Ambient temperature and Covid-19 transmission: An evidence from a region of Iran based on weather station and satellite data

The association between weekly mean temperature and the epidemic of influenza across 122 countries/regions, 2014-2019

The study examined the association between weekly mean temperature and influenza cases across 122 countries/regions (2014-2019) using a distributed lag non-linear model (DLNM). We analyzed 3145206 cases of overall influenza (Flu-All), with influenza A (Flu-A) and influenza B (Flu-B) accounting for 73.49% and 26.51%, respectively. Within a lag of 2 weeks, Flu-All incidence demonstrated a bimodal temperature relationship, with peak relative risks (RR) of 6.02 (95% CI: 1.92-20.77) at -8 ℃ and 3.08 (95% CI: 1.27-7.49) at 22 ℃. Flu-A exhibited a similar bimodal pattern, with RRs of 3.76 (95% CI: 2.39-5.91) at -8 ℃ and 2.08 (95% CI: 1.55-2.80) at 22 ℃. Flu-B demonstrated a single risk peak at 1 ℃ (RR = 4.48, 95% CI: 1.74-11.55). Subgroup analyses of climate zones revealed variations: tropical zones peaked at 12 ℃ (RR = 1.37, 95% CI: 1.08-1.74), while dry and temperate zones exhibited the highest risk at -5 ℃, with RRs of 4.49 (95% CI: 2.46-7.15) and 5.23 (95% CI: 3.17-8.64), respectively. Cold zones peaked at 1 ℃ (RR = 5.96, 95% CI: 3.76-9.43). Subgroup analyses of influenza transmission zones (ITZs) revealed variations: Africa showed higher risk between 6 ℃-14 ℃, Asia showed higher risk below 3 ℃, and Europe exhibited distinct risks of influenza peaks at -1 ℃ (Eastern), 1 ℃ (Southwest), and -20 ℃ (Northern). Elevated risks above 11 ℃ were identified in the Americas and Oceania. These findings establish a predictive framework for influenza outbreak preparedness by integrating regional temperature patterns with global climate variability.

The effect of heatwave and cold spell on cardiovascular disease mortality in central China, 2018-2022

Heatwave and cold spell have been linked to cardiovascular disease (CVD) mortality. However, due to the varying definitions of heatwave and cold spell, their impacts on CVD mortality are inconsistent.

METHODS

A time series study in Hunan province, central of China, from 2018 to 2022, was conducted to test the relationship between heatwave, cold spell and CVD mortality. According to different percentiles of daily mean temperatures and exposure duration, we built 9 kind of definitions for heatwave and cold spell. Distributed lag non-linear model was used to analyze the associations between heatwave, cold spell and CVD mortality, and the attributable fraction (AF) were estimated.

RESULTS

The relative risks of CVD mortality associated with heatwave and cold spell varied depending on the definitions, ranging from 1.154 (95% CI: 1.148-1.160) to 1.229 (95% CI: 1.215-1.243) for heatwaves, and from 1.196 (95% CI: 1.192-1.201) to 1.290 (95% CI: 1.282-1.297) for cold spells. Under the definition of 95th percentile with ≥ 4-d duration (P95_4d), the total AF of CVD mortality attributable to heatwave was the largest at 8.43 (95% CI: 7.92-8.94). For the definition of 5th percentile with ≥ 3-d duration (P5_3d), the total AF attributable to cold spell was the largest at 12.96 (95% CI: 12.64-13.28). For heatwave and cold spell, higher CVD mortality risks were observed in females and the elderly over 75 years than males and young people.

DISCUSSION

We found that both heatwave and cold spell could increase the mortality risk of CVD. The results highlight the importance of implementing warning systems for extreme temperature.

Associations of heatwaves and their characteristics with ischaemic stroke hospital admissions

Ischaemic stroke (IS) has a heavy disease burden. Although epidemiological research has suggested that heatwaves are associated with cardiovascular disease, there is a lack of empirical evidence for a correlation between heatwaves and IS. The China Meteorological Administration defines a heatwave as a wave lasting ≥ 3 days, with a maximum temperature of ≥ 35℃. We collected data on daily meteorological conditions, air pollution, and IS admissions in Hunan Province from 2018 to 2019. A generalized additive model and distributed lag nonlinear model were used to determine the associations between heatwaves and IS admissions. We analysed 329,876 admitted patients with IS in Hunan Province from 2018 to 2019. The main effect of heatwaves was that they significantly increased the risk of hospitalization for IS. The single-day lag maximum risk occurred at a daily average temperature of 30.88℃ (RR = 1.05, 95% CI: 1.04-1.06) and at a daily maximum temperature of 35.82℃ (RR = 1.05, 95% CI: 1.03-1.06). The use of the 5th and subsequent days of a heatwave as a reference showed that the 1st-2nd days (RR = 1.07, 95% CI: 1.02-1.12) and the 3rd-4th days (RR = 1.68, 95% CI: 1.03-1.10) of the heatwave increased the risk of hospitalization for IS. Compared with the third and subsequent heatwaves, the first (RR = 1.27, 95% CI: 1.19-1.35) and second (RR = 1.24, 95% CI: 1.16-1.32) heatwaves had greater impacts on the risk of hospitalization for IS. The risk of IS hospitalization was also exacerbated by high relative humidity (RR = 1.25, 95% CI: 1.16-1.35) and a low diurnal temperature range (RR = 1.08, 95% CI: 1.02-1.14) during the heatwave period. In our study, the main effects of heatwaves increased the risk of IS hospitalization. The effects varied according to the day of the heatwave, the timing of the heatwave, the DTR during the heatwave, and the humidity during the heatwave. This evidence has significant implications for the strategic planning of public health interventions to mitigate adverse health outcomes associated with heatwaves.

