Climate Change and Cascading Risks from Infectious Disease

Frequency and Outcome of Emergency Penetrating Keratoplasty in Infectious Keratitis in Sweden During the 21st Century

PURPOSE

To study the frequency over time and outcome of penetrating keratoplasty (PK), "keratoplasty à chaud," in patients with infectious keratitis with 2-year follow-up data.

METHODS

This register-based study included keratitis cases that had undergone PK in Sweden between 2001 and 2020 and reported to the Swedish Corneal Transplant Register.

RESULTS

During the study period, 69 eyes were subjected to acute PK due to progressive infectious keratitis. The number increased from 2 annual procedures in the first half of the study period to 5 in the second half ( P = 0.01). Preoperative corneal perforation was present in 43.5% (n = 30) of the eyes. Two years after surgery, follow-up data were completed in the register for 53 eyes; of these, 62.3% (n = 33) were considered to have functioning grafts, and 20.8% (n = 11) had experienced a rejection episode. The visual acuity improved from hand motion to counting fingers ( P = 0.002), and the proportion of eyes with a visual acuity of ≤1.0 logMAR increased from 5.7% (n = 3) before the surgery to 45.3% (n = 24) at the 2-year follow-up ( P < 0.001).

CONCLUSIONS

The number of active infectious keratitis cases undergoing keratoplasty à chaud increased in Sweden during the 21st century. Most of the cases were successful regarding the structural integrity of the bulb, that is, "had a saved eye" and even a functioning graft 2 years after corneal transplantation. The visual gain was distinct, albeit modest. In cases with severe infectious keratitis, and even a concomitant perforation in the cornea due to the infection, corneal transplantation should continue to be an option.

An Overview of Climate Changes and Its Effects on Health: From Mechanisms to One Health

Human activities, primarily the burning of fossil fuels, widespread deforestation, soil erosion or machine-intensive farming methods, manufacturing, food processing, mining, construction, and the iron, cement, steel, and chemicals industries, have been the main drivers of the observed increase in Earth's average surface temperature and climate change. Rising global temperatures, extreme weather events, ecosystems disruption, agricultural impacts, water scarcity, problems in access to good quality water, food and housing, and profound environmental disruptions such as biodiversity loss and extreme pollution are expected to steeply increase the prevalence and severity of acute and chronic diseases. Its long-term effects cannot be adequately predicted or mitigated without a comprehensive understanding of the adaptive ecosystems. Studying the complex interaction between environmental aggressors and the resilient adaptive responses requires the exposomic and the One Health approaches. The problem is broad and affects the whole ecosystem, plants, pets, and animals in addition to humans. The central role of the epithelial barrier, microbiome, and diet as key pillars for an adaptive tolerogenic immune response should be explored for increasing resilience at the individual level. A radical change in mindset worldwide, with sustainable solutions and adaptive strategies and climate resilience and health equity policies at their center, should be achieved quickly through increased awareness based on solid scientific data.

Natural Compounds and Their Analogs as Antivirals Against Dengue Virus: A Review

Dengue virus (DENV) continues to pose a significant global health challenge, causing diseases such as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. While efforts in vaccine development and antiviral drug discovery are ongoing, effective therapeutic options remain limited. In this review, we highlight natural compounds and the analogs that demonstrated antiviral activity against DENV in in vitro and in vivo studies. Specifically, these studies examine alkaloids, phenolic acids, phenols, flavonoids, terpenoids, and glycosides which have shown potential in inhibiting DENV entry, replication, and reducing the cytokine storm. By focusing on these bioactive compounds and the analogs, a comprehensive overview of their promising roles is provided to advance therapeutic strategies for combating DENV infection.

A framework for managing infectious diseases in rural areas in low- and middle-income countries in the face of climate change-East Africa as a case study

Climate change is having unprecedented impacts on human health, including increasing infectious disease risk. Despite this, health systems across the world are currently not prepared for novel disease scenarios anticipated with climate change. While the need for health systems to develop climate change adaptation strategies has been stressed in the past, there is no clear consensus on how this can be achieved, especially in rural areas in low- and middle-income countries that experience high disease burdens and climate change impacts simultaneously. Here, we highlight the need to put health systems in the context of climate change and demonstrate how this can be achieved by taking into account all aspects of infectious disease risk (i.e., pathogen hazards, and exposure and vulnerability to these pathogen hazards). The framework focuses on rural communities in East Africa since communities in this region experience climate change impacts, present specific vulnerabilities and exposure to climate-related hazards, and have regular exposure to a high burden of infectious diseases. Implementing the outlined approach can help make health systems climate adapted and avoid slowing momentum towards achieving global health grand challenge targets.

