A systematic evidence review of the effect of climate change on malaria in Iran

Protocol for a systematic review of economic evaluations considering costs and health outcomes of weather and climate-related extreme events in humans

BACKGROUND

Extreme weather and climate-related events are increasing in frequency and intensity, which pose substantial human casualties and economic losses. The healthcare and health-determining sectors require information about how extreme weather events affect the population's health, healthcare and other sectors' capacities to prepare for and manage these events and their aftermath. We aim to conduct a systematic review to identify the recent evidence on the costs and health outcomes of extreme weather events in humans.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines were followed for reporting this protocol. A comprehensive search will be conducted using several search engines, for example, PubMed, Scopus and Institute for Scientific Information Web of Science. Peer-reviewed and grey literature published in English that evaluated the health outcomes and costs of extreme climate events will be retrieved without restriction on the publication year or geographical location. Two reviewers will independently assess each study for inclusion. Study quality will be evaluated with the recommended quality assessment tools. Data will be reported using descriptive statistics, graphical plots and a narrative synthesis.

ETHICS AND DISSEMINATION

An ethical assessment was not required. The data generated from the systematic review will be disseminated through peer-reviewed journal articles and international conferences and will inform our original research study.

PROSPERO REGISTRATION NUMBER

This systematic review has been registered at the International Prospective Register of Systematic Reviews (registration ID: CRD42024582635).

Malaria in Nepal: A Spatiotemporal Study of the Disease Distribution and Challenges on the Path to Elimination

Malaria incidence (MI) has significantly declined in Nepal, and this study aimed to investigate the spatiotemporal distribution and drivers of MI at the ward level. Data for malaria cases were obtained from the National Surveillance System from 2013 to 2021. Data for covariates, including annual mean temperature, annual mean precipitation, and distance to the nearest city, were obtained from publicly available sources. A Bayesian spatial model was used to identify factors associated with the spatial distribution of MI. Between 2013 and 2021, 7278 malaria cases were reported in Nepal, with a crude incidence rate of 3.0 cases per 100,000 person-years at risk (PYR). MI showed a seasonal variation, with the highest number of cases reported between May and September. The annual MI decreased in recent years from 1.9 per 100,000 PYR in 2018 to 0.1 per 100,000 PYR in 2021. Spatial clustering of MI was observed at the ward level, with most hotspot areas detected in the western Terai plains and upper river valley (URV) areas. Incidence was associated with annual mean precipitation in mm (β = 0.201; 95% CrI: 0.042, 0.360). The shift of the malaria hotspots to the URVs presents a challenge for implementing timely prevention and control activities.

Gender characteristics, social determinants, and seasonal patterns of malaria incidence, relapse, and mortality in Sistan and Baluchistan province and other province of Iran: A systematic review and meta-analysis

INTRODUCTION

Malaria is a climate-dependent disease influenced by gender, social determination, seasonal patterns, and relapse incidence This study reviews these characteristics of malaria in the Sistan and Baluchistan (S&B) province and another province of Iran.

METHODS

This systematic review and meta-analysis was conducted through systematic and manual searches in electronic databases such as PubMed, Web of Science, Scopus, Science Direct, Google Scholar, and the Scientific Information Database. Studies from the S&B province, published from 1990 to 2024, written in Farsi and English, and reporting incidence, relapse, or death were included in this study. The quality of the studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Out of 1941 studies initially identified, 43 were included in the systematic review, with 12 studies on relapse and 43 on incidence included in the meta-analysis. The combined results of the 43 primary studies using the random effect model showed that the frequency of malaria among infected women is 32% in S&B, 22% in other parts of Iran and 24% in the whole of Iran. This is 68%, 77% and 75% in men respectively. Among the primary studies, 8 deaths were reported in two studies, all of which were men. The incidence rate of malaria relapse varied from 0.30% to 46%. Based on the random effect model, the malaria relapse rate in Iran was estimated at 9%. The highest incidence of malaria in Iran was between spring and summer, and the lowest incidence was winter and spring. Most studies showed a downward trend in malaria incidence of malaria between 1986 to 2019. In term of socio-demographic status, malaria was more common in rural areas (82%). Although 28% were employed, and in term of age, young and old individuals (15 to 50 years) had the highest rate of infection.