Seasonal variation of Covid-19 incidence and role of land surface and air temperatures: a case study in the west of Iran

.In this study, we assessed the impact of satellite-based Land Surface Temperature (LST) and Air Temperature (AT) on covid-19. First, we spatio-temporally kriged the LST and applied bias correction. The epidemic shape, timing, and size were compared after and before adjusting for the predictors. Given the non-linear behavior of a pandemic, a semi-parametric regression model was used. In addition, the interaction effect between the predictors and season was assessed. Before adjusting for the predictors, the peak happened at the end of hot season. After adjusting, it was attenuated and slightly moved forward. Moreover, the Attributable Fraction (AF) and Peak to Trough Relative (PTR) were % 23 (95% CI; 15, 32) and 1.62 (95%CI; 1.34, 1.97), respectively. We found that temperature might have changed the seasonal variation of covid-19. However, given the large uncertainty after adjusting for the variables, it was hard to provide conclusive evidence in the region we studied.

Covid-19 outbreak associated with demographic-meteorological factors in the arid and semi-arid region Iran: case study Gonabad city, 2020-2021

Since the (Covid-19) pandemic outbreak, questioning regarding climate and incident of Covid-19 infection rates has been debated, while there is no clear research evidence until now in Iran. This study has focused on investigating the association between Covid-19 cases and demographic -meteorological factors in arid and semi-arid zones of Iran (from March 1, 2020, to January 31, 2022) by analyzing with Via Poisson and negative binomial regression. As a result, the incidence rate of both Covid-19 hospitalization and mortality cases reached peaks in the summer followed by the autumn. Interestingly, Covid-19 hospitalization cases are associated with humidity, temperature, and wind factors seasonally and monthly, but mortality cases are just associated with wind. In conclusion, the result demonstrated that demographicand meteorological factorsare positively and negatively associated with Covid-19 cases. Therefore, identifying the environmental factors contributing to the excess Covid-19 can help to prevent future pandemic waves in Iranian arid and semi-arid zone.

Elucidating the role of environmental management of forests, air quality, solid waste and wastewater on the dissemination of SARS-CoV-2

The increasing frequency of zoonotic diseases is amongst several catastrophic repercussions of inadequate environmental management. Emergence, prevalence, and lethality of zoonotic diseases is intrinsically linked to environmental management which are currently at a destructive level globally. The effects of these links are complicated and interdependent, creating an urgent need of elucidating the role of environmental mismanagement to improve our resilience to future pandemics. This review focused on the pertinent role of forests, outdoor air, indoor air, solid waste and wastewater management in COVID-19 dissemination to analyze the opportunities prevailing to control infectious diseases considering relevant data from previous disease outbreaks. Global forest management is currently detrimental and hotspots of forest fragmentation have demonstrated to result in zoonotic disease emergences. Deforestation is reported to increase susceptibility to COVID-19 due to wildfire induced pollution and loss of forest ecosystem services. Detection of SARS-CoV-2 like viruses in multiple animal species also point to the impacts of biodiversity loss and forest fragmentation in relation to COVID-19. Available literature on air quality and COVID-19 have provided insights into the potential of air pollutants acting as plausible virus carrier and aggravating immune responses and expression of ACE2 receptors. SARS-CoV-2 is detected in outdoor air, indoor air, solid waste, wastewater and shown to prevail on solid surfaces and aerosols for prolonged hours. Furthermore, lack of protection measures and safe disposal options in waste management are evoking concerns especially in underdeveloped countries due to high infectivity of SARS-CoV-2. Inadequate legal framework and non-adherence to environmental regulations were observed to aggravate the postulated risks and vulnerability to future waves of pandemics. Our understanding underlines the urgent need to reinforce the fragile status of global environmental management systems through the development of strict legislative frameworks and enforcement by providing institutional, financial and technical supports.