Infectious disease Flashcards
BACTERIAL MENINGITIS
i) what organism most commonly causes pneumococcal disease? what causes meningococcal? what is the most common causative in neonates
ii) name four presenting features? what causes a non blanching rash?
iii) name three symptoms that may be seen in neonates/babies?
iv) name three indications for doing aan LP
v) what is kernigs test and brudzinskis test?
i) pneum = strep pneumoniae
meningococc - neisseria meningitidis
neonates > group B strep is most common
ii) px with fever, neck stiff, vomit, headache, photophobia, alt conc
non blanching rash > meningococcal septicaemia
iii) non spec symptoms eg hypotonia, decreased feeding, lethargy, bulging fontanelle
iv) <1m old px with fever, 1-3m fever and unwell, <1yr unexplained fever and other features of serious illness
v) test for meningeal irritation
kernigs - lay on back, flex hip and knee > pain
brudinzski - lay flat, lift head and neck and flex chin > invol flex of hip and knees is positive test
MANAGEMENT OF BACTERIAL MENINGITIS
i) what should be done in the community if there is suspected meningitis and a non blanching rash?
ii) in hospital what two investigations should be done prior to starting abx?
iii) what abx is given <3m? what is given to cover listeria? what is given >3m? what abx can be added if there is risk of pen resistant pneumococcus eg recent travel
iv) what can be given to reduce risk of hearing loss and neurol damage?
i) STAT injection of benzylpenicillin
ii) blood culture and LP but dont delay abx if very unwell
iii) cefotaxime + amox for listeria cover
>3m - ceftriaxone
vancomycin if risk of pen resis pneum
iv) steroids eg Dex QDS for 4 days if >3m and LP confirms bac men
VIRAL MENINGITIS
i) what is the most common causative? name two others?
ii) what should CSF be sent for?
iii) what drug may be given? what can be given as prophylaxis for contacts?
iv) what is the main complication? name two others
i) HSV
also enterovirus and VZV
ii) send CSF for viral PCR testing
iii) give aciclovir is HSV or VZV
give ciprofloxacin for prophylaxis
iv) hearing loss main complication
also epilepsy, seizures, cog impair, mem loss, ceb palsy
LP RESULTS
i) what appearance does it have in bacterial/viral men?
ii) what is the protein content in each?
iii) what is glucose content in each?
iv) what type of WC are seen in each?
v) which one is culture positive
i) bac - cloudy
viral - clear
ii) bac - high protein
viral - small inc or normal protein
iii) bac - low glucose
viral - normal glucose
iv) bac see increased neuts
viral see inc lymphocytes
v) bac is culture positive
ENCEPHALITIS
i) what is it? what is a non infective cause? what is the most common viral cause? what is the most common cause in children? in neonates?
ii) what question must always be asked
iii) name four ways it can px
iv) name four investigations that should be done
v) what is the the contra indication to doing an LP? name five other things? in what condition must you not do an LP
i) inflammation of the brain
viral > HSV
children - HSV1, neonates HSV2
non infective = autoimmune
ii) ask about vacc status - polio/mumps/measles can cause encephalitis
iii) altered conc, altered cog, unusual behaviour, focal neurol symptoms, fever, seizures
iv) LP > viral PCR, CT scan if LP is CI, MRI, throat swab, HIV testing for all patients
v) LP CI in increased intracranial pressure
GCS <9, HD unstable, active seizure, bulging fontanelle
dont do LP in meningococcal septicaemiaa
MANAGEMENT OF ENCEPHALITIS
i) what is given if HSV, VZV is the causative?
ii) what is given if CMV is the causative
iii) what should be done before stopping abx
iv) name three complications
i) HSV/VZV > aciclovir
ii) CMV > ganciclovir
iii) repeat LP to ensure success prior to stopping abx
iv) fatigue, personality change, memory chnge, headache, chronic pin
NEONATAL SEPSIS
i) what is it? what constitutes early onset? late onset? which two causative agents account for 2/3 cases?
ii) what organism causes most early onset sepsis? how is it transmitted?
iii) how is late onset most commonly contracted? name two common causatives?
iv) name three risk facators
v) what is the primary thing neonates present with? give three symptoms of this? which measure is not reliable?
i) bacteria/virus in the blood in first 28d of kife
early onset within 72 hours of birth
late onset 7-28 days of life
most common due to GBS and e coli
ii) early - mostly group B strep from mum during birth
iii) late onset transmission from contcts eg staph epidermidis, pseudomonas, klebs
iv) previous baby with GBS, mother with GBS colonisation/bacteriuria/temp >38/membrane rupture >18hours, prematurity (<37wks), low birth weight, maternal chorioamnioitis (infec of placenta and amniotic fluid)
v) 85% present with respiratory distress > grunting, nasal flaring, accessory muscle use, inc RR
temperature is not reliable
MANAGEMENT OF NEONATAL SEPSIS
i) name four blood investigations that should be done? name two special tests
ii) what is first line management? when should CRP be measured?
iii) at what point may abx be stopped? how long do most neonates hve abx tx for?
i) cultures x2, FBC (may have high or low WCC), CRP, blood gas
urinalysis or LP
ii) first line mx is IV benzylpenicillin with gentamycin
measure CRP 18-24hrs post abx
iii) stop abc if CRP <10 or negative cultures at 48 hours
most neonates have abx for 10 days
SEPTIC ARTHRITISS
i) what is M;F ratio? name three joints commonly affected?