CONCLUSION

This systematic review and meta-analysis revealed a lower incidence of malaria in women compared to men. The findings highlight the need for health care and the importance of targeted malaria control interventions, especially for men, rural areas, hot weather conditions, and young to middle-aged age groups, particularly in the S&B province.

The issue of climate change and the spread of tropical diseases in Europe and Italy: vector biology, disease transmission, genome-based monitoring and public health implications

BACKGROUND

Climate change significantly influences the distribution and severity of tropical diseases. Rising temperatures, changing precipitation patterns, and extreme weather events are transforming the habitats of vectors like mosquitoes and ticks, promoting their proliferation and geographic spread. These changes have facilitated the resurgence of diseases such as malaria, dengue, and chikungunya fever in previously unaffected areas, including parts of Europe and Italy.

OBJECTIVE AND METHODS

This review aims to explore the relationship between climate change and the spread of vector-borne and tropical parasitic diseases across Europe, with a particular focus on Italy. Recent studies are analyzed to identify emerging trends in disease transmission influenced by shifting climates. Genome-based monitoring and predictive models incorporating climatic and ecological data are highlighted as methods to enhance disease surveillance and preparedness.

RESULTS

The analysis reveals a clear link between climate change and altered disease patterns. The proliferation of vectors into new territories is associated with increased incidence of diseases. Genome-based tools demonstrate their utility in tracking the evolution of pathogens, particularly regarding changes in virulence, drug resistance, and adaptability to new climates. Predictive models have proven effective in anticipating outbreaks and supporting timely public health interventions.

CONCLUSIONS

To mitigate the risks posed by climate-induced changes in disease dynamics, continuous monitoring and international collaboration are essential. Strengthening health systems' resilience through mitigation and adaptation strategies is crucial for preventing future epidemics. These insights contribute to the development of sustainable long-term policies for managing tropical diseases in the context of climate change, ensuring timely responses to public health emergencies.

Impact of temperatures on malaria incidence in vulnerable regions of Pakistan: empirical evidence and future projections

Malaria remains a major health challenge in developing countries, with climate change intensifying its impact. Pakistan is among the most vulnerable nations. This study examines the relationship between temperature and malaria cases in two highly affected districts, Bannu and Lakki Marwat, to inform climate-adaptive interventions.We analyzed monthly malaria cases (2014-2022) from the Integrated Vector Control/Malaria Control Program in Khyber Pakhtunkhwa, combined with gridded meteorological data from Copernicus ERA5-Land. Time-series analysis using distributed lag nonlinear models and quasi-Poisson regression was applied to assess the associations.The findings suggest that as temperatures exceed 22.4°C, malaria transmission increases by 9 to 10% for every 1°C rise in both districts. In Bannu, up to 39.8% of reported malaria cases could be attributed to heat, while in Lakki Marwat, 54.1% of cases were attributable to heat. Under high emission scenarios, heat-related malaria cases could increase by 0.8 to 3.5% by the 2060s. Relationship between temperature and malaria transmission is complex and is influenced by environmental factors such as precipitation and humidity.Given Pakistan's limited healthcare infrastructure, addressing climate-driven malaria risks is urgent. Recent severe floods and malaria surges highlight the need for climate adaptation measures and strengthened healthcare systems to enhance community resilience.

The Real Experience of Lay Responders Performing Cardiopulmonary Resuscitation: A Synthesis of Qualitative Evidence

Objectives

To synthesize qualitative evidence on the experience of lay responders performing cardiopulmonary resuscitation (CPR).

