ID & GUM Flashcards
amoebiasis treatment
metronidazole to kill active parasites
diloxanide furoate to kill cysts
aspiration for large liver abscesses
abx that disrupt folate synthesis
trimethoprim
sulfonamides
abx that disrupt bacterial ribosome function
30S:
tetracyclines, aminoglycosides
50S:
macrolides, clindamycin, linezolid, chloramphenicol
vanc and gent adverse effects
red man
ototoxic
nephrotoxic
macrolide adverse effects
P450 inhibition
cholestasis
thrombophlebitis
QTc prolongation
abx c/i in myaesthenia gravis
gentamicin
galactomannan antigen is present in
aspergillosis
ABPA hypersensitivity type
1 and 3
aspergillosis tests
invasive and chronic: serum galactomannan
ABPA: IgE, aspergillus specific IgE and IgG, eosinophilia
CPA: IgG
XR nodules, consolidation, infiltrates, cavities
HRCT: nodules, halo, air crescent
HRCT/MRI brain: focal lesions, SOL, abscesses, haemorrhagic lesions
meningitis organisms
neisseria
strep pneumoniae
hib
in neonates: strep agalactiae, ecoli, strep pneumoniae, listeria
meningitis treatment
benpen stat (300/600/1200mg)
IV ben pen/cefotaxime/chloramphenicol
add vanc if foreign travel
meningitis prophylaxis
ciproflox stat
for contacts within 7 days prior to onset of illness
normal vaginal pH
< 4.5
BV micro-organisms
gardnerellam atopobium
prevotella
mycoplasma hominis
mobiluncus
reduced lactobacilli
brucellosis pathophysiology
invades nearby mucosa
lymphatic spread
> haematogenous spread
> reticuloendothelial system
re-infection can occur as immunity following infection is not adequate
incubation days to months
brucellosis treatment
dual or triple therapy 6 weeks
notifiable disease
specialist involvement if pregnant or < 8y
PO doxy and IM strep
or
PO quinolone and rifampicin
or
PO doxy and rifampicin
diagnosing c diff
stool PCR and glutamate dehydrogenase immunoassay
50% of patients have plaques on colonoscopy/sigmoidoscopy
cellulitis microorganisms
strep pyogenes and staph aureus
pseudomonas aeruginosa (hot tubs, sponges)
vibrio vulnificus (saltwater)
aeromonas hydrophilia (freshwater)
erysipelothrix (butcher, vet)
mycobacteria marinum (aquarium)
pasteurella, capnocytophaga (dog/cat bite)
eikenella (human bite)
strep moniliformis (rodent bite)
strep pneumoniae, haemophilus, anaerobes (injury, burns, immunocompromised)
abx for cellulitis with lymphoedema
amox
avoiding sexual contact with chlamydia
additional 7 days after treatment with azithromycin
test after 3-6 months for re infection
chlamydia treatment if pregnant/breastfeeding
azithromycin
amox
erythromycin
test of cure after 3 weeks if pregnant
botulism
gram positive bacillus
flaccid paralysis
food born/wound/infant/inhalation bioterrorism
toxins A, B, E cleave SNARE proteins at NMJ
> inhibits release of ACh
botulism presentation
blurred vision, diplopia, ptosis (CN III, IV, VI)
dysarthria, dysphagia (oculobulbar or CN IX, X, XII)
symmetrical descending flaccid paralysis
absent deep tendon reflexes
urinary retention, constipation, postural hypotension, dry mouth
GI symptoms if food borne or infantile
typically afebrile
management of botulism
mechanical ventilation if upper airway compromise
horse heptavalent antitoxin for adults
IVIG for infants
surgical debridement for wound botulism
cryptosporidiosis
most common cause of infectious diarrhoea in pt with HIV
contaminated water or food with oocysts
oocytes shed for 7 days
chronic infection in immunocompromised
dx: stool microscopy, stool antigens, stool PCR
tx: mostly supportive, nitazoxanide
congenital CMV
sensorineural deafness
LD, developmental delay
sight problems
CMV transmission
blood, transplant
sexual contact
saliva
placental
latency sites: endothelial cells of arterial walls, T cells
CMV treatment
valganciclovir or ganciclovir 1 month for immunocompromised or congenital infection
dengue vaccine
should only be used in people previously infected due to increased risk of severe dengue
diagnosing dengue
RT PCR
NSI
ELISA IgM and IgG (IgG indicates past infection)
