Aug 2026· Frontiers in Pediatrics· Vol 14· 0 citations· 36 references
Medicine
TL;DR
High temperature and high relative humidity were associated with increased daily outpatient visits for HA in Guangzhou, whereas low temperature and lower relative humidity were associated with fewer visits in the main model.
Abstract
Objective Herpangina (HA) is a common acute infectious disease in children that may exhibit epidemiological patterns associated with meteorological factors. This study investigated the short-term and lagged associations of temperature and relative humidity with daily outpatient visits for HA in Guangzhou and explored patterns across sex and age groups. Methods Daily outpatient visits for HA, daily mean temperature, relative humidity, and particulate matter with an aerodynamic diameter of 2.5 micrometers or less (PM2.5) were collected from January 1, 2014 to December 31, 2023. A quasi-Poisson generalized linear model combined with distributed lag nonlinear models was used to estimate exposure-lag-response associations. Temperature, relative humidity, and PM2.5 cross-basis terms were included simultaneously, with adjustment for long-term trends, seasonality, day of week, public holidays, and the COVID-19 period. Results During the study period, 83,146 HA outpatient visits were recorded, 56.4% of which were among male patients. Daily outpatient visits showed clear seasonal variation, with larger peaks generally occurring during summer and autumn. Compared with the median temperature (24.38 °C), the cumulative RR was 0.482 (95% CI: 0.353–0.657) at the 2.5th percentile (10.77 °C) and 1.966 (95% CI: 1.714–2.254) at the 97.5th percentile (30.63 °C) over lags 0–14 days. Compared with the median relative humidity (79.15%), the cumulative RR was 0.878 (95% CI: 0.795–0.970) at the 10th percentile (62.21%) and 1.477 (95% CI: 1.297–1.682) at the 97.5th percentile (93.21%) over lags 0–20 days. High-temperature and high-humidity associations were observed across sex and age strata. The lower-humidity association was less robust in sensitivity analyses. Conclusion High temperature and high relative humidity were associated with increased daily outpatient visits for HA in Guangzhou, whereas low temperature and lower relative humidity were associated with fewer visits in the main model. The lower-humidity estimate was less stable across alternative temporal-control settings. These findings support incorporating lagged meteorological information into HA surveillance and preparedness.
This study aims to quantify the short-term association between ambient air pollutants and outpatient visits for conjunctivitis using empirical data. Methods: This study collected daily outpatient visits for conjunctivitis in Jiayuguan City from January 1, 2023 to December 31, 2024, as well as meteorological and air pollutant data during the same period. We used a quasi-Poisson generalized linear regression model that incorporates a distributed lag nonlinear model to analyze the nonlinear relationship and lag effect between pollutant exposure and the risk of outpatient visits for conjunctivitis, and conducted stratified analysis by gender, age and season to identify susceptible populations. Results: A total of 14,598 cases of conjunctivitis were included during the study. The results showed that particulate matter (PM
2.5
and PM
10
) was not statistically significantly associated with outpatients for conjunctivitis, and the exposure-response curve showed a downward trend. Conversely, gaseous pollutants (NO
2
and CO) showed a significant positive linear correlation with outpatients for conjunctivitis, with the effect being stronger in the cold season. NO
2
was significant at lag1-3, lag5 days and lag02–07 days, with each 10 µg/m
3
increase corresponding to an RR of 1.126 (95% CI 1.050, 1.208), corresponding to a 12.60% increase in patient visits. CO had the strongest effect at lag07 days (RR = 1.836, 95% CI 1.126, 2.991). Furthermore, NO
2
primarily increases conjunctivitis visits in women and children (0–14 years), while CO exposure is significantly associated with conjunctivitis visits in men and older adults (≥ 65 years). Conclusions: In this arid, industrial city in Northwest China, gaseous pollutants (rather than particulate matter) are the key environmental factor driving the increase in conjunctivitis outpatient visits. This study reveals the differentiated effects of specific pollutants on populations with different demographic characteristics, highlighting the public health significance of strengthening ocular surface health protection for specific vulnerable subgroups during the cold season.
