Kesheng Li

Is high relative humidity associated with childhood hand, foot, and mouth disease in rural and urban areas?

OBJECTIVE To examine the relationship between relative humidity and childhood hand, foot and mouth disease (HFMD) in Hefei, China, and to explore whether the effect is different between urban and rural areas. STUDY DESIGN Retrospective ecological study. METHODS A Poisson generalized linear model combined with a distributed lag non-linear model was used to examine the relationship between relative humidity and childhood HFMD in a temperate Chinese city during 2010-2012. RESULTS The effect of relative humidity on childhood HFMD increased above a humidity of 84%, with a 0.34% (95% CI: 0.23%-0.45%) increase of childhood HFMD per 1% increment of relative humidity. Notably, urban children, male children, and children aged 0-4 years appeared to be more vulnerable to the effect of relative humidity on HFMD. CONCLUSIONS This article study indicates that high relative humidity may trigger childhood HFMD in a temperate area, Hefei, particularly for those who are young and from urban areas.

Impact of weather factors on hand, foot and mouth disease, and its role in short-term incidence trend forecast in Huainan City, Anhui Province.

Hand, foot, and mouth disease (HFMD) is one of the most common communicable diseases in China, and current climate change had been recognized as a significant contributor. Nevertheless, no reliable models have been put forward to predict the dynamics of HFMD cases based on short-term weather variations. The present study aimed to examine the association between weather factors and HFMD, and to explore the accuracy of seasonal auto-regressive integrated moving average (SARIMA) model with local weather conditions in forecasting HFMD. Weather and HFMD data from 2009 to 2014 in Huainan, China, were used. Poisson regression model combined with a distributed lag non-linear model (DLNM) was applied to examine the relationship between weather factors and HFMD. The forecasting model for HFMD was performed by using the SARIMA model. The results showed that temperature rise was significantly associated with an elevated risk of HFMD. Yet, no correlations between relative humidity, barometric pressure and rainfall, and HFMD were observed. SARIMA models with temperature variable fitted HFMD data better than the model without it (sR2 increased, while the BIC decreased), and the SARIMA (0, 1, 1)(0, 1, 0)52 offered the best fit for HFMD data. In addition, compared with females and nursery children, males and scattered children may be more suitable for using SARIMA model to predict the number of HFMD cases and it has high precision. In conclusion, high temperature could increase the risk of contracting HFMD. SARIMA model with temperature variable can effectively improve its forecast accuracy, which can provide valuable information for the policy makers and public health to construct a best-fitting model and optimize HFMD prevention.

Exposure to bisphenol A and the development of asthma: A systematic review of cohort studies

BACKGROUND There is conflicting evidence about the association between bisphenol A (BPA) exposure and childhood asthma risk. We aimed to review the epidemiological literature on the relationship between prenatal or postnatal exposure to BPA and the risk of childhood asthma/wheeze. METHODS The PubMed database was systematically searched, and additional studies were found by searching reference lists of relevant articles. RESULTS Six studies fulfilled the eligibility criteria. Three studies found that prenatal BPA exposure is associated with an increased risk of childhood wheeze, while another study reported a reduced risk of wheeze. Regarding the postnatal BPA exposure, three studies demonstrated an increased risk of childhood asthma/wheeze. CONCLUSIONS The mean prenatal BPA was associated with the risk of childhood wheeze/asthma. Besides, the influence of BPA exposure during the second trimester of pregnancy on the prevalence of childhood wheeze was marked. Further studies are urgently needed to explore the underlying mechanism about adverse effect of BPA exposure on childhood wheeze/asthma.

Prenatal antibiotic use and risk of childhood wheeze/asthma: A meta-analysis

Existing body of knowledge suggests that antibiotic use during pregnancy was inconsistently associated with childhood wheeze/asthma. The aim of this study was to determine whether exposure to antibiotic during pregnancy could increase the risk for childhood wheeze/asthma using a comprehensive meta‐analysis.

