Genome sequencing reveals underdiagnosis of primary ciliary dyskinesia in bronchiectasis

BACKGROUND

Bronchiectasis can result from infectious, genetic, immunological and allergic causes. 60-80% of cases are idiopathic, but a well-recognised genetic cause is the motile ciliopathy, primary ciliary dyskinesia (PCD). Diagnosis of PCD has management implications including addressing comorbidities, implementing genetic and fertility counselling and future access to PCD-specific treatments. Diagnostic testing can be complex; however, PCD genetic testing is moving rapidly from research into clinical diagnostics and would confirm the cause of bronchiectasis.

METHODS

This observational study used genetic data from severe bronchiectasis patients recruited to the UK 100,000 Genomes Project and patients referred for gene panel testing within a tertiary respiratory hospital. Patients referred for genetic testing due to clinical suspicion of PCD were excluded from both analyses. Data were accessed from the British Thoracic Society audit, to investigate whether motile ciliopathies are underdiagnosed in people with bronchiectasis in the UK.

RESULTS

Pathogenic or likely pathogenic variants were identified in motile ciliopathy genes in 17 (12%) out of 142 individuals by whole-genome sequencing. Similarly, in a single centre with access to pathological diagnostic facilities, 5-10% of patients received a PCD diagnosis by gene panel, often linked to normal/inconclusive nasal nitric oxide and cilia functional test results. In 4898 audited patients with bronchiectasis, <2% were tested for PCD and <1% received genetic testing.

CONCLUSIONS

PCD is underdiagnosed as a cause of bronchiectasis. Increased uptake of genetic testing may help to identify bronchiectasis due to motile ciliopathies and ensure appropriate management.

Emergent themes from a quality improvement programme for CLABSI/CAUTI prevention in ICUs amid the COVID-19 pandemic

Objectives

Healthcare-associated infection (HAI) prevention has been difficult for healthcare providers to maintain during the COVID-19 pandemic. This study summarises themes for maintaining infection prevention activities learnt from the implementation of a quality improvement (QI) programme during the pandemic.

Methods

We conducted qualitative analysis of participants’ semistructured exit interviews, self-assessments on HAI prevention activities, participant-created action plans, chat-box discussions during webinars and informal correspondence.

Setting

Intensive care units (ICUs) with elevated rates of central line-associated bloodstream infections (CLABSI) and/or catheter-associated urinary tract infections (CAUTI) participating in the Agency for Healthcare Research and Quality Safety Programme for ICUs: Preventing CLABSI and CAUTI.

Results

Forty-nine ICU teams who participated in the programme between December 2019 and April 2021 found ways to maintain activities such as daily huddles, multidisciplinary rounds, and central line and indwelling urinary catheter monitoring despite barriers, including staff turnover, a lack of time, staff fatigue and pandemic-related guidelines limiting providers’ time around patients. We use four themes to summarise the ICU teams’ adaptations that allowed them to sustain infection prevention activities: (1) Units had CLABSI and CAUTI prevention teams, policies and practices established prior to the pandemic; (2) Units were flexible in their implementation of those policies and practices; (3) Units maintained consistent buy-in for and engagement in HAI prevention activities among both leadership and care teams throughout the pandemic and (4) Units looked to learn from other units in their facility and beyond.

Conclusions

Future shocks such as the pandemic must be anticipated, and the healthcare system must be resilient to the resulting disruptions to HAI prevention activities. This study encountered four themes for successful maintenance of infection prevention activities during the current pandemic: the value of a pre-existing infection prevention infrastructure; a flexibility in approach; broad buy-in for maintaining QI programmes and the facilitation of idea-sharing.

Magseed localisation of non-palpable breast lesions: experience from a single centre

AIM

To prospectively analyse patients undergoing magnetic seed (Magseed) localisation (MSL) to evaluate the outcome, and to retrospectively compare re-excision rates for MSL with previous wire-guided localisation (WGL) to assess the hypothesis that the introduction of MSL may lead to a lower re-excision rate.

