Fever in returned traveller Flashcards
what is the incubation period of malaria?
at minimum 14 days post infection.
this means that someone visiting northern Thailand for 3 days, who has been home for 1 day is unlikely
where is chloroquine an effective anti malarial?
the resistance to this drug is so widespread that it would almost never be indicated
what is the treatment of severe malaria?
artesunate is the recommended
why is quinine considered a second line treatment?
it is not because of resistance. it is due to the difficulty with dosing
why do we need to follow up closely in falciparum patients EVEN when they have achieved clearance after treatment?
there is a 30% chance of coinfection with vivax, if the patient was infected in pacific region
in the same manner, there is a risk of falciparum infection in vivax patients
(usually we treat vivax with artemether/lumefantrine then with primaquine to knock over the liver buggers)
what is the treatment of choice for liver stage vivax/ovale?
primaquine is the treatment of choice for this condition.
what is the clinical presentation of typhoid fever?
usually presents as an undifferentiated fever, often with headache, malaise and abdominal pain
there can be “rose spots” seen
splenomegaly is common
typically there are 4 phases to the disease
- first week is fevers
- high fever, delirium and rose spots. Abdo pain starts badly
- abdo bleeding, dehydration, neuro psych issues
- slow loss of fever
what causes typhoid fever?
how do we diagnose it?
how do we treat?
it is caused by salmonella typhi - it is a gram negative intracellular organism that can also hide in macrophages
can sometimes hide in the gallbladder too leading to carriage
stool culture is positive in around 30% of patients
bone marrow culture is positive in around 90% (due to macrophage hiding)
blood cultures also taken
serology is useless
cipro is first line
azithryomycin is second line - but it’s a bit unusual. Azithro usually doesn’t have gram negative coverage, but accumulates in macrophages!
how can you differentiate falciparum from other malarial species?
only falciparum has multiple parasites in a red blood cell
also, falciparum can cause high parasitaemia count, but vivax rarely gets above 1% (meaning about 1 parasite per field)
a patient returns from africa with fever. USS reveals 7cm liver abscess.
under what condition would you NOT perform a tap of the abscess?
you would not aspirate if you were concerned about an Entamoeba histolytica infection.
in that case you would use metronidazole
headache, fever and sore eyes in someone coming back from Thailand.
what would be your initial concern?
would a rash point you towards or away from your diagnosis?
this is more classical for Dengue. However, it is worthwhile considering excluding malaria
A rash would be more suspicious of Dengue. Rash is not a feature of malaria unless there is petechial bleeding.
Often the rash is blanching in Dengue. At the time of rash onset, the serology (IgM) should become positive.
what’s the common cause of eosinophilic meningitis in Australia?
rat-lungworm (Angiostrongylus cantonensis). This bad boy lives in the pulm vessels of the rat, then is spread to snails/slug. Eventually into humans and spreads to CSF.
YUMBO
what is the commonest presentation of Ascaris lumbricoides?
this bad boy can head up your bile duct and cause cholangitis
it can also cause intestinal obstruction
p.s. this creeper is up to 35cm long! can be excreted in faeces, but can survive for years in the soil! gross!