Yanan Zhang, Guorui Song, Bo Zheng et al.· Aerosol and Air Quality Rese...· 0 citations
OBJECTIVE
To examine the seasonal distribution of AECOPD hospitalizations in Shijiazhuang (2020-2024), the lag associations of air pollutants (PM2.5, PM10, NO2, O3, SO2, CO) and meteorological factors (mean temperature, diurnal temperature range) across seasons, and to explore the season-specific models for high-incidence admission days as an exploratory environmental-surveillance analysis rather than a ready-to-deploy clinical early-warning system.
METHODS
This city-wide retrospective time-series study analyzed 22,468 AECOPD admissions in Shijiazhuang from January 1, 2020 to December 31, 2024, using hospitalization front-page records covering all tertiary, secondary, and community hospitals in the city, obtained from the municipal medical insurance database (inpatient admissions only; ED discharges without admission were not included). Each year was divided by solar terms into spring (3/7-6/7), summer (6/8-9/7), autumn (9/8-12/7), and winter (12/8-3/6), with daily air pollution and meteorological data matched to admissions. Univariate and multivariate Poisson generalized linear regression (GLM) assessed single-day lag associations (lags 0-7 as eight separate lags); multivariable models and prediction features used the 7-day mean of lags 0-6 (admission day + preceding 6 days), not an 8-day lag0-7 average. Using each factor's 7-day cumulative window as input, we built logistic regression, random forest, and gradient boosting models and evaluated high-incidence-day prediction via fivefold time-series cross-validation, treating the many lag × pollutant × season tests as exploratory. Sensitivity analyses added during revision included collinearity diagnostics (VIF/correlation matrix), quasi-Poisson models with smooth time, a distributed-lag nonlinear temperature model (DLNM), COVID-period analyses, humidity/heating checks, alternative lag windows, and a near-term exposure prediction re-run.
RESULTS
AECOPD admissions peaked in winter and were the lowest in summer (winter 6,009; spring 5,854; autumn 5,554; summer 5,051); the male-to-female ratio was ∼3.7:1 and mean age 71.7 ± 9.1 years. After multivariate adjustment, each 10 µg/m³ rise in winter PM10 and NO2 was associated with a 6.9% (IRR 1.069, 95%CI 1.052-1.085) and 8.9% (1.089, 1.050-1.129) higher admission rate, respectively. A 1 °C fall in mean temperature corresponded to a 4.4% increase (IRR 0.958, 0.947-0.969) and a 1 °C wider diurnal range to a 5.5% increase (1.055, 1.034-1.077). O3 was positively associated in summer and autumn (1.035, 1.015-1.056; 1.022, 1.005-1.039). Apparent protective multipollutant IRRs (e.g., winter PM2.5) were interpreted cautiously given collinearity. Prediction discrimination was the modest even when above chance: winter random forest fivefold CV AUC of 0.653 ± 0.112; other seasons ranged 0.50-0.62. Overall, environmental exposures were weak predictors of high-incidence days. Diagnostic re-analyses (Section 3.4), after reconciling the panel to the locked 22,468-admission cohort, showed acceptable collinearity (all VIF < 5, addressed with single-pollutant models), overdispersion handled by quasi-Poisson, and nonlinear temperature effects by DLNM (cold-induced excess, heat-related reduction), alongside a 2022 admission trough (∼50-54% of 2020/2024) and a near-term exposure re-run (same-day and lags 1-3 features) that reproduced the modest winter discrimination (AUC ≈0.66); against a calendar-only baseline the incremental value of the environmental block was small (overall ΔAUC ≈ +0.02 to +0.045), indicating the exposures are primarily explanatory rather than operationally predictive.
