Multivariate analysis of determinants of bacterial contamination of whole-blood donations.

BACKGROUND AND OBJECTIVES: Introduction of bacteria into blood components at the collection stage seems to be a frequent occurrence. We therefore assessed determinants of bacterial contamination of whole-blood donations to gain insight into contamination mechanisms and direct prevention. MATERIALS AND METHODS: A cross-sectional study was carried out on donors accepted for whole-blood donation in four French blood banks. Each blood bank used its own two-stage procedure for phlebotomy site preparation. Contamination was identified by culturing two 15-ml samples (collected aseptically at the outset of donation) in a BacT/Alert 240 system. Determinants were assessed by logistic regression analysis. RESULTS: Bacterial contamination, mainly by skin flora, occurred in 76 (2.2%) out of 3385 donations. Significant determinants were as follows: the blood bank (odds ratio [OR] range = 3.0-5.6, P < 0.001); lack of repetition of scrub (OR = 2.7, P = 0.032); and donor age > 35 years (OR = 1.8, P = 0.036). CONCLUSION: Systematic scrub repetition should be implemented to reduce bacterial contamination by skin flora at the collection stage. Further research is required to clarify the role of different antiseptic agents and of donor age.

[Methodology for the development of a program for following and maintaining the competency of human resources]. / Méthodologie de développement d'un programme de suivi et maintien des compétences des ressources humaines.

The progressive introduction of a management program for the maintenance and assessment of staff competence has also focussed attention on the human factor, a major consideration in risk management and quality control. This article has examined the relevant tools and practical means of application, and proposes a methodology combining a methodical analysis of processes with the determination of the minimal knowledge required for participation in the practical and theoretical training programs that provide a means of objective evaluation. The results obtained in terms of technical, organizational and cultural impact have also been analyzed.

Efficacy of a new collection procedure for preventing bacterial contamination of whole-blood donations.

BACKGROUND: Transfusion-related bacterial contamination is a serious problem. The introduction of bacteria into donations at the collection stage seems frequent, despite well-conducted phlebotomy site preparation. Additional preventive measures are required. STUDY DESIGN AND METHODS: The aim of this study was to assess the potential efficacy of excluding the first 15 mL of blood to reduce the bacterial contamination of donations. A special device allowed the aseptic collection of two samples at the beginning of donation: S1 (first 15 mL) and S2 (next 15 mL). Bacteriologic cultures of S1 and S2 were performed by using an automated system. The procedure's efficacy was measured by the proportion of positive donations in S1 that were then negative in S2. RESULTS: S1 and/or S2 were positive in 76 (2.2%) of 3385 donations. In about three-fourths of the culture-positive donations, contamination was detected in the first 15-mL sample only. Gram-positive cocci accounted for 81 percent of species, gram-positive bacilli for 14 percent, and gram-negative bacilli for 5 percent. The new procedure would have prevented the introduction of bacteria in 55 donations, reducing to 0.6 percent the risk of contamination from the first 15 mL collected. CONCLUSION: Although the final effect on blood component bacterial contamination rates cannot be derived from the study, excluding the first 15 mL of blood may reduce the rate of bacterial contamination in donations.

Pseudomonas aeruginosa endophthalmitis caused by contamination of the internal fluid pathways of a phacoemulsifier.

PURPOSE: To report 4 cases of Pseudomonas aeruginosa endophthalmitis caused by internal contamination of the internal pathways of a phacoemulsifier. SETTING: Ophthalmology Center, Perpignan, France. METHODS: Four clinical cases of postoperative endophthalmitis occurred after phacoemulsification. An investigation was necessary to prove the cause of the bacteriological contamination. RESULTS: Serotyping and ribotyping of the Pseudomonas aeruginosa strains obtained from the vitreous samples and from the phacoemulsifier showed that all these strains were identical and that the initial site of the contamination was the phacoemulsifier. CONCLUSIONS: The profession should be cognizant of this cause of endophthalmitis, although its occurrence is rare. Cataract surgeons should test samples from the collection bags of their phacoemulsifiers to ensure there is no bacteriological contamination.

Prevalence surveys of nosocomial infections using a random sampling method in Marseille hospitals.

In 1992, we conducted two prevalence surveys on hospital-acquired infections (HAIs) in a group of eight university affiliated hospitals with a total of 4462 acute care beds. Most of the intensive care units (ICUs) already had a prospective surveillance scheme. The need for HAI rates that could be estimated easily and economically led us to develop a prevalence survey by using a stratified sampling method. The units were distributed into four groups: ICU; clean surgery; other surgery; and medical. In each group a sample of units was randomly selected using different sampling fractions. The first survey was conducted in May and involved 1220 patients. The second survey in November included 1389 patients. The HAI rates in May and November were 8.6% (95% CI 7.4-9.8%) and 7.1% (95% CI 6-8.2%), respectively. This study allowed us to direct resources towards high risk units and clean surgical procedures. Based on the results, prospective surveillance was implemented in units of the clean surgery group.

[Cleaning protocol for endoscopic instruments in gynecology]. / Protocole d'hygiène du matériel endoscopique en gynécologie.