Transgression of planetary boundaries and the effects on child health through an infectious diseases lens

PURPOSE OF REVIEW

Life on earth, as we know it, is changing. The likelihood of more frequent pandemics and disease outbreaks is something that current global healthcare infrastructure is ill equipped to navigate. Human activity is forcing our planet into a new geologic epoch, the Anthropocene, which is typified by increased uncertainty resulting from human disruption of earth's life-giving ecosystems. Plagues and pandemics have always been unfortunate partners to periods of disruption, as they will be again if the frequency and severity of climate and conflict-mediated disasters increase in coming years. If we continue to exceed and degrade the planetary boundaries that protect human health, our children and their children will reap the consequences.

RECENT FINDINGS

Scientists have defined nine 'safe operating' planetary boundaries for life in all its glorious diversity to thrive on planet earth. Recent evidence suggests that six of these nine boundaries have already been transgressed, but the potential implications for these transgressions upon child health is not well articulated. We highlight how contravention of these boundaries will impact infectious disease risk and humans' ability to survive and thrive. We reflect specifically on how paediatricians are called upon to speak up for the most vulnerable members of our species, young children and as yet unborn future generations.

SUMMARY

Post COVID-19 initiatives to improve pandemic preparedness and response are certainly warranted, but pandemic prevention should include committed efforts not to exceed safe planetary boundaries. Willingly exceeding these boundaries has deep moral consequences that are poorly articulated by current ethical frameworks. Paediatricians are best placed to develop and champion the neglected 'third dimension' of medical ethics, recognizing the moral imperative to protect the long-term best interests of children and future generations.

Exploiting venom toxins in paratransgenesis to prevent mosquito-borne disease

Mosquitoes are responsible for the transmission of numerous pathogens, including Plasmodium parasites, arboviruses and filarial worms. They pose a significant risk to public health with over 200 million cases of malaria per annum and approximately 4 billion people at risk of arthropod-borne viruses (arboviruses). Mosquito populations are geographically expanding into temperate regions and their distribution is predicted to continue increasing. Mosquito symbionts, including fungi, bacteria and viruses, have desirable traits for mosquito disease control including spreading horizontally and vertically through mosquito populations and potentially colonising multiple important vector species. Paratransgenesis, genetic modification of mosquito symbionts with effectors to target the pathogen rather than the vector, is a promising strategy to prevent the spread of mosquito-borne diseases. A variety of effectors can be expressed but venom toxins are excellent effector candidates because they are target specific, potent and stable. However, the only toxins to be explored in mosquito paratransgenesis to date are scorpine and mutated phospholipase A2. To enhance the scope, effectiveness and durability of paratransgenesis, an expanded arsenal of effectors is required. This review discusses other potential toxin effectors for future paratransgenesis studies based on prior in vitro and in vivo antiparasitic and antiviral studies and highlights the need for further research and investment in this area. In terms of mosquito-borne diseases, paratransgenesis strategies have been developed to target Plasmodium. We postulate the potential to apply this principle to target arboviruses using antiviral toxin effectors.

Virus-like particle-based vaccines targeting the Anopheles mosquito salivary protein TRIO

