Transfusion-transmitted bacterial infection: risks, sources and interventions.
Explore the source record for details and available documents.
Clostridium Infections↗
Biomedical subjects
S Hartley
Publications and source records attributed to S Hartley.
Evaluation of the 3D BacT/ALERT automated culture system for the detection of microbial contamination of platelet concentrates.
Bacterial transmission remains the major component of morbidity and mortality associated with transfusion-transmitted infections. Platelet concentrates are the most common cause of bacterial transmission. The BacT/ALERT 3D automated blood culture system has the potential to screen platelet concentrates for the presence of bacteria. Evaluation of this system was performed by spiking day 2 apheresis platelet units with individual bacterial isolates at final concentrations of 10 and 100 colony-forming units (cfu) mL-1. Fifteen organisms were used which had been cited in platelet transmission and monitoring studies. BacT/ALERT times to detection were compared with thioglycollate broth cultures, and the performance of five types of BacT/ALERT culture bottles was evaluated. Sampling was performed immediately after the inoculation of the units, and 10 replicates were performed per organism concentration for each of the five types of BacT/ALERT bottles. The mean times for the detection of these 15 organisms by BacT/ALERT, with the exception of Propionibacterium acnes, ranged from 9.1 to 48.1 h (all 10 replicates were positive). In comparison, the time range found using thioglycollate was 12.0-32.3 h (all 10 replicates were positive). P. acnes' BacT/ALERT mean detection times ranged from 89.0 to 177.6 h compared with 75.6-86.4 h for the thioglycollate broth. BacT/ALERT, with the exception of P. acnes, which has dubious clinical significance, gave equivalent or shorter detection times when compared with the thioglycollate broth system. The BacT/ALERT system detected a range of organisms at levels of 10 and 100 cfu mL-1. This study validates the BacT/ALERT microbial detection system for screening platelets. Currently, the system is the only practically viable option available for routinely screening platelet concentrates to prevent bacterial transmission.
Aerobiosis↗
Commentary on 'community based service delivery in rehabilitation: the promise and the paradox' by Kendall, Buys and Larner.
Explore the source record for details and available documents.
Community Health Services↗
Evaluation of the BacT/Alert automated blood culture system for detecting bacteria and measuring their growth kinetics in leucodepleted and non-leucodepleted platelet concentrates.
BACKGROUND AND OBJECTIVE: To evaluate the BacT/Alert automated blood culture system for the detection of bacteria in platelet concentrates, and to determine bacterial growth kinetics in leucodepleted and non-leucodepleted units. MATERIALS AND METHODS: Apheresis (Cobe Leucocyte Reduction System [LRS]) and pooled buffy coat-derived (Optipress) platelet concentrates (PCs) were tested. Six organisms were used for spiking the PCs: Clostridium perfringens, Bacillus cereus, Group B Streptococcus, Staphylococcus epidermidis, Staphylococcus aureus and Escherichia coli. Units were inoculated to give a final concentration of approximately equal to 1 and 50 colony-forming units (CFU)/ml. On days 0, 2 and 5, BacT/Alert standard aerobic and anaerobic bottles were inoculated with a 5-ml fill volume and bacteria were enumerated. RESULTS: The BacT/Alert Automated blood culture system gave rapid determination times of spiked units, with all positives detected within 48 h and 98.1% detected within 24 h. In general, as the inoculum concentration increased, the detection time decreased. Rapid growth was obtained with all organisms tested except for B. cereus, which failed to grow on four occasions. Bacterial numbers on day 2 ranged from 10(5) to 10(11) CFU/ml and on day 5 ranged from 10(4) to 10(12) CFU/ml. Growth was not significantly greater in leucodepleted units. CONCLUSIONS: The study confirmed that PCs are an excellent growth medium for bacteria. Rapid and substantial growth was obtained with all organisms under test. Leucodepletion does not appear to enhance bacterial proliferation. The BacT/Alert automated blood culture system could rapidly detect contamination of units. Bacterial screening using an automated blood culture system is therefore a potential option.
Bacteria↗
Evaluation of donor arm disinfection techniques.
