Traveler's diarrhea.

This article presents a review of causes, presentation, and diagnosis of traveler's diarrhea. Treatment and prevention of this common problem is described in some detail. Finally, a practical and cost-effective approach to evaluating and treating a returning traveler is presented.

Colonic perforation in unsuspected amebic colitis.

Unsuspected amebic colitis presenting as inflammatory bowel disease, as in our patient, has been previously reported (4, 7, 8). Misdiagnosis, delay in antibiotic treatment, and institution of immunosuppression were the result of failure to identify the parasite in stool specimens and have resulted in suffering, morbidity, mortality, and surgery. In all previously reported cases, routine stool studies failed to identify E. histolytica (4, 7, 8). The correct diagnosis was only established after reviewing the surgical specimen or biopsies obtained endoscopically. Because the erroneous diagnosis of inflammatory bowel disease can lead to disastrous complications, it is imperative to exclude amebic colitis prior to undertaking steroid therapy, especially in patients with a prior history of travel to or residence in areas with endemic E. histolytica (17). We recommend obtaining at least three stool specimens for microscopic examination, as well as testing for serum amebic antibody. Patients should submit fresh stool specimens directly to the laboratory to allow for prompt diagnostic evaluation. Such an approach might lead to the improved diagnosis of amebiasis.

Diagnosis and monitoring of Whipple disease by polymerase chain reaction.

BACKGROUND: Whipple disease is a chronic, multisystem disorder associated with infection with Tropheryma whippelii, an organism that has not yet been grown on artificial media. In some cases, the diagnosis of Whipple disease is uncertain if it is based on histology alone. Although antibiotic regimens of various durations have been used, the disease recurs in about one third of cases. No test for cure is available. OBJECTIVE: To develop a test that is more sensitive and specific than histologic examination to diagnose Whipple disease and monitor the effects of antibiotic therapy. DESIGN: Retrospective, laboratory-based evaluations of stored tissue specimens. PATIENTS: 30 patients with clinically diagnosed, histologically confirmed Whipple disease and 8 patients in whom Whipple disease was clinically suspected but who did not have definitive histologic evidence. MEASUREMENTS: Pretreatment and post-treatment biopsy specimens of the small bowel and lymph node were tested by polymerase chain reaction for the presence of T. whippeli DNA. RESULTS: Results on PCR were positive in 29 of the 30 specimens from patients with histologically confirmed disease (sensitivity, 96.6%; specificity, 100%) and in 7 of the 8 specimens from patients in whom disease was clinically suspected. Small-bowel biopsy specimens were obtained after treatment from 17 patients (median duration of follow-up, 119 months); specimens from 12 of these patients had positive results on PCR. When these cases were correlated with therapeutic outcome, it was found that 7 of the 12 patients had clinical relapse during subsequent follow-up or had never responded to treatment (positive predictive value, 58% [95% CI, 28% to 85%]). In contrast, none of the 5 patients whose post-treatment biopsy specimens had negative results on PCR had relapse (negative predictive value, 100% [CI, 48% to 100%]; P = 0.044). No correlation was found between post-treatment histology and clinical outcome (P > 0.2). CONCLUSIONS: Polymerase chain reaction is highly sensitive and specific when used to confirm the diagnosis of Whipple disease, to identify inconclusive and suspicious cases, and to monitor response to therapy. A negative result on PCR may predict a low likelihood of clinical relapse; a positive test result that remains positive despite therapy may be associated with a poor clinical outcome. Histopathologic evaluation of post-treatment specimens does not predict clinical cure or relapse.