What is the best approach to manage diarrhea in a patient with Human Immunodeficiency Virus (HIV)?

Management of Diarrhea in HIV-Infected Patients

Begin with oral rehydration using WHO-recommended electrolyte solutions (such as Ceralyte or Pedialyte) for all HIV patients with diarrhea, while simultaneously obtaining stool and blood cultures to identify bacterial pathogens—particularly Salmonella, Shigella, and Campylobacter—since these organisms cause severe disease with high rates of bacteremia in immunocompromised patients. 1, 2

Initial Assessment and Risk Stratification

Immediately assess three critical parameters:

• Severity markers: Document stool frequency, volume, presence of blood/mucus, fever, and signs of dehydration (postural light-headedness, reduced urination, tachycardia, orthostasis) 1, 2
• CD4+ count: Patients with CD4+ <200 cells/µL are at highest risk for bacteremia and require blood cultures in addition to stool studies 1, 2
• Epidemiologic exposures: Recent travel, unsafe food consumption (raw eggs, undercooked poultry/meat, unpasteurized dairy), animal contact, antiretroviral therapy changes, and recent antibiotic use 1

Obtain blood cultures from any HIV patient with diarrhea and fever, as Salmonella bacteremia occurs frequently in advanced HIV disease and constitutes an AIDS-defining illness when recurrent 1, 2

Rehydration Strategy

Administer oral rehydration solutions approaching WHO concentrations (Na 90 mM, K 20 mM, Cl 80 mM, HCO3 30 mM, glucose 111 mM) for all patients with dehydrating diarrhea 1, 2. This approach is superior to IV fluids for patients able to take oral fluids—it is less painful, safer, less costly, and the patient's thirst naturally prevents overhydration 1. Reserve IV fluids only for severe dehydration when oral intake is impossible 2.

Pathogen-Specific Antimicrobial Therapy

Salmonella Gastroenteritis

Treat all HIV patients with Salmonella gastroenteritis with ciprofloxacin 750 mg twice daily for 14 days to prevent extraintestinal spread, particularly in those with advanced immunosuppression 1, 2. This recommendation differs from immunocompetent hosts where antibiotics may prolong shedding 1.

• For Salmonella bacteremia: Extend treatment beyond 14 days and monitor clinically for 5-7 days of persistent fever despite appropriate therapy 1
• For recurrent Salmonella septicemia (CD4+ <200 cells/µL): Consider secondary prophylaxis for ≥6 months after acute treatment, though weigh this against risks of long-term antibiotic exposure 1, 2
• In children: HIV-exposed infants <3 months and severely immunosuppressed children require treatment with TMP-SMX, ampicillin, cefotaxime, or ceftriaxone; use fluoroquinolones only if no alternatives exist 1, 2

Shigella Infections

Initiate fluoroquinolone therapy (ciprofloxacin) for 3-7 days as first-line treatment 1. Internationally acquired cases have high TMP-SMX resistance rates, and HIV patients experience more adverse effects from TMP-SMX 1. For bacteremia, extend treatment to 14 days 1.

Campylobacter Infections

Start empiric therapy with either ciprofloxacin or azithromycin for 7 days pending susceptibility results, recognizing increasing fluoroquinolone resistance 1. For mild disease, some clinicians withhold therapy unless symptoms persist beyond several days 1.

• For bacteremia: Treat for >2 weeks and consider adding an aminoglycoside as a second agent 1
• Special consideration: HIV patients are at risk for non-jejuni non-coli Campylobacter species (C. fetus, C. upsaliensis, H. cineadi) that require special culture conditions—notify your laboratory of HIV status 1

Management of Treatment Failure

If diarrhea persists after appropriate antimicrobial therapy:

• Obtain drug susceptibility testing of isolates 1
• Evaluate for malabsorption of oral antibiotics, undrained abscesses, or drug interactions 1
• Consider Clostridium difficile infection, particularly after gram-negative bacterial enteritis diagnosis 1
• Reassess for other opportunistic infections if initial workup was negative 2, 3

Noninfectious Diarrhea Management

When infectious workup is negative, consider antiretroviral therapy-related diarrhea (particularly protease inhibitors) or HIV enteropathy 4, 5, 6. The incidence of noninfectious diarrhea has increased in the ART era while opportunistic infections have decreased 4.

For symptomatic relief:

• Use antiperistaltic agents (loperamide, diphenoxylate) only for mild diarrhea 1, 3
• Discontinue immediately if symptoms persist >48 hours 1, 2, 3
• Never use in patients with high fever or bloody stools 1, 3
• Never use in children 1, 3

Optimize antiretroviral therapy, as potent ART remains the cornerstone for treating AIDS-related diarrhea and can lead to resolution of chronic diarrhea, weight gain, and clearance of parasites like Cryptosporidium and Enterocytozoon bieneusi 6, 7

Prevention Strategies

Food safety counseling is critical, especially for CD4+ <200 cells/µL:

• Avoid completely: Raw/undercooked eggs, poultry, meat, seafood (especially shellfish), unpasteurized dairy products and juices, raw seed sprouts 1, 2
• Cook poultry to internal temperature 180°F (82°C) and red meat to 165°F (74°C) 1
• Prevent cross-contamination: Wash hands, cutting boards, counters, and utensils after contact with uncooked foods 1, 2
• Wash produce thoroughly before consumption 1, 2

For travelers:

• Consider ciprofloxacin 500 mg daily as prophylaxis depending on immunosuppression level and travel destination, though routine prophylaxis is not generally recommended due to resistance concerns 1, 2
• Provide ciprofloxacin 500 mg twice daily for 3-7 days to take empirically if severe traveler's diarrhea develops 1, 2
• Avoid fluoroquinolones in children <18 years and pregnant women; consider TMP-SMX as alternative 1

Critical Pitfalls to Avoid

Do not withhold antibiotics from HIV patients with Salmonella gastroenteritis based on immunocompetent host data showing prolonged shedding—the risk of bacteremia and disseminated disease outweighs this concern 1, 2.

Do not continue antiperistaltic agents beyond 48 hours or use them in febrile/bloody diarrhea, as this can worsen outcomes and mask serious infections 1, 3.

Do not forget to evaluate household contacts of HIV patients with salmonellosis or shigellosis for asymptomatic carriage to prevent recurrent transmission 1, 2.

Monitor closely for recurrence in patients with advanced disease (CD4+ <200 cells/µL) who have had Salmonella septicemia, as relapse rates are high 1, 2.