Isopropyl alcohol is as efficient as chlorhexidine to prevent contamination of blood cultures.

BACKGROUND: False-positive blood cultures can lead to unnecessary risks and misuse of antibiotics; to reduce rates of false-positives, it would be useful to determine whether use of an antiseptic with a prolonged effect is required. METHODS: Clinical study of efficacy (blinded and randomized) to compare the rate of blood culture contamination when skin antisepsis was performed with 70% isopropyl alcohol or 2% chlorhexidine gluconate in 70% isopropyl alcohol in 2 hospitals. Patients aged 16 years or older with suspected bloodstream infection who were allocated in the emergency room, internal medicine ward, or intensive care unit were included. RESULTS: Five of 563 (0.9%) blood cultures from the isopropyl arm and 10 of 539 (1.9%) from the chlorhexidine arm were contaminated. No significant differences were observed among the rate of contamination (χ2=1.27; P = .3) or the relative risk of contamination (relative risk = 2.09; 95% confidence interval, 0.72-6.07; P = .2). CONCLUSIONS: The rates of blood contamination were not different when isopropyl alcohol and chlorhexidine were compared. Isopropyl alcohol could be used for skin antisepsis before blood collection.

Decontamination of stethoscope membranes with chlorhexidine: Should it be recommended?

OBJECTIVE: To determine differences in the recontamination of stethoscope membranes after cleaning with chlorhexidine, triclosan, or alcohol. METHODS: Experimental, controlled, blinded trial to determine differences in the bacterial load on stethoscope membranes. Membranes were cultured by direct imprint after disinfection with 70% isopropyl alcohol, 1% triclosan, or 1% chlorhexidine and normal use for 4 hours. As a baseline and an immediate effect control, bacterial load of membranes without disinfection and after 1 minute of disinfection with isopropyl alcohol was determined as well. RESULTS: Three hundred seventy cultures of in-use stethoscopes were taken, 74 from each arm. In the baseline arm the median growth was 10 CFU (interquartile range [IQR], 32-42 CFU); meanwhile, in the isopropyl alcohol immediate-effect arm it was 0 CFU (IQR, 0-0 CFU). In the arms cultured after 4 hours, a median growth of 8 CFU (IQR, 1-28 CFU) in the isopropyl alcohol arm, 4 CFU (IQR, 0-17 CFU) in the triclosan arm, and 0 CFU (IQR, 0-1 CFU) in the chlorhexidine arm were seen. No significant differences were observed between the bacterial load of the chlorhexidine arm (after 4 hours of use) and that of the isopropyl alcohol arm (after 1 minute without use) (Z= 2.41; P > .05). CONCLUSIONS: Chlorhexidine can inhibit recontamination of stethoscope membranes and its use could help avoid cross-infection.

Chlorhexidine avoids skin bacteria recolonization more than triclosan.

BACKGROUND: We do not know whether differences exist between the residual effect of 2% chlorhexidine in 70% isopropyl alcohol when compared with 1% triclosan in 70% isopropyl alcohol. METHODS: Using an analytic, longitudinal, controlled, and comparative experimental trial, with blinded measurements, we recruited healthy, adult volunteers from the University of Guanajuato who completed a stabilization phase of skin microbiota and had no history of skin allergies. Four 25-cm2 areas of the inner surface of the forearms were designated for study: unscrubbed control for establishing baseline bacterial counts, scrubbed control with tridistilled water, scrubbed with chlorhexidine, and scrubbed with triclosan. Quantitative cultures were taken of all the areas at 0, 3, and 24 hours, using agar plates with neutralizing agents. RESULTS: A total of 135 healthy volunteers were tested. At 24 hours, the unscrubbed control counts were 288 CFU/cm2, whereas the scrubbed control counts were 96 CFU/cm2; 24 CFU/cm2 for chlorhexidine and 96 CFU/cm2 for triclosan (Kruskal-Wallis χ2H = 64.27; P <.001). CONCLUSIONS: Chlorhexidine is the best antiseptic option when a prolonged antiseptic effect is needed; for instance, when implanting medical devices or performing surgical procedures.

[Is effective a shortened surveillance system of bloodstream infection?]. / Es eficaz un sistema de vigilancia acortado en las infecciones del torrente sanguíneo?

