The impact of anti-mould prophylaxis on Aspergillus PCR blood testing for the diagnosis of invasive aspergillosis.

BACKGROUND: The performance of the galactomannan enzyme immunoassay (GM-EIA) is impaired in patients receiving mould-active antifungal therapy. The impact of mould-active antifungal therapy on Aspergillus PCR testing needs to be determined. OBJECTIVES: To determine the influence of anti-mould prophylaxis (AMP) on the performance of PCR blood testing to aid the diagnosis of proven/probable invasive aspergillosis (IA). METHODS: As part of the systematic review and meta-analysis of 22 cohort studies investigating Aspergillus PCR blood testing in 2912 patients at risk of IA, subgroup analysis was performed to determine the impact of AMP on the accuracy of Aspergillus PCR. The incidence of IA was calculated in patients receiving and not receiving AMP. The impact of two different positivity thresholds (requiring either a single PCR positive test result or ≥2 consecutive PCR positive test results) on accuracy was evaluated. Meta-analytical pooling of sensitivity and specificity was performed by logistic mixed-model regression. RESULTS: In total, 1661 (57%) patients received prophylaxis. The incidence of IA was 14.2%, significantly lower in the prophylaxis group (11%-12%) compared with the non-prophylaxis group (18%-19%) (P < 0.001). The use of AMP did not affect sensitivity, but significantly decreased specificity [single PCR positive result threshold: 26% reduction (P = 0.005); ≥2 consecutive PCR positive results threshold: 12% reduction (P = 0.019)]. CONCLUSIONS: Contrary to its influence on GM-EIA, AMP significantly decreases Aspergillus PCR specificity, without affecting sensitivity, possibly as a consequence of AMP limiting the clinical progression of IA and/or leading to false-negative GM-EIA results, preventing the classification of probable IA using the EORTC/MSGERC definitions.

Design of dental surgeries in relation to instrument decontamination.

Recent guidelines advise that the decontamination of dental instruments should be undertaken outwith the treatment area. The aim of this study was to determine the physical area of rooms in dental surgeries that decontaminate instruments within and outwith the treatment area respectively, and other factors relating to practice layout and ventilation. Data were collected by interview and observation of dental healthcare workers in dental practice in Scotland, UK. Room layouts were recorded and measured at floor, benchtop and above benchtop heights. Thirteen surgeries with instrument decontamination processes occurring in the treatment area and seven surgeries with instrument decontamination outwith the treatment area were selected at random for detailed analysis of room dimensions. Of the 179 dental surgeries surveyed, 55% were located in converted residential premises and most practitioners (91%) did not share premises with other healthcare providers. The median number of rooms in the practices was 8 (range: 2-21) and the median number of surgeries present was 3 (range: 1-6). Regardless of whether instrument decontamination facilities were housed within the treatment area or not, the average treatment area room size for both was 15.8m(2) (range: 7.3-23.9) (P=0.862), with 20% of the room area available as work surfaces. The median size of the seven instrument decontamination rooms (local decontamination units) was 7.6m(2) (range: 2.9-16.0), with, on average, 63% of the room used for work surfaces. This survey suggests that the historical location of dental surgeries in converted residential properties places many restrictions on appropriate design for healthcare premises.

An evaluation of a pilot study of a web-based educational initiative for educating and training undergraduate dental students in infection prevention.

OBJECTIVE: Evaluate the views of undergraduate dental students on a pilot web-based e-learning programme to establish its merit in providing education in infection prevention and control. The initiative was commissioned by NHS Education for Scotland as an educational resource for healthcare workers. Design, SAMPLE AND SETTING: This was a retrospective analysis of questionnaire data from the first cohort of dental students completing the programme in a UK dental school. METHODS: Dental students studied the course during the first three years of the curriculum. Data were collated via an anonymous semi-structured questionnaire distributed at a post-course feedback session. RESULTS: Sixty percent (51/85) of students returned questionnaires with 90% stating their knowledge of infection control had improved. Specific areas included: undertaking infection control audits (88%), managing sharps injuries (73%), use of personal protective equipment (55%) and hand hygiene (55%). On the other hand, 72% perceived the programme as too generic with just over half advocating a resource more relevant to dentistry. CONCLUSION: The programme has the potential to be a useful teaching aid but requires modification. A customised version for dental students has subsequently been commissioned.

Evaluation of a course on the operation and management of a local decontamination unit for undergraduate dental students.

OBJECTIVE: Describe the formulation of learning outcomes and evaluate a new course for undergraduate dental students in managing a local decontamination unit (LDU). DESIGN, SAMPLE AND SETTING: This was a retrospective analysis of questionnaire data from the first cohort of dental students completing the LDU managers course in a UK dental school. METHODS: All final year dental students were invited to complete a course evaluation. Data were collated via an anonymous semi-structured questionnaire distributed at a post-course session. RESULTS: A response rate of 95% was achieved. The majority (89%) improved their knowledge of decontamination and felt that the course material was relevant (81%) to their future role as a dental practitioner. Students stated that the practical elements of the course provided a valuable educational experience, while tutorials on health and safety and quality management systems proved less popular. The use of an e-learning programme to support the lectures and practical sessions was also useful in achieving the learning outcomes. The one-week intensive course proved challenging for both students and staff. We identified short comings both locally and nationally in the availability of appropriately trained staff to teach this core topic. CONCLUSION: We describe a series of learning outcomes to support competencies in instrument decontamination for dental undergraduates and a purpose built training facility. The evaluation of the course suggests this model meets current and future General Dental Council (GDC) requirements for training of dental undergraduates. We identified a shortage of appropriately qualified teachers in this subject area and recommend that these deficiencies are addressed as part of a coordinated national strategy.

A review of dental implants and infection.

Dental implants have become increasingly common for the management of tooth loss. Despite their placement in a contaminated surgical field, success rates are relatively high. This article reviews dental implants and highlights factors leading to infection and potential implant failure. A literature search identified studies analysing the microbial composition of peri-implant infections. The microflora of dental peri-implantitis resembles that found in chronic periodontitis, featuring predominantly anaerobic Gram-negative bacilli, in particular Porphyromonas gingivalis and Prevotella intermedia, anaerobic Gram-negative cocci such as Veillonella spp. and spirochaetes including Treponema denticola. The role of Staphylococcus aureus and coagulase-negative staphylococci that are typically encountered in orthopaedic infections is debatable, although they undoubtedly play a role when isolated from clinically infected sites. Likewise, the aetiological involvement of coliforms and Candida spp. requires further longitudinal studies. Currently, there are neither standardised antibiotic prophylactic regimens for dental implant placement nor universally accepted treatment for peri-implantitis. The treatment of infected implants is difficult and usually requires removal. In the UK there is no systematic post-surgical implant surveillance programme. Therefore, the development of such a project would be advisable and provide valuable epidemiological data.