What should be included in the infectious disease workup for a patient with respiratory and gastrointestinal symptoms following recent travel to Pakistan?

From the Guidelines

For a patient with respiratory and GI symptoms after travel to Pakistan, the infectious workup should include testing for common travel-related infections, with a focus on typhoid fever, given the high incidence of enteric fever in this region, as noted in the 2009 study 1. The workup should start with basic tests including complete blood count, comprehensive metabolic panel, and stool studies (ova and parasites, culture, and PCR for pathogens like Salmonella, Shigella, Campylobacter, and E. coli) as recommended by the 2017 Infectious Diseases Society of America guidelines 1. Consider testing for typhoid fever with blood cultures and serologic tests, as the sensitivity of blood cultures is reported to be 40-80% within a week of symptoms onset 1. For respiratory symptoms, obtain a chest X-ray and test for tuberculosis with a PPD skin test or interferon-gamma release assay. Test for malaria with thick and thin blood smears or rapid diagnostic tests, especially if fever is present. Consider testing for viral hepatitis (A, B, E), dengue fever, and COVID-19. Depending on exposure history, tests for brucellosis, Q fever, or leishmaniasis may be warranted. While awaiting results, supportive care with hydration is essential. Empiric antibiotic therapy may be considered based on symptom severity, with options including azithromycin 500mg daily for 3 days for traveler's diarrhea or ciprofloxacin 500mg twice daily for 3-5 days if bacterial infection is strongly suspected, although ceftriaxone is now preferred as a first-line agent for enteric fever due to increasing fluoroquinolone resistance in Asia 1. Some key points to consider in the workup include:

• The patient's travel history and exposure to potential infectious agents
• The presence of fever, which is almost invariable in cases of enteric fever 1
• The need for blood cultures, which have the highest yield within a week of symptoms onset 1
• The importance of testing for antimicrobial resistance, given the high rates of resistance in Pakistan 1

From the Research

Infectious Workup for Recent Travel to Pakistan

Given the patient's recent travel to Pakistan and presentation with respiratory and GI symptoms, the following should be considered in the infectious workup:

• A detailed travel history, including the chronology of symptoms, medical risk factors, and exposures, to help facilitate clinical decision making 2
• The possibility of enteric fever (typhoid and paratyphoid fever), which is common in many low- and middle-income countries, including Pakistan 3, 4
• The potential for antibiotic resistance, including fluoroquinolone resistance in South Asia, and the emergence of extensively drug-resistant strains of enteric fever in Pakistan 3, 4
• Other infectious diseases prevalent in Pakistan, such as malaria, although the patient's symptoms do not specifically suggest this diagnosis 5

Diagnostic Considerations

The diagnostic workup should include:

• Blood cultures and molecular tests to diagnose enteric fever 3
• Widal test and blood film preparation to diagnose typhoid fever and malaria 5
• A thorough history of itinerary and specific exposures to guide the diagnosis of respiratory infections 6
• Consideration of the patient's age, medical history, and other risk factors to guide the diagnostic workup 2, 5

Treatment Considerations

The treatment of enteric fever may involve the use of cephalosporins, such as ceftriaxone, although the choice of antibiotic should be guided by local resistance patterns and the patient's specific clinical presentation 3

• The use of fluoroquinolones, such as ciprofloxacin, may be limited by resistance patterns in South Asia 3
• The potential benefits and risks of vaccination against typhoid fever should be considered, particularly for travelers to endemic areas 4