The role of epidemiology in informing United States childhood immunization policy and practice.

One of the ten greatest public health achievements is childhood vaccination because of its impact on controlling and eliminating vaccine-preventable diseases (VPDs). Evidence-based immunization policies and practices are responsible for this success and are supported by epidemiology that has generated scientific evidence for informing policy and practice. The purpose of this report is to highlight the role of epidemiology in the development of immunization policy and successful intervention in public health practice that has resulted in a measurable public health impact: the control and elimination of VPDs in the United States. Examples in which epidemiology informed immunization policy were collected from a literature review and consultation with experts who have been working in this field for the past 30 years. Epidemiologic examples (e.g., thimerosal-containing vaccines and the alleged association between the measles, mumps, and rubella (MMR) vaccine and autism) are presented to describe challenges that epidemiologists have addressed. Finally, we describe ongoing challenges to the nation's ability to sustain high vaccination coverage, particularly with concerns about vaccine safety and effectiveness, increasing use of religious and philosophical belief exemptions to vaccination, and vaccine hesitancy. Learning from past and current experiences may help epidemiologists anticipate and address current and future challenges to respond to emerging infectious diseases, such as COVID-19, with new vaccines and enhance the public health impact of immunization programs for years to come.

The influence of orthosis options on walking parameters in spinal cord-injured patients: a literature review.

OBJECTIVE: Orthoses for various joints sections are considered to greatly influence the gait function and energy expenditure in spinal cord-injured (SCI) patients. The aim of this review was to determine the influence of orthoses characteristics and options on the improvement of walking in patients with SCI. METHODS: A search was performed using the Population Intervention Comparison Outcome (PICO) method, based on selected keywords; studies were identified electronically in the Science Direct, Google Scholar, Scopus, Web of Knowledge and PubMed databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was used to report the results. Assessment of the quality of all articles was performed based on the Physiotherapy Evidence Database (PEDro scale). RESULTS: Twelve studies evaluated the effects of different hip joint options on walking parameters and energy expenditure. Five studies investigated the role of knee joint options on gait parameters and compensatory trunk motion. Only five studies analyzed modified ankle joints on gait parameters in SCI patients. Nine studies analyzed gait parameters in SCI patients as powered orthoses and exoskeleton. These studies had a low level of evidence according to the PEDro score (2/10). CONCLUSION: The various joint types of orthoses appear to be critical in the improvement of walking in patients with SCI. In particular, 'user friendly' orthoses that support the related structure such as the hip joint with a reciprocating mechanism, activated knee joint and movable ankle joint with dorsiflexion assist enable SCI patients to optimize their walking pattern when wearing an orthoses system.

The influence of orthotic gait training with an isocentric reciprocating gait orthosis on the walking ability of paraplegic patients: a pilot study.

OBJECTIVES: The aim of this study was to evaluate the influence of walking with an isocentric reciprocating gait orthosis (IRGO) by spinal cord injury (SCI) patients on walking speed, distance walked and energy consumption whilst participating in a 12-week gait re-training program. METHODS: Six people with motor complete SCI (mean age 29 years, weight 63 kg and height 160 cm with injury levels ranging from T8 to T12) participated in this study. Gait evaluation was performed at baseline and after 4, 8 and 12 weeks. Walking speed and heart rate were measured to calculate the resulting physiological cost index (PCI). RESULTS: Reductions in energy consumption were observed after 4, 8 and 12 weeks compared with baseline but were not significant. However, walking distance increased significantly (P=0.010, P=0.003 and P=0.005, respectively) and also did so during the 8-12-week period (P=0.013). Walking speed also improved, but not significantly. CONCLUSION: Intensive gait training with the IRGO improved walking speed and the distance walked by paraplegics, as well as reducing the PCI of walking, as compared with baseline during the whole 12-week period. This indicates that further improvements in these parameters may be expected when utilizing gait training longer than 8 weeks.

The influence of new reciprocating link medial linkage orthosis on walking and independence in a spinal cord injury patient.