Methods

Qualitative evidence synthesis was performed using the Thomas and Harden method. The PubMed, Cochrane Library, Web of Science, OVID Medline, Embase, CINAHL, CNKI, and WanFang databases were systematically searched. The quality of the research was assessed by the Critical Assessment Skills Program Tool (CASP).

Results

A total of 5,610 studies were identified, and 9 studies were included in the analysis. Four analytical themes were generated: emotional ambivalence before CPR, psychological tolerance during CPR, perceived experience after CPR, and enhancing psychological resilience.

Conclusion

Lay responders face complicated psychological experience during CPR, which may be susceptible to psychological effects such as "loss aversion," "bystander effects" and "knowledge curse." In addition to the timely retraining of CPR, lay responders should be instructed to manage psychological distress and improve psychological resilience. More importantly, the psychological sequelae may be long-lasting, requiring ongoing psychological intervention and follow-up based on valuing transdisciplinarity across endeavours.

A systematic review of the factors associated with malaria infection among forest rangers

INTRODUCTION

Malaria is a vector-borne disease that initially manifests as fever, headache, and chills. The illness could progress to more severe conditions, including lethargy, impaired consciousness, convulsions, shortness of breath, blood in urine, jaundice, and haemorrhage if left untreated. The risk of contracting malaria is considerably heightened in specific occupational settings, particularly among forest rangers, following frequent exposure to natural habitats. Consequently, advancing the understanding of malaria and emphasising how specific occupational environments (including those of forest rangers) contribute to disease risk and management is imperative.

OBJECTIVE

The present study aims to determine the factors associated with malaria infection among forest rangers by systematically reviewing electronic articles from three databases (EBSCOhost, ScienceDirect, and ResearchGate).

METHODS

The current review was prepared based on the updated preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. First, three independent reviewers screened the titles and abstracts of the data collected. The information was then stored in Endnote20 based on the inclusion and exclusion criteria. The articles were critically appraised with the mixed methods appraisal tool (MMAT) to assess their quality.

RESULT

A total of 103, 31, and 51 articles from EBSCOhost, ScienceDirect, and ResearchGate, respectively, were selected, resulting in 185 unique hits. Nevertheless, only 63 full-text publications were assessed following a rigorous selection screening, from which only five were included in the final review. The studies revealed that several factors contribute to malaria infection among forest rangers. The parameters were classified into sociodemographic, individual, and living condition-related.

CONCLUSION

A better understanding of malaria progresses and identifying its potential risk factors is essential to impact worker well-being. The findings might be utilised to improve malaria infection prevention programme implementations, hence maximising their success. Pre-employment and regular health screenings could also aid in evaluating and identifying potential risks for malaria infection among forest rangers.

Impacts of climate change on occupational health indicators in the three climatic regions of Iran

Climate change has increased the exposure risk of workers to occupational health risk factors and diseases. This study aims to investigate the impacts of climate change on the occupational health indicators at the workplaces in Iran. This study was conducted during 2021 in three climatic regions of Iran. Required data was collected from Health Deputies of Medical Universities and Iran Meteorological Organization. Stepwise linear regression model used for data analysis and predictions were done based on three scenarios of SSP1-2.6, SSP3-7.0, and SSP5-8.5 during the period of 2021-2100. This indicated 2.6 and 2.9 times higher percentage of workers who were exposed to heat stress and Ultra Violet (UV) radiation, respectively, in the provinces understudy. This study suggests a holistic approach to address potential impacts of climate change on workers' health and safety that would benefit in making decisions on climate-related planning and developing the adaptation strategies at workplaces.

