Infectious disease Flashcards
Give an example of Group A strep?
strep pyogenes
What does strep pyogenes cause?
erysipelas impetigo cellulitis T2 necrotising fasciitis pharyngitis tonsilitis
What causes type 1 and 2 necrotising fasciitis?
T1: clostridium perfringens
T2: streptococcus pyogenes
What immunological reactions can group A strep cause?
rheumatic fever
post strep glomerulonephritis
Symptoms of P.falciparum?
cyclical fever (every 48h) splenomegaly neurological involvement-> altered GCS and seizures D&V metabolic acidosis shock
P.falciparum findings on blood film?
ring trophozoites
crescent shaped gametocytes
mauer’s clefts
double dotted rings
P.falciparum treatment?
mild: oral macaroni
severe: IV artesunate, hypoglycaemia management, hydrate cautiously
monitior parasitaemia
P.vivax findings on blood film?
schaffners dots
P.ovale findings on blood film?
enlarged red cells
comet forms
P.malariae findings on blood film?
daisy head appearance
square ring forms
Mx for p.vivax, ovale and malariae?
chloroquine
Where is vivax found?
South america and asia
Where is falciparum found?
africa
symptoms for p.vivax, ovale and malariae?
indolent up to a year to start to have symptoms, esp vivax
vivax/ovale cyclical fever 48h
malariae cyclical fever 72h
Ix for malaria?
3 thick and thin blood films (thick = parasite, thin = species)
Look for parasitaemia
malaria rapid antigen detection tests (plasmodial HRP-II, parasite LDH)
prevention of malaria?
anti-malarial prophylaxis with quinine
bite prevention - repellentandents
when to admit someone with malaria?
severe/complicated malaria falciparum malaria child pregnant >=65yo
Malaria Mx?
variable
non-falciparum: chloroquinine
mild falciparum (not vomiting, parasitaemia <2% and ambulant): artemisinin combination therapy/atovaquone-proguanil or quinine + doxy
severe: IV artesunate/IV quinine
what causes typhoid?
salmonella typhi or paratyphoid
complications of typhoid?
GI perforation
myocarditis
hepatitis
nephritis
S/S typhoid ?
Fever + bradycardia anorexia (WL +++) GI: diarrhoea or constipation cough malaise, myalgia headache
SPLENOMEGALY, bradycardia, trunk ROSE SPOTS
what is sphygmo thermal dissociation?
fever + bradycardia
Ix typhoid?
blood culture [diagnostic]
other - FBC, LFT, stool
Mx typhoid?
IV ceftriaxone OR IV cefotaxime
2nd: azithromycin
what causes dengue?
Aedes aegyptii mosquito
usually SE asia and S.Africa
incubation of dengue?
short (5 days)
if loner consider HIV seroconversion
S/S dengue?
low WCC, low platelets, low Hb Headache (retro-orbital) sunburn like rash high fever and myalgia hepatomegaly, abdominal distension
What is dengue haemorrhagic fever?
secondary infection with different strain
- severe capillary leak, hypotension, haemorrhagic manifestations
Ix dengue?
gold standard is PCR viral antigen, serology IgM
FBC, LFTs, serum albumin
Mx dengue?
supportive
ITU
What causes Q Fever?
coxiella burnetii
Q fever transmission?
goats, sheep, cattle, milker aerosols
S/S Q fever?
fever, pneumonia, abscess
Ix Q fever?
serology
Mx Q fever ?
doxycycline
Brucellosis transmission?
goats, sheep, cattle, milk, meat, aerosols
S/S brucellosis?
fever
back pain
orchitis
abscess
Mx brucellosis?
doxycycline + gent/rifampicin
Lyme disease is caused by?
borrelia burgdorferi
ixodes tick
Stages of lyme disease
rash -> malaise carditis,meningitis -> CNS signs
S/S lyme disease?
fever
erythema chronicum migrans (bulls eye rash)
Mx lyme disease?
doxycycline
amoxicillin if doxy CI (e.g. pregnancy)
What causes leptospirosis?
L.interrogans (gram -ve spirochete)
transmitted by farm animals, contaminated water and RAT URINE
S/S leptospirosis?
fever, constitutional, ARF, jaundice, UVEITIS, high fever, bilateral calf pain
Ix leptospirosis
serology
Mx leptospirosis
doxycycline
Cause of anthrax?
bacillus anthraces
transmitted by cows
S/S anthrax
pulmonary sings, cutaneous (eschar)
GI signs