OBJECTIVES: The purpose of this paper is to describe the development and evaluation of a new medial linkage reciprocating gait orthosis (MLRGO) that incorporates a reciprocal mechanism and is sensitive to pelvic motion to potentially assist paraplegic patients to walk and provide functional independence. CASE DESCRIPTION AND METHODS: The new orthosis was constructed and tested by a 20-year-old female paraplegic subject with transverse myelitis at T10 level, who was 4 years post injury and had also been an isocentric reciprocating gait orthosis (IRGO) user for 2 years. She received gait training for 12 weeks before undertaking gait analysis, and also completed a questionnaire that was designed to assess the perceived functionality of the new MLRGO when compared with an IRGO. RESULTS: The results demonstrated improvements in gait velocity, step length and cadence, and also improvement in functional independence with the new orthosis compared with an IRGO. CONCLUSION: The results demonstrated that this new MLRGO could be used for paraplegic patients who would like an improvement in functional independence and ambulation.

The efficiency of orthotic interventions on energy consumption in paraplegic patients: a literature review.

Study design:This is a systematic literature review.Objectives:Different types of orthoses have been developed to enable and facilitate ambulation in individuals with paraplegia. However, their effect on energy consumption while ambulating is not clear. The objective of this review was to compare the energy expenditure required to walk with these devices.Methods:Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method, and based on selected keywords and their composition according to the Population Intervention Comparison Outcome (PICO) method, a search was performed in Science Direct, Google Scholar, Scopus, Web of Knowledge and PubMed databases. The searches were restricted to papers published in the English language and were conducted during February 2014; the last access to the database was on 25 February 2014. A total of 24 articles were chosen for final evaluation.Results:Hybrid orthoses reduce energy consumption compared with mechanical orthoses when used for walking by paraplegic patients. The isocentric reciprocating gait orthosis has been shown to be more effective than other reciprocating orthoses in reducing energy consumption. Energy consumption when walking with powered orthoses (PO) and hybrid orthoses was also reduced compared with when walking with conventional orthoses.Conclusions:The hybrid orthoses and PO could be effective alternatives in rehabilitation for spinal cord injury patients to help improve the energy consumption.Spinal Cord advance online publication, 20 January 2015; doi:10.1038/sc.2014.227.

Design and analysis of a new medial reciprocal linkage using a lower limb paralysis simulator.

STUDY DESIGN: A feasibility study on the effect of a new reciprocating orthosis on specific gait parameters for use by people with spinal cord injury. OBJECTIVES: The aim of this study was to design and develop a new medial linkage orthosis (MLO) mechanism incorporating a reciprocating motion and to determine its efficacy in improving specific spatiotemporal, kinematic and kinetic parameters while ambulating when worn by healthy subjects. This was achieved via the use of a lower limb paralysis simulator (LLPS). METHODS: A reciprocating joint with a remote center of motion was designed for use as an MLO. A prototype was fabricated and incorporated into an orthosis and equipped with a saddle to make the reciprocating motion possible. The efficacy of the orthosis was evaluated on four able-bodied healthy subjects who were trained to walk with the MLO attached to the LLPS. RESULTS: Mean walking speed, stride length, stride time and cadence was 0.09±0.007 m s(-1), 0.42±0.01 m, 4.89±0.45 s and 29.54±4.32 steps min(-1), respectively, when healthy subjects walked with the new orthosis. The mean hip joint torque produced was 0.36±0.13 Nm. CONCLUSION: In this study a new MLO was designed and fabricated that provided a reciprocating mechanism using a four-bar mechanism to set the virtual axis of the mechanism in a more proximal position than hinge-type joints. Further investigation is currently underway to assess its effect on gait parameters and energy expenditure in paraplegic patients.

Comparison of new medial linkage reciprocating gait orthosis and isocentric reciprocating gait orthosis on energy consumption in paraplegic patients: a case series.

