Polio survivors have poorer walking adaptability than healthy individuals

BackgroundFalling is a major health problem in polio survivors, often occurring as a result of tripping, slipping or misplaced steps. Therefore, reduced walking adaptability possibly plays an important role.Research questionDoes walking adaptability, assessed on an interactive treadmill, differ between polio survivors and healthy individuals?MethodsIn this cross-sectional study, 48 polio survivors with at least one reported fall in the past year and/or fear of falling and 25 healthy individuals of similar age walked at self-selected comfortable fixed speed on an instrumented treadmill. Walking adaptability was measured as i) target-stepping accuracy (determined as variable error [VE] in mm independent of speed) in three conditions; 0 %, 20 % and 30 % variation in step length and width, and ii) anticipatory and reactive obstacle avoidance (ObA and ObR, in percentage successfully avoided). All trials were checked for valid step detection.Results46 polio survivors (mean ± SD age: 63.2 ± 8.7 years) and 25 healthy individuals (64.3 ± 6.6 years, p = 0.585) showed valid step detection. Compared to healthy individuals (mean±SE VE: 30.6±1.2 mm), polio survivors stepped less accurately onto targets (36.4±0.9 mm, p = 0.001), especially with their least-affected leg. Polio survivors avoided fewer obstacles successfully (mean±SE ObA: 83±3 %, ObR: 59±4 %) than healthy individuals (100±0.3 %, p < 0.001 and 94±3 %, p < 0.001, respectively), with a stronger decline in success rates from anticipatory to reactive obstacle avoidance for polio survivors (p < 0.001).SignificancePolio survivors reporting falls and/or fear of falling had a demonstrably reduced walking adaptability, especially so for reactive obstacle avoidance, which requires step adjustments under high time-pressure demands. Future research should study the merit of walking-adaptability assessment to currently used clinical methods of fall-risk assessment within this population.     

Altered supraspinal motor networks in survivors of poliomyelitis: A cortico-muscular coherence study

ObjectivePoliomyelitis results in changes to the anterior horn cell. The full extent of cortical network changes in the motor physiology of polio survivors has not been established. Our aim was to investigate how focal degeneration of the lower motor neurons (LMN) in infancy/childhood affects motor network connectivity in adult survivors of polio.MethodsSurface electroencephalography (EEG) and electromyography (EMG) were recorded during an isometric pincer grip task in 25 patients and 11 healthy controls. Spectral signal analysis of cortico-muscular (EEG-EMG) coherence (CMC) was used to identify the cortical regions that are functionally synchronous and connected to the periphery during the pincer grip task.ResultsA pattern of CMC was noted in polio survivors that was not present in healthy individuals. Significant CMC in low gamma frequency bands (30–47 Hz) was observed in frontal and parietal regions.ConclusionThese findings imply a differential engagement of cortical networks in polio survivors that extends beyond the motor cortex and suggest a disease-related functional reorganisation of the cortical motor network.SignificanceThis research has implications for other similar LMN conditions, including spinal muscular atrophy (SMA). CMC has potential in future clinical trials as a biomarker of altered function in motor networks in post-polio syndrome, SMA, and other related conditions.     

Reintroducing OPV in Israel on the journey to global polio eradication – Estimation at a low rate of contraindicated population

IntroductionThe 2013 reemergence of wild poliovirus in Israel led to the reinstatement of a routine OPV vaccination. Fearing VAPP in immunocompromised, the MOH regulated contraindications for vaccination candidates and household contacts. In this study we estimate the size of the contraindicated population to OPV vaccination.MethodWe studied vaccination candidates aged 2–9 and 14–23 months and probable household contacts. Using the rate of contraindications extracted for each study group from a medical records database, a statistical model was built to estimate the probability of contraindications in candidates.Results3.9% of the 2–9-month-old study group and 4% of the 14–23-month-old group had contraindications by either self or household contacts.ConclusionA statistical model can provide an estimation of the contraindicated population and can be used in the future when devising vaccination campaigns. In contrast to concerns raised by the MOH, our findings show a smaller than anticipated contraindicated population.     

Crutch art painting in the middle age as orthopaedic heritage (Part I: the lepers,the poliomyelitis,the cripples)

Throughout time from antiquity, the major objective of crutches was to restore, as close as possible, the functional capacity formerly held by a limb deficient person. The crutch is probably the oldest tool of the orthopaedist. It is probably also the most neglected in terms of progress from antiquity until the 20th century. The aim of this paper is to give a view of the different crutches used in this period by different people and to observe the influence of this period on the progress of the design of crutches.     

Development and factor analysis of an index of post-polio sequelae

Purpose. This present study describes the development, factor structure and initial validation of the Index of Post-Polio Sequelae (IPPS).

Method. The IPPS was tested on a sample of 849 community-dwelling polio survivors between the ages of 40 and 93 years old who participated in a large, national study of menopause and aging in late polio. Items from the IPPS were submitted to a factor analysis using principal components extraction and rotated to oblique simple structure using promax rotation. Convergent validity was assessed using bivariate correlation.

