Recent Advances on Selenium Nutrition and Keshan Disease.

Keshan disease (KD) is a type of endemic cardiomyopathy with an unknown cause. It is primarily found in areas in China with low selenium levels, from northeast to southwest. The nutritional biogeochemical etiology hypothesis suggests that selenium deficiency is a major factor in KD development. Selenium is important in removing free radicals and protecting cells and tissues from peroxide-induced damage. Thus, low environmental selenium may affect the selenium level within the human body, and selenium level differences are commonly observed between healthy people in KD and nonKD areas. From the 1970s to the 1990s, China successfully reduced KD incidence in endemic KD areas through a selenium supplementation program. After years of implementing prevention and control measures, the selenium level of the population in the KD areas has gradually increased, and the prevalence of KD in China has remained low and stable in recent years. Currently, the pathogenesis of KD remains vague, and the effect of selenium supplementation on the prognosis of KD still needs further study. This paper comprehensively reviews selenium deficiency and its connection to KD. Thus, this study aims to offer novel ideas and directions to effectively prevent and treat KD in light of the current situation.

A randomized trial of vitamin D supplementation to prevent seasonal influenza and enterovirus infection in children.

PURPOSE: This study aimed to evaluate whether vitamin D supplementation can reduce the incidence of influenza and enterovirus infection in Taiwanese children. METHODS: This randomized, double-blind, controlled trial included children aged two to five years between April 2018 and October 2019 from daycare centers. All the participants were randomly assigned to a vitamin D supplementation group (2000 IU/day) or placebo group for one month. The primary outcome was the incidence of influenza and enterovirus infection in the following six months, and the secondary outcome was the incidence of influenza and enterovirus infection in the children's household members. RESULTS: Two hundred and forty-eight children participated. The vitamin D group showed a relative risk reduction of 84% against influenza compared to the placebo group but did not reach statistical significance. Kaplan-Meier curves revealed that the placebo group had a higher probability of influenza infection than the vitamin D group (log-rank test, p = 0.055), but the incidence of enterovirus infection was similar between the two groups (p = 0.946) among children. Among children's household members, the incidence of influenza (p = 0.586) and enterovirus infection (p = 0.528) were both similar between the two groups. All children who were tested for serum 25(OH)D levels after vitamin D intervention had 25(OH)D levels above 30 ng/ml CONCLUSION: Vitamin D supplementation may have a small preventative effect against influenza infection but does not affect enterovirus infection among preschool children. A high-dose short-term vitamin D intervention might be a way to elevate children's serum vitamin D levels in the first month of starting kindergarten.

A Spatial Ecology Study of Keshan Disease and Hair Selenium.

Few spatial ecological studies on hair selenium (Se) and Keshan disease (KD) have been reported. To investigate the relationships of hair Se with KD and economic indicators and to visualize the evidence for KD precise prevention. An ecological study design was employed. The levels of hair Se of 636 adult men (≥ 18 years old) living in rural, general cities and developed cities in 15 KD endemic provinces and 11 KD non-endemic provinces in mainland China were measured using hydride generation atomic fluorescence spectrometry. Spatial description and spatial analysis of hair Se were conducted. The subjects were adults aged. The hair Se level of the residents of KD endemic areas was 0.30 mg/kg, statistically significantly lower than that of non-endemic areas 0.34 mg/kg (Mann-Whitney U test, p = 0.007). The hair Se level of the 636 people was 0.33 mg/kg. The hair Se levels of the residents of the developed cities, general cities, and rural were 0.35 mg/kg, 0.33 mg/kg, and 0.32 mg/kg, respectively, with statistical significance (Kruskal-Wallis H test, P = 0.032). Spatial regression analysis showed that the spatial distribution of hair Se was positively correlated with per capita GDP. Selenium deficiency may still exist among residents living in the KD endemic areas. The results of spatial description and analysis of hair Se provided visualized evidence for targeting key provinces for precise prevention of Keshan disease, including assessment of KD elimination. The hair Se level of the mainland Chinese males was probably between 0.31 and 0.33 µg/g in 2015.

Clinical Course of Enterovirus D68 in Hospitalized Children.

