Prospective, randomized, placebo-controlled trial of norfloxacin for the prophylaxis of recurrent urinary tract infection in women.

Thirty women were randomized in a double-blind, placebo-controlled study to receive either norfloxacin, 200 mg orally daily at bedtime, or placebo for the prevention of recurrent bladder infection. Subjects were followed monthly to monitor compliance and symptoms, for urine culture and periurethral and anal canal swabs to monitor colonization, and for blood specimens for hematologic and biochemical studies to monitor safety. During 1 year of follow-up, 10 of 15 placebo subjects and none of 15 norfloxacin subjects developed infection (P less than 0.001). Adverse effects occurred with equal frequencies in the two groups. For norfloxacin subjects, only 2 (1.6%) of 129 periurethral and 4 (3.1%) of 129 anal canal swabs showed colonization with aerobic gram-negative organisms, while 16 (22%) of 73 periurethral and 47 (64%) of 73 anal canal swabs from placebo subjects showed colonization. Daily therapy with norfloxacin at bedtime is effective in preventing recurrent cystitis. During 1 year of norfloxacin therapy, colonization was infrequent and superinfection with norfloxacin-resistant organisms did not occur.

Long-term antimicrobial prophylaxis for recurrent urinary tract infection in women.

Thirteen women and two preadolescent girls who suffered recurrences after six months of prophylaxis with trimethoprim (TMP; 40 mg) and sulfamethoxazole (SMZ; 200 mg) taken thrice weekly at bedtime were enrolled in a 24-month study of prophylaxis with the same region. During 29.1 cumulative patient-years of prophylaxis, two infections due to Escherichia coli and one each due to Staphylococcus epidermidis and Streptococcus faecalis occurred (0.14 infection/patient-year). MICs for these isolates were less than or equal to 2 micrograms of TMP/ml and greater than 512 micrograms of SMZ/ml. During prophylaxis, 106 of 116 cultures from the periurethral area and 66 of 97 cultures from the anal and canal yielded no aerobic gram-negative bacilli. In three patients, the periurethral area was colonized with aerobic gram-negative bacilli with MICs of greater than or equal to 2 micrograms of TMP/ml. Thirteen patients were followed after the discontinuation of prophylaxis. Eight suffered recurrences, seven with organisms susceptible to TMP. After one year the remaining five had experienced no recurrences. It is concluded that long-term prophylaxis with 40 mg of TMP and 200 mg of SMZ thrice weekly is an effective, well-tolerated regimen that can maintain an infection-free state in women with histories of frequent urinary reinfections.

Clostridium difficile and cytotoxin in feces of patients with antimicrobial agent-associated pseudomembranous colitis.

Thirty patients with antimicrobial agent-associated pseudomembranous colitis (PMC) were studied for the presence of Clostridium difficile and its cytotoxin in feces. Either colonoscopy or barium enema radiography was required in three patients for the diagnosis of PMC because of nondiagnostic findings at sigmoidoscopy. Both the organism and cytotoxin were detected in 27 of the 30 patients; Staphylococcus aureus was excluded as the cause of PMC in two of the remaining patients. Eighteen of 19 patients with C. difficile-induced PMC who were treated with oral vancomycin had a salutary response; seven patients, however, had a relapse of colitis following the discontinuation of vancomycin. In general, relapses of colitis responded to retreatment with vancomycin. The implication of C. difficile as a cause of diarrhea is best achieved by the demonstration of colonic mucosal plaques or of a pseudomembrane. The value of fecal culture for C. difficile and cytotoxin assay is limited by the existence of asymptomatic carriers.

Chemoprophylaxis for Neisseria meningitidis in an isolated Arctic community.

Community chemoprophylaxis with a regimen of sequential minocycline/rifampin (adults) or rifampin alone (children [less than 12 years of age]) was undertaken in a remote Arctic community one year after an outbreak of meningitis due to Neisseria meningitidis serogroup B. Nasopharyngeal carriage rates of N. meningitidis before prophylaxis were 32.4% in Inuit (Eskimos) and 6% in Caucasians, with maximal carriage (44.8%) in adolescents. Serogroup B accounted for 63.9% of all isolates before prophylaxis. One week after prophylaxis, the nasopharyngeal carriage rates were 0.8% in Inuit who had received prophylaxis and 33.3% in those who had not received prophylaxis (P less than 0.005). This reduction persisted at nine weeks after prophylaxis, when carriage rates were 1.2% in those who had received prophylaxis and 22.6% in individuals who had not received prophylaxis. Of the strains obtained before prophylaxis, 7.8% were sulfadiazine-resistant, whereas 35% of all isolates obtained from prophylaxis were sulfadiazine-resistant. Rifampin- or minocycline-resistant strains were not identified either before or after prophylaxis.

Amoxicillin therapy of acute urinary infections in adults.

Fifty-two patients, 48 females and 4 males, with suspected urinary infection were treated with amoxicillin. Twenty-two females with presumed bladder infection were treated with amoxicillin, 250 mg three times a day for 7 days; 26 females and 4 males with presumed renal infection were treated with amoxicillin, 500 mg three times a day for 14 days. Five patients were immediate treatment failures, with positive urine cultures during therapy. All five patients had been infected with amoxicillin-resistant urinary pathogens. Three patients, treated as for bladder infections, reinfected during 6 weeks of follow-up, and only one relapsed. Two patients, treated as for renal infections, reinfected, whereas four relapsed. During therapy, amoxicillin-susceptible gram-negative rods were eradicated from the periurethral area in all but one patient. Of 28 patients studied, 19 acquired a predominant growth of either resistant aerobic gram-negative rods or Candida albicans from periurethral cultures. Our findings suggest that these two regimens of amoxicillin achieve satisfactory cure rates in urinary infection, but both regimens significantly alter the normal periurethral flora.