travel infections Flashcards
why are travel related infections increasing?
people are traveling more
traveling to more exotic regions
more underlying medical conditions
war/natural distasters = migration of populations brining new microbes
emerging infections e.g. Zika, SARS, COVID
what to ask when suspecting a travel related infection
why is it important to know when symptoms arised?
where have you traveled (upto last 6months)?
when did symptoms arise?
when did you travel
incubation times are different for different diseases
also can then identify is it is acute, subacute or chronic
helps narrow down what infection they might have
why is travel history important?
differnt strains from around the world have different antigens, and antibiotic resistance (abroard antimicrobial stweardship os worse)
important if you need to implemet infection prevention on the ward and lab when handling their tests
what could an animal bite cause?
what could mosquito bite cause?
dead animals?
ticks?
undercooked food
rabies
malaria or dengue
ebola
rickettsia
salmonella
what are the 5 main species of malaria?
what are the most common?
if been to africa what strain would you suspect?
if been to india what strain would you suspect?
what is the vector?
where is it present?
plasmodium falciparum, vivax, ovale, malariae, knowelsii
plasmodium falciparum, plasmodium vivax
plasmodium falciparum
vivax/ovale
female anopheles mosquito
commonest imported infection to UK
tropical - africa, SA, N australia, south asia
symptoms of malaria?
minimum incubation time?
how long can plasmodium vivax/ovale take to show symptoms?
what would Hx show?
what would examination show?
often vauge : headache, fever, cough, big spleen, vom, fatigue
6 days
1+ year! lays dormant in liver
recent travel, fever and chills and sweats every few days
few signs- fever and splenomegaly
when is there severe malaria?
what does severe falciparium malaria cause?
when do you rule out malaria?
what is the life cycle of a mosquito ? - long just copy and pasted
when more than 2% of RBC are infected by the parasites on the blood film
3 X negative blood films
Once a mosquito bites someone the plasmodium moves from the mosquito’s salivary gland and into the blood stream of the person. When it is in the bloodstream, the plasmodium is in the sporozoite stage of its life cycle. Once these sporozoites get into the bloodstream, they go straight for the liver.
The P. falciparum then begin to multiply asexually in liver and mature from sporozoites to merozoites. Once they’re ready, they burst out from the liver and go straight into the bloodstream where they attack and enter erythrocytes, particularly targeting older erythrocytes.
Now that they’ve gotten into the erythrocyte, the plasmodium begins to replicate (asexually) and mature (over about 2-3 days). When they’re ready to burst out of the erythrocyte,
new mostquitos sucks blood and then the parasite enters new mostiquto and travels as vector to another huma
investigations for malaria?
treatment?
flaciparum ?
vivax, ovale, malariae?
3 X blood films
FBC, U&Es, LFT, glucose, coagulation
head CT is neuro symtoms
chest X ray
depends on sepcies
antimalarial - artesuante
chloroquine - falciparum is resistant
primaquine for dormant hypnozoites to prevent relapse from liver cells
hwo to prevent malaria?
ABC
A -Asess risk of area travelling to
B- Bite prevention
C- Chemoprophylaxis
typhoid and paratyphoid (enteric fever)
where is it found?
mechanism of infection?
source?
what microbe causes it?
what is their shape and gram stain?
what adheres to the payers patches?
where does it reside?
asia
faecal oral from contaminated food/water
human carriers or cases
salmonella typhi, salmonella paratyphi A, B and C
gram -ive bacillus
fimbriae on bacteria survive gastric acid and attach to ileal lymphoid tissue and enter RE system
macrophages in liver, spleen and BM
enteric fever signs/symptoms?
what is milder, paratyphoid ot typoid?
what investigations would you do?
systemic = bacteriaemia or sepsis, diffuse abdominal pain and constipation, bradycardia. If left untreated, it may also cause GI haemorrhage and bowel perforation - die
paratyphoid
FBC = mild anaemia, lymphopaenia, raised LFT
+ive blood culture
serology not reliable
enteric fever treatment?
how to prevent enteric infection?
its multidrug reistant :(((
fluoroquilones used but may have resistance
usually use IV ceftriaxone (cephalosporin) or a macrolide for 7-14 days
hygiene in food and drink, vaccine - but not that effective
if someone has a fever and rash, what would i be thinking they have?
childhood virus - measles, rubella, parovirus
acute HIV
rickettsia from a tick
what is dengue fever?
how many serotypes?
where is it found?
what mosquito is the vector?
what would the first infection present like?
what would a second infection with a different serotype present like?
commonest arbovirus (vector virus)
4
africa, asia, india
aedes mosquito
usually very mild
more severe - antibody dependent enhancement
causes dengue haemorrhagic fever and shock
what is myiasis?
Myiasis is the parasitic infection of the body of a live animal by fly larvae (maggots) which grow inside the host while feeding on its tissue.