OBJECTIVES: As energy consumption during orthotics walking has main role in rehabilitation of walking in individuals with spinal cord injury (SCI), the aim of this study was comparison between new medial linkage orthosis (new MLO) and isocentric reciprocating gait orthosis (IRGO) on energy consumption in paraplegic patients. METHODS: Four people with motor incomplete SCI (mean age 34.5 years, mass 73 kg and height 175 cm with injury levels ranging from T8-T12) participated in this study. Gait evaluation was performed using new MLO compared with using conventional IRGO. Walking speed and heart rate were measured to calculate the physiological cost index (PCI) to estimate metabolic energy consumption. RESULTS: Reductions in energy consumption were observed using new MLO compared with using IRGO, but the difference was not statistically significant. However, walking distance and walking speed also improved, but not significantly. CONCLUSION: All subjects had faster speeds of walking, walked longer distances and had lower PCI when using new MLO compared to walking with IRGO. Consequently, this orthosis should be examined and considered with larger sample size.

The effect of ankle joint mobility when using an isocentric reciprocating gait orthosis (IRGO) on energy consumption in people with spinal cord injury: preliminary results.

OBJECTIVES: The aim of this study was to evaluate the effect of walking with isocentric reciprocating gait orthoses (IRGOs) utilizing two designs of ankle foot orthoses (AFOs) on specific outcome measures in people with spinal cord injury (SCI). METHODS: Four volunteer SCI subjects participated in this study, and were fitted with an IRGO equipped with either solid or dorsiflexion-assisted AFOs in a randomized order. Subjects walked at their self-selected speed along a flat walkway to enable a comparison of walking speed, endurance and the resulting physiological cost index (PCI) to be performed. RESULTS: Increased walking speed, increased distance walked and less PCI were demonstrated in walking with the IRGO incorporating dorsiflexion-assisted AFOs as compared to walking with an IRGO plus solid AFO as a control condition. CONCLUSION: This study demonstrated that people with SCI could walk at relatively higher speeds and with greater endurance and a reduced PCI when utilizing an IRGO with dorsiflexion-assisted AFO components compared to solid ones. It is therefore concluded that the IRGO incorporating dorsiflexion-assisted AFOs may be an effective alternative in helping to reduce the energy consumption experienced by people with SCI.

Comparison of gait between healthy participants and persons with spinal cord injury when using a powered gait orthosis-a pilot study.

OBJECTIVES: The aim of this study was to evaluate the effect of a powered gait orthosis (PGO) on the temporal-spatial parameters and kinematics of walking in both healthy participants and persons with spinal cord injury (SCI) using three-dimensional motion analysis to facilitate further development of such devices. METHODS: Kinematics and temporal spatial data were obtained from three healthy participants and four persons with SCI who walked using the same design of PGO. RESULTS: Walking speed was reduced by 28% and step length by 29% in healthy individuals when walking with PGO compared with normal walking and that recorded for persons with SCI was approximately one-third that of normal walking. There were significant differences in hip and knee joint ranges of motion in comparison between walking with PGO in healthy participants and walking with PGO in persons with SCI. CONCLUSION: Walking with a PGO by healthy participants significantly reduced critical gait parameters, and further development work is needed to produce a more effective device to match closely the gait parameters of normal walking by healthy participants. Significant differences between normal walking and that evidenced with the PGO by both healthy participants and persons with SCI were detected.

The influence of ankle joint mobility when using an orthosis on stability in patients with spinal cord injury: a pilot study.

OBJECTIVES: Perceived risk of falling is an important factor for people with spinal cord injury (SCI). This study investigated the influence of ankle joint motion on postural stability and walking in people with SCI when using an orthosis. METHODS: Volunteer subjects with SCI (n=5) participated in this study. Each subject was fitted with an advanced reciprocating gait orthosis (ARGO) equipped with either solid or dorsiflexion-assist type ankle-foot orthosis (AFOs) and walked at their self-selected speed along a flat walkway to enable the comparison of walking speed, cadence and endurance. A force plate system and a modified Falls Efficacy Scale (MFES) were utilized to measure postural sway and the perceived fear of falling, respectively. RESULTS: There were significant differences in the mean MFES scores between two types of orthosis (P=0.023). When using two crutches, there was no significant difference in static standing postural sway in the medio-lateral (M/L) direction (P=0.799), but significant difference in the antero-posterior (A/P) direction (P=0.014). However, during single crutch support, there was a significant difference in both M/L (P=0.019) and A/P (P=0.022) directions. Walking speed (7%) and endurance (5%) significantly increased when using the ARGO with dorsi flexion assisted AFOs. There was no significant deference between two types of orthoses in cadence (P=0.54). CONCLUSIONS: Using an ARGO with dorsiflexion-assisted AFOs increased the fear of falling, but improved static postural stability and increased walking speed and endurance, and should therefore be considered as an effective orthosis during the rehabilitation of people with SCI.

