Gastrointestinal infections are a significant cause of morbidity and mortality worldwide. According to the WHO World Heath Statistics report, diarrheal disease is the second leading worldwide cause of mortality in children under five years of age, accounting for 15% of all deaths in 2008. In the United States, the CDC estimates that each year, roughly 1 in 6 Americans (48 million people) get sick from foodborne or waterborne disease. Although many cases are self-limiting, 128,000 patients are hospitalized and 3,000 die each year.
Clinicians and laboratorians face a number of challenges in the diagnosis of infectious diarrhea. Laboratory identification of enteric pathogens currently incorporates a range of different methods, including microscopic examination, culture, immunoassay and molecular methods. These methods can be cumbersome and perform with varying sensitivities, specificities and turnaround times. Current IDSA recommendations for the diagnosis of diarrheal illnesses include a number of steps:
- Evaluate severity and duration of diarrheal illness.
- Obtain history and physical examination. Has the patient been exposed to seafood or the seacoast? Do they a recent travel history, suggesting “Traveler’s Diarrhea”? Do they have fever? Do they have any underlying conditions or immunosuppression?
- Treat for dehydration.
- Is this an isolated case or are there others? Could this be an outbreak situation? Have the appropriate health department officials been notified?
- Is blood present, suggesting invasive colitis with a bacterial etiology?
- Was onset after antibiotic treatment or > 3 days of hospitalization, suggesting Clostridium difficile?
- Is diarrhea persistent for > 7 days, suggesting a parasitic etiology?
Correct identification of the cause of the infection will determine the appropriate course of treatment. Should the patient receive supportive therapy only or should they also be treated with antibiotics to shorten the duration of the illness and carrier state?
Traditional testing methodologies (including culture, EIA, fluorescence, toxin testing, parasite studies, molecular methods) may take several days to complete and may be performed by different laboratories or be referred as a send-out test. Recent advances in molecular tests for diarrheal pathogens and toxins—particularly those that use multiplexing technologies—can greatly reduce the time required for accurate diagnosis of the cause of infectious diarrhea. Timely and reliable results can be generated in a few hours or within a day, allowing clinicians to make informed decisions on patient treatment and management.
How is the diagnosis of infectious diarrhea handled in your institution?
Are there areas for improvement?
How can your workflow be more efficient and provide a faster time to result?