Long-lasting household damage from Cyclone Idai increases malaria risk in rural western Mozambique

Cyclone Idai in 2019 was one of the worst tropical cyclones recorded in the Southern Hemisphere. The storm caused catastrophic damage and led to a humanitarian crisis in Mozambique. The affected population suffered a cholera epidemic on top of housing and infrastructure damage and loss of life. The housing and infrastructure damage sustained during Cyclone Idai still has not been addressed in all affected communities. This is of grave concern because storm damage results in poor housing conditions which are known to increase the risk of malaria. Mozambique has the 4th highest malaria prevalence in sub-Saharan Africa and is struggling to control malaria in most of the country. We conducted a community-based cross-sectional survey in Sussundenga Village, Manica Province, Mozambique in December 2019-February 2020. We found that most participants (64%) lived in households that sustained damage during Cyclone Idai. The overall malaria prevalence was 31% measured by rapid diagnostic test (RDT). When controlling for confounding variables, the odds of malaria infection was nearly threefold higher in participants who lived in households damaged by Cyclone Idai nearly a year after the storm. This highlights the need for long-term disaster response to improve the efficiency and success of malaria control efforts.

The relationship between climate change and malaria in South-East Asia: A systematic review of the evidence

Background: Climatic change is an inescapable fact that implies alterations in seasons where weather occurrences have their schedules shift from the regular and magnitudes intensify to more extreme variations over a multi-year period. Southeast Asia is one of the many regions experiencing changes in climate and concurrently still has endemicities of malaria. Given that previous studies have suggested the influence of climate on malaria's vector the Anopheles mosquitoes and parasite the Plasmodium group, this study was conducted to review the evidence of associations made between malaria cases and climatic variables in Southeast Asia throughout a multi-year period. Methods: Our systematic literature review was informed by the PRISMA guidelines and registered in PROSPERO: CRD42022301826 on 5 th February 2022. We searched for original articles in English and Indonesian that focused on the associations between climatic variables and malaria cases. Results: The initial identification stage resulted in 535 records of possible relevance and after abstract screening and eligibility assessment we included 19 research articles for the systematic review. Based on the reviewed articles, changing temperatures, precipitation, humidity and windspeed were considered for statistical association across a multi-year period and are correlated with malaria cases in various regions throughout Southeast Asia. Conclusions: According to the review of evidence, climatic variables that exhibited a statistically significant correlation with malaria cases include temperatures, precipitation, and humidity. The strength of each climatic variable varies across studies. Our systematic review of the limited evidence indicates that further research for the Southeast Asia region remains to be explored.

Climate variability, socio-economic conditions and vulnerability to malaria infections in Mozambique 2016-2018: a spatial temporal analysis

Background

Temperature, precipitation, relative humidity (RH), and Normalized Different Vegetation Index (NDVI), influence malaria transmission dynamics. However, an understanding of interactions between socioeconomic indicators, environmental factors and malaria incidence can help design interventions to alleviate the high burden of malaria infections on vulnerable populations. Our study thus aimed to investigate the socioeconomic and climatological factors influencing spatial and temporal variability of malaria infections in Mozambique.

Methods

We used monthly malaria cases from 2016 to 2018 at the district level. We developed an hierarchical spatial-temporal model in a Bayesian framework. Monthly malaria cases were assumed to follow a negative binomial distribution. We used integrated nested Laplace approximation (INLA) in R for Bayesian inference and distributed lag nonlinear modeling (DLNM) framework to explore exposure-response relationships between climate variables and risk of malaria infection in Mozambique, while adjusting for socioeconomic factors.

Results

A total of 19,948,295 malaria cases were reported between 2016 and 2018 in Mozambique. Malaria risk increased with higher monthly mean temperatures between 20 and 29°C, at mean temperature of 25°C, the risk of malaria was 3.45 times higher (RR 3.45 [95%CI: 2.37-5.03]). Malaria risk was greatest for NDVI above 0.22. The risk of malaria was 1.34 times higher (1.34 [1.01-1.79]) at monthly RH of 55%. Malaria risk reduced by 26.1%, for total monthly precipitation of 480 mm (0.739 [95%CI: 0.61-0.90]) at lag 2 months, while for lower total monthly precipitation of 10 mm, the risk of malaria was 1.87 times higher (1.87 [1.30-2.69]). After adjusting for climate variables, having lower level of education significantly increased malaria risk (1.034 [1.014-1.054]) and having electricity (0.979 [0.967-0.992]) and sharing toilet facilities (0.957 [0.924-0.991]) significantly reduced malaria risk.