Malaria is a highly lethal infectious disease caused by Plasmodium parasites. These parasites are transmitted to vertebrate hosts when mosquitoes of the Anopheles genus probe for a blood meal. Sporozoites, the infectious stage of Plasmodium, transit to the liver within hours of injection into the dermis. Vaccine efforts are hindered by the complexity of the parasite's lifecycle and the speed at which the infection is established in the liver. In an effort to enhance immunity against Plasmodium, we produced a virus-like particle (VLP)-based vaccine displaying an epitope of TRIO, an Anopheles salivary protein that has been shown to enhance mobility and dispersal of sporozoites in the dermis. Previous work demonstrated that passive immunization with TRIO offered protection from liver infection and acted synergistically with a Plasmodium-targeted vaccine. Immunization of mice with TRIO VLPs resulted in high-titer and long-lasting antibody responses that did not significantly drop for over 18 months post-immunization. TRIO VLPs were similarly immunogenic when combined with an anti-malaria vaccine targeting the L9 epitope of the Plasmodium falciparum circumsporozoite protein. However, when used in a malaria challenge mouse model, TRIO VLPs only provided modest protection from infection and did not boost the protection provided by L9 VLPs.IMPORTANCEProteins present in the salivary glands of mosquitos have been shown to enhance the transmission efficiency of mosquito-borne pathogens, suggesting that interventions targeting the activity of these proteins could reduce transmission. Here, we looked at the efficacy of a vaccine targeting TRIO, an Anopheles mosquito salivary protein that has been reported to enhance Plasmodium falciparum malaria infection. We show that this vaccine can elicit strong anti-TRIO antibody responses, but these antibodies only result in a modest decrease in infection.

Occupational allergy and climate change

PURPOSE OF REVIEW

Climate change influences working conditions in various ways, affecting employee health and safety across different sectors. Climatic factors like rising temperatures, increased UV radiation, and more frequent extreme weather events pose risks to in both indoor and outdoor workers. Allergic diseases of the respiratory tract and the skin may emerge due to climate change. This review summarizes current aspects of both direct and indirect consequences of climate change and associated exposures in diverse work environments, focusing on occupational allergies.

RECENT FINDINGS

Outdoor workers, in particular, are increasing susceptible to ubiquitous pollen allergens. Additionally, they may experience climate-related increases in allergens typically associated with specific workplaces, such as Cryptostroma corticale. Changes in production processes, along with altered workplaces exposures, can lead to new sensitizations and trigger allergies, representing indirect consequences of climate change. Furthermore, lifestyle changes aimed to promoting climate protection and sustainability (e.g. the introduction of insects as a protein source or using enzymes), may also contribute to the emergence of new allergens.

SUMMARY

The emergence of new occupational sensitization sources from novel or modified allergen exposures must be addressed within the framework of workplace safety and health, necessitating proactive measures to safeguard workers and mitigate risks.

Genetic diversity of Plasmodium falciparum reticulocyte binding protein homologue-5, which is a potential malaria vaccine candidate: baseline data from areas of varying malaria endemicity in Mainland Tanzania

BACKGROUND

The limited efficacy of the two recently approved malaria vaccines, RTS,S/AS01 and R21/Matrix- M™, highlights the need for alternative vaccine candidate genes. Plasmodium falciparum Reticulocyte Binding Protein Homologue 5 (Pfrh5) is a promising malaria vaccine candidate, given its limited polymorphism, its essential role in parasite survival, a lack of immune selection pressure and higher efficacy against multiple parasites strains. This study evaluated the genetic diversity of Pfrh5 gene among parasites from regions with varying malaria transmission intensities in Mainland Tanzania, to generate baseline data for this potential malaria vaccine candidate.

METHODS

This study utilized secondary data of 697 whole-genome sequences which were generated by the MalariaGEN Community Network. The samples which were sequenced to generated the data were collected between 2010 and 2015 from five districts within five regions of Mainland Tanzania, with varying endemicities (Morogoro-urban district in Morogoro region, Muheza in Tanga, Kigoma-Ujiji in Kigoma, Muleba in Kagera, and Nachingwea district in Lindi region). Wright's fixation index (FST), Wright's inbreeding coefficient (Fws), Principal component analysis (PCA), nucleotide diversity (π), haplotype network, haplotype diversity (Hd), Tajima's D, and Linkage disequilibrium (LD) were used to assess the diversity of the gene.