BACKGROUND AND OBJECTIVE: To validate a standardized optimal national procedure for donor arm disinfection. MATERIALS AND METHODS: A direct swabbing and plating technique was used to enumerate bacteria present on the arm pre- and postdisinfection. Twelve donor arm disinfection techniques were evaluated. RESULTS: The Medi-Flex Adapted method, consisting of a two-stage process with an initial application of isopropyl alcohol followed by tincture of iodine, produced the best arm disinfection. A percentage reduction in bacterial counts of 99.79% (logarithmic reduction of 2.67) was obtained. Postdisinfection, 70% of donors had bacterial counts of zero, and 98% had counts of 10 or less. CONCLUSION: The Medi-Flex disinfection method offers the English National Blood Service a validated, optimal 'best practice' disinfection technique and should contribute significantly to the reduction in risk of transmission of bacteria by transfusion.
2-Propanol↗
Bacterial contamination of amniotic membrane.
AIM: In the light of interest being shown in amniotic membrane grafts for use in ocular surgery, this study aims to identify the bacterial contaminants commonly found on placental membranes from both caesarean and vaginal deliveries. METHODS: Samples of placental membrane were taken following both elective caesarean and normal vaginal deliveries. Bacterial contaminants were identified. RESULTS: All samples were contaminated. A greater number of different species were recovered from the vaginal deliveries, including several which were actually or potentially pathogenic. CONCLUSION: There is a greater risk of contamination from pathogenic bacteria on placentas from vaginal deliveries. It is recommended that amnion for use in ocular surface procedures should be retrieved only from placentas following elective caesarean deliveries.
Amnion↗
Collaborative development of a new course and service in Sri Lanka.
Great Ormond Street Hospital (GOSH) has a long established service development and research programme with Sri Lankan colleagues. The Centre for International Child Health (CICH) is an academic unit with public health interests in the countries of the South. Together a group of collaborators at GOSH, CICH and in Sri Lanka worked together to plan how a cadre of health workers could be prepared to work with people with communication disabilities. This is not an uncommon aim in under-served countries and there is a small published literature about the courses which have been developed. Choices about models for training, service delivery and ensuring sustainability in emerging services for people with communication disabilities are complex. Links can be made with development work in other disciplines. The literature relating to these issues in countries such as Sri Lanka is examined.
Developing Countries↗
An exploration of the Malawian perspective on children's everyday skills: implications for assessment.
PURPOSE: The aim of this study was to consider Malawian concepts of psychosocial development in children and to draw implications for the devising of an instrument to measure everyday skills in children. METHOD: Key informant interviews, focus groups and other interviews, video tapes and observations of children were undertaken in a rural village in Malawi, with a focus on 4-5-year-olds. RESULTS: A well adapted child of this age is expected to show first of all understanding of social responsibilities, with regards respect, obedience, cooperation, ability to socialize with other children, ability to carry out 'children's chores', to know people by names but more importantly how they are related to the child. The child should also show memory skills sufficient to carry messages. Such a child is described as intelligent/clever, characteristics important for survival. CONCLUSION: There are significant implications for the justification for the development of an instrument to measure everyday skills in African communities.
Activities of Daily Living↗
The Pruitt-Inahara shunt maintains mean middle cerebral artery velocities within 10% of preoperative values during carotid endarterectomy.
OBJECTIVE: The purpose of this study was to assess the ability of the Pruitt-Inahara shunt to maintain adequate middle cerebral artery velocities during carotid endarterectomy. STUDY DESIGN: Prospectively collected data recorded during 548 carotid endarterectomies performed at a single university hospital were analyzed to look at changes in cerebral blood flow velocities at different stages during the procedure. Parallel data relating to blood pressure and end-tidal carbon dioxide were also examined. RESULTS: During the first carotid artery cross clamp, middle cerebral artery velocity fell by 42%. A total of 169 patients (31%) had velocities that fell below 15 cm/s (electrical activity in the brain becomes altered below this level). After shunt insertion, only 2% of patients had middle cerebral artery velocities less than 15 cm/s. In only one patient was the velocity less than 10 cm/s. Increased systolic or diastolic blood pressure raised flow through the shunt significantly (P =.001). When two criteria used for selective shunt use were compared, only a moderate correlation was found between absolute middle cerebral artery velocity after carotid cross clamping and percentage change in middle cerebral artery velocity relative to preclamp values. CONCLUSIONS: The Pruitt-Inahara shunt is able to maintain adequate middle cerebral artery velocity in 98% of patients undergoing carotid endarterectomy. Alterations in blood pressure can significantly affect flow through the shunt.
Blood Flow Velocity↗
The development of a protocol to manage the potential of groundwater contamination from on-site sanitation.