Conclusion

Our current study identified lag patterns and association between climate variables and malaria incidence in Mozambique. Extremes in climate variables were associated with an increased risk of malaria transmission, peaks in transmission were varied. Our findings provide insights for designing early warning, prevention, and control strategies to minimize seasonal malaria surges and associated infections in Mozambique a region where Malaria causes substantial burden from illness and deaths.

Charting the evidence for climate change impacts on the global spread of malaria and dengue and adaptive responses: a scoping review of reviews

BACKGROUND

Climate change is expected to alter the global footprint of many infectious diseases, particularly vector-borne diseases such as malaria and dengue. Knowledge of the range and geographical context of expected climate change impacts on disease transmission and spread, combined with knowledge of effective adaptation strategies and responses, can help to identify gaps and best practices to mitigate future health impacts. To investigate the types of evidence for impacts of climate change on two major mosquito-borne diseases of global health importance, malaria and dengue, and to identify the range of relevant policy responses and adaptation strategies that have been devised, we performed a scoping review of published review literature. Three electronic databases (PubMed, Scopus and Epistemonikos) were systematically searched for relevant published reviews. Inclusion criteria were: reviews with a systematic search, from 2007 to 2020, in English or French, that addressed climate change impacts and/or adaptation strategies related to malaria and/or dengue. Data extracted included: characteristics of the article, type of review, disease(s) of focus, geographic focus, and nature of the evidence. The evidence was summarized to identify and compare regional evidence for climate change impacts and adaptation measures.

RESULTS

A total of 32 reviews met the inclusion criteria. Evidence for the impacts of climate change (including climate variability) on dengue was greatest in the Southeast Asian region, while evidence for the impacts of climate change on malaria was greatest in the African region, particularly in highland areas. Few reviews explicitly addressed the implementation of adaptation strategies to address climate change-driven disease transmission, however suggested strategies included enhanced surveillance, early warning systems, predictive models and enhanced vector control.

CONCLUSIONS

There is strong evidence for the impacts of climate change, including climate variability, on the transmission and future spread of malaria and dengue, two of the most globally important vector-borne diseases. Further efforts are needed to develop multi-sectoral climate change adaptation strategies to enhance the capacity and resilience of health systems and communities, especially in regions with predicted climatic suitability for future emergence and re-emergence of malaria and dengue. This scoping review may serve as a useful precursor to inform future systematic reviews of the primary literature.

The Impact of Meteorological Factors on Communicable Disease Incidence and Its Projection: A Systematic Review

Background: Climate change poses a real challenge and has contributed to causing the emergence and re-emergence of many communicable diseases of public health importance. Here, we reviewed scientific studies on the relationship between meteorological factors and the occurrence of dengue, malaria, cholera, and leptospirosis, and synthesized the key findings on communicable disease projection in the event of global warming. Method: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 flow checklist. Four databases (Web of Science, Ovid MEDLINE, Scopus, EBSCOhost) were searched for articles published from 2005 to 2020. The eligible articles were evaluated using a modified scale of a checklist designed for assessing the quality of ecological studies. Results: A total of 38 studies were included in the review. Precipitation and temperature were most frequently associated with the selected climate-sensitive communicable diseases. A climate change scenario simulation projected that dengue, malaria, and cholera incidence would increase based on regional climate responses. Conclusion: Precipitation and temperature are important meteorological factors that influence the incidence of climate-sensitive communicable diseases. Future studies need to consider more determinants affecting precipitation and temperature fluctuations for better simulation and prediction of the incidence of climate-sensitive communicable diseases.

Health effects of climate change: an overview of systematic reviews

OBJECTIVES

We aimed to develop a systematic synthesis of systematic reviews of health impacts of climate change, by synthesising studies' characteristics, climate impacts, health outcomes and key findings.