RESULTS

Of the sequences used in this study, 84.5% (n = 589/697) passed quality control and 313 (53.1%) were monoclonal (contained infections from a single strain of P. falciparum) and were used for haplotype diversity and haplotype network analysis. High within-host diversity (Fws < 0.95) was reported in Kigoma-Ujiji (60.7%), Morogoro-urban (53.1%), and Nachingwea (50.8%), while Muleba (53.9%) and Muheza (61.6%) had low within-host diversity (Fws ≥ 0.95). PCA did not show any population structure and the mean FST value was 0.015. Low nucleotide diversity values were observed across the study sites (mean π = 0.00056). A total of 27 haplotypes were observed among the 313 monoclonal samples and under-fives exhibited higher haplotype counts. The Pf3D7 was detected as Hap_1, which occurred in 16/313 (5.1%) monoclonal sequences. Negative Tajima's D values were observed among the parasite populations in all the study sites.

CONCLUSION

Low levels of polymorphism in the pfrh5 gene were observed based on low nucleotide and haplotype diversity, a lack of population structure and negative Tajima's D values. This study provides essential data on the diversity of the Pfrh5 gene indicating that it can be considered in the development of the next generation malaria vaccines. Robust and intensive studies of this and other candidate genes are crucial to support the prioritization of the Pfrh5 gene for potential inclusion in a broadly cross-protective malaria vaccine.

Assessing tick attachments to humans with citizen science data: spatio-temporal mapping in Switzerland from 2015 to 2021 using spatialMaxent

BACKGROUND

Ticks are the primary vectors of numerous zoonotic pathogens, transmitting more pathogens than any other blood-feeding arthropod. In the northern hemisphere, tick-borne disease cases in humans, such as Lyme borreliosis and tick-borne encephalitis, have risen in recent years, and are a significant burden on public healthcare systems. The spread of these diseases is further reinforced by climate change, which leads to expanding tick habitats. Switzerland is among the countries in which tick-borne diseases are a major public health concern, with increasing incidence rates reported in recent years.

METHODS

In response to these challenges, the "Tick Prevention" app was developed by the Zurich University of Applied Sciences and operated by A&K Strategy Ltd. in Switzerland. The app allows for the collection of large amounts of data on tick attachment to humans through a citizen science approach. In this study, citizen science data were utilized to map tick attachment to humans in Switzerland at a 100 m spatial resolution, on a monthly basis, for the years 2015 to 2021. The maps were created using a state-of-the-art modeling approach with the software extension spatialMaxent, which accounts for spatial autocorrelation when creating Maxent models.

RESULTS

Our results consist of 84 maps displaying the risk of tick attachments to humans in Switzerland, with the model showing good overall performance, with median AUC ROC values ranging from 0.82 in 2018 to 0.92 in 2017 and 2021 and convincing spatial distribution, verified by tick experts for Switzerland. Our study reveals that tick attachment to humans is particularly high at the edges of settlement areas, especially in sparsely built-up suburban regions with green spaces, while it is lower in densely urbanized areas. Additionally, forested areas near cities also show increased risk levels.

CONCLUSIONS

This mapping aims to guide public health interventions to reduce human exposure to ticks and to inform the resource planning of healthcare facilities. Our findings suggest that citizen science data can be valuable for modeling and mapping tick attachment risk, indicating the potential of citizen science data for use in epidemiological surveillance and public healthcare planning.

Introduction of Vector-Borne Infections in Europe: Emerging and Re-Emerging Viral Pathogens with Potential Impact on One Health

The rise and resurgence of vector-borne diseases (VBDs) in Europe pose an expanding public health challenge, exacerbated by climate change, globalization, and ecological disruptions. Both arthropod-borne viruses (arboviruses) transmitted by ticks such as Crimean-Congo hemorrhagic fever and arboviruses transmitted by mosquitoes like dengue, Chikungunya, Zika, and Japanese encephalitis have broadened their distribution due to rising temperatures, changes in rainfall, and increased human mobility. By emphasizing the importance of interconnected human, animal, and environmental health, integrated One Health strategies are crucial in addressing this complex issue. Europe faces increased risk due to the expanding habitats of disease-carrying organisms, the spread of new species like Aedes albopictus since 2013, and increased movement of infected individuals between countries, leading European countries to implement strategies such as enhanced surveillance systems, public awareness campaigns, and prompt outbreak response strategies. However, the lack of both targeted antiviral therapies and vaccines for many arboviruses, together with undetected or asymptomatic cases, hamper containment efforts. Therefore, it is important to have integrated strategies that combine climate modeling, disease surveillance, and public health interventions to address expected changes in disease patterns due to global changes. This review explores the spread of arboviruses in Europe, highlighting their historical context, current transmission dynamics, and their impact on public health.