Results. Three factors were extracted that accounted for approximately 53% of the variance in the original IPPS items. Factor 1 (Pain) was loaded most heavily by two items referring to muscle and joint pain. Factor 2 (Atrophy) was loaded by items referring to muscle atrophy, involved muscle weakness, and fatigue. Factor 3 (Bulbar) was comprised of two items referring to breathing and swallowing problems. Bivariate correlations between health and psychosocial variables and each of the factors all were significant and in expected directions.

Conclusions. This first validation of a standardized scale to assess the severity of post-polio sequelae in polio survivors suggests a psychometrically sound instrument whose factor structure represents commonly reported problems in the extant post-polio literature.     

Body composition assessment in Taiwanese individuals with poliomyelitis

Chang K-H, Lai C-H, Chen S-C, Hsiao W-T, Liou T-H, Lee C-M. Body composition assessment in Taiwanese individuals with poliomyelitis.

Objectives

To measure the changes in the total and regional body fat mass, and assess the clinical usefulness of the body mass index (BMI) in detecting overweight subjects with sequelae of poliomyelitis.

Design

Prospective, cross-sectional study.

Setting

General community.

Participants

Subjects with poliomyelitis (n=17; age range, 42–57y; mean, 47y; 12 men, 5 women) and able-bodied people (n=17) matched by sex, age, body weight, and body height participated in the study.

Interventions

Not applicable.

Main Outcome Measures

Total and regional body composition was measured with dual-energy x-ray absorptiometry. Clinical characteristics such as blood pressure, serum biochemical studies, and habitual behaviors (daily cigarette smoking, alcohol consumption, and exercise regimen) of all participants were evaluated.

Results

Compared with able-bodied controls, subjects with poliomyelitis had a 50% greater total body fat mass, significant increases in the regional fat mass in every part of the body, and had the greatest increase of fat mass in the thorax. Nearly all the subjects (94%) with poliomyelitis were obese according to standards of body composition. However, one third of them had a BMI value of less than 25.0kg/m².

Conclusions

People with poliomyelitis have a higher prevalence of obesity and a significant increase in total and regional fat mass. Current BMI underestimates the total body fat mass percentage compared with the control; therefore, a population-specific BMI should be used to address the prevalence of obesity in postpolio survivors.     

Spanish newsreel NO-DO (1943-1975). The diffusion of science as a legitimizing instrument of the Franco regime: polio and other immuno-preventable diseases

The official NO-DO newsreels were screened in Spain on a weekly basis from 1943 to 1981. These official news and documentary programmes were compulsory in cinemas from the moment they were first produced until the end of the Francoist dictatorship (1975). NO-DO held an information monopoly and was used as the regime's propaganda tool to indoctrinate the population, building stories tailored to the regime's interests and masking social realities. In this study, we examined newsreels on medical subjects relating to diseases preventable by vaccination. A majority of reports centred on poliomyelitis, and two differentiated periods could be defined, coinciding with the development of Franco regime's foreign policy. Further, from the gender perspective, we analyse the female stereotypes in the battle against vaccine preventable diseases Therefore, the news coverage of polio is of special relevance. In conclusion, this topic offers a good opportunity to reflect on the political role of popular science and science communication in a specific historical context.     

Enhancing viral vaccine production using engineered knockout vero cell lines – A second look

The global adoption of vaccines to combat disease is hampered by the high cost of vaccine manufacturing. The work described herein follows two previous publications (van der Sanden et al., 2016; Wu et al., 2017) that report a strategy to enhance poliovirus and rotavirus vaccine production through genetic modification of the Vero cell lines used in large-scale vaccine manufacturing. CRISPR/Cas9 gene editing tools were used to knockout Vero target genes previously shown to play a role in polio- and rotavirus production. Subsequently, small-scale models of current industry manufacturing systems were developed and adopted to assess the increases in polio- and rotavirus output by multiple stable knockout cell lines. Unlike previous studies, the Vero knockout cell lines failed to achieve desired target yield increases. These findings suggest that additional research will be required before implementing the genetically engineered Vero cell lines in the manufacturing process for polio- and rotavirus vaccines to be able to supply vaccines at reduced prices.     

Assessment of poliovirus antibody seroprevalence in polio high risk areas of West Africa

We conducted a serological survey of anti-polio antibodies in polio high-risk areas of Mali, Guinea and Cote d’Ivoire to assess risk of future poliovirus outbreaks.Random community sampling of children 6–11 and 36–48 months-old was conducted; neutralizing antibodies against poliovirus were detected using microneutralization assay.We analysed 1059/1064 (99.5%) of enrolled children. Seroprevalence to poliovirus type 1 (PV1) across all age groups and locations ranged between 92 and 100%, for PV2 it was 77–100%, and 89–95% for PV3. PV2 seroprevalence in the younger age group in Guinea and Cote d’Ivoire was <80%. History of <4 polio vaccine doses and acute malnutrition were associated with seronegativity (OR = 2.1 CI95% = 1.5–3.1, OR = 1.8 CI95% = 1.1–3.3 respectively).The risk of poliovirus outbreak following importation is low because of high population immunity to PV1, however, due to large cohort of PV2 seronegative children any future detection of vaccine-derived poliovirus type 2 requires urgent response to arrest rapid spread.