Effect of rocker shoe design features on forefoot plantar pressures in people with and without diabetes.

BACKGROUND: There is no consensus on the precise rocker shoe outsole design that will optimally reduce plantar pressure in people with diabetes. This study aimed to understand how peak plantar pressure is influenced by systematically varying three design features which characterise a curved rocker shoe: apex angle, apex position and rocker angle. METHODS: A total of 12 different rocker shoe designs, spanning a range of each of the three design features, were tested in 24 people with diabetes and 24 healthy participants. Each subject also wore a flexible control shoe. Peak plantar pressure, in four anatomical regions, was recorded for each of the 13 shoes during walking at a controlled speed. FINDINGS: There were a number of significant main effects for each of the three design features, however, the precise effect of each feature varied between the different regions. The results demonstrated maximum pressure reduction in the 2nd-4th metatarsal regions (39%) but that lower rocker angles (<20°) and anterior apex positions (>60% shoe length) should be avoided for this region. The effect of apex angle was most pronounced in the 1st metatarsophalangeal region with a clear decrease in pressure as the apex angle was increased to 100°. INTERPRETATION: We suggest that an outsole design with a 95° apex angle, apex position at 60% of shoe length and 20° rocker angle may achieve an optimal balance for offloading different regions of the forefoot. However, future studies incorporating additional design feature combinations, on high risk patients, are required to make definitive recommendations.

The physiological cost index of walking with mechanical and powered gait orthosis in patients with spinal cord injury.

OBJECTIVES: Mechanical orthoses, such as the hip knee ankle foot orthosis (HKAFO) and the isocentric reciprocating gait orthosis (IRGO), are both used for walking in spinal cord injury (SCI) patients. The aim of this study was to analyze the energy expenditure during walking with these orthoses compared with a powered gait orthosis (PGO) in patients with SCI. METHODS: Five patients with SCI who were experienced users of HKAFOs participated in this study. Subjects were also fitted with an IRGO and PGO and underwent a specific gait training program. Patients walked along a flat walkway using the three types of orthosis at their self-selected walking speed. A stop watch and a polar heart rate monitor were used to measure the speed of walking and heart rate. RESULTS: Walking speed, the distance walked and the physiological cost index (PCI) all improved with both the new PGO and the IRGO as compared with the HKAFO. CONCLUSIONS: A PGO can improve walking speed and the distance walked and reduce the PCI of walking as compared with mechanical orthoses, probably due to the activated movements of the lower limb joints.

Feasibility study for a controllable orthotic knee joint.

PURPOSE: The purpose of this study was to demonstrate the feasibility of producing an orthotic knee joint that could lock and unlock during ambulation for eventual use in a reciprocating gait orthosis (RGO) for severely disabled patients. METHOD: Three prototype orthotic knee joints incorporating braking mechanisms were designed and manufactured to demonstrate their ability to withstand a maximum calculated sagittal plane bending moment of 73 Nm. Each was then subjected to bench trials to test their performance against the required specification. RESULTS: Although all three joints achieved the requirement to sustain the specified externally applied bending moments, the hydraulic disc brake system proved significantly superior and was selected for more comprehensive testing. CONCLUSIONS: The results confirmed the feasibility of utilising a hydraulic braking mechanism within an orthotic knee joint to withstand the knee flexing moments during walking in a lower limb orthosis. This gave the development group confidence to progress to the prototype design phase with the specific aim of eventually incorporating such a joint in an RGO designed for severely disabled patients such as those with complete paraplegia up to level T4 and those with severe neurological dysfunction.

Somatostatin receptor subtypes 2 and 5 mediate inhibition of egg yolk-induced gall bladder emptying in mice.