MATERIALS AND METHODS

MSL commenced at University Hospital Crosshouse in December 2017. No other changes were made to radiological or surgical practice during this time. Data were collected prospectively on all patients undergoing MSL between December 2017 and December 2019, in a single breast unit. Data were gathered retrospectively on patients who had undergone localised breast procedures between January 2016 and December 2019 for comparison of re-excision rates.

RESULTS

Two hundred and fifty-five patients underwent MSL surgery between December 2017 and December 2019. Of those, 98% (n=250) patients underwent successful MSL at the first attempt. The Magseed was identified intraoperatively in 100% patients and surgical excision was performed. The re-excision rate reduced from 18.9% in 2016/2017, to 11.6% in 2018/2019 (p=0.098).

CONCLUSION

In conclusion, Magseed localisation has proved to be a safe and effective way of localising breast lesions, with the advantage of high accuracy. The reduction in re-excision rates at University Hospital Crosshouse with the introduction of Magseed® localisation is a potential benefit, which requires further study.

Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season

We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95/150/220  GHz dataset. The Q/U maps now reach depths of 2.8, 2.8, and 8.8  μK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈600 square degrees at 95 GHz and ≈400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.009. These are the strongest constraints to date on primordial gravitational waves.

Norwich COVID-19 testing initiative pilot: evaluating the feasibility of asymptomatic testing on a university campus

Background

There is a high prevalence of COVID-19 in university-age students, who are returning to campuses. There is little evidence regarding the feasibility of universal, asymptomatic testing to help control outbreaks in this population. This study aimed to pilot mass COVID-19 testing on a university research park, to assess the feasibility and acceptability of scaling up testing to all staff and students.

Methods

This was a cross-sectional feasibility study on a university research park in the East of England. All staff and students (5625) were eligible to participate. All participants were offered four PCR swabs, which they self-administered over two weeks. Outcome measures included uptake, drop-out rate, positivity rates, participant acceptability measures, laboratory processing measures, data collection and management measures.

Results

798 (76%) of 1053 who registered provided at least one swab; 687 (86%) provided all four; 792 (99%) of 798 who submitted at least one swab had all negative results and 6 participants had one inconclusive result. There were no positive results. 458 (57%) of 798 participants responded to a post-testing survey, demonstrating a mean acceptability score of 4.51/5, with five being the most positive.

Conclusions

Repeated self-testing for COVID-19 using PCR is feasible and acceptable to a university population.

Abstract P285: Thrombectomy Treatment Times Pre-Post Early Activation of Interventional Radiology Team

Background: Reducing treatment time for ischemic stroke is crucial. In 2017, an urban Comprehensive Stroke Center (CSC) in the Pacific Northwest (PNW) initiated early activation of the interventional radiology team (Early-IR) based on first responder LAMS’ score of 4 or 5 to improve thrombectomy treatment times (door-to-arterial access times [DTAA]) for acute ischemic stroke patients. Policy efficacy has not been evaluated.

Objectives: 1) Compare DTAA times and clinical outcomes pre vs post Early-IR initiation using a multi-state stroke registry. 2) Compare DTAA times and clinical outcomes between the PNW and other CSCs in the same multi-state stroke registry.

Methods: Included ischemic stroke patients arrived via emergency medical services from 01/01/2015 to 03/30/2020 at PNW CSC and from 05/15/2017 to 03/31/2020 at five other CSCs. Mann-Whitney U test and multiple linear regression were used to compare DTAA among patients arriving Pre-Early IR vs Post-Early IR at PNW and then to compare PNW vs other CSCs during the Post-Early IR phase. Discharge disposition and ambulation were compared using Pearson’s chi-squared tests. Models were adjusted for admission NIHSS, age, gender, race, IV tPA treatment, comorbidities and medications at admission.

Results: A total of 156 PNW patients were included in the primary analysis, 32.1 % (n=50) in the Pre- and 67.9% (n=106) in the Post-Early IR groups. Bivariate analyses showed DTAA was faster Post-Early IR (131 minutes vs 92 minutes, p<.001) and remained faster after adjusting for covariates (B=-.500, p <.001). Early IR did not significantly impact discharge disposition ( p =.620) or ambulation ( p =.995) (Table 1). Comparing the PNW to five other CSCs during the Post-Early IR period showed no significant difference in DTAA or secondary outcomes (Table 1).