The provision of water supply and sanitation services to the developing and water scarce areas of South Africa is one of the goals of the Reconstruction and Development Programme. One of the principles of the South African National Sanitation Policy stipulates that sanitation systems which have unacceptable impacts on the environment cannot be considered to be an adequate form of sanitation. The greatest contamination concern with respect to ventilated improved pit toilets is in relation to groundwater resources. To this end the National Sanitation Co-ordination Office (NaSCO) and the Directorate of Geohydrology of the Department of Water Affairs and Forestry have developed "A Protocol to Manage the Potential of Groundwater Contamination from On-Site Sanitation". The aim of the protocol is to ensure that reasonable measures are taken to guard against contamination of valuable groundwater resources by inappropriately located or designed sanitation systems. The protocol focuses on dry on-site sanitation systems and provides a brief background to the current understanding of groundwater contamination by on-site sanitation systems. It also presents a procedure to be followed by those involved in implementing new, or upgrading old systems--the procedure allows the field worker to assess whether groundwater resources may be at risk of pollution. The protocol is specifically aimed at engineering and technical staff who are not groundwater specialists.
Humans↗
Comparative growth of ectomycorrhizal basidiomycetes (Hebeloma spp.) on organic and inorganic nitrogen.
In the largely organic soils in which ectomycorrhizas are commonly found, a preference for absorbing organic nitrogen over mineral forms is likely to be an advantage, especially where mineralisation rates are low. To determine rates of both independent and preferential growth of ectomycorrhizal basidiomycetes on organic and inorganic nitrogen, strains of Hebeloma were grown on nutrient agar media containing either NH4+ or glutamic acid as the sole source of nitrogen, on both single medium and split plate Petri dishes. Growth rates on the split plate Petri dishes, where the fungi had access to both nitrogen sources, were generally greater than on the single medium dishes. Growth on glutamic acid was at least equal to, and usually greater than, that on NH4+. In some cases growth on NH4+ alone appeared severely inhibited, a condition that was partially alleviated by access to glutamic acid on the split plates Petri dishes. This highlights a potential pitfall of single nitrogen source growth studies. The greater growth of most strains on glutamic acid suggests an adaptation to organic nitrogen utilisation in these strains. If this is so in soils with low mineralisation rates, direct uptake of amino acids by ectomycorrhizal plants could by-pass the bottle neck that requires mineral nitrogen to be made available for plant uptake.
Basidiomycota↗
Influence on general practitioners of teaching undergraduates: qualitative study of London general practitioner teachers.
OBJECTIVE: To examine the perceived effect of teaching clinical skills and associated teacher training programmes on general practitioners' morale and clinical practice. DESIGN: Qualitative semistructured interview study. SETTING: General practices throughout north London. SUBJECTS: 30 general practitioners who taught clinical skills were asked about the effect of teaching and teacher training on their morale, confidence in clinical and teaching skills, and clinical practice. RESULTS: The main theme was a positive effect on morale. Within teacher training this was attributed to developing peer and professional support; improved teaching skills; and revision of clinical knowledge and skills. Within teaching this was attributed to a broadening of horizons; contact with enthusiastic students; increased time with patients; improved clinical practice; improved teaching skills; and an improved image of the practice. Problems with teaching were due to external factors such as lack of time and space and anxieties about adequacy of clinical cover while teaching. CONCLUSION: Teaching clinical skills can have a positive effect on the morale of general practitioner teachers as a result of contact with students and peers, as long as logistic and funding issues are adequately dealt with.
Anxiety↗
Multidisciplinary team renal rehabilitation: interventions and outcomes.
Multidisciplinary team renal rehabilitation produces positive patient outcomes by broadening the knowledge base and evening out the work load. Rehabilitation is no longer viewed as an extra program to patient care done by a few people but seen as an integral part of the patients' care and dialysis treatment. Focusing on the 5E's of renal rehabilitation developed by the Life Options Rehabilitation Advisory Council, Renal Care Group of the Midwest, Inc has achieved positive clinical patient outcomes, such as meeting dialysis adequacy benchmark goals. Interventions and outcomes of two of the 5E's, education and exercise, are discussed.
Exercise Therapy↗
Can students learn comparable clinical skills in general practice and hospital settings?. Students are discriminating consumers of educational experience.
Explore the source record for details and available documents.
Education, Medical, Undergraduate↗
Optimal timing for collection of PBPC after glycosylated G-CSF administration.
