American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the treatment protocol for diarrhea caused by ETEC (travelers' diarrhea)?

1. Amoxicillin × 7 days

2. Fluoroquinolone × 3 days, azithromycin × 1 dose, or rifaximin × 3 days

3. Tetracycline × 5 days

4. Metronidazole × 5 days

The correct answer is: Fluoroquinolone × 3 days, azithromycin × 1 dose, or rifaximin × 3 days

The treatment protocol for diarrhea caused by Enterotoxigenic Escherichia coli (ETEC), commonly associated with traveler's diarrhea, typically includes the use of antibiotics that are effective against this organism. In this case, fluoroquinolones, azithromycin, or rifaximin are recommended treatment options. Fluoroquinolones, such as ciprofloxacin, are commonly used due to their efficacy against most strains of ETEC and their relatively quick course of treatment (usually around three days). Azithromycin, given as a single dose, is particularly beneficial in areas where there is a concern about antibiotic resistance and may be preferred in some cases due to its excellent safety profile. Rifaximin is a non-absorbable antibiotic that has shown effectiveness against ETEC and can be administered over a short duration of three days, making it a suitable option as well. The other options listed are generally not suitable for treating ETEC diarrhea. Amoxicillin is not effective against ETEC due to resistance. Tetracycline has historically been used but is less favored now due to the emergence of resistance and the availability of more effective agents. Metronidazole is primarily used for anaerobic infections and protozoal infections and does