e coli virulence factorw
verotoxin (shiga like) > bloody diarrhoea, HUS
heat stable/labile enterotoxins > watery diarrhoea
p fimbriae > UTI
K1 capsular polysaccharide > neonatal meningitis, pneumonia
lipopolysaccharide > bacteraemia, septic shock
e coli subtypes
EIEC (invasive) > dystentery
ETEC (toxigenic) > watery diarrhoea, heat labile and stable toxins
EPEC (no toxin) > diarrhoea
EHEC > HUS, bloody diarrhoea
EAEC (aggregative) > persistent diarrhoea
filariasis
mosquito borne (anopheles, culex)
dx: microfilariae on blood film, anti filarial IgG4
labs may be negative as lymphoedema can develop years after infection
preventative albendazole/ivermectin/DEC
tx: DEC
tropical pulmonary eosinophilia is a complication
dermatophytes vs yeasts
Dermatophytes:
trichophyton rubrum/interdigitale
epidermophyton floccosum (tinea pedis/corporis/cruris/unguium)
yeasts:
candidiasis
pityrosporu, orbicularis (pityriasis versicolour)
cryptococcus and histioplasmosis are dimorphic
cryptococcus presentation
immunocompromised host
subacute (1-2 weeks)
headache, fever, confusion
histioplasmosis
found in soil containing bird/bat droppings
affects immunocompromised
spores turn into yeast cells at body temp
> macrophages ingest alveoli
> microconidia transform into yeasts
asymptomatic or flu like symptoms
dx:
CXR often normal or may show calcified granulomas
urine PCR and antigens
serum antibodies after 2-6 weeks
tx: amphoteracin B (need to monitor renal function
when to refer/admit gonorrhoea
conjunctival
pregnant
unresponsive to treatment
ascending infection
admit: disseminated, PID
treating diarrhoea in HIV
CMV: ganciclovir
microsporidium: albendazole
MAI: 12m anti TB
cyclo/isospora: cotrimox
salmonella/shigella: azithro
HAART side effect: loperamide
cryptosporidium: supportive
HIV 1 vs 2
1 is worldwide
2 is endemic to west africa
factors that increase risk of HIV transmission
concurrent STIs esp HSV-1 and other ulceratives
hep C coinfection
high viral load
advanced stage of disease
seroconversion
development of persistent detectable antibody response to HIV
stages of HIV infection
infection
clinical latency after seroconversion- progressive fall in CD4 and rise of viral load over 5-10y
early and late AIDS
HIV diagnosis
serology for antibody- 3 month window between inoculation and seropositive
test for HIV RNA and p24 in window
also test for Hep B and C
HAART drugs
NRTI- zidovudine, lamivudine
NNRTI- efavirenz, nevirapine
protease inhib- ritonavir, darunavir, saquinavir
integrase inhib- rategravir, elvitegravir
hookworm
helminth, lives in small intestine of host
infects human host through skin as larvae in sand/soil contaminated with faeces
> migrates to lungs and gut
> cutaneous larvae migrans, GI symptoms incl bleeding, protein loss, SOB and wheeze
ancylostoma duodenale
necator americanus
leprosy treatment
dapsone + rifampicin + clofazimine
listeria treatment
generally supportive
amox or cotrimox if immunosuppressed or pregnant or > 60y
ampicillin + gent if meningitis or systemic infection
lyme disease organism
europe- borellia garinii, afzelii
n america- borellia burgdorferi
lyme disease presentation stages
1 (localised):
erythema migrans at bite site
1-4 weeks post bite
fever, headache, regional lymphadenopathy
2:
weeks to months post stage 1
myalgia, further rash, arthritis, neuro/cardiac
3 (chronic complications):
months to years later
oligoarthritis, neuro, acrodermatitis atrophicans
diagnosing lyme disease
IgM and IgG serology
confirm positive ELISA with immunoblotting
inflam markers will be normal in stage 2 and 3
if ELISA negative within 4 weeks, repeat
if ELISA negative within 12 weeks, do immunoblot
jarisch herxheimer reaction
self limiting reaction to abx in lyme disease
onset hours to days following start of abx
falciparum malaria treatment
uncomplicated- artemesinin tablets
severe- IV artesunate or IV quinine then doxy
malaria associated with severe anaemia, AKI, splenic rupture