Daily administration of granulocyte colony-stimulating Factor (G-CSF) results in progenitor cell mobilization with maximum blood levels achieved after 4-7 days. In this study the short-term effects of glycosylated G-CSF at a dose of 5 microg/kg s.c. were determined so as to allow optimization of the timing of progenitor cell collection. In the first study involving 20 normal volunteers, a significant fall in neutrophil count and G-CSF levels was observed 2 h after the G-CSF injection. To investigate this phenomenon serial measurements were made in a further six volunteers after the 6th daily injection of G-CSF. A fall in the neutrophil count occurred which was maximal at 1 h and recovered to baseline within 3 h. There was also a fall in CD34+ cells (P = 0.034), GM-CFC (P = 0.025) and BFU-E (P = 0.066) and recovery to baseline levels took 4-12 h. We conclude that glycosylated G-CSF should not be given immediately prior to stem cell collection.
Adult↗
Fatal Clostridium perfringens sepsis from a pooled platelet transfusion.
A male patient with acute myeloid leukaemia received a pooled platelet preparation prepared by Optipress system on the last day of its shelf life. The patient collapsed after two-thirds of the contents had been transfused. Clostridium perfringens was isolated from the platelet bag within 18 h of the acute event. Metronidazole, gentamicin and Clostridium antiserum were then administered in addition to the broad spectrum antibiotics started previously. However, the patient died 4 days after the platelets were transfused. The cause of death was given as cardiovascular shock, entirely compatible with an overwhelming bacteraemic and septic episode. A coroner's verdict of accidental death due to transfusion of a contaminated unit of platelets was recorded. On subsequent investigation Cl. perfringens type A serotype PS68,PS80 (identical to that found in the platelet bag) was cultured from the venepuncture site of the arm of one of the donors who contributed towards the platelet pool. The donor had two young children and frequently changed nappies. Faecal contamination of the venepuncture site was the suspected source for the transmission of Cl. perfringens, an organism commonly found in the soil and intestinal tract of humans. This case dramatically highlights the consequences of transfusing a bacterially contaminated unit. It is vital that such incidents are investigated and reported so that the extent of transfusion-associated bacterial transmission can be monitored and preventative measures taken if possible.
Acute Disease↗
Service development to meet the needs of 'people with communication disabilities' in developing countries.
PURPOSE: In spite of the catastrophic consequences of impaired communication skills on the quality of human life, development of services for people with communication disabilities have low priority in health care and rehabilitation. Nowhere is this more apparent than in developing countries. The low coverage levels of the limited services which do exist in these countries, indicate a need to develop new and innovative service structures. It is to this end, given the limited literature available, that this review looks mainly at articles of a descriptive nature based on clinical experience. The review seeks to identify ideology which could be used to under-pin alternative service delivery and structures. METHOD: Three collections of literature relevant to the topic under discussion are identified, one collection relates to impairment categories, one to disability perspectives and one to speech and language therapy provision. It is recognized that all three collections are needed to form a basis for innovative change, but this review aims to examine the latter collection only, referring the reader to items in the other collections, when relevant. RESULTS: The information reviewed is analysed for recurring themes and the results are seen to concur with many of the disability perspectives expressed in present day literature.
Communication Disorders↗
Crossover study of the haematological effects and pharmacokinetics of glycosylated and non-glycosylated G-CSF in healthy volunteers.
A cross-over study of glycosylated and non-glycosylated G-CSF was performed in 20 healthy male volunteers to compare the effects of the different forms of G-CSF, the extent of inter-individual progenitor cell mobilization and to determine whether any differences observed were related to the serum concentrations of G-CSF attained. The peak WBC achieved during 6 d of G-CSF administration at a dose of 5 microg/kg/d was significantly higher with the glycosylated than the non-glycosylated product (P = 0.02) as was the peak level of granulocyte-monocyte colony forming cells (GM-CFC) (P=0.03). The average GM-CFC count on days 5, 6 and 7 was 28% higher with the glycosylated product (P=0.003). Serum concentrations of G-CSF achieved were significantly higher with the non-glycosylated G-CSF, however, suggesting that the difference in bio-efficacy was not due to a difference in G-CSF stability. Marked inter-individual variation in progenitor mobilization was observed, but this was not related to serum G-CSF levels. The G-CSF concentrations on day 6 were approximately one third of those on day 1, with both forms of G-CSF.
Adjuvants, Immunologic↗