Multiplex Lateral Flow Assay and the Sample Preparation Method for the Simultaneous Detection of Three Marine Toxins.

A multiplex lateral flow immunoassay (LFA) has been developed to detect the primary marine biotoxin groups: amnesic shellfish poisoning toxins, paralytic shellfish poisoning toxins, and diarrhetic shellfish poisoning toxins. The performance characteristics of the multiplex LFA were evaluated for its suitability as a screening method for the detection of toxins in shellfish. The marine toxin-specific antibodies were class-specific, and there was no cross-reactivity between the three toxin groups. The test is capable of detecting all three marine toxin groups, with working ranges of 0.2-1.5, 2.5-65.0, and 8.2-140.3 ng/mL for okadaic acid, saxitoxin, and domoic acid, respectively. This allows the multiplex LFA to detect all three toxin groups at the EU regulatory limits, with a single sample extraction method and dilution volume. No matrix effects were observed on the performance of the LFA with mussel samples spiked with toxins. The developed LFA uses a simple and pocket-sized, portable Cube Reader to provide an accurate result. We also evaluated the use of this Cube Reader with commercially available monoplex lateral flow assays for marine toxins.

High-Throughput Time-Lapse Fluorescence Microscopy Screening for Heterogeneously Expressed Genes in Bacillus subtilis.

Elucidating phenotypic heterogeneity in clonal bacterial populations is important for both the fundamental understanding of bacterial behavior and the synthetic engineering of bacteria in biotechnology. In this study, we present and validate a high-throughput and high-resolution time-lapse fluorescence microscopy-based strategy to easily and systematically screen for heterogeneously expressed genes in the Bacillus subtilis model bacterium. This screen allows detection of expression patterns at high spatial and temporal resolution, which often escape detection by other approaches, and can readily be extrapolated to other bacteria. A proof-of-concept screening in B. subtilis revealed both recognized and yet unrecognized heterogeneously expressed genes, thereby validating the approach. IMPORTANCE Differential gene expression among isogenic siblings often leads to phenotypic heterogeneity and the emergence of complex social behavior and functional capacities within clonal bacterial populations. Despite the importance of such features for both the fundamental understanding and synthetic engineering of bacterial behavior, approaches to systematically map such population heterogeneity are scarce. In this context, we have elaborated a new time-lapse fluorescence microscopy-based strategy to easily and systematically screen for such heterogeneously expressed genes in bacteria with high resolution and throughput. A proof-of-concept screening in the Bacillus subtilis model bacterium revealed both recognized and yet unrecognized heterogeneously expressed genes, thereby validating our approach.

Centralized Reminder/Recall to Increase Immunization Rates in Young Children: How Much Bang for the Buck?

OBJECTIVE: We compared the effectiveness and cost-effectiveness of: 1) centralized reminder/recall (C-R/R) using the Colorado Immunization Information System (CIIS) versus practice-based reminder/recall (PB-R/R) approaches to increase immunization rates; 2) different levels of C-R/R intensity; and 3) C-R/R with versus without the name of the child's provider. METHODS: We conducted 3 sequential cluster-randomized trials involving children aged 19 to 25 months in 15 Colorado counties in March 2013 (trial 1), October 2013 (trial 2), and May 2014 (trial 3). In C-R/R counties, the intensity of the intervention decreased sequentially in trials 1 through 3, from 3 to 1 recall messages. In PB-R/R counties, practices were offered training using CIIS and financial support. The percentage of children with up-to-date (UTD) vaccinations was compared 6 months after recall. A mixed-effects model assessed the association between C-R/R versus PB-R/R and UTD rates. RESULTS: C-R/R was more effective in trials 1 to 3 (relative risk = 1.11; 95% confidence interval 1.01-1.20; P = .009). Effectiveness did not decrease with decreasing intervention intensity (P = .59). Costs decreased with decreasing intensity in the C-R/R arm, from $18.72 per child brought UTD in trial 1 to $10.11 in trial 3. Costs were higher and more variable in the PB-R/R arm, ranging from $20.63 to $237.81 per child brought UTD. C-R/R was significantly more effective if the child's practice name was included (P < .0001). CONCLUSIONS: C-R/R was more effective and cost-effective than PB-R/R for increasing UTD rates in young children and was most effective if messages included the child's provider name. Three reminders were not more effective than one, which may be explained by the increasing accuracy of contact information in CIIS over the course of the trials.