Conclusion: Early IR decreased thrombectomy treatment initiation times for ischemic stroke patients at the PNW CSC.

First Direct Measurement of ^{22}Mg(α,p)^{25}Al and Implications for X-Ray Burst Model-Observation Comparisons

Type-I x-ray bursts can reveal the properties of an accreting neutron star system when compared with astrophysics model calculations. However, model results are sensitive to a handful of uncertain nuclear reaction rates, such as ^{22}Mg(α,p). We report the first direct measurement of ^{22}Mg(α,p), performed with the Active Target Time Projection Chamber. The corresponding astrophysical reaction rate is orders of magnitude larger than determined from a previous indirect measurement in a broad temperature range. Our new measurement suggests a less-compact neutron star in the source GS1826-24.

New Measurement of ^{12}C+^{12}C Fusion Reaction at Astrophysical Energies

Carbon and oxygen burning reactions, in particular, ^{12}C+^{12}C fusion, are important for the understanding and interpretation of the late phases of stellar evolution as well as the ignition and nucleosynthesis in cataclysmic binary systems such as type Ia supernovae and x-ray superbursts. A new measurement of this reaction has been performed at the University of Notre Dame using particle-γ coincidence techniques with SAND (a silicon detector array) at the high-intensity 5U Pelletron accelerator. New results for ^{12}C+^{12}C fusion at low energies relevant to nuclear astrophysics are reported. They show strong disagreement with a recent measurement using the indirect Trojan Horse method. The impact on the carbon burning process under astrophysical scenarios will be discussed.

Improvements in National Code Red transfusion practice in Scotland after adoption of recommendations from the Scottish National Code Red 2015 review

AIMS

The Scottish Transfusion and Laboratory Support in Trauma Group (TLSTG) previously reviewed all National Code Red activations between June 1st 2013 and October 31st 2015, generating a number of recommendations to be adopted to optimise the transfusion support given to patients following major trauma in Scotland. A repeat National survey was undertaken for all patients for whom Code Red was activated between 1st November 2015 and 31st December 2017.

METHODS

A clinical and transfusion lead for each centre entered anonymised data onto a secure electronic database (REDCap).

RESULTS

During the study period there were 66 activations (24 South-East of Scotland, 32 West, 10 East). Mean age was 45 years and 88% were male. Mean Injury Severity Score (ISS) was 28 with 75% blunt trauma. 93% (62/66) of Code Red patients received blood components with a 300% increase in pre-hospital transfusion (48 vs 16 patients; p<0.001). Median time from 999 call to Code Red activation reduced significantly to 37 min from 70 min (p = 0.01) giving the hospital more time to prepare transfusion components. 78% patients received pre-hospital tranexamic acid (TXA; improved from 70%, p = 0.67, ns). Concentrated Red Cell (CRC): Fresh Frozen Plasma (FFP) ratio was always less than 2:1 and below 1.4:1 at 90 min, compared to 2013-15 when CRC: FFP ratios did not drop to below 2:1 until 150 min after arrival in the ED. Mean time for Full Blood Count (FBC; 46 mins versus 81; p = 0.004) and clotting (53 mins versus 119; p<0.001) result was reduced. Survival to hospital discharge was unchanged (66% versus 63%; p = 1.00 ns).

CONCLUSIONS

Code Red practice has improved in several ways since our last survey with earlier Code Red activation, more patients receiving pre-hospital transfusion and improved CRC:FFP ratios. Interventions such as earlier on scene Code Red activation, provision of pre-hospital TXA, Emergency Department (ED) resuscitation room pre-thawed FFP and point-of-care viscoelastic coagulation testing have all contributed to these improvements in transfusion practice in Scotland.