INTRODUCTION: Surveillance is necessary for bloodstream infection control. Daily monitoring of the central venous catheter (CVC) use, a time-demanding process, is the standard denominator to calculate the infection rate; surveillance of only one day per week has been proposed as alternative. OBJECTIVE: To determine whether surveillance of one day per week is similar to daily monitoring in a second-level hospital. MATERIAL AND METHODS: Daily monitoring of CVC utilization ratio was done during nine weeks in four locations of a second-level hospital. For each day, proportional differences respect to the global CVC utilization ratio was estimated. An ANOVA test was done to find differences between each weekday. RESULTS: CVC usage surveillance was performed for 9 weeks, so nine determinations were obtained for each weekday. No significant differences were found between each day (F = 2.20, p = 0.056). The lowest sampling discrepancy was found on Wednesdays. CONCLUSIONS: According to previous studies, and our own data, monitoring the CVC use one day per week is a reasonable alternative to the daily surveillance.

Chlorhexidine is a better antiseptic than povidone iodine and sodium hypochlorite because of its substantive effect.

BACKGROUND: The present study compared both the antiseptic efficacy of sodium hypochlorite against that of chlorhexidine gluconate in isopropyl alcohol and the substantive effect of chlorhexidine, povidone iodine, and sodium hypochlorite. METHODS: This was a 2-step study that included volunteers. In step 1, 4 skin areas were tested for bacteria in colony-forming units (CFU): 2 were controls to determine baseline bacteria or the effect of scrubbing, and 2 were treated with 10% hypochlorite or 2% chlorhexidine in isopropyl alcohol. Every subject was tested 4 times. The second step tested the substantive effect of 10% povidone-iodine and the aforementioned antiseptics. RESULTS: For the first step, 30 volunteers were studied, resulting in 120 determinations for each control and antiseptic. No differences between chlorhexidine gluconate (median 115 CFU/cm(2)) and sodium hypochlorite (median 115 CFU/cm(2)) were found. Both antiseptics were significantly different from rubbing control (317 CFU/cm(2)) and basal control (606 CFU/cm(2)). Only chlorhexidine showed a substantive effect. CONCLUSION: We consider that chlorhexidine gluconate in isopropyl alcohol, sodium hypochlorite, and povidone-iodine is equally effective for procedures that do not require a long action. However, chlorhexidine is desirable for procedures such as catheter insertion, skin preparation for surgery, or handwashing prior to surgery.

Asymptomatic bacteriuria in preadolescent girls.

BACKGROUND: The detection of asymptomatic bacteriuria in preadolescent girls may be important due to its effects on subsequent pregnancies. OBJECTIVE: To describe the prevalence of asymptomatic bacteriuria in preadolescent girls and the value of the nitrite test for screening. MATERIAL AND METHODS: Cross-sectional study in girls aged 9 to 13 years. Bacteriuria was defined as the growth of > 100,000 CFU/mL in 2 consecutive urine specimens. RESULTS: Three hundred and twenty seven girls were included. Asymptomatic bacteriuria was found in 7 girls, so the prevalence was 2.1% (95% CI, 1 to 4.4%). Escherichia coli was the isolated agent in all the cases. Focused interrogatory found history of urinary symptoms in 6 girls. The utility values of the nitrite test were: sensitivity, 1; specificity, 0.9; positive likelihood ratio, 10; and negative predictive value, 1. CONCLUSIONS: The prevalence of asymptomatic bacteriuria in preadolescent girls in this Mexican study is similar to the one reported internationally; it is reasonable to consider its early detection to avoid its effects on future pregnancies. Nitrite test seems to be good for screening.

Povidone-iodine against sodium hypochlorite as skin antiseptics in volunteers.

BACKGROUND: This study was conducted to compare the antiseptic efficacy of sodium hypochlorite of electrochemical production with that of povidone-iodine in human voluntaries. METHODS: Three areas of 25 cm(2) each were selected from the forearms; 1 was designated as control to determine the baseline bacterial count; and 2 more were selected to swab 10% povidone-iodine or 10% sodium hypochlorite. Every volunteer was studied on 3 separated occasions. Quantitative skin cultures were performed on agar plates containing a neutralizer. RESULTS: Forty-eight healthy subjects were enrolled for a total of 144 determinations for every antiseptic and control. The bacterial counts from the control areas showed a median of 1500 colony-forming units (CFU)/cm(2). For the areas treated with sodium hypochlorite, the median was 192 CFU/cm(2). For the areas treated with povidone-iodine, the median was 231 CFU/cm(2). When the colony counts for the areas treated with antiseptics were compared with those of the controls, the difference was significant (Kruskal-Wallis test (H) = 55.7, P < .001). The difference in counts between the areas treated with antiseptics was not significant (difference in z values <1960). CONCLUSION: The present study did not find differences in antiseptic action between 10% povidone iodine and 10% sodium hypochlorite.