or IV cefotaxime.
For patients with immediate penicillin or cephalosporin hypersensitivity, use IV ciprofloxacin OR IV chloramphenicol.
- Listeria monocytogenes:
Use benzylpenicillin
In patients hypersensitive to penicillin, use trimethoprim + sulfamethoxazole.
- Haemophilus influenzae type b:
Use ceftriaxone or cefotaxime
If proven susceptible, use benzylpenicillin.
If hypersensitive to penicillin or cephalosporin, use IV ciprofloxacin or IV chloramphenicol.
Culture negative endocarditis
Coxiella burnetti
Bortenella
chlamydia
Legionella
likely cause of infection
Dental disease- Strep viridans
Prolonged indwelling vascular catheter and IVDU – Staph aureus
Procedures involving gut and perineum – Enterococcus fecalis
Bowel malignancy- Strep bovis
Soft tissue infection- Staphylococci
Dukes criteria for IE
Major criteria:
- A positive blood culture for IE. Typical organism growing in 2 cultures in absence of a primary focus.
- A persistently positive blood culture
- A positive serological test for Q fever.
- ECHO evidence-mass, abscess, dehiscence.
- New valvular regurgitation.
Minor criteria:
- Predisposition: predisposing heart condition or intravenous drug use.
- Fever: temperature ≥ 38C (100.4F).
- Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial haemorrhage, conjunctival haemorrhages, Janeways Lesion.
- Immunologic phenomena: glomerulonephritis, Oslers nodes, Roths spots, rheumatoid factor.
- Microbiological evidence: a positive blood culture but not meeting a major criterion as noted above, or serological evidence of an active infection with an organism that can cause infective endocarditis.
- Echocardiogram: findings consistent with infective endocarditis but not meeting a major criterion as noted above.
Diagnosis requires Two major clinical criteria, one major and three minor criteria, or five minor criteria are met
IE rx
In general, empiric therapy should cover staphylococci (Methicillin susceptible and resistant),streptococci and enterococci.
Appropriate choices would include:
Flucloxacillin + Penicillin + Gentamicin or
Vancomycin + Gentamicin.
Strep endocarditis– Penicillin and gentamicin
Enterococcal endocarditis– Ampicillin and gentamicin
Staph endocarditis – Vancomycin (If MRSA) or Flucloxacillin plus Gentamicin.
Culture negative endocarditis– ceftriaxone and gentamicin.
(active against bartonella/strep/HACEK)
Q fever endocarditis– doxycycline and plaquenil and rifampicin.
Fever in a returned traveller
Think of malaria,dengue and typhoid.
-malaria most common
Incubation periods:
If < 10 days: malaria, dengue.
If 10-21 days: malaria, typhoid fever,
If >21 days: malaria.
Geographical Locations:
1) Malaria:
– Papua New Guinea, India, Pakistan, Africa, Indonesia.
2) Enteric fever (typhoid/parathyphpoid):
– South central and Southeast Asia
3) Dengue:
– Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are the most seriously affected
