RESUMO
The objective of the study was to compare the safety and efficacy of three treatment protocols for the prevention of travelers' diarrhea: once-daily ciprofloxacin versus trimethoprim/sulfamethoxazole (TMP/SMZ) once daily versus placebo for the prevention of travelers' diarrhea. The study population was comprised of participants in 2-week medical-missions projects based in Latin America and the Caribbean. The diverse age group and varied study sites closely resembles the population of travelers who seek pretravel advice from physicians. A prospective, randomized, double-blind, placebo-controlled comparison was designed. Subjects who developed diarrhea, defined as three stools in 8 hours plus one or more signs of an enteric infection, were considered prophylaxis failures. Stool specimens were collected and examined for the presence of enteric pathogens. DNA probes were used to determine the presence of diarrheagenic E. coli. Bacterial colony blots were used. Adverse events were recorded by participants in a diary. Three hundred and forty-four subjects were entered in the study, of which two hundred and seventy-eight subjects met the criteria for the efficacy and safety review. Subjects were randomly assigned to receive ciprofloxacin (500 mg), TMP/SMZ (160/800 mg), or placebo. Five of the 99 (5%) subjects taking ciprofloxacin, 14 of the 87 (16%) taking TMP/SMZ, and 30 of the 92 (33%) taking placebo experienced diarrhea. Bacterial pathogens were identified more commonly in the TMP/SMZ and placebo groups than in the ciprofloxacin-treated group. The incidence of adverse reactions was 9.0%, 14.8%, and 7.5% for ciprofloxacin, TMP/SMZ, and placebo subjects, respectively (p =.287). Ciprofloxacin 500 mg once daily provides safe and effective prophylaxis for travelers' diarrhea and is superior to TMP/SMZ (160/800 mg).
