Week 3 - C.Diff Case Study Flashcards
Hfow many americans die each year from c.diff infections?
500,000
How is c.diff transmitted?
C. diff- transmitted fecal-oral route and hospital workers and devices (fomite) may be intermediaries
Acquired through the ingestion of endospores
Increase in incidence and severity possibly due to the emergence of more virulent strains like B1/NAP1/027, which produce more toxin as well as binary toxin
nosocomial
Disease that originates in the hospital..
What are some risk factors for CDI?
Living with infants (84% are carriers)
Taking an antibiotic
Gastric acid suppression - proton pump inhibitors
Antineoplastic (anti cancer drug)
Hospitilization
Immunocomproamised or elderly individuals
What does an antibiotic do that increases the risk for acquiring C.Diff?
Antibiotics diminish healthy bacteria allowing C. diff to multiply and begin producing toxins
How do proton pump inhibitors increase risk for C.Diff?
Acidic environment is inhibited and therfore is less effective in killing foreign organisms when they enter the body
Why do C. Diff infections frequently reoccur?
What are symptoms of C. Diff infection?
Fever
Abdominal pain
Watery diarrhea (key symptom)
-3 or more loose stools for 1-2 days sans blood
Dehydration
Pseudomembranous Colitis
Severe complications include perforation of colon, dehydration, death
Sepsis- inflammation leading to decrease in blood volume
Toxic megacolon becomes so
swollen that it creates pressure on lungs making breathing difficult
DDx
Diarrhea can be side effect from many antibiotics
So first step to see if it is C.Diff is to STOP antibiotic
Watery diarrhea is often caused by viruses (rotavirus, Norovirus)
Bacteria (E. coli 157:H7, Vibrio cholerae, Campylobacter, Salmonella, Shigella, Yersinia, and Clostridium difficile)
Protozoan (Giardia, Cryptosporidium, and Cyclospora)
Most if these infections are self-limiting and not life-threatening, but knowing cause is critical for choosing the correct antimicrobial
C. Diff Diagnosis
Positive stool test for toxin
Increased WBC > 15,000 cells/mm3
Direct visualization by sigmoidoscopy of pseudomembranous colitis
What is ELISA?
Enzyme linked immunosorbent assay
It tests for toxin A and B, some strains are A-neg and B-pos
If target substance is present in immobilized sample then peroxidase enzyme
generates purple color or can use fluorescence to detect
Toxin only stable for 2hrs
Some pts will be false negative* so more tests may need to be done
What test is recommended over ELISA?
GDH
C. Diff culture - problem is that pts may carry strain but aren’t having infection.. not used any more.
What is pseudomembranous colitis composed of?
Neutrophils, dead epithelial cells, and inflammatory debris
What is a general feature of the class of bacterial Clostridium?
They produce more toxins than any other bacteria genus
Not all of the toxins cause disease*