Typhoid/Paratyphoid Flashcards
What is the incubation period for typhoid fever?
Water borne - 7-10 days
Food borne 3-10 days
Who do you perform microbiological tests in for patients with diarrhoea?
Recommended in travelers with severe or persistent symptoms
or In those who fail empiric therapy
What would you suspect if a patient has a high WCC and typhoid fever?
Bowel perforation (usually get leucopenia)
Perforation of terminal ileum
If you were to investigate diarrhoea, what tests would you perform?
Stool microscopy exam
Stool culture
Antigen tests
Multiplex PCR
Cause of travellers diarrhoea
Most common - bacterial: ETEC, shigella, campy, salmonella, aeromonas, EAEC
Parasites: giardia, cryptosporidium, entamoeba, cyclospora
Virus: rotavirus, norovirus (if OUTBREAK)- may be ETEC confection
How do you classify mild/mod/severe?
Mild - no interference with daily activity
Mod - some disturbance to daily activity
Severe - dysentery (blood/mucus) or significant disturbance to daily activity
When do you develop complications with typhoid fever?
Between weeks 2 and 3
What are the most common causes of travellers diarrhoea?
Norovirus and ETEC
Complications of Typhoid fever
gastrointestinal bleeding, myocarditis, or central nervous system
involvement, bowel perforation, hepatitis, Pneumonitis/Perforation
How to treat travellers diarrhoea?
Hydration, loperamide
Mild: No ABx
Mod: Consider ABx
Severe: ABx
Which antibiotic would you administer in campylobacter resistant to ciprofloxacin/from a country with high cipro resistance?
Azithromycin
Who do you investigate and treat?
Diarrhea lasting > 14 days
Diagnosis
◦ O + P (include coccidians), stool cultures
◦ C.diff toxin if history of antibiotics
If negative results
◦ Consider empirical antimicrobial therapy
◦ If no response administer antiprotozoal therapy
Explain the key pathogenesis of typhoid fever
Phase I: Bacteremia and/or endotoxemia: S. typhi penetrates primarily in terminal ileum -> liver, spleen, nodes
Phase II: Localization and/or complications
Classic presentation of travellers diarrhoea?
First week of travel, usually day 3
Diarrhoea plus abdo pain, fever, vomiting - may have blood in stools
Usually resolves by day 7
Why not give chloramphenicol in typhoid fever?
Risk of relapse high
How do you treat chronic carriage of typhoid?
Ciprofloxacin for 4 weeks
Classic symptoms of typhoid fever
Malaise, headache, fever, abdo pain initially first 7 days. No sweating!
Abdo pain, diarrhoea after 7 days. May have constipation
Fagets sign - relative bradycardia
Rose spots - not petechial
HSM
Complications after 14 days
Child with fever, HSM and rash. What is the diagnosis?
Typhoid fever - rose spots
Gold standard investigation for typhoid
Blood cultures (BACTEC)
How do you manage GI bleeding sec to typhoid?
Medical Rx for typhoid
Blood transfusion
Consider bowel resection
First line drugs for typhoid fever
Ciprofloxacin - high cure rate
7-10 days
What is the definition of travellers diarrhoea?
Classical: 3 or more bowel motions in 24 hrs plus an associated symptom (fever, malaise, nausea, abdo pain)
Moderate: 1 or 2 watery or loose stools over 24 hours plus some associated symptom or
more than 3 watery or loose stools without associated symptoms
Mild: 1 or 2 watery or loose stools over 24 hours without associated symptoms
What are the classic lab findings for typhoid feature?
Leucopenia
Left shift
No eosinophils
Mildly deranged LFTs
Treatment options for travellers diarrhoea?
Ciprofloxacin or Azithromycin
Which antibiotic would you recommend for prophylaxis of travellers diarrhoea, and who would you give it to?
Rifaximin
High risk of complications (previous bowel resection/ileostomy) or high risk of infection (immunocompromised)
What other tests for typhoid fever?
Stool culture (more positive in children)
Bone marrow (independent of antibiotics given - very sensitive)
Bile culture
What Is persistent travellers diarrhoea?
Diarrhoea lasting >2 weeks
Fever, diarrhoea, abdo pain with rose spots in patient in China. Likely organism?
Salmonella paratyphi - most likely in China (more than typhi)
What is the Widal test?
indirect agglutination test for enteric fever - not very effective - <30%
What organism is typhoid?
Gram negative
