Compliance with a protocol for intrapartum antibiotic prophylaxis against neonatal group B streptococcal sepsis in women with clinical risk factors.

OBJECTIVE: The aim of this study was to determine the prevalence of clinical risk factors (CRF) for neonatal sepsis in laboring women and to evaluate clinician compliance with a CRF-based protocol for intrapartum antibiotic prophylaxis (IAP). METHODS: A retrospective chart audit was undertaken at a district hospital (A) and a tertiary obstetric hospital (B) in Sydney, Australia between 1996 and 1998, to determine compliance with IAP in women with defined CRF. RESULTS: Eighty-five (12%) women at Hospital A and 117 (19%) at Hospital B had one or more CRF. Overall compliance rates with the IAP protocols were 65 and 50% at Hospitals A and B respectively, but varied according to maternal, obstetric and sepsis-related risk factors. We postulate that differences between the hospitals were related to protocol implementation. CONCLUSIONS: Compliance with a CRF-based protocol was lower than previously reported. Improvements in protocol development, implementation and maintenance are required to enhance compliance with IAP based on CRF

Investigating genome reduction of Bordetella pertussis using a multiplex PCR-based reverse line blot assay (mPCR/RLB)

BACKGROUND: The genetic composition of the bacterium causing whooping cough, Bordetella pertussis, has been investigated using microarray studies in order to examine potential genetic contributors to the disease re-emergence in the past decade. Regions of difference (RDs) have been previously identified as clusters of genes flanked by insertion sequences which are variably present in different sets of isolates, and have also been shown to be potential markers of B. pertussis evolution. This study used microarray data to identify and select a panel of RDs; primers and probes for these RDs were then designed to test for the presence or absence of these regions in a novel and less expensive multiplex PCR-based reverse line blot (mPCR/RLB) assay. By comparing the presence or absence of RDs, we aimed to determine the genomic variability of a diverse collection of B. pertussis strains and how they have changed over time. RESULTS: A B. pertussis specific mPCR/RLB using 43 genes representing 30 RDs, was developed and used to characterise a set of 42 B. pertussis isolates. When mapped against the previously identified evolutionary relationships of the strains, the losses of two RDs - BP0910A - BP00930 and BP1948-BP1962 - were found to be associated with significant events in B. pertussis history: the loss of BP0910A - BP00930 coincided with introduction of whole cell vaccines in the 1950s while that of BP1948-BP1962 occurred after the introduction of acellular vaccines. The loss of BP1948-BP1962 also coincided with expansion of the most recent B. pertussis strains. CONCLUSIONS: The mPCR/RLB assay offers an inexpensive and fast method of determining the gene content of B. pertussis strains and also confirms that gene losses are an ongoing feature of B. pertussis evolution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1756-0500-7-727) contains supplementary material, which is available to authorized users

Compliance With Protocols for Prevention of Neonatal Group B Streptococcal Sepsis: Practicalities and Limitations

Objective: To compare two protocols for intrapartum antibiotic prophylaxis (IAP) against neonatal group B streptococcal (GBS) sepsis, with respect to staff compliance, in a prospective cohort study in the obstetric units of a community hospital (A) and a university teaching hospital (B). Methods: Cohorts comprised about 500 women attending antenatal clinics at each hospital (total 1096). Women identified as GBS carriers at 26–32 weeks'gestation and those who had intrapartum clinical risk factors (CRF) were eligible for IAP. Compliance was defined as the proportion of women eligible for IAP who received it according to protocol–as determined by audit of case records–and compared between hospitals and according to indication. Results: Overall, 39% of women were eligible for IAP. Indications were GBS carriage alone (21%), CRF alone (13% ) and both (5% ). Compliance was similar for GBS carriers at both hospitals: 78% at Hospital A and 76% at Hospital B. However, because of the poor predictive value of screening before 32 weeks, only 65%of intrapartum GBS carriers actually received IAP. For women with CRF only, compliance was significantly lower at Hospital B than Hospital A (56 vs. 75%; p= 0.03). Conclusions: According to currently recommended protocols, about one-third of healthy women are eligible for intrapartum antibiotics to prevent neonatal GBS sepsis. In practice, antibiotics are often used inefficiently because of poor compliance with protocols and poor predictive values of selection criteria. Better implementation strategies should improve compliance, but GBS vaccines are needed to replace prophylactic antibiotic use, with its associated disadvantages