DESIGN

We conducted an overview of systematic reviews of health impacts of climate change. We registered our review in PROSPERO (CRD42019145972). No ethical approval was required since we used secondary data. Additional data are not available.

DATA SOURCES

On 22 June 2019, we searched Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Cochrane and Web of Science.

ELIGIBILITY CRITERIA

We included systematic reviews that explored at least one health impact of climate change.

DATA EXTRACTION AND SYNTHESIS

We organised systematic reviews according to their key characteristics, including geographical regions, year of publication and authors' affiliations. We mapped the climate effects and health outcomes being studied and synthesised major findings. We used a modified version of A MeaSurement Tool to Assess systematic Reviews-2 (AMSTAR-2) to assess the quality of studies.

RESULTS

We included 94 systematic reviews. Most were published after 2015 and approximately one-fifth contained meta-analyses. Reviews synthesised evidence about five categories of climate impacts; the two most common were meteorological and extreme weather events. Reviews covered 10 health outcome categories; the 3 most common were (1) infectious diseases, (2) mortality and (3) respiratory, cardiovascular or neurological outcomes. Most reviews suggested a deleterious impact of climate change on multiple adverse health outcomes, although the majority also called for more research.

CONCLUSIONS

Most systematic reviews suggest that climate change is associated with worse human health. This study provides a comprehensive higher order summary of research on health impacts of climate change. Study limitations include possible missed relevant reviews, no meta-meta-analyses, and no assessment of overlap. Future research could explore the potential explanations between these associations to propose adaptation and mitigation strategies and could include broader sociopsychological health impacts of climate change.

Climatic changes and their role in emergence and re-emergence of diseases

Global warming and the associated climate changes are predictable. They are enhanced by burning of fossil fuels and the emission of huge amounts of CO2 gas which resulted in greenhouse effect. It is expected that the average global temperature will increase with 2-5 °C in the next decades. As a result, the earth will exhibit marked climatic changes characterized by extremer weather events in the coming decades, such as the increase in temperature, rainfall, summertime, droughts, more frequent and stronger tornadoes and hurricanes. Epidemiological disease cycle includes host, pathogen and in certain cases intermediate host/vector. A complex mixture of various environmental conditions (e.g. temperature and humidity) determines the suitable habitat/ecological niche for every vector host. The availability of suitable vectors is a precondition for the emergence of vector-borne pathogens. Climate changes and global warming will have catastrophic effects on human, animal and environmental ecosystems. Pathogens, especially neglected tropical disease agents, are expected to emerge and re-emerge in several countries including Europe and North America. The lives of millions of people especially in developing countries will be at risk in direct and indirect ways. In the present review, the role of climate changes in the spread of infectious agents and their vectors is discussed. Examples of the major emerging viral, bacterial and parasitic diseases are also summarized.

Do climate changes alter the distribution and transmission of malaria? Evidence assessment and recommendations for future studies

Malaria, a mosquito-borne infectious disease, is considered a significant global health burden. Climate changes or different weather conditions may impact infectious diseases, specifically those transmitted by insect vectors and contaminated water. Based on the current predictions for climate change associated with the increase in carbon dioxide concentrations in the atmosphere and the increase in atmospheric temperature, the Intergovernmental Panel on Climate Change predicts that in 2050, malaria may threaten some previously unexposed areas worldwide and cause a 50% higher probability of malaria cases. Climate-based distribution models of malaria depict an increase in the geographic distribution of the disease as global environmental temperatures and conditions worsen. Researchers have studied the influence of changes in climate on the prevalence of malaria using different mathematical models that consider different variables and predict the conditions for malaria distribution. In this context, we conducted a mini-review to elucidate the important aspects described in the literature on the influence of climate change in the distribution and transmission of malaria. It is important to develop possible risk management strategies and enhance the surveillance system enhanced even in currently malaria-free areas predicted to experience malaria in the future.