Study of 3He(n,p)3H reaction at cosmological energies with trojan horse method

In the network of reactions present in the Big Bang nucleosynthesis, the 3He(n, p)3H has an important role which impacts the final 7Li abundance. The Trojan Horse Method (THM) has been applied to the 3He(d, pt)H reaction in order to extract the astrophysical S(E)-factor of the 3He(n, p)3H in the Gamow energy range. The experiment will be described in the present work together with the first preliminary results.

Use of electronic medical records to conduct surveillance of malaria among Peace Corps volunteers

Objective

The Peace Corps’ disease surveillance for Peace Corps Volunteers (PCVs) was incorporated into an electronic medical records (EMR) system in 2015. We evaluated this EMR-based surveillance system, focusing particularly on malaria as it is deadly but preventable.

Materials and Methods

In 2016, we administered a survey to Peace Corps Medical Officers (PCMOs), who manage PCVs’ medical care, and semistructured phone interviews to headquarters staff. We assessed the structure of the surveillance system and its utility to stakeholders, evaluated surveillance case definitions for malaria, and compared clinical information in the EMR for malaria cases captured by surveillance during the first half of 2016.

Results

Of 131 PCMOs, 77 (59%) completed the survey. Of 53 respondents in malaria-endemic nations, 98% believed most PCVs contact them about possible malaria. Of 134 cases with a malaria clinical diagnosis in the EMR between January and August 2016, 58 (43% sensitivity) were reported to the surveillance system by PCMOs. The remaining cases in the surveillance system were added during data cleaning, which is time-intensive. Among the 48 malaria cases identified by surveillance between January and June 2016, positive predictive value was 67%.

Discussion

Areas for improvement include streamlining PCMO documentation, refining case definitions, and improving data quality. With such improvements, surveillance data can be used to inform epidemiological analysis, clinical care, health education, and policy.

Conclusion

The EMR is an important tool for malaria surveillance among PCVs and, with the refinements mentioned, could serve as a framework for other multinational organizations to monitor their staff.

Immune response to temperature stress in three bivalve species: Pacific oyster Crassostrea gigas, Mediterranean mussel Mytilus galloprovincialis and mud cockle Katelysia rhytiphora

Summer mortality of some bivalve species is often associated with the change of environmental temperature. This study compares the response of immunological parameters to temperature change in three marine bivalves: Pacific oyster Crassostrea gigas, Mediterranean mussel Mytilus galloprovincialis and mud cockle Katelysia rhytiphora. Each species was exposed to three temperatures, 15 °C, 20 °C and 25 °C for 14 days. The total haemocyte count (THC), phagocytosis, reactive oxygen species (ROS) and the activity of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) were used as indicators to measure the response of each species to different temperatures. The highest temperature (25 °C) significantly increased the THC and phagocysis of haemocytes in all species. The SOD and CAT activities in the haemocytes of M. galloprovincialis and K. rhytiphora rapidly increased with temperature elevation, concomitantly with the increase of ROS ions. In contrast, the increases of ROS and SOD in C. gigas only occurred from 20 °C to 25 °C, suggesting that this intertidal species is more adaptive to different temperature levels. This study indicates that the activities of antioxidant enzymes can reflect the immune response of marine bivalves to thermal stress. Intertidal species such as Pacific oysters have a greater tolerance to thermal stress than subtidal species (e.g. Mediterranean mussel) and demersal species buried in sand (e.g. cockle).

Description of complex viewing geometries of fusion tomography diagnostics by ray-tracing

Ray-tracing techniques are applied to bolometry, a diagnostic where the finite collection volume is particularly sensitive to the machine and detector configuration. A technique is presented that can handle arbitrarily complex aperture and collimator geometries, neglecting reflection effects. Sight lines from the ASDEX Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with the slit geometry. By using the full 3D machine model for the detector box and first wall, effects such as occlusion and vignetting were included in the calculation of the bolometer's étendue. Inversion matrices calculated with the ray-tracing technique were compared with the more conventional single-ray approach and shown to be naturally more constrained, requiring less regularisation. The two models were tested on a sample radiation scenario, and the common single-ray approximation is shown to be insufficient. These results are particularly relevant for the divertor where strong emission gradients may be present. The technique developed generalises well to arbitrarily complex viewing geometries and collimators, opening up a new design space for bolometer configurations that might not normally have been considered.

