Returned Traveler Flashcards
Fever in returned traveler: walking bare foot?
Strongyloides
Fever in returned traveler: Lived / worked with pigs?
JE
Fever in returned traveler: aid work, development work (more prolonged period of time overseas)?
TB, Cholera, JE
Fever in returned traveler: fresh water?
Schistosomiasis, leptospirosis
Fever in returned traveler: sea water?
Vibrio spp infections
Fever in returned traveler: Birds?
Fever in returned traveler: Bats?
Fever in returned traveler: rates?
Birds = influenza
Bats = lyssa
Rates = leptospirosis
Fever in returned traveler: Jungle trek / lots of hiking?
Scub typhus
Fever in returned traveler: caving?
Histoplasmosis
Fever in returned traveler: wading in rice paddy?
Leptospirosis
What is ebola? briefly describe transmission, incubation period, presentation, tretment?
Ebolaviruses are part of the family of filoviridea. It is a type of haemorhagic fever, others include lassa, junin
Transmission from fruit bats to human.
Person to person transmission via blood, bodily secretions, or other bodily fluids (nil airborne transmission)
Incubation 2-21 days
Presentation: sudden onset fevers, rash, GI upset (vom, dia). Can present with internal and external bleeding
Treatment is quarantine and supportive
How is ebola vaccinated against currently?
Ring vaccination
- vaccination given to contacts and contacts of the contacts
- prevents transmission
What is neurocysticercosis? briefly describe transmission, incubation period, presentation, treatment?
THis is disease due to accidental ingestion of and infection with the paracite Taenia solium (pork tape worm). This is ingested via way of food contaminated with taenia solium.
It is the most common parasitic infection of the CNS worldwide. Also a common form of acquired epilepsy
Presentation depends on host immune system
Often can be aspymptomatic
Main presentations inc:
- epilepsy (70%)
- headache or dizziness
- stroke
- neuropsychiatric dysfunction
Treatment depends on viability of organisms as per imaging. consists of combination of:
- supportive care (ie antiepileptics)
- Steroids
- antiparasitic drugs
High clinical suspicion for malaria but first smear negative. What is the next step?
Repeat thick and thin film (smear) at least 3 times over next 36-48hrs
parasitaemia is often transient and can be missed with one smear, therefore when have high suspicion need to repeat
What are the five types of malaira spp? Which one is the worst?
- Plasmodium Falciparum (severe disease, worst)
- Plasmodium Vivax (severe disease, common but slightly less common in aus)
- Plasmodium ovale
- PLasmodium Malariae
- P. Knowlesi (seen more in malaysia, philipines, thiuland, burma)
Pt returning from africa and papa new guinea. What type of malaria spp is he most likely to have?
P. Falciparum
Pt returning from asia pacific. What type of malaria spp is he most likely to have?
P. Vivax
Briefly explain the lifecycle of malaria?
- Mosquito bite
- Sporozoite injected into blood
- Travels to liver and develops further in liver parenchyma
- Merozoite is released fom liver into blood
- Penetrates RBCs, initially forms a ring form, then immature schizont, then mature schizont, then multiple microgammetocytes.
- Microgammetocytes exit RBC, killing it
- mosquito bite takes up the released microgametocyte and macrogametocyte
Which forms of malaria form hyponozoites? what is the implication of these?
Vivax and ovale
hypnozotites can persist in liver for approx 5 years or so leading to delayed development of malaria (many years after travel)
How does Malaria present?
Presentation is often non specific
- fever, rigors, headache, malaise and myalgias (whole body pain)
Non specific examination findings:
- jaundice and splenomagaly are suggesting
Mild anaemia and thrombocytopenia are common
How is severe malaria defined?
Malaria that:
- involves teh CNA (cerebral malaria)
- kidneys (AKI, renal failure)
- Severe anaemia
- Macroscopic haemaglobinuria
- Haemorhage
- Shock
- ARDS
- Shock
At what level of parasitaemia would malaria be treated as severe malria regardless of presentation?
Parasitaemia >2% treat as sever because of risk of developing clinical severe malaria at these levels is high
Explain the tests involved in Dx malaria?
Thick and thin film
- Thick film: blood put on slide, air dried, then stained with dye that lyses red cells and releases the parasite to be viewed with microscope
- Thin film: blood on slide, smears aiming for monolayer. Heated to fix red cells then stained (process prevents lysis of RBCs). Can see parasites inside intact RBCs
- Malaria ICT (antigen test) - detection of plasmodium LDH or falciperum LDH, or HRP
- PCR
What is the utility of a separate thick and thin film in malaria Dx?
Thick film is initial test, very sensative but unable to detect morphology of RBCs, unable to tell spp of malaria
- this is because there are layers and layers of RBCs on top of each other
Thin film subsequent test, gives more info on morphology of RBCs and parasites in RBCs
What can cause false positive for the malria ICT (antigen test)?
Rheumatoid factor positive pts
What tests are used to monitor response to malaria treatment?
BLood smears
Cant use malaria ICT (antigen test) as the antigen can persist despite treatment
Treatment of severe malaria?
1st line - IV artesunate
2nd line - IV quinine (more adverse events, inferior to IV artesunate)
When pt improved, switch to oral
Whers does resistant malaria typically originate from? how is it treated initially?
Originoates along the mekong river area (THailand, vietnam, cambodia, Laos, Myanmar)
Treated with IV artesunate and IV quinine epmirically due to developing artesunate resistance
How is uncomplicated malaria (ie not severe malaria) treated?
1st line - PO artemether + Lumefantrine (20+100mg RIamet)
- Note need to use IV medications if pt vomiting ie cant keep tabs down
Can use alternative regime (if teh pt was not taking for prophylaxis)
- Atovaquone + proguanil (Malerone)
- Mefloquine
- Quinine + doxycycline
- Quinine + clindamycin - use in preg and children