BACKGROUND: Somatostatin inhibits gall bladder contraction. Impaired gall bladder emptying is associated with gall bladder stone formation. The incidence of cholecystolithiasis is high in patients treated with a somatostatin agonist octreotide, which predominantly interacts with somatostatin receptor subtype 2 (SSTR2). Therefore, it is believed that SSTR2 regulates gall bladder contraction; however, evidence has not been provided. Here, we evaluate the effects of SSTR1-SSTR5-selective agonists on egg yolk-induced gall bladder contraction in mice. METHODS: Homozygous deletion of SSTR2 and SSTR5 was generated by cross-mating of SSTR2(-/-) with SSTR5(-/-) mice. Mice of different genotypes were injected with SSTR1-5-selective agonists or octreotide 15 min before induction of gall bladder emptying by egg yolk. One hour later, gall bladders were removed and weighed. KEY RESULTS: Egg yolk-reduced gall bladder weights in all mice, irrespective of their genotype. Octreotide was the most potent inhibitor of gall bladder emptying in wild-type mice. In contrast, agonists with high selectivity for SSTR2 or SSTR5 inhibited gall bladder emptying by approximately 50-60%, whereas SSTR1-, SSTR3- and SSTR4-selective agonists failed to influence gall bladder contraction. In SSTR2(-/-) mice, octreotide and an SSTR5-selective agonist inhibited gall bladder emptying by approximately 50%, whereas SSTR2-selective agonists were inactive. Octreotide inhibited gall bladder emptying in SSTR5(-/-) mice by approximately 50%, without any effect in SSTR2(-/-)/SSTR5(-/-) mice. CONCLUSIONS & INFERENCES: Our study provides evidence for the role of SSTR2 and SSTR5 in regulating gall bladder emptying in mice.

The biomechanics and clinical efficacy of footwear adapted with rocker profiles--evidence in the literature.

BACKGROUND: Rocker profiles are the most commonly prescribed external therapeutic shoe modification. However, the prescription criteria for rocker profiles have historically been based on theoretical considerations with minimal scientific study and validation. OBJECTIVE: Rocker profiles are used to afford pressure relief for the plantar surface of the foot, to limit the need for sagittal plane motion in the joints of the foot and to alter gait kinetics and kinematics in proximal joints. This paper reviews the literature relating to biomechanical and clinical efficacy. METHOD: A literature search was undertaken in Medline, PubMed, Recal, Cochrane database and Scopus. RESULTS AND CONCLUSIONS: Efficacy is demonstrated with regards to relief of forefoot plantar pressures. However, the definitive profile shape has not been demonstrated. The effectiveness of rocker-soled shoes in restricting sagittal plane motion in individual joints of the foot is unclear. Rocker profiles have minimal effect on the kinetics and kinematics of the more proximal joints of the lower limb, but more significant effects are seen at the ankle. Further research is warranted on the effects of rocker profiles on individual joints of the foot and the manner in which they effect lower limb muscle activity and gait patterns.

Public health surveillance for smallpox - United States, 2003-2005.

In June 1987, nearly 10 years after the World Health Organization (WHO) declared smallpox eradicated, the Council of State and Territorial Epidemiologists (CSTE) recommended removal of smallpox, a highly contagious viral disease, from the National Notifiable Diseases Surveillance System (NNDSS). However, the attacks of September 11, 2001, raised concern that smallpox (variola) virus, might exist in laboratories other than two WHO-designated repositories and could be used as an agent of biologic terrorism. In response to this concern, CSTE and CDC recommended in June 2003 that smallpox again be made reportable through NNDSS and that all states, territories, and cities add smallpox to their lists of reportable diseases. In 2005, CSTE conducted a cross-sectional survey in the United States and its territories to assess key components for surveillance of suspected smallpox disease, including legal reporting requirements, laboratory testing, and training and education (e.g., oral presentations and guides). This report summarizes the results of that survey, which indicated that 100% had the capacity to receive and investigate reports, 94% of states had legal requirements to report suspected smallpox disease, 70% had mandatory laboratory reporting of results indicative of smallpox disease, and 68% were providing ongoing training and education of health-care providers and public health staff.