Seeking Sepsis in the Emergency Department- Identifying Barriers to Delivery of the Sepsis 6

The Sepsis 6 is an internationally accepted management bundle that, when initiated within one hour of identifying sepsis, can reduce morbidity and mortality. This management bundle was advocated by the Scottish Patient Safety Programme as part of its Acute Adult campaign launched in 2008 and adopted by NHS Tayside in 2012. Despite this, the Emergency Department (ED) of Ninewells Hospital, a tertiary referral centre and major teaching hospital in Scotland, was displaying poor success in the Sepsis 6.

We therefore set out to improve compliance by evaluating the application of all aspects of the NHS Tayside Sepsis 6 bundle within one hour of ED triage time, to identify what human factors may influence achieving the one hour The Sepsis 6 bundle. This allowed us to tailor a number of specific interventions including educational sessions, regular audit and personal feedback and check list Sepsis 6 sticker. These interventions promoted a steady increase in compliance from an initial rate of 51.0% to 74.3%.

The project highlighted that undifferentiated patients create a challenge in initiating the Sepsis 6. Pyrexia is a key human factor-trigger for recognising sepsis with initial nursing assessment being vital in recognition and identifying the best area (resus) of the department to manage severely septic patients. EDs need to recognise these challenges and develop educational and feedback plans for staff and utilise available resources to maximise the Sepsis 6 compliance.

Mapping and evaluation of physical activity interventions for school-aged children

OBJECTIVES

A high degree of de-regulation, organisational fragmentation and funding cuts throughout UK schools in recent years has obscured the definitive structure and effectiveness of physical activity (PA) provision offered to children. This pilot study aimed to map the current structure and context of PA provision offered to school children in Southampton, and its alignment with existing empirical evidence about the likely effectiveness of such interventions.

STUDY DESIGN

Utilising a qualitative approach, the study focused upon school-based PA provision, since this setting was conjectured to show greater diversity when compared to settings outside of school, lending itself to further interventions than non-school PA provision.

METHODS

Interventions offered across nine schools (three junior, two primary, four secondary) were investigated and mapped through semi-structured interviews. Findings were benchmarked against other cities similar to Southampton in indices of multiple deprivation status via interviews with city council workers.

RESULTS

Interviews highlighted only three formal PA specific interventions currently operating, and a hand full of informal interventions. Limited PA provision was attributed to a lack of time, money, and priority devoted towards PA within schools. Considerable disparity exists between the high prevalence of sport-oriented provision compared with the low prevalence of PA specific provision. Interviews with Portsmouth and Bristol city councils suggest that such findings may not be unique to Southampton.

CONCLUSIONS

In contrast to the extensive literature base detailing numerous PA interventions in school-aged children, our data suggest that a very small amount of such knowledge appears to translate into PA provision offered in Southampton schools. Our data highlight a significant discrepancy between sport and PA provision across schools. It is possible that the inability to successfully differentiate between sport and PA may present a further obstacle to the successful uptake of PA in the future. An extension of the PA mapping carried out, both countywide and nationally, provides a possible avenue for future research to confirm or contrast these initial insights.

Component reductions in oxygen delivery generate variable haemodynamic and stress hormone responses

BACKGROUND

In clinical practice, global oxygen delivery (DO2) is often considered as a whole; however pathological and adaptive responses after a decrease in individual constituents of the DO2 equation (cardiac output, haemoglobin, oxyhaemoglobin saturation) are likely to be diverse. We hypothesized that an equivalent decrease in DO2 after reductions in each separate component of the equation would result in different haemodynamic, tissue oxygenation, and stress hormonal responses.

METHODS

Anaesthetized, fluid-resuscitated male Wistar rats were subjected to circulatory, anaemic, or hypoxic hypoxia (by haemorrhage, isovolaemic haemodilution, and breathing a hypoxic gas mix, respectively), produced either rapidly over 5 min or graded over 30 min, to a targeted 50% decrease in global oxygen delivery. Sham-operated animals acted as controls. Measurements were made of haemodynamics, skeletal muscle tissue oxygen tension, blood gas analysis, and circulating stress hormone levels.