Is greater temperature change within a day associated with increased emergency admissions for schizophrenia

BACKGROUND Diurnal temperature range (DTR), as an important index of climate change, has been increasingly used to evaluate the impacts of temperature variability on human health. However, little is known about the effects of DTR on schizophrenia. OBJECTIVE The present study aims to examine the relationship between DTR and schizophrenia admissions, and further, to explore whether the association varied by individual characteristics and study periods. METHODS A Poisson generalized linear regression combined with distributed lag non-linear model (DLNM) was applied to analyze daily DTR and schizophrenia data from Hefei, China during 2005 to 2014, after adjusting for long-term and seasonal trends, mean temperature, relative humidity and other confounding factors. RESULTS An acute adverse effect of extremely high DTR on schizophrenia was observed, with a 2.7% (95% CI: 1.007-1.047) increase of daily schizophrenia admissions after exposure to extremely high DTR (95th percentile vs. 50th percentile). The risk for schizophrenia onset due to large DTR exposure increased from the first five years (2005-2009) to the second five years (2010-2014). Additionally, the patient aged 15-29 and 50-64years, male patients, patients born in spring/autumn, and married patients appeared to be more vulnerable to DTR effect. However, there was no significant association between moderately high DTR (75th percentile) and schizophrenia. CONCLUSIONS This study suggests that extremely high DTR is a potential trigger for schizophrenia admissions in Hefei, China. Our findings may provide valuable information to decisions-makers and guidance to health practitioners.

Nonlinear and Interactive Effects of Temperature and Humidity on Childhood Hand, Foot and Mouth Disease in Hefei, China.

Background: Hand, foot and mouth disease (HFMD) is one of the major infectious diseases among children and remains a health threat, especially among Asian countries. Many epidemiologic studies suggested significant association of air temperature and humidity with childhood HFMD; however, evidence on the temperature effects on childhood HFMD in temperate cities is limited, and the interactive effects of temperature and humidity have not been studied yet. Methods: Daily counts of HFMD in children younger than 15 years of age and daily meteorologic variables during 2010 to 2012 were obtained in Hefei, China. A distributed lag nonlinear model was applied to estimate the potential nonlinear association between temperature and childhood HFMD. The interactive effects between temperature and humidity on childhood HFMD were also investigated. Results: Temperature rise was associated with higher risk of childhood HFMD. Within the incubation period of HFMD, temperature rise appeared to have the acute effects on childhood HFMD, and a 5°C increase of temperature at lag 0–6 days was associated with 24.8% (95% confidence interval: 11.94%–39.10%) increase of childhood HFMD. Females and children of 0–4 years of agewere more vulnerable to temperature rise. Notably, there were obvious combined effects between temperature and humidity on childhood HFMD—the risk of childhood HFMD elevated at higher temperature and humidity level. Conclusions: This study provides evidence that temperature and humidity may jointly affect childhood HFMD, and such interactive impact needs to be considered when evaluating the temperature–childhood HFMD relationship.

Asthma and Risk of Stroke: A Systematic Review and Meta-analysis

BACKGROUND Several studies have suggested that asthma is associated with an increased risk of stroke. However, the results are inconsistent. The aim of this study is to investigate the relation of asthma and the risk of stroke through a systematic review and meta-analysis of published research. METHODS Pertinent studies were identified by a search of the PubMed and the Web of Science databases to June 2015. Study-specific hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled using fixed-effect or random-effect models when appropriate. Associations were tested in subgroups representing different participants and study characteristics. Publication bias was assessed with Eggers test. RESULTS Five articles comprising 524,637 participants and 6031 stroke cases were eligible for inclusion. Asthma was associated significantly with increased risk of stroke, and the pooled HR was 1.32 (95% CI: 1.13, 1.54, I(2)=80.4%). Subgroup analyses revealed that the association between asthma and stroke risk was stronger among female patients (HR = 1.42, 95% CI: 1.15-1.76) and prospective cohort study design (HR = 1.52, 95% CI: 1.21-1.91). CONCLUSION Asthma is associated with a significantly increased risk of stroke. This finding may have clinical and public health importance.

Daily temperature change in relation to the risk of childhood bacillary dysentery among different age groups and sexes in a temperate city in China

BACKGROUND In recent years, many studies have found that ambient temperature is significantly associated with bacillary dysentery (BD). However, there is limited evidence on the relationship between temperature and childhood BD in temperate areas. OBJECTIVES To investigate the relationship between daily mean temperature (MT) and childhood BD in China. METHODS Data on daily MT and childhood BD between 2006 and 2012 were collected from the Bureau of Meteorology and the Centre for Disease Control and Prevention in Hefei, Anhui Province, China. A Poisson generalized linear regression model combined with a distributed lag non-linear model was used to analyse the effects of temperature on childhood BD across different age and sex subgroups. RESULTS An increase in temperature was significantly associated with childhood BD, and each 1 °C increase corresponded to an increase of 1.58% [95% confidence interval (CI) 0.46-2.71%] in the number of cases of BD. Children aged 0-5 years and girls were particularly sensitive to the effects of temperature. CONCLUSIONS High temperatures may increase the risk of childhood BD in Hefei. Children aged 0-5 years and girls appear to be particularly sensitive to the effects of high temperature.