Collaborative centralized reminder/recall notification to increase immunization rates among young children: a comparative effectiveness trial.

IMPORTANCE: Reminder/recall notifications used by primary care practices increase the rates of childhood immunizations, but fewer than 20% of primary care practitioners nationally deliver such reminders. A reminder/recall notification conducted centrally by health departments in collaboration with primary care practices may reduce practice burden, reach children without a primary care practitioner, and decrease the cost of reminders/recalls. OBJECTIVE: To assess the effectiveness and cost-effectiveness of collaborative centralized (CC) vs practice-based (PB) reminder/recall approaches using the Colorado Immunization Information System (CIIS). DESIGN, SETTING, AND PARTICIPANTS: We performed a randomized pragmatic trial from September 7, 2012, through March 17, 2013, including 18,235 children aged 19 to 35 months in 15 Colorado counties. INTERVENTIONS: In CC counties, children who needed at least 1 immunization were sent as many as 4 reminders/recalls by mail or autodialed telephone calls by the CIIS. Primary care practices in these counties were given the option of endorsing the reminder/recall notification by adding the practice name to the message. In PB counties, primary care practices were invited to web-based reminder/recall training and offered financial support for sending notifications. MAIN OUTCOMES AND MEASURES: Documentation of any new immunization within 6 months constituted the primary outcome; achieving up-to-date (UTD) immunization status was secondary. We assessed the cost and cost-effectiveness of each approach and used a generalized linear mixed-effects model to assess the effect of the intervention on outcomes. RESULTS: In PB counties, 24 of 308 primary care practices (7.8%) attended reminder/recall training and 2 primary care practices (0.6%) endorsed reminder/recall notifications. Within CC counties, 129 of 229 practices (56.3%) endorsed the reminder/recall letter. Documentation rates for at least 1 immunization were 26.9% for CC vs 21.7% for PB counties (P < .001); 12.8% vs 9.3% of patients, respectively, achieved UTD status (P < .001). The effect of CC counties on children's UTD status was greater when the reminder/recall notification was endorsed by the primary care practice (19.2% vs 9.8%; P < .001). The total cost of the CC reminder/recall was $28 620 or $11.75 per child for any new immunization and $24.72 per child achieving UTD status; the total cost to the 2 practices that conducted PB reminders/recalls was $74.00 per child for any immunization and $124.45 per child achieving UTD status. The modeling resulted in an adjusted odds ratio of 1.31 (95% CI, 1.16-1.48) for any new immunization in CC vs PB counties. CONCLUSIONS AND RELEVANCE: A CC reminder/recall notification was more effective and more cost-effective than a PB system, although the effect size was modest. Endorsement by practices may further increase the effectiveness of CC reminder/recall. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01557621.

Population-based versus practice-based recall for childhood immunizations: a randomized controlled comparative effectiveness trial.

OBJECTIVES: We compared the effectiveness and cost-effectiveness of population-based recall (Pop-recall) versus practice-based recall (PCP-recall) at increasing immunizations among preschool children. METHODS: This cluster-randomized trial involved children aged 19 to 35 months needing immunizations in 8 rural and 6 urban Colorado counties. In Pop-recall counties, recall was conducted centrally using the Colorado Immunization Information System (CIIS). In PCP-recall counties, practices were invited to attend webinar training using CIIS and offered financial support for mailings. The percentage of up-to-date (UTD) and vaccine documentation were compared 6 months after recall. A mixed-effects model assessed the association between intervention and whether a child became UTD. RESULTS: Ten of 195 practices (5%) implemented recall in PCP-recall counties. Among children needing immunizations, 18.7% became UTD in Pop-recall versus 12.8% in PCP-recall counties (P < .001); 31.8% had documented receipt of 1 or more vaccines in Pop-recall versus 22.6% in PCP-recall counties (P < .001). Relative risk estimates from multivariable modeling were 1.23 (95% confidence interval [CI] = 1.10, 1.37) for becoming UTD and 1.26 (95% CI = 1.15, 1.38) for receipt of any vaccine. Costs for Pop-recall versus PCP-recall were $215 versus $1981 per practice and $17 versus $62 per child brought UTD. CONCLUSIONS: Population-based recall conducted centrally was more effective and cost-effective at increasing immunization rates in preschool children.