The procedure for cleaning endoscopic material include successive step which must be applied correctly: preliminary treatment, predisinfection or cleaning, rinsing, sterilization or disinfection. If sterilization is performed, the material is stocked until its next use. If cold disinfection is performed, the material is rinsed then stocked but cold disinfection must be performed again before using the material again. Personnel who manipulate must of course wear gloves. Cold disinfection is insufficient. Material used for endoscopic gynaecological surgery should be sterilized with an autoclave since it is the only method which can prevent infection.

[Bacteriostatic and bactericidal study of rifabutine and clofazimine in combination against Mycobacterium avium-intracellulare and Mycobacterium xenopi]. / Etude bactériostatique et bactéricide de la rifabutine et de la clofazimine en association vis-à-vis de Mycobacterium avium-intracellulare et de Mycobacterium xenopi.

The authors have tested the sensibility to rifabutine and clofazimine of seventeen strains of M. avium and eleven strains of M. xenopi. They compared the ability of these and other antimicrobial agents ciprofloxacin, amikacin and erythromycin alone or in combinations to inhibit the growth of strains of the M. avium complex and of M. xenopi. The purpose of this investigation was also to examine the bactericidal action of these antimicrobial agents and to determine the ability of combinations to kill strains of M. avium and M. xenopi.

[Identification of the principal species of the genus Serratia by a simplified system]. / Identification des principales espèces du genre Serratia par une galerie simplifiée.

A reduced identification system for the genus Serratia is proposed. The usefulness of this system was shown by identification of 720 strains from clinical specimens or natural environment. Computation of "diagnosis ability coefficient" and principal component analysis made it possible to reduce this identification system to 9 tests. Numerical taxonomy displayed the 9 recognized species.

[Sensitivity of 7 mycobacterial species to new quinolones]. / Etude de la sensibilité de sept espèces de mycobactéries aux nouvelles quinolones.

The authors have tested the sensibility to three new quinolones of forty one strains of mycobacteria belonging to seven different species. They have observed, in particular, susceptibility for the species M. tuberculosis, M. fortuitum, M. kansasii, M. marinum and M. xenopi to ciprofloxacin and ofloxacin and a limited sensibility for these same species to pefloxacin. In association with others antibiotics, amikacin, erythromycin, thienamycin, trimethoprim-sulfamethoxazole, the three have shown some additive effects and in a few cases synergistic effects.

[Identification of coagulase-negative Staphylococci. Significance of miniaturized systems]. / Identification des staphylocoques à coagulase négative. Intérêt des galeries miniaturisées.

To evaluate accuracy of API Staph. and Staph. Ident. systems for identification of coagulase-negative Staphylococci, the authors have tested 235 clinical and environmental isolates. The results obtained were compared with those of conventional method of Kloos and Schleifer. API Staph. and Staph. Ident. correctly identified respectively 64 and 53 p. cent of the strains. Diagnosis ability coefficient (Descamps and Véron) are close. It should be necessary to compare identification obtained using analytical profile index with described characteristics of species.

[Value of the germ-carrier method for testing of the activity of disinfectants against mycobacteria strains]. / Intérêt de la méthode des porte-germes pour tester l'activité de désinfectants vis-à-vis de souches de mycobacteries.

We investigated bactericidal activity of four disinfectants against mycobacterium smegmatis and others mycobacteria species such as those responsible for respiratory and lymphadenitis diseases. We used the germ carried method according to all the AFNOR requisites changing only the strains culture conditions and for some studies time of contact (15 and 30 minutes). In addition we realized a preliminary essay to control efficacy of washing in order to maximally eliminate the product after the time of contact. Under AFNOR standard conditions (15 minutes) only phenolic complex and glutaraldehyde solution were bactericidal for all strains including M. tuberculosis. Another series of test with contact during 30 minutes showed that with aldehyde and quaternary ammonium compounds bactericidal activity was limited against M. fortuitum and M. chelonei and nearly non existent at usual concentrations against M. kansasii, M. avium and M. tuberculosis.

[Measure of the activity of a quaternary aldehyde-ammonia complex against reference bacteria strains and 50 hospital strains]. / Mesure de l'activité d'un complexe aldéhyde-ammoniums quaternaires vis-à-vis de souches bactériennes de référence et de cinquante souches hospitalières.

Concentrations of a disinfectant complex effective against hospital strains were determined using the dilution-neutralization method (AFNOR T72 150). Results were compared to those obtained with reference bacterial strains. A 99.999% reduction in viable bacteria requires significantly higher concentrations for hospital isolates than for reference strains.

[Antibacterial kinetics of fosfomycin (author's transl)]. / Cinétique de l'activité antibactérienne de la fosfomycine.

The authors studied, with the Autobac machine, the kinetics of antibacterial activity of fosfomycin against Staphylococcus aureus, Streptococcus D' Streptococcus pneumoniae, Neisseria meningitidis, Acinetobactor lwoffi, Haemophilus influenzae, Salmonella typhimurium, Escherichia coli, Proteus rettgeri, Klebsiella pneumoniae, Serratia marcescens and Pseudomonas aeruginosa. A correlation appears between the kinetics of fosformycin antibacterial action and the microbial growth rate.