Multiplex PCR and Reverse Line Blot Hybridization Assay (mPCR/RLB)

Multiplex PCR/Reverse Line Blot Hybridization assay allows the detection of up to 43 molecular targets in 43 samples using one multiplex PCR reaction followed by probe hybridization on a nylon membrane, which is re-usable. Probes are 5' amine modified to allow fixation to the membrane. Primers are 5' biotin modified which allows detection of hybridized PCR products using streptavidin-peroxidase and a chemiluminescent substrate via photosensitive film. With low setup and consumable costs, this technique is inexpensive (approximately US$2 per sample), high throughput (multiple membranes can be processed simultaneously) and has a short turnaround time (approximately 10 hours)

Assignment of Streptococcus agalactiae isolates to clonal complexes using a small set of single nucleotide polymorphisms

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus agalactiae </it>(Group B Streptococcus (GBS)) is an important human pathogen, particularly of newborns. Emerging evidence for a relationship between genotype and virulence has accentuated the need for efficient and well-defined typing methods. The objective of this study was to develop a single nucleotide polymorphism (SNP) based method for assigning GBS isolates to multilocus sequence typing (MLST)-defined clonal complexes.</p> <p>Results</p> <p>It was found that a SNP set derived from the MLST database on the basis of maximisation of Simpsons Index of Diversity provided poor resolution and did not define groups concordant with the population structure as defined by eBURST analysis of the MLST database. This was interpreted as being a consequence of low diversity and high frequency horizontal gene transfer. Accordingly, a different approach to SNP identification was developed. This entailed use of the "Not-N" bioinformatic algorithm that identifies SNPs diagnostic for groups of known sequence variants, together with an empirical process of SNP testing. This yielded a four member SNP set that divides GBS into 10 groups that are concordant with the population structure. A fifth SNP was identified that increased the sensitivity for the clinically significant clonal complex 17 to 100%. Kinetic PCR methods for the interrogation of these SNPs were developed, and used to genotype 116 well characterized isolates.</p> <p>Conclusion</p> <p>A five SNP method for dividing GBS into biologically valid groups has been developed. These SNPs are ideal for high throughput surveillance activities, and combining with more rapidly evolving loci when additional resolution is required.</p

Should I stay or should I go? Patient understandings of and responses to source-isolation practices

Isolation of patients, who are colonised or infected with a multidrug-resistant organism (source-isolation), is a common practice in most acute health-care settings, to prevent transmission to other patients. Efforts to improve the efficacy of source-isolation in hospitals focus on healthcare staff compliance with isolation precautions. In this article we examine patients’ awareness, understandings and observance of source-isolation practices and directives with a view to understanding better the roles patients play or could play in transmitting, or limiting transmission, of multidrug-resistant organisms (MRO). Seventeen source-isolated adult surgical patients and two relatives participated in video-reflexive ethnography and interviews. We learned that, although most of these patients wanted to protect themselves and others from colonisation/infection with a MRO, they had a limited understanding of what precautions they could take while in isolation and found it difficult to obtain ongoing information. Thus, many patients regularly left their source-isolation rooms without taking appropriate precautions and were potentially contributing to environmental contamination and transmission. Some patients also interacted with other patients and their personal belongings in ways that exposed other patients, unnecessarily, to colonisation/infection risk. By not providing patients with adequate information on infection risk or how they could contribute to their own safety or that of others, they are denied the opportunity to fully engage in their healthcare. To improve the efficacy of source-isolation and contact precautions in general, patient care providers should consider colonised or infected patients as active partners in reducing transmission and involve patients and relatives in regular, ongoing conversations about transmission prevention

