Infectious disease 2 Flashcards
What deficiency contribute to prolonged measles?
Vitamin A deficiency
Measles pathognomic clinical features?
Koplik spots
Macular blanching rash starting at face and descends
Treatment of ADEM? Acute disseminated encephalomyelitis?
IV Methylprednisolone
What antibodies found in ADEM?
anti-MOG
NMDA encephalitis strongly associated with?
Ovarian teratoma
How does HSV1 gain entry into brain?
Trigeminal nerve
Commonest organism to cause IE?
Staph aureus
Transpeptidation meaning?
Peptidoglycan layer formation by PBP protein
Enterococcus faecalis IE - treatment?
Ampicillin and Ceftriaxone as effective as
Ampicillin and Gentamicin
When can Staph aureus bacteremia treated for only 2 weeks?
No implanted prosthesis No endocarditis No more MRSA in f/up blood cultures No any further sites of infection No more fever post treatment - > 72 hours
Dexamethasone given for which meningitis and why?
Pneumococcal meningitis
Reduce brain edema and Neuronal hearing loss
Reduce effect of antibiotic-mediated bacteriolysis
Benzylpenicillin given for which meningitis?
Listeria meningitis
When considered ceftriaxone resistant meningitis?
MIC > 0.5 - So add vancomycin in this case
Neisseria meningitis prophylaxis?
- normal population?
- pregnancy?
Normal population-Rifampicin
Pregnancy - IM ceftriaxone
Spleen remove what?
Encapsulated bacteria Opsonized bacteria (properdin)
Commonest organism to cause of OPSI?
H. Influenzae and Streptococcus pneumonia
Which meningococcal is difficult to vaccinate against?
MEN Type B - polysaccharide similar to fetal nerve cells - very non-immunogenic
Why conjugate better than polysaccharide vaccine?
T-cell mediated - produce alot of MEMORY B CELLS
why give conjugate vaccine prior to polysaccharide vaccine?
Polysaccharide causes HYPER-responsiveness of immune system
Risk factors for OPSI
Children < 5 yrs old
Splenectomy for hematological disease
Post splenectomy - first 2- 3 yrs
Infectivity of Covid19 formula?
To stop pandemic aim R to ?
R0 ( reproduction number) = c x p x d
New cases generated directly from single case where EVERYONE is susceptible
c = Contacts per unit time p = probability of transmission d = duration of infectiousness of cases
Rt =effective reproduction number
New cases generated directly from a single case where not everyone is susceptible
R < 1
What is herd immunity threshold?
Proportion of immune individuals in a population that must be exceeded to prevent disease transmission
HIT = 1 - 1/R0
What is secondary attack rate - SAR?
Proportion of susceptible individuals who have contact with positive cases = become infected, developing disease and infect others
*Spouse has highest SAR
Multi-lobular pneumonia suspicious for?
Atypical pneumonia
Nitrites in urine?
Only Gram NEGATIVE bacteria
nitrate convert to nitrite
Impetigo a/w mainly?
Nasal carriage pathogen - Staph aureus,
Staph pyogenes is 2nd commonest
Cellulitis commonest bacteria?
If cellulitis with DM - what antibiotics?
Strep pyogenes
Pip-Taz = cover pseudomonas + anaerobic
Erypsipelas - commonest cause?
Strep pyogenes
Commonest STI in women?
Chlamydia trachomatis
Fitz-Hugh Curtis clinical features?
Gonoccal perihepatitis
RUQ mimicking Cholecystitis
violin-string = perihepatitis ( adhesion between liver capsule/peritoneum)
Gonococcal infection main symptoms
Triad symptoms?
anorectal pain and discharge
Poly digs my tendons
- Polyarthritis
- Dermatitis
- Tenosynovitis