BACKGROUND: Enterovirus D68 (EV-D68) has been sporadically reported as a cause of respiratory tract infections. In 2014, an international outbreak of EV-D68 occurred and caused severe respiratory disease in the pediatric population. METHODS: A retrospective chart review was performed of children admitted to Children's Mercy Hospital from August 1, 2014, to September 15, 2014, with positive multiplex polymerase chain reaction testing for EV/rhinovirus (RV). Specimens were subsequently tested for EV-D68, and clinical data were obtained from the medical records. Patients with EV-D68 were compared with children presenting simultaneously with other EV/RV. RESULTS: Of 542 eligible specimens, children with EV-D68 were significantly older than children with other EV/RV (4.6 vs. 2.2 years, P < 0.001). Children with EV-D68 were more likely to have a history of asthma (38.6% vs. 30.0%, P = 0.04) or recurrent wheezing (22.1% vs. 14.8%, P = 0.04). EV-D68-positive children more commonly received supplemental oxygen (86.7% vs. 65.0%, P < 0.001), albuterol (91.2% vs. 65.5%, P < 0.001) and corticosteroids (82.9% vs. 58.6%, P < 0.001). Age ≥5 years was an independent risk factor for intensive care unit management in EV-D68-infected children. Children with a history of asthma or recurrent wheezing and EV-D68 received supplemental oxygen (92.7% vs. 82.4%, P = 0.007) and magnesium (42.7% vs. 29.7%, P = 0.03) at higher rates and more continuous albuterol (3 vs. 2 hours, P = 0.03) than those with other EV/RV. CONCLUSIONS: EV-D68 causes severe disease in the pediatric population, particularly in children with a history of asthma or recurrent wheezing. EV-D68-positive children are more likely to require therapy for refractory bronchospasm and may need intensive care unit- level care.

An approach to assessment of Keshan disease elimination at the township level.

BACKGROUND: The aim of this study was to pilot a method of a small-scale survey for the assessment of Keshan disease (KD) elimination at township level. METHODS: The prevalence of chronic KD was obtained by case-searching the whole population. The endemic village with the highest prevalence of chronic KD was selected as the key village for the survey of latent KD prevalence rate among permanent residents. The selenium levels in the head hair of individuals in the key village was measured. The professionals of the department of endemic disease control, the township and village doctors were surveyed by pre-designed questionnaire survey for KD interventions. RESULTS: We conducted this study in 2013. Yuanbao township had a population of 16 487 people and 14 862 permanent residents. There were no acute or subacute KD cases in the previous 5 years. The prevalence rate of chronic KD and natural chronic KD were 6.7/10 000 and 3.4/10 000 respectively. The prevalence rate of latent KD was 250.6/10 000, higher than the elimination criterion. The head hair selenium levels were 0.23±0.18 mg/kg. CONCLUSIONS: The small-scale survey methodology for assessing KD elimination at township level was feasible. KD among the people living in Yuanbao township has not been eliminated.

Association of Tic Disorders and Enterovirus Infection: A Nationwide Population-Based Study.

There has been growing interest in the association between infectious disease and mental disorders, but an association between enterovirus (EV) infection and tic disorders has not been sufficiently explored. Herein, we aim to investigate the association between EV infection and incidence of tic disorders in a nationwide population-based sample using Taiwan's National Health Insurance Research Database. We identified individuals aged ≤18 years prior to 2005 with an inpatient diagnosis of EV infection and/or history of EV infection. Tic disorder was operationalized using International Classification of Disease, Revision 9, Clinical Modification (ICD-9-CM) codes 307.20-307.23. A total of 47,998 individuals with history of EV infection were compared to 47,998 sex-, age-, and urbanization-matched controls on incidence of tic disorders. The mean ±â€Šstandard deviation follow-up period for all subjects was 9.7 ±â€Š3.6 years; the mean latency period between initial EV infection and incident diagnosis of tic disorder diagnosis was 5.4 ±â€Š2.8 years. EV infection was significantly associated with greater incidence of tic disorders (hazard ratio [HR] = 1.24, 95% CI: 1.07-1.45). When subgrouped on the basis of central nervous system (CNS) involvement, EV infection with CNS involvement was not significantly associated with greater incidence of tic disorders when compared to controls (HR = 1.25, 95% CI: 0.64-2.43); EV infection without CNS involvement was significantly associated greater incidence of tic disorders when compared to controls (HR = 1.24, 95% CI: 1.07-1.45). In addition, hospitalization for an EV infection did not increase the hazard for greater incidence of tic disorders (HR = 1.32, 95% CI: 1.04-1.67 with hospitalization and 1.22, 95% CI: 1.04-1.44 without hospitalization). EV infection is temporally associated with incidence of tic disorders. Our observations add to the growing body of literature implicating immune-inflammatory system in the pathoetiology of brain disorders in a subpopulation of individuals and serve as a clarion call for surveillance of symptoms suggestive of tic disorders in individuals with history of EV infection.