Environment, Lifestyles, and Climate Change: The Many Nongenetic Contributors to The Long and Winding Road to Autoimmune Diseases

A critical unanswered question is what is causing the increase in the prevalence of autoimmunity and autoimmune diseases around the world. Given the rapidity of change, this is likely the result of major recent alterations in our exposures to environmental risk factors for these diseases. More evidence is becoming available that the evolution of autoimmune disease, years or even decades in the making, results from multiple exposures that alter susceptible genomes and immune systems over time. Exposures during sensitive phases in key developmental or hormonal periods may set the stage for the effects of later exposures. It is likely that synergistic and additive impacts of exposure mixtures result in chronic low-level inflammation. This inflammation may eventually pass thresholds that lead to immune system activation and autoimmunity, and with further molecular and pathologic changes, the complete clinical syndrome emerges. Much work remains to be done to define the mechanisms and risk and protective factors for autoimmune conditions. However, evidence points to a variety of pollutants, xenobiotics, infections, occupational exposures, medications, smoking, psychosocial stressors, changes in diet, obesity, exercise, and sleep patterns, as well as climate change impacts of increased heat, storms, floods, wildfires, droughts, UV radiation, malnutrition, and changing infections, as possible contributors. Substantial investments in defining the role of causal factors, in whom and when their effects are most important, the necessary and sufficient gene-environment interactions, improved diagnostics and therapies, and preventive strategies are needed now to limit the many negative personal, societal, and financial impacts that will otherwise occur.

[Emerging pathogens of ocular infections due to environmental changes-What lies ahead?]

Due to the global effects of climate change numerous infectious diseases are increasingly spreading to regions that were previously hardly or only slightly affected. As ocular involvement is possible in many of these infectious diseases, we must also adapt to new pathogens and clinical pictures in Germany in the medium to long term. Using selected bacterial, viral and mycotic pathogens and diseases as examples, the causes of the increase in dissemination and the consequences for ophthalmology are presented.

Buruli ulcer: An epidemiological update from Japan

Japan is one of the rare non-tropical countries with documented cases of Buruli ulcer (BU). Mycobacterium ulcerans subsp. shinshuense has been identified as the causative agent. The first report of BU in Japan dates back to 1982, with sporadic reports thereafter. Recently, the number of cases has been on the increase, and 50 cases (57.7%) are from the past decade alone, out of a total of 87 cases reported to date. Japan's well-developed healthcare facilities play a crucial role in enabling detailed investigations and providing appropriate treatment for patients, contributing to a favorable prognosis. However, the rarity of the disease results in lack of awareness among healthcare professionals, leading to frequent delays in diagnosis. This article aims to offer an updated overview of BU cases in Japan and to raise awareness of BU among dermatologists and other healthcare professionals in a non-endemic setting.

Flaviviruses-Induced Neurological Sequelae

Flaviviruses, a group of single-stranded RNA viruses spread by mosquitoes or ticks, include several significant neurotropic viruses, such as West Nile virus (WNV), Japanese encephalitis virus (JEV), tick-borne encephalitis virus (TBEV), and Zika virus (ZIKV). These viruses can cause a range of neurological diseases during acute infection, from mild, flu-like symptoms to severe and fatal encephalitis. A total of 20-50% of patients who recovered from acute flavivirus infections experienced long-term cognitive issues. Here, we discuss these major neurotropic flaviviruses-induced clinical diseases in humans and the recent findings in animal models and provide insights into the underlying disease mechanisms.

Time trends in malaria incidence from 1992 to 2021 in high-risk regions: An age‑period‑cohort analysis based on the Global Burden of Disease study 2021

OBJECTIVES

Malaria, caused by plasmodium parasites, remains one of the world's most significant infectious diseases due to its high incidence and mortality. This study aims to analyze malaria incidence globally, identify high-risk regions, and examine long-term trends in incidence to provide important evidence for malaria eradication.

METHODS

We used data from the Global Burden of Disease Study 2021, applying the age-period-cohort model to estimate the effects of age, period, and cohort on malaria incidence from 1992 to 2021. We calculated the net drift (overall annual percentage change), local drift (annual percentage change for each age group), longitudinal age curves (expected longitudinal age-specific rates), and period (cohort) relative risks.

