Tropical GI

Question 1

What is the most important thing to aid diagnosis in tropical GI problems?

Answer 1

A really detailed and accurate history.

Important for incubation periods and identifying likely pathogens.

Question 2

What are the common examination findings in an unwell returned traveller?

Answer 2

Fever, rash, hepatosplenomegaly, lymphadenopathy, insect bites and wounds

Question 3

What are the most common diseases in returned travellers?

Answer 3

RTI- international air travel and circulating air systems
Travellers diarrhoea
Malaria
Enteric fever- typhoid and paratyphoid fever
Arboviruses- Dengue/Chikungunya/Zika (more common in cities)

Question 4

What infection control precautions do you take with returned travellers?

Answer 4

Isolate until infectious disease ruled out

Question 5

What is acute travellers diarrhoea?

Answer 5

3 loose stolls per day associated with low fever in 30%

Question 6

What causes travellers diarrhoea?

Answer 6

Normally Enterotoxigenic e coli (different water => different E coli than the e coli in our gut)
Sometimes campylobacter, salmonella, shingella (longer incubation of a couple of days)
Cruise ships = norovirus and rotavirus
Rarely (associated with dysentery/blood in stool) amoebic diarrhoea, e coli 0157 cholera (very watery diarrhoea and dehydrated)

Question 7

What investigations if you suspect acute travellers diarrhoea?

Answer 7

Stool culture and Stool wet prep for microscopy to look for amoebic trophozoites

Question 8

What is the treatment for acute travellers diarrhoea?

Answer 8

Supportive- fluid rehydration

Ciprofloxacin can be used in those still travelling but high antibiotic resistance in Asia- use azithromyicin

Question 9

Where is enteric fever most common?

Answer 9

Indian subcontinent.

Question 10

What are the symptoms of enteric fever?

Answer 10

Long incubation 1-8 weeks.

Fever, headache, constipation/diarrhoea, dry cough.

Question 11

What are the complications of enteric fever?

Answer 11

GI bleeding/perforation
Encephalopothy
Bone and joint infections

Question 12

What causes enteric fever?

Answer 12

Salmonella typhi or paratyphi

Question 13

How is eteric fever diagnosed?

Answer 13

Blood cultures as usually bacteraemic.
Stool or urine sample or bone marrow.
Lab precautions taken.

Question 14

What is the treatment for enteric fever?

Answer 14

Empirical if serve = IV Ceftriaxone
Otherwise wait for sensitivities and use ciprofloxacin (high resistance), azithromycinor ceftriaxone.
Fever can take days to reduce. Be patient. All patients isolated

Question 15

How effective is the typhoid vaccine?

Answer 15

70% against salmonella typhi and does not protect against paratyphi

Question 16

What can cause fever and pre-hepatic jaundice?

Answer 16

Malaria- break down of RBCs.
HUS as a complication of diarrhoeal illness from Ecoli 0157 or Shigella.
Sickle cell crisis triggered by infection.

Question 17

What can cause fever and hepatic jaundice?

Answer 17

Hepatitis A and E (occasionally B)
Leptospirosis => haemorrhagic and renal failure)
Malaria- damage hepatocytes
Enteric fever
Viral haemorrhagic fever (ebola)

Question 18

What can cause fever and post hepatic jaundice?

Answer 18

Ascending cholangitis and helminths

Question 19

What investigations are important for travellers returning with jaundice?

Answer 19

Malaria test
FBC/UE/LFT/coagulation
Blod cultures
USS abdomen to rule out obstruction
Serological testing for viruses eg Hepatitis

Question 20

What is amoebiasis?

Answer 20

Infection with entamaeba histolytica- protozoa.

Question 21

How is amoebiasis spread?

Answer 21

Faecal oral- associated with poor sanitation

Question 22

WHat are the symptoms of amoebiasis?

Answer 22

Asymptomatic carriage
Amoebic dysentery (abdo pain, fever, bloody diarrhoea, toxic megacolon, puritanism)

Question 23

What are the investigations for amoebiasis?

Answer 23

Stoll microscopy
AXR for toxic megancolon
Endoscopy for biopsy- not in toxic megacolon

Question 24

Amoebic liver abscess is a complication of amoebiasis but may not have had dysentery symptoms. It is more common in men. T or F?

Answer 24

True

Question 25

How is amoebic liver abscesses/amoebiasis treated?

Answer 25

Metronidazole or tinidazole

Question 26

What is giardiasis?

Answer 26

Infection with giadia intestinalis (a flagellated protozoa)

Invades the duodenum and proximal ileum . Faecal oral spread. Incubation 7 days

Question 27

What is the presentation of giadia?

Answer 27

Watery diarrhoea, bloating, flatulence, abdominal cramps, weight loss

Question 28

What are the investigations for giadia?

Answer 28

Stool microscopy for cycts
PCR tests
OGD for duodenal biopsy occasionally

Question 29

What is the treatment for giadia?

Answer 29

Tinidazole or metronidazole

Question 30

What are the 3 main types of helminths?

Answer 30

Round worms (Nematodes)
Flukes (Trematodes)
Tapeworms (Cestodes)

Question 31

How are helminth infections diagnosed?

Answer 31

Adult wor or eggs passed in the stool

Question 32

What is the life cycle of Intestinal nematodes (round worms) the most common helminth infection in the world?

Answer 32

Eggs ingested
Hatch in small intestine and invade gut wall and venous system
Travel via venous system to liver and heart to reach lungs.
Break into alvioli and ascend tracheobronchial tree where they are swallowed in to the gut and mature into adult worms and produce eggs.

Question 33

What are the features of severe schistosomiasis?

Answer 33

Adult worms in portal venuloes leading to hepatomegaly and liver fibrosis and portal hypertension

Question 34

Where doe infection with tape worms come from?

Answer 34

Undercooked meat. Some tapeworms can produce extra intestinal symptoms

Question 35

Trypanasoma cruzi is transmitted by the kissing bug and can cause mega colon and oesophagus. T or F?

Answer 35

True