1. A gastrointestinal problem

2. History
68-year-old male attends an orthopaedic clinic as an emergency with a 3-day history of general malaise and fevers
Family practitioner is concerned as the patient was discharged 1 week ago following methicillin-sensitive Staphylococcus aureus joint infection of prosthetic left hip after revision surgery for recurrent dislocations

3. History (cont’d) Total of 6-week treatment with flucloxacillin:
First 2 weeks at a dose of 2 g 6-hourly IV followed by
Four weeks at a dose of 1 g 6-hourly orally
Good recovery and off antibiotics at discharge
Family practitioner had started erythromycin 250 mg 6-hourly 3 days ago, but symptoms are getting worse
Patient has had three episodes of loose bowel motions over the last 2 days, but not frank diarrhoea

4. Examination
Hip wound appears slightly red but healed and there is no discharge
Left hip not painful
Lower abdomen slightly tender, otherwise gastrointestinal tract examination normal
Clinical examination otherwise unremarkable
Pulse 96 beats/minute; BP 145/90 mmHg
Temperature 38.2°C
WBC count 16.5 x 109/L (normal range 4.5–11.0 x 109/L)
CRP 76 mg/L (normal range <10 mg/L)
BP, blood pressure; CRP, C-reactive protein; WBC, white blood cell

5. What is your diagnosis? Relapse of hip infection Viral gastroenteritis
Bacterial gastroenteritis
Antibiotic-associated diarrhoea
Irritable bowel syndrome
Diverticulitis
Perforation of bowel
Obstruction of bowel
Other

6. Initial tests and treatment
Ultrasound of left hip joint showed no fluid collection
X-ray of abdomen is normal

7. What specimen(s) would you collect now?
Blood culture
Faeces sample for culture and microscopy
Hip aspirate for culture and microscopy
Haemoglobin and blood cell counts
Urea and electrolytes
Liver function test
All/several
Other

8. Which pathogen(s) would you suspect?
S. aureus
Coagulase-negative staphylococci
Gram-negative pathogens
Mycobacterium tuberculosis
Salmonella spp.
Shigella spp.
Campylobacter spp.
Clostridium difficile
Other

9. What antibiotic regimen (if any) would you prescribe initially?
IV flucloxacillin
IV third-generation cephalosporin
IV ciprofloxacin
IV glycopeptide
Piperacillin/tazobactam
Meropenem
One of the above plus metronidazole
One of the above plus an aminoglycoside
Other

10. Treatment Diagnosis was relapse of hip infection
Treatment started with flucloxacillin 2 g 6-hourly IV

11. Follow-up
Overnight, the patient started to have profuse watery diarrhoea
Abdominal pain increased
Patient remained febrile
WBC count next morning 27.6 x 109/L (normal range 4.5–11.0 x 109/L)
Laboratory report of positive test for C. difficile toxin in the faeces

12. Which faeces test does your institution use for C
Which faeces test does your institution use for C. difficile associated diarrhoea (CDAD)?
Tissue culture for cytotoxin detection
Culture for the organism
Toxin immunoassay detection
Gene detection
Other
Do not know

13. Laboratory testing for C. difficile
No single test is accurate or reproducible
A compromise solution to C. difficile infection testing is to use a two-step algorithm:
Step 1. Glutamate dehydrogenase (or nucleic acid amplification test) to allow detection of colonised patients
Step 2. Toxin detection by any appropriate method
If Step 1 is positive and Step 2 is negative, then retest as ‘at risk’
Debast SB, et al. Clin Microbiol Infect 2014;20(Suppl. 2):1–26; Poutanen SM, Simor AE. CMAJ 2004;171:51–8

14. CDAD
Disease ranges from asymptomatic carriage through diarrhoea to pseudomembranous colitis and death
Estimated incidence is 38–95 cases per 100,000 patient days and 3.4–8.4 cases per 1000 admissions
Case mortality is 1–2.5%
Carriage is 1–3% in healthy adults
Acquisition rate estimated at 13% for hospital stays of <2 weeks and 50% if >4 weeks
Individuals sharing a room with a C. difficile-positive patient acquire the organism after a stay of 3.2 days, compared with 18.9 days for other individuals
Schroeder MS. Am Fam Physician 2005;71:921–8

15. What would you prescribe now?
Continue IV flucloxacillin and add oral metronidazole
Continue IV flucloxacillin and add oral vancomycin
Continue IV flucloxacillin and add oral fidaxomicin
Stop IV flucloxacillin and add oral metronidazole
Stop IV flucloxacillin and add oral vancomycin
Stop IV flucloxacillin and add oral fidaxomicin
Other

16. What other measures should be considered?
Select appropriate antibiotic treatment
Stop precipitating antibiotic if possible
Stop any gastric acid suppressive therapy
Supportive care (e.g. fluid balance, etc.)
Infection control source precautions
Infection control environmental precautions
Some of the above
All of the above
None of the above

17. Contact precautions
From Muto, CA. Poor outcomes associated with Clostridium difficile (CD)-associated diarrhea: Identification and control (slides with transcript) [PowerPoint]; Available from Accessed 19 March, Used with permission from RMEI, LLC, and Postgraduate Institute for Medicine

18. Follow-up Flucloxacillin was continued
Oral metronidazole 250 mg 8-hourly added
Hip aspirate reported as having low numbers of WBCs and no growth
Blood cultures were negative
C. difficile reported as metronidazole-sensitive
Patient continued to be pyrexial with profuse watery diarrhoea
Sigmoidoscopy showed no evidence of pseudomembranous colitis

19. Treatment and outcome
After 5 days, during which there was no improvement, flucloxacillin and metronidazole were stopped
Oral vancomycin 500 mg 6-hourly was started
The patient made a slow improvement
Discharged home in 10 days
No recurrence of hip sepsis

20. Readmission
Readmitted after 10 days with 2-day history of increasingly severe diarrhoea
Faeces test found to be positive for CDAD
Laboratory tests showed dehydration with albumin 15 g/L (normal range 35–50 g/L) and WBC count 18.7 x 109/L (normal range 4.5–11.0 x 109/L)

21. What would you prescribe for recurrent CDAD?
Standard oral metronidazole dose and duration
Standard oral vancomycin dose and duration
High-dose oral vancomycin (2 g/day) for standard duration
Tapered oral vancomycin doses over 21 days
Pulsed (3-day) standard oral vancomycin dose over 27 days
Fidaxomicin
Probiotics
Probiotics and one of the above
Other

22. Treatment and outcome Treated with general supportive care
Started fidaxomicin 200 mg bid for 10 days
Admitted into isolation and contact precautions started
Response was slow initially, with reduction in stool frequency
Good improvement by day 7 and discharged home to continue therapy
There were no further relapses

23. Key learning points Always take an antibiotic history
If there is a recent history of antibiotics and the patient has loose bowel motions, always consider CDAD
If CDAD is present, stop the other antibiotics as soon as possible
Perform risk assessment of CDAD cases and select therapy accordingly
Always remember infection control measures

24. AIM core principles Patient outcomes Antibiotic choice Resistance
Select the most appropriate antibiotic depending on the patient, risk factors, suspected infection and resistance
Antibiotic choice
If appropriate, change antibiotic dosage or therapy based on resistance and pathogen information
Resistance
Recognise that prior antimicrobial administration is a risk factor for the presence of resistant pathogens
Infection control
Wash hands adequately and wear gloves appropriately

25. BioHub at Alderley Park, Alderley Edge, Cheshire. SK10 4TG. U. K
BioHub at Alderley Park, Alderley Edge, Cheshire. SK10 4TG. U.K. Telephone: