Alteration of normal gastric flora in neonates receiving ranitidine.

OBJECTIVES: To determine if the administration of ranitidine to neonates leads to an increase in gastric pH to > or = 4 and if this increase in gastric pH correlates with gastric colonization. STUDY DESIGN: 628 pH measurements and 276 gastric cultures were obtained from 86 neonates. Twenty-three patients received ranitidine and 63 patients served as controls. RESULTS: Treated patients had a mean gastric pH of 5.6 compared with a control mean pH of 4.4 (p < 0.0001). Gastric pH was significantly affected by feeding and postnatal age. 54 patients were colonized with pathogenic bacteria and/or yeast (n = 20 treated, n = 34 control). Length of hospitalization (p < 0.0001), increase in gastric pH (p < 0.01), days of antibiotics before culture (p < 0.0001), and ranitidine use (p < 0.0001) were associated with an increased rate of colonization. CONCLUSIONS: The use of ranitidine did lead to a significant increase in gastric pH and with this increase in gastric pH gastric colonization rates increased. No increased frequency of infection was found in ranitidine-treated infants.

Optical immunoassay for rapid detection of group A beta-hemolytic streptococci. Should culture be replaced?

OBJECTIVE: To evaluate an optical immunoassay rapid antigen test to detect group A beta-hemolytic streptococci directly from throat swab specimens. DESIGN: Criterion standard with "blinded" comparison. Double-swab pharyngeal samples were obtained; one swab was cultured and the other was used for the rapid antigen test. SETTING: Microbiology laboratory in a primary care center at a university teaching hospital. PATIENTS: Two hundred sixty-two outpatients with pharyngitis. MAIN OUTCOME MEASURE: The results of the optical immunoassay rapid antigen test were compared with results of standard aerobic culture. RESULTS: Sixty-two (24%) of 262 samples were culture-positive; 48 of these 62 were positive by the optical immunoassay rapid test (sensitivity, 77%). Of the 200 culture-negative samples, seven (4%) were positive by the rapid test (specificity, 96%). CONCLUSION: The optical immunoassay performed well, but like other rapid tests, is not sensitive enough to replace standard culture for detection of group A beta-hemolytic streptococci.

Explanation for false-positive urine cultures obtained by bag technique.

OBJECTIVE: To test whether a urine bag technique, previously shown in circumcised male infants 1 month to 1 year of age to yield no false-positive cultures, would give similar results in newborns (females and circumcised and uncircumcised males). DESIGN: Prospective study in which periurethral and urine specimens were obtained from healthy newborns. After the periurethral specimen was obtained, the perineum was washed and a urine bag applied. The urine bag was removed immediately after voiding and the urine was cultured. SETTING: Normal newborn nursery and pediatric hospital. SUBJECTS: Ninety-eight healthy full-term newborns (49 female and 49 male) admitted to the normal nursery during a 4-month period. MAIN RESULTS: Isolation of a pathogen from the bag urine reflected periurethral flora. In 20 (95%) of the 21 urine specimens from which a pathogen was isolated, the same pathogen was detected on the periurethra. Sixteen of the 21 urine cultures were falsely positive (> 10(4) colony-forming units of pathogen per milliliter). In 50 (98%) of the 52 urine samples that yielded no growth, the periurethral culture was also negative. In the remaining 25 urine samples in which nonpathogens were detected, the periurethra yielded nonpathogens or no growth. Thus, if a pathogen was isolated from a bag urine sample, the same pathogen was detected on the periurethra 95% of the time. Conversely, if the bag urine sample was negative for a pathogen, the periurethral culture was negative 100% of the time. The presence of a pathogen on the periurethra was more common in female than male neonates (16 of 49 vs four of 49; P = .004), and none of the 14 circumcised male neonates had a pathogen detected on their periurethra or in their urine. CONCLUSION: This study explains the finding of false-positive cultures with the bag technique. Pathogens detected in bag urine samples reflected pathogens on the periurethra. Until a bag collection technique that avoids contamination by periurethral flora can be developed, urethral catheterization and suprapubic aspiration remain the methods of choice for obtaining a urine specimen in female and uncircumcised male neonates.

Defining unnecessary disinfection procedures for single-dose and multiple-dose vials.

BACKGROUND: Recommendations in the literature conflict on the necessity of disinfecting single-use vials prior to aspiration of fluid. Interventions to disinfect the stopper surface on multiple-dose vials vary considerably. OBJECTIVES: To determine the necessity of alcohol disinfection of the stopper on single-dose vials and to compare povidone-iodine and alcohol versus alcohol-only disinfection of the stopper prior to each needle penetration on multiple-dose vials. METHODS: The rubber stopper surfaces of 100 single-dose vials were cultured for the presence of bacteria. To determine the efficacy of two procedures for disinfection of multiple-dose vials, 87 stopper surfaces routinely disinfected with both povidone-iodine and alcohol were cultured for bacteria. After a change in practice, 100 multiple-dose vials routinely disinfected with alcohol only were cultured for the presence of bacteria. RESULTS: Of the cultures done on single-dose vial stoppers, 99% were sterile. A comparison of the two disinfection techniques for multiple-dose vials revealed that 83 (95%) of the 87 vials prepped with both povidone-iodine and alcohol were sterile, compared with all stoppers disinfected with alcohol only. CONCLUSIONS: This study shows the lack of necessity of any disinfection procedure on the rubber stopper of single-dose vials and the efficacy of alcohol only for disinfecting the stopper of multiple-dose vials.

Making a presumptive diagnosis of urinary tract infection by using a urinalysis performed in an on-site laboratory.

The purpose of our study was to characterize the utility of certain elements of urinalysis, singly or in combination, in identifying children with urinary tract infections (i.e., positive findings on urine culture). Laboratory results for urine specimens subjected to both urinalysis and culture in an on-site outpatient clinic (office) laboratory during a 36-month period were reviewed. All specimens were collected by one of three methods (the midstream void technique, urethral catheterization, or suprapubic aspiration of urine) from children with symptoms to assist in documenting a possible urinary tract infection. Specimen processing by certified technologists was initiated within 10 minutes of collection. Sensitivity, specificity, and positive and negative predictive values were determined for each test or combination of tests. Of 689 specimens, 102 (14.8%) had positive culture results. The combination of dipstick analysis (leukocyte esterase and nitrite tests) and of microscopic examination for bacteria had a sensitivity of 100% and a negative predictive value of 100%. The nitrite test had a specificity of 100% and a positive predictive value of 100%. We conclude that, when properly collected specimens are evaluated promptly by certified technologists, the rate of accuracy in detecting or ruling out a urinary tract infection (i.e., positive findings on urine culture) with certain elements of the urinalysis is high.

Hand washing in pediatric ambulatory settings. An inconsistent practice.

The first phase of this study was performed to determine the rate of breaks in hand washing technique by physicians in two pediatric ambulatory settings and to determine whether this technique was influenced by the physician's level of training. The second phase was performed to determine if reminding physicians to wash their hands would decrease the rate of breaks. A hand washing break in technique was defined as not washing hands before patient contact. The observations were made by medical students accompanying the providers. In the 496 encounters during the first phase, 254 breaks (51.2%) occurred. In the 293 encounters during the second phase, 150 (51.2%) breaks occurred. During both phases, the rates of hand washing breaks among the four groups of providers (residents in postgraduate years 1 through 3 and faculty) were similar. Breaks in hand washing technique occur at an unacceptably high rate in outpatient settings.

Early treatment of Campylobacter jejuni enteritis.

The bacteriologic and clinical effects of early antibiotic treatment of Campylobacter jejuni enteritis were studied. Erythromycin rapidly eliminated C. jejuni from stools, whereas trimethoprim-sulfamethoxazole did not. Despite its bacteriologic effectiveness, erythromycin did not reduce the duration or severity of diarrhea, abdominal pain, or other symptoms.

Comparison of three topical antimicrobials for acute bacterial conjunctivitis.

One hundred fifty-eight patients, 21 years of age or less, presenting with culture-positive (Haemophilus influenzae or Streptococcus pneumoniae) conjunctivitis were treated with trimethoprim-polymyxin B (TP), gentamicin sulfate (GS) or sodium sulfacetamide (SS) ophthalmic solution for 10 days. Clinical response at 3 to 6 days after start of therapy was similar for all test agents: 26 of 55 (47%) patients cured, 25 of 55 (45%) improved for TP; 28 of 57 (49%) cured, 26 of 57 (46%) improved for GS; and 19 of 46 (41%) cured, 22 of 46 (48%) improved for SS. Clinical response at 2 to 7 days after completion of therapy was also similar: 46 of 55 (84%) patients cured, 5 of 55 (9%) improved for TP; 50 of 57 (88%) cured, 5 of 57 (9%) improved for GS; and 41 of 46 (89%) cured, 2 of 46 (4%) improved for SS. Bacteriologic response at 2 to 7 days after completion of therapy was similar for all antimicrobials: 44 of 55 (83%) patients for TP; 39 of 57 (68%) for GS; and 33 of 46 (72%) for SS.