Tropical sprue after travel to Tanzania

Sprue tropicale

Tropical sprue associates prolonged diarrhea, a malabsorption syndrome, and nutritional deficiency in patients who live in or have visited tropical areas. Pathogenesis is still unknown but an infectious cause is suspected. Macrocytic anemia and hypoalbuminemia are present, together with progressive villus atrophy of the small intestine. Treatment with tetracycline, folic acid and proper nutritional support generally results in full recovery.

Tropical sprue is associated with contamination of small bowel with aerobic bacteria and reversible prolongation of orocecal transit time

BACKGROUND

In tropical sprue (TS), response to antibiotics may suggest a role for bacterial contamination of the small bowel, which is known in diseases with prolonged orocecal transit time (OCTT).

METHODS

We studied 13 patients with TS (diagnosed by standard criteria) for frequency, nature and degree of bacterial contamination of the small bowel by quantitative culture of jejunal aspirate, glucose hydrogen breath test (GHBT), and OCTT by lactulose hydrogen breath test before and after treatment. Twelve patients with constipation-predominant irritable bowel syndrome (IBS) and 12 healthy subjects served as controls.

RESULTS

Ten of 13 patients with TS had bacterial contamination compared with 3/12 with IBS (all aerobic, P < 0.05). Median colony count in TS (36 000 CFU/mL, 400 to > 100 000) was higher than IBS (700 CFU/mL, 100-1000, P < 0.05). Gram-negative aerobic bacilli were commonly isolated in TS but not in IBS. Median OCTT was longer in TS (180 m, 40 - 240) than IBS (110 m, 70 - 150, P = 0.008) and healthy subjects (65 m, 40 - 110, P = 0.0007, Wilcoxon rank sum test). Orocecal transit time in TS correlated with fecal fat (Spearman's rank correlation coefficient 0.69, P < 0.05). Orocecal transit time and fecal fat, repeated in 8/13 patients, decreased with treatment for TS (195 m, 130-240 vs 125 m, 90-200, P = 0.02; 8 g/24 h, 6.8-19.6 vs 7 g/24 h, 4.2-9, P = 0.04, respectively).

CONCLUSION

Aerobic bacterial contamination of the small bowel is common in patients with TS. Prolonged OCTT in TS correlated with fecal fat and normalized in a subset of patients after treatment.

Diarrhea in the returned traveler

Diarrhea in the returned traveler is a common problem that can be caused by a number of different pathogens. A history of the patient's travel and exposures, the duration of illness, the response to prior treatment, and the clinical syndrome can help to establish a good etiologic differential diagnosis on which further therapy can be based. Many of these patients can be treated empirically with antibiotics, either a fluoroquinolone or azithromycin, without further microbiologic evaluation. Those patients with severe or persistent disease or comorbid illnesses, or those who have failed empiric therapy, should undergo further microbiologic evaluation with directed stool cultures and ova and parasite screening. For those patients with negative evaluations, further empiric therapy may be warranted if syndromes are suggestive of specific agents of infection, such as by Giardia or Cyclospora species. Other patients may require endoscopic evaluation to exclude diagnoses such as tropical sprue or inflammatory bowel disease.