[Significance of selenium in the pathogenesis and therapy of cardiovascular diseases and those requiring intensive care]. / A szelén szerepe a cardiovascularis és intenzív kezelést igénylo betegségek létrejöttében és kezelésében.

Selenium deficiency results in profound changes in cellular defence mechanisms against oxidative stress, which plays an important role in the development of cardiovascular disease and the associated risk factors. Increased formation and decreased elimination of reactive oxygen radicals contribute to the complicated mechanisms of sepsis and related disorders. Use of selenium in prevention and treatment of the above mentioned conditions is not a new idea, but controversial data were published in relation to both fields recently. The aim of the present review is to summarize the most important results related to this area.

[Syndrome "sickly child"].

Scientific review is devoted to the urgent problem of child health care--Syndrome "sickly child" described in detail the category of "frequently ill children" repeated respiratory diseases, the pathogens that cause diseases of the respiratory tract. Paying attention to factors contributing to re-respiratory morbidity, including genetically determined causes (disturbances in the state of health of the mother), is represented by the genetic determinism of repeated and recurrent diseases related to blood groups. The development of an immune imbalance is manifested by changes in the cellular, humoral immune response and nonspecific resistance factors characterizing the changes of local immunity in this category of children that shape the development of chronic disease. We describe the effect of an allergic component to the severity of respiratory disease and the relationship with the mechanisms of neuroendocrine and immune systems. Correction of the immune resistance of sickly children was conducted cycloferon contributing to reduce the incidence and duration of repeated episodes of acute respiratory infections per year.

The prevalence of Keshan disease in China.

BACKGROUND: Sentinel surveillance of Keshan disease (KD) is limited by unable to give the prevalence rates and their estimates. This study was to find the national KD prevalence and the estimated patient numbers to provide evidence toward modifying the policy of KD prevention and control. METHOD: Using a probability proportional to population size, randomized, multistage, and cluster sampling, we surveyed 101,127, measured grain selenium levels; and surveyed household income with pre-designed questionnaires. RESULTS: The national prevalence rates of KD, chronic KD and latent KD were 2.21%, 0.50%, and 1.71% respectively. Chronic KD patients are mainly in the provinces where KD had been seriously epidemic. The KD prevalence rate was higher in females (2.20%) than in males (1.98%). These were also higher in older age groups. The cases younger than 30 years accounted for 13.6%, indicating the possibility that KD is still occurring. Nationally, the estimated numbers of KD and chronic KD patients are 1,675,500 (95% CI, 1,608,500-1,747,300) and 379,800 (95% CI, 346,700-412,800) respectively. Multiple logistic regression analysis indicated that family income was a significant dependent variable (OR: -0.258, 95% CI: -0.332 to -0.185, p<0.001). More than 2000 chronic KD patients found in the study were treated in 2009-2011. The limitation of this study was that sampling size was determined at national level. CONCLUSION: KD is still a public health issue among the people of the historically severe endemic areas. Selenium supplementation, self-management program for chronic KD patients and translation epidemiology of KD surveillance should be strengthened.

An original discovery: selenium deficiency and Keshan disease (an endemic heart disease).

This is a review article telling a 50-years old story about the studies on selenium deficiency and Keshan disease in China, an endemic heart disease with high case-fatality, as an example of translational research. Extensive cross-sectional epidemiological studies showed that low selenium concentrations in cereal grains and low selenium status of local residents were associated with the occurrence of Keshan disease. Several large population based intervention trials using oral administration of sodium selenite tablets showed significant reduction of Keshan disease incidence. Based on the above evidence, it was concluded that selenium deficiency is the major cause of Keshan disease, although other etiological factors could not be ruled out. The implications of the findings include: provided critical scientific evidence for selenium being an essential trace element for humans; as scientific basis for identifying minimum requirement and RDA/RNI for selenium; and as solid reference for the formulation of effective preventive measures for Keshan disease in China.

