Tropical infections of GI tract Flashcards
what conditions could fever of a returned traveller be related to?
Respiratory tract infections – pneumonia/influenza, COVID-19
Traveler’s diarrhoea
Malaria
Enteric fever (typhoid/paratyphoid fever)
Arboviruses – Dengue/Chikungunya/Zika
what are some questions of consider for an ill returning traveller
Where have they been?
Rural/urban
What was the accommodation like (air conditioning)?
When did they go?
When did they get back?
When did they start becoming unwell?
Did they have insect bites – any tick bites?
What are their symptoms?
Is anyone else unwell?
What did they do when away?
Swimming/water sports/animal contact/bat caves/walking in bush/sex/work
What precautions did they take – vaccinations/malaria prophylaxis/bite protection/condoms
what should you look for in examination of an ill returned traveller
Fever Rash Hepatosplenomegaly Lymphadenopathy Insect bites Wounds
what is acute travellers fever and what is it caused by?
– 3 loose stool in 24h
Common causes:
Enterotoxigenic E. coli
Bacteria – Campylobacter, Salmonella, Shigella
Viruses – particularly Norovirus (often cause outbreaks on cruise ships)
Others
Amoebic colitis (Entamoeba histolytica)
Cholera – toxin mediated disease often associated with outbreaks – refugee camps
Blood in stool indicates dysentery
Usually bacterial (Campylobacter, Shigella, E coli O157) or E. histolytica
what investigations should be done for acute travellers diarrhoea
Stool culture
Stool microscopy for cysts / parasites (normally fresh stool)
what is the treatment for acute travellers diarrhoea
Supportive – fluid rehydration (oral/IV)
Bloody diarrhea with systemic upset may warrant treatment
In those travelling a fluoroquinolone (ciprofloxacin) single dose can stop worsening
Antibiotic resistance – now very common especially in Asia where a macrolide (azithromycin) may be more useful
what is enteric fever
Typhoid or paratyphoid fever
Most common in those returning from Indian subcontinent and SE Asia
Often in people visiting family or friends
Incubation period 7-18 days (though occasionally up to 60 days)
blood in stool
dysentery
indications for fever and jaundice
Pre-hepatic (haemolytic)
- Malaria
- HUS as complication of diarrhoeal illness – E.coli 0157, Shigella
- Sickle cell crisis triggered by infection
Hepatic
- Acute viral hepatitis – mainly Hepatitis A and E (occasionally Hepatitis B)
- Leptospirosis – Weils diseases (acute liver failure and renal failure)
- Malaria
- Enteric fever
- Rickettsia (scrub typhus, Rocky Mountain spotted fever etc)
- Viral haemorrhagic fever
Post-hepatic – ascending cholangitis – and helminths
main hepatitis’s which causes fever and jaundice
A and E
what does leptospirosis- weils disease cause
causes acute liver failure and renal failure
what does enteric fever cause
hepatitis
how do you investigate a patient with fever and jaundice
Thick and thin blood films for malaria parasites (rapid antigen test – less specific) Blood film for red cell fragmentation FBC/UE/LFT/coagulation Blood cultures USS abdomen Serological testing for viruses
what is the management and treatment of jaundice and fever
Appropriate isolation and infection control procedures
Supportive – may need dialysis if acute kidney injury
If acute liver failure – hepatology/transplant unit
Directed to pathogen isolated
Discussion with infectious diseases
where are Helminth infections limited
in gut and migrates to tissues
what are Helminth infections associated with
eosinophilia
how is Helminth infections diagnosed
adult worm passed or the eggs in stool
how are helminths subdivided to
nematodes - round worms ascariasis
trematodes - flukes - schistosomiasis (cause fibrosis on liver)
cestodes - tapeworms