Development and experience with an algorithm to evaluate suspected smallpox cases in the United States, 2002-2004.

Concerns that smallpox, an eradicated disease, might reappear because of a bioterror attack and limited experience with smallpox diagnosis in the United States prompted us to design a clinical algorithm. We used clinical features of classic smallpox to classify persons presenting with suspected smallpox rashes into 3 categories: those with high, those with moderate, and those with low risk of having smallpox. The classification guides subsequent diagnostic strategies, limiting smallpox laboratory testing to high-risk persons to minimize the number of false-positive test results. From January 2002 through June 2004, the Centers for Disease Control and Prevention (CDC) received 43 consultations regarding suspected smallpox cases. No patient was at high risk for having smallpox. One patient was tested for the presence of variola virus. Varicella was the diagnosis for 23 cases (53%). The algorithm worked well to guide clinical and public health responses to suspected smallpox cases. The poster is available from CDC, and an interactive version and laboratory protocol are available at http://www.bt.cdc.gov/agent/smallpox/diagnosis/riskalgorithm/index.asp. We recommend use of the algorithm in the United States and elsewhere.

Evaluation of an early two-dose measles vaccination schedule.

Vaccination at 6 months of age followed by routine revaccination is recommended when exposure of infants to measles is likely. Dade County, Florida, began this early two-dose schedule during a large epidemic in 1986-1987 (i.e., 22% of cases occurred in infants aged 6-11 months). This schedule was continued routinely in high-risk areas. The effect of an early two-dose schedule on measles prevention in the county was examined by comparing measles vaccination coverage and epidemiology before (1985-1987) and after (1988-1996) the schedule became routine. To assess serologic response, seroprevalence of measles antibody among children aged 4-6 years in 1995 was examined. To evaluate vaccine effectiveness, a case-control study was conducted among preschool-aged children. Among those aged 2 years, vaccination coverage with > or =1 dose increased from 75% to 94% in 1996. The number of annual cases declined, and endemic measles transmission reportedly ended after 1993. Seroprevalence of plaque reduction neutralization antibody (titer > 1:120) among those receiving vaccination according to an early two-dose schedule and a single dose at age > or =12 months was 94% (95% confidence interval: 89, 98) and 98% (95% confidence interval: 95, 100). In these groups, vaccine effectiveness was comparably high. Early two-dose measles vaccination is associated with improved coverage and a comparably high level of humoral immunity and clinical protection as a single dose at age > or =12 months. This strategy can be useful in areas at high risk for measles among infants.

Prostaglandin receptor EP(4) mediates the bone anabolic effects of PGE(2).

Prostaglandin (PG) E(2) is a potent inducer of cortical and trabecular bone formation in humans and animals. Although the bone anabolic action of PGE(2) is well documented, the cellular and molecular mechanisms that mediate this effect remain unclear. This study was undertaken to examine the effect of pharmacological inactivation of the prostanoid receptor EP(4), one of the PGE(2) receptors, on PGE(2)-induced bone formation in vivo. We first determined the ability of EP(4)A, an EP(4)-selective ligand, to act as an antagonist. PGE(2) increases intracellular cAMP and suppresses apoptosis in the RP-1 periosteal cell line. Both effects were reversed by EP(4)A, suggesting that EP(4)A acts as an EP(4) antagonist in the cells at concentrations consistent with its in vitro binding to EP(4). We then examined the effect of EP(4) on bone formation induced by PGE(2) in young rats. Five- to 6-week-old rats were treated with PGE(2) (6 mg/kg/day) in the presence or absence of EP(4)A (10 mg/kg/day) for 12 days. We found that treatment with EP(4)A suppresses the increase in trabecular bone volume induced by PGE(2). This effect is accompanied by a suppression of bone formation indices: serum osteocalcin, extent of labeled surface, and extent of trabecular number, suggesting that the reduction in bone volume is due most likely to decreased bone formation. The pharmacological evidence presented here provides strong support for the hypothesis that the bone anabolic effect of PGE(2) in rats is mediated by the EP(4) receptor.