CONCLUSION
AECOPD admissions show high winter incidence, with PM10, NO2, CO, low temperature, and a wide diurnal range as the main winter associated factors, and summer-autumn O3 exposure warranting attention. The 7-day cumulative-exposure model showed only the modest discrimination in winter (AUC ≈0.65) and is best viewed as an exploratory, hypothesis-generating surveillance analysis rather than a preliminary operational early-warning tool.
Higher temperature was consistently associated with rapid increases in AR outpatient visits in this humid subtropical population, providing epidemiological evidence for climate-sensitive AR prevention and support the incorporation of meteorological indicators into seasonal surveillance, early warning systems, and healthcare resource planning.
Jian Peng, Ganglei Shen, Kehong Zhang et al.· Frontiers in Public Health· 0 citations
Meteorological factors may influence the risk of foodborne diseases (FBDs), but evidence comparing different case definitions and pathogen-specific associations within the same surveillance system remains limited. This study aimed to investigate the relationship between short-term exposure to meteorological factors and FBDs in Ningbo, China. We used data from the Ningbo Foodborne Disease Surveillance System and the daily meteorological data of the Ningbo Meteorological Bureau for time-series analysis. Generalized additive models and distributed lag nonlinear models were used to evaluate the associations adjusted for long-term trends, seasonal changes, day of week, and holidays. A stratified analysis was carried out by sex, age, and pathogens. We found that short-term temperature rise was significantly associated with risk of clinically diagnosed FBD cases (mean: relative risks [RR] = 1.028, 95% confidence interval [CI]: 1.006-1.049; minimum: RR = 1.025, 95% CI: 1.004-1.047). Sex- and age-stratified analyses indicated positive temperature associations in both sexes and in several age groups between 15 and 64 years. Pathogen-specific analyses show that there is a positive relationship for Vibrio parahaemolyticus (mean temperature: RR = 1.087, 95% CI: 1.021-1.157), whereas an inverse relationship for Norovirus (mean temperature: RR = 0.965, 95% CI: 0.938-0.993). The findings remained robust in sensitivity analyses. These findings may inform targeted seasonal and pathogen-specific surveillance.
Yi-Chao Dai, Dan-Jie Jiang, B. Lu et al.· Foodborne pathogens and dise...· 0 citations
This study quantifies humid-heat-related OID risks and investigates the socioeconomic determinants driving spatial vulnerability in Anhui, China, highlighting an “adaptation deficit” in less-developed regions.
Mengyuan Gao, Jinling Song, Jing Wu et al.· BMC Public Health· 0 citations
Background Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonotic disease with a high case fatality rate and expanding geographic distribution in Japan. Comprehensive evaluations that integrate meteorological, environmental, and demographic factors remain limited. This study aimed to quantify these associations. Methods We conducted a nationwide prefecture-level time-series analysis using weekly SFTS surveillance data in Japan from March 2013 to December 2025. A generalized additive mixed model adjusting for nonlinear seasonality and long-term trends was used to assess (1) the associations between SFTS risk and meteorological, environmental and demographic factors, and (2) the value of the factor at which risk become highest. Results A total of 1237 SFTS cases were reported. Mean temperature and precipitation showed inverted U-shaped associations with SFTS risk, with peak risks observed at 21.8 °C (relative risk [RR]: 1.78, 95% confidence interval [CI]: 1.26–2.52) and 156.6 mm (RR: 1.30, 95% CI: 1.04–1.62), respectively. Atmospheric pressure and forest coverage were positively associated with SFTS risk, with maximum RRs of 2.06 (95% CI: 1.44–2.93) at 1027.1 hPa and 6.58 (95% CI: 4.95–8.74) at 0.84, respectively. Mean altitude showed an inverse association, with the highest RR observed at 45.0 m (RR: 3.99, 95% CI: 1.81–8.76). Conclusions The increasing number and geographic expansion of SFTS cases highlight the growing public health importance of this disease in Japan. Our findings improve understanding of factors associated with SFTS transmission and may inform future risk assessment and public health preparedness.
Fangyu Yan, Sophearen Ith, N. Kitamura et al.· One Health· 0 citations
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