Community perspectives on the benefits and risks of technologically enhanced communicable disease surveillance systems: A report on four community juries

Background Outbreaks of infectious disease cause serious and costly health and social problems. Two new technologies – pathogen whole genome sequencing (WGS) and Big Data analytics – promise to improve our capacity to detect and control outbreaks earlier, saving lives and resources. However, routinely using these technologies to capture more detailed and specific personal information could be perceived as intrusive and a threat to privacy. Method Four community juries were convened in two demographically different Sydney municipalities and two regional cities in New South Wales, Australia (western Sydney, Wollongong, Tamworth, eastern Sydney) to elicit the views of well-informed community members on the acceptability and legitimacy of: making pathogen WGS and linked administrative data available for public health research using this information in concert with data linkage and machine learning to enhance communicable disease surveillance systems Fifty participants of diverse backgrounds, mixed genders and ages were recruited by random-digit-dialling and topic-blinded social-media advertising. Each jury was presented with balanced factual evidence supporting different expert perspectives on the potential benefits and costs of technologically enhanced public health research and communicable disease surveillance and given the opportunity to question experts. Results Almost all jurors supported data linkage and WGS on routinely collected patient isolates for the purposes of public health research, provided standard de-identification practices were applied. However, allowing this information to be operationalised as a syndromic surveillance system was highly contentious with three juries voting in favour, and one against by narrow margins. For those in favour, support depended on several conditions related to system oversight and security being met. Those against were concerned about loss of privacy and did not trust Australian governments to run secure and effective systems. Conclusions Participants across all four events strongly supported the introduction of data linkage and pathogenomics to public health research under current research governance structures. Combining pathogen WGS with event-based data surveillance systems, however, is likely to be controversial because of a lack of public trust, even when the potential public health benefits are clear. Any suggestion of private sector involvement or commercialisation of WGS or surveillance data was unanimously rejected

Mandatory influenza immunisation of health-care workers

Seasonal influenza imposes an enormous but poorly defined burden of excess deaths, hospital admissions, and health-care costs, and often spreads within health-care facilities. Hospital patients with influenza are a potential source of infection for health-care workers that are not immunised, with attack rates among health-care workers of 18–24%.1 Unfortunately, health-care workers infected with influenza often continue to work, despite symptoms, with potentially devastating consequences for high-risk patients, including those who are very young, elderly, or immunocompromised—for example, patients receiving bone-marrow transplants have a high risk of pneumonia and death from influenza.2 Trivalent subunit influenza vaccines are 70–90% effective3 and safe, with mild side-effects in less than 10% of recipients.4 Immunisation of health-care workers can reduce exposure to, and illness and death from, influenza among patients in long-term care facilities5 even with modest uptake rates6 (at an estimated cost of £51–405 per life-year saved), as well as reducing infection and absenteeism among health-care workers that have been immunised (with estimated savings of £12 per vaccinee).5 In a bone-marrow-transplant unit in the USA, increasing immunisation uptake from 12% to 58% among health-care workers, was associated with a reduction in nosocomial influenza infections from 14 to 4 cases per 10 000 patients days.7 Despite this evidence and recommendations by major health authorities for yearly immunisation of health-care workers,8 uptake is often poor (less than 30%). Immunisation uptake rarely exceeds 60%, even when vaccine is free and easily accessible,5 and 9 which is inadequate to protect the most vulnerable patients, many of whom are unimmunised because of immunosuppression or comorbidities. Uptake can be increased by various interventions, including staff education, active promotion, incentives, declination forms, clinical leadership, and provision of free vaccine at convenient locations, such as mobile carts,8 and 10 but increases are often modest and difficult to sustain over successive season