RESULTS

In 2021, the global age-standardized incidence rate of malaria declined to 3485.3 per 100,000 (95% uncertainty interval [UI]: 2804.5-4435.7), a 5.24% decrease since 1992. Sub-Saharan Africa has the highest age-standardized rate at 20,225.9 per 100,000 (95% UI: 16,033.5-25,862.6), accounting for 92% of all new cases globally. From 1992 to 2021, age-standardized malaria incidence rates generally declined across highest-risk regions, although Sub-Saharan Africa saw the smallest decline, with a net drift of -0.74% (95% confidence interval: -1.32 to 0.17). The 0-4 age group faces the highest risk, which decreases with age.

CONCLUSION

Malaria continues to threaten public health in Sub-Saharan Africa, particularly among the 0-4 age group. Efforts should focus on enhancing access to malaria control measures and implementing targeted public health policies for priority groups.

Climate change and the emergence and exacerbation of infectious diseases: A review

Experts expressed severe concerns over the possibility of increasing burden of infectious diseases as the planet's climate began to change years ago. There have been increased rates of climate-related catastrophes and as global temperatures rise, emergence of certain viruses has become a serious concern. Vectors are susceptible to changing temperatures as they exhibit innate responses to thermal stress to increase survivability. Climate change impacts virus reservoirs, increasing transmission rates of vectors. Vector-borne diseases have already witnessed increasing numbers compared to before. Certain non-endemic areas are encountering their first-ever infectious disease cases due to increasing temperatures. Tick-borne diseases are undergoing transformations provoking a heightened prevalence. Food-borne illnesses are expected to increase owing to warmer temperatures. It is important to recognize that climate change has a multivariable impact on the transmission of viruses. With climate change comes the potential of increasing interspecies interactions promoting jumps. These factors must be considered, and an informed strategy must be formulated. Adaptation and mitigation strategies are required to curb these diseases from spreading. Despite significant evidence that climate change affects infectious diseases, gaps in research exist. We conducted this review to identify the potential role climate change plays in the emergence of new viruses.

Spatial examination of social and environmental drivers of Middle East respiratory syndrome coronavirus (MERS-CoV) across Kenya

Climate and agricultural land-use change has increased the likelihood of infectious disease emergence and transmissions, but these drivers are often examined separately as combined effects are ignored. Further, seldom are the influence of climate and agricultural land use on emerging infectious diseases examined in a spatially explicit way at regional scales. Our objective in this study was to spatially examine the climate, agriculture, and socio-demographic factors related to agro-pastoralism, and especially the combined effects of these variables that can influence the prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels across northern Kenya. Our research questions focused on: (1) How MERS-CoV in dromedary camels has varied across geographic regions of northern Kenya, and (2) what climate, agriculture, and socio-demographic factors of agro-pastoralism were spatially related to the geographic variation of MERS-CoV cases in dromedary camels. To answer our questions, we analyzed the spatial distribution of historical cases based on serological evidence of MERS-CoV at the county level and applied spatial statistical analysis to examine the spatial relationships of the MERS-CoV cases between 2016 and 2018 to climate, agriculture, and socio-demographic factors of agro-pastoralism. Regional differences in MERS-CoV cases were spatially correlated with both social and environmental factors, and particularly ethno-religious camel practices, which highlight the complexity in the distribution of MERS-CoV in dromedary camels across Kenya.

The 2024 report of the Lancet Countdown on health and climate change: facing record-breaking threats from delayed action

Despite the initial hope inspired by the 2015 Paris Agreement, the world is now dangerously close to breaching its target of limiting global multiyear mean heating to 1·5°C. Annual mean surface temperature reached a record high of 1·45°C above the pre-industrial baseline in 2023, and new temperature highs were recorded throughout 2024. The resulting climatic extremes are increasingly claiming lives and livelihoods worldwide.

The Lancet Countdown: tracking progress on health and climate change was established the same year the Paris Agreement entered into force, to monitor the health impacts and opportunities of the world’s response to this landmark agreement. Supported through strategic core funding from Wellcome, the collaboration brings together over 300 multidisciplinary researchers and health professionals from around the world to take stock annually of the evolving links between health and climate change at global, regional, and national levels.