ii) name three symptoms? name two signs
iii) what two investigations are done? what may be seen
iv) what is the kocher criteria for diagnosis?
i) 2:1
hip, knee, ankle
ii) symptoms - joint pain, limp, fever, sys unwell
signs - swollen red joint, decreased movement of affected joint
iii) joint aspirate and culture > see raised wcc
iv) kocher criteria for dx - fever >38, non weight bearing, high ESR, high WCC
CHICKENPOX
i) what is the infective cause? what happens if this is reaactivated in DRG?
ii) how is the virus spread? in relation to the rash - when is a person infective?
iii) name three symptoms? how does the rash change over time (3)
iv) what is the mainstay of tx? how long should children be kept off school?
v) what should be given to a newborn with peripartum exposure? name two complications
i) varicella zoster virus (VZV) > shingles if reactivated in DRG
ii) spread through resp droplets
infective 4d pre rash until 5 d after rash starts
iii) fever, itchy rash on head and trunk then spreads
macular > papular > vesicular
iv) mainstay tx is supportive - keep cool, trim nails, calamine lotion
keep off school until lesions are crusted over around 5 days
v) give VZV Ig
complications - secondary bac infection of lesions (cellulitis or nec fasc) - increased risk of this with NSAIDs
MEASLES
i) what is it caused by? how is it transmitted? what is incubation period? when is it infective from?
ii) name three symptoms in the prodome? what may be seen on the buccal mucosa
iii) where does the rash start? how can the rash be described? what can also happen that spares the palms and soles of the feet?
iv) what is the mainstay of mx? name two instances someone should be admitted? what type of antibodies can. be detected within a few days of rash onset
v) what is the most common complication? name two others? what can be offered to an unvaccinated child contact?
i) caused by RNA paramyxovirus
transmitted via aerosol transmission
patient infective from prodrome until 4d post rash onset (incubation 10-14d)
ii) prodrome - irritaable, conjunctivitis, feverr
buccal mucosa - white spots
iii) rash starts behind ears then spreads to whole body
maculopapular rash - blotchy and confluent
desquamation after aaround 7 days
iv) mainstay is supportive - admit if immsupp or pregnant
detect IgM ABs within a few days of rash onset
v) otitis media most common complicaation
pneumonia, enceph, confusion
offer uncacc child cintact MMR vaccine within 72hrs
MUMPS
i) is it caused by a bacteria or virus? how long does it last?
ii) what happens in the prodome? (4) what symptom follows this and is a key feature?
iii) name two complications it can px with?
iv) what investigation should be done? what is tx mainstay?
i) viral infection spread by resp droplets > self limiting and lasts 7 days
ii) prodome of flu like symptoms eg fever, muscle ache, lethargy, decreased appetite
iii) can px with complications - abdo pain (pancreatitis), testicular pain (orchitis), confus/neck stiff (meningitis)
iv) dx with PCR testing on saliva or test ABs to mumps
mainstay is supportive - rest/fluids/analgesia
GLANDULAR FEVER
i) what is the causative virus? what are the three principle symptoms
ii) what may develop in response to amoxicillin? name two other symptoms?
iii) what type of antibodies are found in the blood 6 weks later? name two tests thata can be done to diagnose?
iv) what type of antibodies are seen early in acute infection? what type of antibodies persist and give immunity?
v) how long does it usually last? what two things should be avoided? name three complications
i) EBV
fever, sore throat, fatigue
ii) may get itchy rash in response to amox
other symp - lymphadenopathy and splenomegaly
iii) heretophile antibodies (non spec)
monospot test (incuate blood with horse RBC), paul bunnel test (inc with RBC from sheep)
iv) early see IgM, late see IgG
v) self limiting usually lasts 2-3 weeks
avoid ETOH (EBV impacts liver alcohol processing)
avoi contact sport (risk of splenic rupture)
complicats - splenic rupture, glomneph, haemolutic anaemia, burkitts lymphoma
PAEDIATRIC HIV
i) which type of HIV is most common? name three ways it can be vertically transmitted
ii) what is the mode of delivery determined by? what will allow for normal vaginal/caesarean/caesarean plus IV zidovudine?
iii) what mothers viral load dictates whether a baby is high or low risk?
iv) is breastfeeding ever reccomended?
i) HIV1
vertical - pregnancy, birth, breastfeeding
ii) mode of delivery is determined by mothers viral load
<50 copies - normal vaginal
>50 / > 400 - caesarean
>10,000 give IV zido during caesarian
iii) viral load over or under 50
iv) HIV can be transmitted via breastfeeding even if viral load is undetectable so it is never reccomended
PAEDIATRIC HIV TESTING AND TX
i) what may give false positive results? what is the first line test?
ii) which test is done at 3m? which is done at 24m?
iii) what type of therapy is given? can vaccines be given? what may be given if CD4 count iss low and protects against PCP?
i) <18m can have positive results due to maternal ABs crossing placenta - false positive
first line - HIV antibody screen
ii) 3m - HIV AB screen, 24m - test for virus in the blood (never get false pos)
iii) anti retroviral therrapy
can give vaccs but not live if immsupp
give prophylactic co-trimoxazole (septrin) if low CD4 count to protect against PCP