Suboptimal selenium supply--a continuing problem in Keshan disease areas in Heilongjiang province.

This study explores whether the declining prevalence of Keshan disease is associated with increasing selenium levels in Keshan disease areas in Heilongjiang province. Six counties endemic with Keshan disease and three non-endemic counties were selected as study areas. In each county, two townships and in each township one village were chosen in which to survey ten families about head hair, grain, and soil samples and to obtain demographic information. Selenium was measured with hydride generation-atomic fluorescence spectrometry. In each county endemic with Keshan disease, one of the villages was chosen to investigate the prevalence of the disease. We collected 534 head hair samples, 446 staple food samples, and 180 soil samples. The selenium levels of head hair and corn in the endemic counties were significantly lower than those in non-endemic counties. Family demographic information was homologous except for the composition of staple food. More residents in Keshan disease areas preferred flour and corn. The detection rate for latent Keshan disease had a significantly negative correlation with the corn selenium level in six counties endemic with Keshan disease. As the population in this region is still at risk for Keshan disease, selenium surveillance measures should be intensified.

Is selenium deficiency really the cause of Keshan disease?

Keshan disease (KD) is a dilated cardiomyopathy closely related with a diet deficient in the mineral selenium. It is named for the northeastern Chinese county Keshan, where the disease prevalence is high because of selenium-deficient soil. KD is a gene-environment interaction disease. Here, we used stepwise multiple regression analysis to analyze the risk factors of the disease and the main clinical features in 71 KD patients and 290 controls. The variables analyzed included age, sex, family history of KD, blood selenium level, glutathione peroxidase-1 (GPx-1) activity, variance at codon198 in GPx-1 gene, residence in an endemic area, abnormal electrocardiography (ECG) findings, and cardiothoracic (CT) ratio. The main risk factors found were low GPx-1 activity, family history of KD and living in an endemic area. The main clinical features were increased cardiac load on ECG and increased CT ratio and Tei index. Public health and clinical prevention efforts could focus on increasing GPx-1 activity to address KD. Is selenium deficiency really the certain cause of KD? This is not at all a settled question. And further study is promptly required to investigate the etiology of KD.

[Surveys on the conditions of Keshan disease and selenium levels of 15 counties in Shandong Province in 2008].

OBJECTIVE: To investigate the conditions of Keshan disease and the selenium nutritional status of residents in Keshan disease endemic area in Shandong Province. METHODS: One site from each of 15 Keshan disease endemic counties in Shandong Province was selected for the survey and 700 subjects in each site were randomly selected for the investigation. Physical examination, electrocardiogram and X-ray radiography of the subjects and the selenium contents of hair, wheat, corn and dried sweet potato were surveyed. RESULTS: A total of 10679 people were investigated in 15 counties and 315 patients were found, including 287 cases of latent type and 28 cases of chronic type, but no acute or subacute type patients were found. There were 1776 cases of abnormal electrocardiogram. Among the 461 cases checked up by radiography, the heart of 195 cases was enlarged. The selenium content of hair, wheat, corn and dried sweet potato were (0.5191 +/- 0.5538), (0.0268 +/- 0.0045), (0.0194 +/- 0.0052) and (0.0193 +/- 0.0039) mg/kg respectively. CONCLUSION: The occurrence of Keshan disease is in a stable status in Shandong Province at present. Hair selenium of residents in Keshan disease endemic area has reached an appropriate level. The selenium nutritional status of residents has improved, and the prevalence of Keshan disease is expected to be decreased in these areas.

Selenium level surveillance for the year 2007 of Keshan disease in endemic areas and analysis on surveillance results between 2003 and 2007.