RESULTS

Whereas haemorrhage generated the largest decrease in cardiac output, and the greatest stress hormone response, haemodilution had the most marked effect on arterial pressure. In contrast, rapid hypoxaemia produced a minor impact on global haemodynamics yet induced the greatest decrease in regional oxygenation. A greater degree of hyperlactataemia was observed with graded insults compared with those administered rapidly.

CONCLUSIONS

Decreasing global oxygen delivery, achieved by targeted reductions in its separate components, induces varying circulatory, tissue oxygen tension, and stress hormone responses. We conclude that not all oxygen delivery is the same; this disparity should be emphasized in classical teaching and re-evaluated in patient management.

The live attenuated chimeric vaccine rWN/DEN4Δ30 is well-tolerated and immunogenic in healthy flavivirus-naïve adult volunteers

WNV has become the leading vector-borne cause of meningoencephalitis in the United States. Although the majority of WNV infections result in asymptomatic illness, approximately 20% of infections result in West Nile fever and 1% in West Nile neuroinvasive disease (WNND), which causes encephalitis, meningitis, or flaccid paralysis. The elderly are at particular risk for WNND, with more than half the cases occurring in persons older than sixty years of age. There is no licensed treatment for WNND, nor is there any licensed vaccine for humans for the prevention of WNV infection. The Laboratory of Infectious Diseases at the National Institutes of Health has developed a recombinant live attenuated WNV vaccine based on chimerization of the wild-type WNV NY99 genome with that of the live attenuated DENV-4 candidate vaccine rDEN4Δ30. The genes encoding the prM and envelope proteins of DENV-4 were replaced with those of WNV NY99 and the resultant virus was designated rWN/DEN4Δ30. The vaccine was evaluated in healthy flavivirus-naïve adult volunteers age 18-50 years in two separate studies, both of which are reported here. The first study evaluated 10³ or 10⁴ PFU of the vaccine given as a single dose; the second study evaluated 10⁵ PFU of the vaccine given as two doses 6 months apart. The vaccine was well-tolerated and immunogenic at all three doses, inducing seroconversion to WNV NY99 in 74% (10³ PFU), 75% (10⁴ PFU), and 55% (10⁵ PFU) of subjects after a single dose. A second 10⁵ PFU dose of rWN/DEN4Δ30 given 6 months after the first dose increased the seroconversion rate 89%. Based on the encouraging results from these studies, further evaluation of the candidate vaccine in adults older than 50 years of age is planned.

An update on tobacco control initiatives in comprehensive cancer control plans

Introduction

Comprehensive cancer control (CCC) coalitions address tobacco use, the leading cause of preventable death in the United States, through formal plans to guide tobacco control activities and other cancer prevention strategies. Best Practices for Comprehensive Tobacco Control Programs (Best Practices) and The Guide to Community Preventive Services(The Community Guide) are used to assist with this effort. We examined CCC plans to determine the extent to which they followed the Centers for Disease Control and Prevention’s (CDC’s) tobacco control and funding recommendations.

Methods

We obtained 69 CCC plans, current as of August 1, 2011, to determine which CDC recommendations from Best Practices and The Community Guide were incorporated. Data were abstracted through a content review and key word search and then summarized across the plans with dichotomous indicators. Additionally, we analyzed plans for inclusion of tobacco control funding goals and strategies.

Results

CCC plans incorporated a mean 4.5 (standard deviation [SD], 2.1) of 5 recommendations from Best Practices and 5.2 (SD, 0.9) of 10 recommendations from The Community Guide. Two-thirds of plans (66.7%) addressed funding for tobacco control as a strategy or action item; 47.8% of those plans (31.9% of total) defined a specific, measurable funding goal.

Conclusion

Although most CCC plans follow CDC-recommended tobacco control recommendations and funding levels, not all recommendations are addressed by every plan and certain recommendations are addressed in varying numbers of plans. Clearer prioritization of tobacco control recommendations by CDC may improve the extent to which they are followed and therefore maximize their public health benefit.