p vivax
causes of nec fasc
staph aureus
strep
clostridiu, perfringens
types of nec fasc
1- polymicrobial
2- group a strep
3- marine organisms
4- fungal
nec fasc risk factors
raised CRP, WBC
raised creat, glucose
low Hb, Na
focal vs generalised neuro disease in AIDS
focal:
toxoplasmosis
TB meningitis
generalised:
cryptococcal meningitis
PML (JC virus)
CMV encephalitis
focal commonly presents w/ dysphagia, hemiparesis, seizures
diagnosing cryptococcal meningitis
CSF india ink
serum cryptococcal antigen
toxoplasmosis treatment
pyrimethamine + sulfadiazine
+ folinic acid to prevent BM suppression
preventing peripheral neuropathy from isoniazid
pyridoxine
PID treatment
ceft + doxy + metro
or
oflox + metro
or
moxiflox
q fever
coxiella burnetti
zoonotic
> doxy
> cotrimox 5/52 if pregnant
rocky mountain spotted fever
rickettsia rickettsii
wrists > trunk > extremities
may be eschar at bite site
> doxy or chloramphenicol
qSOFA
quick sequential organ failure assessment
SBP< 100
RR > 22
GCS < 15
schisto treatment
praziquantel
2 doses for haematobium, mansoni
TDS for japonicum
may need another dose a few weeks later
contact tracing for syphilis
primary: 3/12
secondary: 2y
tertiary: > 2y
patterns of immunodeficiency
neutrophil: recurrent bacterial or fungal skin infections
complement: often incidental, neisseria
B cell: sinopulmonary
T cell: opportunistic (PCP), invasive (CMV), intracellular (salmonella, mycobacteria)
abx for endocarditis
native valve: amox + gent
prosthetic valve: vanc + gent + rifampicin
staph: fluclox
MRSA: vanc + rifamp
strep: benpen +/- gent
HACEK: amox + gent
endocarditis indications for surgery
cardiac failure or haemodynamic compromise
extensive valve incompetence
large veg
emboli or abscess
fungal
abx resistant
abx for TSS
IV clinda + fluclox/vanc
typhoid fever
prolonged fever, abdo pain, rose spot rash
s typhi and s paratyphi
bacteria invade gut wall
> migrate into peyers patches of distal ileum
> spread throughout reticuloendothelial system
>liver, spleen, BM, bloodstream
asymptomatic until bacteraemic
typhoid fever stages
week 1:
high fever, relative bradycardia
disturbed bowel habit (constipation more common)
nausea, prodromal
week 2:
persistent fever, rose spots
diarrhoea, abdo pain, splenomegaly
week 3:
hepatomegaly, bowel perf, GI bleed, meningitis, haemolytic anaemia, acute cholecystitis, renal failure, myocarditis
diagnosing typhoid
blood cultures
stool cultures
bone marrow, rose spot cultures
Widals agglutination test antibodies
typhoid fever treatment
confirmed: ciproflox
extensively resistant: meropenem + azithromycin
suspected: cephalosporin +/- azithromycin
dex for neuro complications
toxoplasmosis treatment
pyrimethamine and sulfadiazine
folinic acid and weekly FBC
prophylaxis: trimethoprim + sulfamethoxazole
spiramycin to prevent vertical transmission
features of severe malaria
Hb < 50
glucose < 2.2
pH < 7.3
lactate > 5
falciparum malaria treatment
uncomplicated: artemesinin PO
severe: IV artesunate or IV quinine then doxy
trypanosomiasis treatment
1st stage:
W African- pentamidine
E African- suramin
2nd stage:
W African- nifurtimox + eflornithine
E African- melarsoprol
chagas: benznidazole or nifurtimox
trypanosomiasis
African- tsetse fly
W African: t brucei gambiense
E Africa: t brucei rhodesiense
S American- reduvid bugs
t cruzi
chagas disease develops after 10-20y
TB treatment
R+I 6 months (12 months if CNS)
P+E 2 months
add steroids for meningitis
add 3 months if pyrazinamide is discontinued due to s/e
RIP- hepatitis, risk increases with age
E- optic neuritis, yellow vision
I- peripheral neuropathy (give with pyridoxine)
R= orange/red urine
opportunistic mycobacterial disease
m kanasii, xenopi, malmoense, avium intracellulare
cause disease identical to TB, undistinguishable on smear
usually underlying COPD, bronchiectasis, previous TB
> rifampicin + ethambutol 9m-2y
UTI treatment in pregnancy
nitro 7/7 (avoid if at term)
amox
cefalexin