Selenium deficiency is widely accepted as a fundamental cause of Keshan disease (KD). In the present study, the selenium levels of hair and food samples of KD in some endemic areas were measured; the prevalence and incidence of KD for the year 2007 in these areas were surveyed. The results for KD surveillance from 2003 to 2007 were analyzed. The selenium level was measured fluorometrically. In 2007, a total of 19,280 residents were surveyed in 15 provinces. The prevalence and incidence of KD were 3.0% and 4.9‰, respectively. In KD and control subjects, the mean levels of hair selenium were respectively 0.3223 mg/kg and 0.4466 mg/kg. The mean level of staple food selenium was 0.0227 ± 0.0144 mg/kg. During the 5 years, the selenium content in hair was always kept at a normal level within inhabitants of KD-endemic areas, but that in staple food was always kept at a lower level. These results indicate that the pathogenic factor has not been drastically eliminated even with the increasing selenium level of internal environment and is still continually damaging public health of KD in endemic areas. Since KD is still a serious threat to public health in its endemic areas, it is of great importance to pay attention to the prevention and control of this disease.

[Roles and functions of WHO Enterovirus Collaborating Center].

The Laboratory of Enteroviruses of the Department of Virology II, National Institute of Infectious Diseases, is functioning as a WHO-designated Collaborating Center for Virus Reference and Research (Enterovirus) in virus isolation and identification, development, evaluation, and quality control of new laboratory diagnosis methods, training technical staffs and experts, preparing, maintaining and supplying of standard reagents and reference materials for the laboratory diagnosis of enterovirus infections including poliomyelitis. The infectious agents surveillance of polioviruses is one of the critical components for the Global Polio Eradication Initiative, and the laboratory diagnosis of non-polio enteroviruses is also important in current outbreaks of hand, foot and mouth disease, mainly due to enterovirus 71. Thus, human resources and consistent international cooperation among technical staffs, based on the global and regional polio laboratory networks, are playing critical roles also in the surveillance activities for non-polio enterovirus infections in the Western Pacific Region.

A prolonged outbreak of polioencephalomyelitis due to infection with a group I porcine enterovirus.

A commercial swineherd in Indiana experienced high death loss of nursery pigs with neurologic disorders for a prolonged period. Polioencephalomyelitis was the consistent histopathological lesion in affected animals. A porcine enterovirus (PEV) classified to group I was isolated from spinal cords and brains collected from the affected animals. The isolate (ISUVDL 200103183) was determined to belong to either serogroup 5 or 6 at the National Veterinary Services Laboratories, Ames, IA. No other significant viral or bacterial agents were isolated from or detected in the animals. A prospective longitudinal serological monitoring of pigs in the index herd for the PEV isolate revealed that colostrum-derived neutralizing antibodies to the virus rapidly declined, and by the age of 21 days the majority of piglets had no or minimal neutralizing antibody against the virus. Seroconversion to the virus then coincided with increased mortality in the herd. Results of diagnostic and cohort observations supported a diagnosis of PEV infection as the cause of the prolonged outbreak of "polio." Investigation into factors that may be contributing to the prolonged problem is currently in progress.

Acute hemorrhagic conjunctivitis.

Acute hemorrhagic conjunctivitis, an infection caused by enterovirus 70 and a variant of coxsackievirus A24, is characterized by the rapid onset of severely painful conjunctivitis and subconjunctival hemorrhage. The condition is usually benign and resolves in five to seven days; however, a polio-like paralysis (radiculomyelitis) develops in approximately one in 10,000 patients infected with enterovirus 70. No treatment is available. Information about acute hemorrhagic conjunctivitis should be provided to patients and the community in order to prevent undue alarm, discourage home remedies and control the spread of this highly contagious disease.

Clinical findings and results of treatment in an outbreak of acute hemorrhagic conjunctivitis in southern Florida.

An epidemic of acute hemorrhagic conjunctivitis in Miami, Florida, involved approximately 800 documented cases and more than 2,500 suspected cases. This epidemic was caused by an enterovirus 70 infection affecting primarily young black people residing within a high-risk area. Acute hemorrhagic conjunctivitis is characterized by the rapid onset of swollen eyelids, foreign-body sensation, burning, watery discharge, and, usually, bilateral ocular involvement. Signs include distinctive bulbar conjunctival hemorrhages and a follicular conjunctival reaction with only mild and infrequent corneal involvement. This infection is short in duration, self-limited, and free of significant ocular sequelae. Symptomatic treatment appears to be as effective as various topical medical regimens for relief of symptoms. Secondary bacterial infections (occurring in individuals who used urine as an eyewash) and one case of a transient acute Bell's palsy were the only complications associated with this acute hemorrhagic conjunctivitis epidemic.