D R Morgan

Nitrofurans in the treatment of gastritis associated with Campylobacter pylori

We conducted a double-blind, placebo-controlled, randomized treatment study in Peruvian adults with antral gastritis associated with Campylobacter pylori. Patients received either 400 mg of furazolidone (n = 14), 400 mg of nitrofurantoin (n = 24), or a placebo (n = 31) for 14 days. Endoscopy was carried out at baseline, 1 day after ceasing therapy, and 6 wk after the end of treatment to verify colonization by C. pylori and determine the extent of gastric inflammation. Treatment with nitrofurantoin or furazolidone markedly reduced or, in some cases, cleared C. pylori from the antrum (p less than 0.0005 compared with placebo). Resolution of acute gastric inflammation, as evidenced by decreased polymorphonuclear leukocyte infiltration and regeneration of the mucus layer, paralleled the reduction in bacterial colonization (p less than 0.005 compared with placebo). A high percentage of patients experienced relapse (recolonization by C. pylori and return to pretreatment levels of gastritis) within 6 wk after cessation of treatment. Significant relief of dyspeptic symptoms was not evident during the study.

Lack of emergence of resistant fecal flora during successful prophylaxis of traveler's diarrhea with norfloxacin.

Norfloxacin, a new quinolone carboxylic acid derivative, was compared with an identical-appearing placebo preparation in a prospective, randomized, double-blind trial for prevention of travelers diarrhea among 120 U.S. students arriving in Mexico. Prophylaxis was continued for 2 weeks. Diarrhea was defined as four unformed stools in 24 h plus an additional symptom of enteric disease. In the norfloxacin prophylaxis group, 4 of 56 subjects (7%) experienced diarrhea, compared with 36 of 59 subjects (61%) in the placebo group. The difference was significant (P less than 0.0001). In contrast to our previous experience with use of trimethoprim-sulfamethoxazole to prevent travelers diarrhea, quantitative stool cultures in the norfloxacin-treated group revealed a significant decline of normal aerobic fecal flora during prophylaxis (P less than 0.0005). Among stool samples from norfloxacin-treated subjects, 32 of 38 (84%) cultured on day 7 and 34 of 37 (92%) cultured on day 14 had no gram-negative bacilli. After norfloxacin was discontinued, fecal flora returned to pretreatment levels. No gram-negative aerobic flora resistant to norfloxacin were found during weekly quantitative cultures before, during, or after therapy.

Furazolidone versus ampicillin in the treatment of traveler's diarrhea

Ninety-four U.S. students who acquired diarrhea in Mexico were treated with furazolidone (47 subjects) or ampicillin (47 subjects) on a double-blind random basis. Of 47 students, 26 (55%) who received furazolidone (100 mg four times daily for 5 days) recovered from illness within 48 h after initiation of therapy, in contrast to 15 of 47 (32%) who received ampicillin (500 mg four times daily for 5 days) (P less than 0.05). Altogether, 74% of students treated with furazolidone and 49% of those receiving ampicillin were well within 72 h (P less than 0.05). When furazolidone was compared with ampicillin, clinical illness was shortened on the average from 65 to 61 h for enterotoxigenic Escherichia coli diarrhea, from 83 to 58 h for shigellosis, from 82 to 51 h for diarrhea unassociated with a detectable agent, and from 72 to 57 h for all cases irrespective of etiology. Although not dramatically effective in the current trial, the broad spectrum of activity of furazolidone is of interest. Because of in vitro activity against Campylobacter strains and known effectiveness in treating giardiasis, furazolidone should be considered in therapy for diarrhea of unknown etiology in certain settings when laboratory processing of stools for etiological agent is not feasible.

Efficacy of Bicozamycin in Preventing Traveler's Diarrhea

Bicozamycin was compared with a placebo in a prospective, randomized, double-blind study of the prevention of acute diarrhea among 30 American travelers newly arrived in Guadalajara, Mexico. None of the 11 subjects given bicozamycin orally for 3 wk at a dosage of 500 mg four times a day developed diarrhea as compared with an incidence of 53% diarrhea (10 of 19 subjects) in the placebo group (p = 0.003). Bicozamycin was well tolerated. Studies of changes in predominant aerobic fecal flora among the 11 subjects treated with bicozamycin showed the appearance of only one highly resistant Citrobacter freundii at the end of 1 wk of therapy and only a total of six resistant isolates at the end of 3 wk. All resistant isolates failed to transfer this resistance to a recipient Escherichia coli. Bicozamycin seems to be well suited and safe as a prophylactic agent against travelers diarrhea.

Role of a novel antidiarrheal agent, BW942C, alone or in combination with trimethoprim-sulfamethoxazole in the treatment of traveler's diarrhea.

The efficacy of BW942C, a novel enkephalinlike pentapeptide antidiarrheal agent, was compared with the efficacy of trimethoprim-sulfamethoxazole (TMP-SMX) and the combination of the two agents in a placebo-controlled trial of the 72-h treatment of acute diarrhea. Subjects with diarrhea but without bloody stools or fever greater than 102 degrees F (38.9 degrees C) were enrolled. Administered to 134 U.S. adults with diarrhea that developed shortly after their arrival in Guadalajara, Mexico, BW942C was more efficacious than TMP-SMX in relieving diarrhea and cramps in the first 12 h of therapy, especially among subjects with diarrhea caused by enterotoxigenic E. coli. In the BW942C treatment group, 25% of subjects eventually took additional therapy because their diarrhea did not respond to BW942C alone. Neurological side effects such as dizziness and light-headedness occurred more frequently among BW942C-treated subjects. Therapy for 3 days with TMP-SMX provided lasting relief comparable with previously reported 5-day therapy. Use of the combination of both agents provided the benefits of prompt relief afforded by BW942C and lasting relief afforded by TMP-SMX. BW942C might prove to be an agent suitable for the treatment of acute diarrhea, with TMP-SMX reserved for treatment of those who do not respond adequately. The empiric use of the combination of BW942C and TMP-SMX appears appropriate for the treatment of severe nondysenteric disease.

DIARRHEA ASSOCIATED WITH E|[period]| COLI PRODUCING SHIGALIKE CYTOTOXIN

College students spending the summer in Mexico were studied for the development of diarrhea. Stool specimens were collected from sick and asymptomatic students. 188 episodes of gastroenteritis were evaluated for salmonella, shigella, campylobacter, enteropathogenic E. coli, enterotoxigenic E. coli (ST,LT), giardia, E. histolytica, and cryptosporidium. 53 episodes occurred for which no etiologic agent could be defined. E. coli isolated from these students and asymptomatic students were assayed for adherence to HEp-2 cells and production of Shiga-like toxin. HEp-2 adherent E. coli were isolated from ill students more frequently than from those who were well (p < 0.05). 50% of strains from sick students with no known etiology were positive for Shiga-like toxin while only 27% of E. coli from asymptomatic individuals were positive. Strains that were positive for Shiga toxin tended to be positive for HEp-2 adherence and strains that were negative for Shiga or HEp-2 tended to be negative for the other marker (p < 0.02). HEp-2 adherence and Shiga toxin production correlated with presence of gastroenteritis in individuals who had no previously described enteric pathogen. This is the first evidence that Shiga toxin production by E. coli may commonly cause enteritis.