Bacterial Enteric Infections Flashcards
(72 cards)
What factors may increase the risk of enteric bacterial infections in individuals with HIV?
HIV-associated alterations in mucosal immunity, intestinal integrity, and treatment with acid-suppressive agents
Rates of Gram-negative bacterial enteric infections are at least 10 times higher among adults with HIV than in the general population.
Which bacteria are most frequently isolated by culture from adults with HIV in the United States?
- Shigella
- Campylobacter
- nontyphoidal Salmonella spp.
Particularly Salmonella enterica serotypes Typhimurium and Enteritidis.
What is the relationship between CD4 T lymphocyte count and the risk of bacterial diarrhea in individuals with HIV?
The risk of bacterial diarrhea is greatest in individuals with clinical AIDS or CD4 counts <200 cells/mm3.
What is a common condition associated with Clostridioides difficile in people with HIV?
Clostridioides difficile–associated infection (CDI)
Low CD4 count (<50 cells/mm3) is an independent risk factor.
What defines severe community-associated diarrhea in people with HIV?
Six or more loose stools per day with or without other signs of systemic illness.
What is the recommended method for diagnosing Gram-negative bacterial enteric infections?
Cultures of stool and blood or stool molecular methods (culture-independent diagnostic tests).
What is the significance of obtaining blood cultures in patients with diarrhea and fever in the context of HIV?
High incidence of bacteremia associated with Salmonella gastroenteritis in people with HIV.
What is the role of endoscopy in diagnosing enteric infections in people with HIV?
Reserved for cases where stool culture, microscopy, and other tests fail to reveal an etiology.
What precautions should be taken to prevent enteric infections in individuals with HIV?
- Wash hands regularly with soap and water
- Use of barriers during sexual practices
- Avoid contact with human feces
Soap and water are preferred over alcohol-based cleansers.
What immunizations are recommended for travelers at risk of bacterial enteric infections?
Immunizations against Salmonella serotype Typhi.
What is the recommended treatment for people with HIV and CD4 count 200–500 cells/mm3 experiencing diarrhea?
- Azithromycin 500 mg PO daily for 5 days
- Ciprofloxacin 500–750 mg PO every 12 hours for 5 days.
What is a key consideration when treating bacterial enteric infections in people with HIV?
Diagnostic fecal specimens should be obtained before initiation of empiric antimicrobial therapy.
Fill in the blank: The risk of a bacterial enteric infection increases as CD4 count ______.
<200 cells/mm3.
What should be considered if no clinical response occurs after 3 to 4 days of therapy for bacterial enteric infections?
Follow-up stool culture with antibiotic susceptibility testing and other methods to detect enteric pathogens.
True or False: Antimicrobial prophylaxis to prevent bacterial enteric illness is routinely recommended for travelers.
False.
What are the potential adverse effects of routine use of fluoroquinolones for prophylaxis in enteric infections?
Toxicity associated with CDI and increasing rates of antimicrobial resistance.
What is the preferred agent for prophylaxis in pregnant people traveling to areas at risk for bacterial enteric infections?
Azithromycin.
What clinical syndromes are associated with Gram-negative enteric bacteria among people with HIV?
- Self-limited gastroenteritis
- Severe and prolonged diarrheal disease
- Bacteremia with or without gastrointestinal illness.
What should be included in the assessment of patients with diarrhea in the context of HIV?
Complete exposure history, medication review, stool frequency and consistency, associated signs and symptoms.
What is the importance of reflex stool cultures and antibiotic sensitivity testing?
To address increasing resistance detected in enteric bacterial infections.
What is the definition of diarrhea for testing C. difficile infection (CDI)?
Three or more loose stools in 24 hours.
What is the initial treatment for suspected bacteremia in patients with HIV?
Ceftriaxone 1–2 g IV every 24 hours until susceptibility results are available
This treatment can be adjusted based on sensitivity results.
When is a carbapenem preferred for empiric therapy?
When Campylobacter or Shigella bacteremia is suspected
This is to ensure effective treatment in potentially resistant cases.
What is the recommended duration of therapy if no pathogen is identified and the patient recovers quickly?
5 days of therapy is recommended
This duration may vary based on stool microbiology results.