Clostridium difficile-associated diarrhea is usually preceded by
Group of answer choices
A) Eating contaminated food.
B) A blood transfusion.
C) Use of broad-spectrum antibiotics.
D) Improper food storage.
E) Travel to an underdeveloped country.
The correct answer and explanation is :
The correct answer is:
C) Use of broad-spectrum antibiotics.
Explanation:
Clostridium difficile-associated diarrhea (CDAD) is a severe form of antibiotic-associated diarrhea caused by the bacterium Clostridium difficile (C. difficile). This condition is most commonly preceded by the use of broad-spectrum antibiotics, which disrupt the normal gut microbiota, allowing C. difficile to overgrow and produce toxins that cause inflammation and diarrhea.
How Antibiotics Lead to CDAD:
- Disruption of Normal Gut Flora: The human intestines contain a diverse microbiome that helps maintain balance and prevents harmful bacteria from overgrowing. Broad-spectrum antibiotics such as clindamycin, fluoroquinolones, cephalosporins, and penicillins kill both beneficial and harmful bacteria, reducing microbial diversity.
- Overgrowth of C. difficile: C. difficile is naturally present in the intestines of some people but is usually kept in check by other bacteria. When antibiotics kill competing bacteria, C. difficile can proliferate.
- Toxin Production: C. difficile produces toxins Toxin A and Toxin B, which damage the intestinal lining, leading to diarrhea, colitis, and, in severe cases, pseudomembranous colitis.
- Transmission and Recurrence: C. difficile spores are highly resistant and can spread through contaminated surfaces and hands, leading to reinfection or transmission in healthcare settings.
Why Other Options Are Incorrect:
- (A) Eating contaminated food: While foodborne illnesses can cause diarrhea, C. difficile infection is primarily linked to antibiotic use, not food contamination.
- (B) A blood transfusion: No evidence suggests a link between blood transfusions and C. difficile infection.
- (D) Improper food storage: This may lead to bacterial food poisoning but not specifically C. difficile infection.
- (E) Travel to an underdeveloped country: Traveler’s diarrhea is usually caused by E. coli, Salmonella, or Shigella, not C. difficile.
Thus, the primary risk factor for C. difficile-associated diarrhea is prior broad-spectrum antibiotic use.