The 2024 report of the Lancet Countdown, building on the expertise of 122 leading researchers from UN agencies and academic institutions worldwide, reveals the most concerning findings yet in the collaboration’s 8 years of monitoring.

The impact of temperature on non-typhoidal Salmonella and Campylobacter infections: an updated systematic review and meta-analysis of epidemiological evidence

BACKGROUND

As temperatures rise, the transmission and incidence of enteric infections such as those caused by Salmonella and Campylobacter increase. This study aimed to review and synthesise the available evidence on the effects of exposure to ambient temperatures on non-typhoidal Salmonella and Campylobacter infections.

METHODS

A systematic search was conducted for peer-reviewed epidemiological studies published between January 1990 and March 2024, in PubMed, Scopus, Embase, and Web of Science databases. Original observational studies using ecological time-series, case-crossover or case-series study designs reporting the association between ambient temperature and non-typhoidal Salmonella and Campylobacter infections in the general population were included. A random-effects meta-analysis was performed to pool the relative risks (RRs) per 1 °C temperature increase, and further meta regression, and subgroup analyses by climate zone, temperature metrics, temporal resolution, lag period, and continent were conducted. The Navigation Guide systematic review methodology framework was used to assess the quality and strength of evidence. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO).

FINDINGS

Out of 3472 results, 44 studies were included in this systematic review encompassing over one million cases each of Salmonella and Campylobacter infections. Geographically, the 44 studies covered 27 countries across five continents and most of the studies were from high income countries. The meta-analysis incorporated 23 Salmonella studies (65 effect estimates) and 15 Campylobacter studies (24 effect estimates). For each 1 °C rise in temperature, the risk of non-typhoidal Salmonella and Campylobacter infections increased by 5% (RR: 1.05, 95% CI: 1.04-1.06), and 5% (RR: 1.05, 95% CI: 1.04-1.07%), respectively, with varying risks across different climate zones. The overall evidence was evaluated as being of "high" quality, and the strength of the evidence was determined to be "sufficient" for both infections.

INTERPRETATION

These findings emphasise the relationship between temperature and the incidence of Salmonella and Campylobacter infections. It is crucial to exercise caution when generalising these findings, given the limited number of studies conducted in low and middle-income countries. Nevertheless, the results demonstrate the importance of implementing focused interventions and adaptive measures, such as the establishment of localised early warning systems and preventive strategies that account for climatic fluctuations. Furthermore, our research emphasises the ongoing need for surveillance and research efforts to monitor and understand the changing dynamics of temperature-related enteric infections in the context of climate change.

FUNDING

Australian Research Council Discovery Projects grant (ARC DP200102571) Program.

Seroprevalence of seven arboviruses of public health importance in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

The arboviruses continue to be a threat to public health and socioeconomic development in sub-Saharan Africa (SSA). Seroprevalence surveys can be used as a population surveillance strategy for arboviruses in the absence of treatment and vaccines for most arboviruses, guiding the public health interventions. The objective of this study was to analyse the seroprevalence of arboviruses in SSA through a systematic review and meta-analysis.

METHODS

We searched PubMed/MEDLINE, Web of Science, Embase, Scopus and ScienceDirect databases for articles published between 2000 and 2022 reporting the seroprevalence of immunoglobulin G (IgG) antibodies to seven arboviruses in various human populations residing in SSA. The included studies were assessed using the checklist for assessing the risk of bias in prevalence studies, and the data were extracted using a standard form. A random effects model was used to estimate pooled seroprevalences. The potential sources of heterogeneity were explored through subgroup analyses and meta-regression. The protocol had been previously registered on International Prospective Register of Systematic Reviews with the identifier: CRD42022377946.

RESULTS

A total of 165 studies from 27 countries, comprising 186 332 participants, were included. Of these, 141 were low-risk and 24 were moderate-risk. The pooled IgG seroprevalence was 23.7% (17.9-30.0%) for Chikungunya virus, 22.7% (17.5-28.4%) for dengue virus, 22.6% (14.1-32.5%) for West Nile virus, 16.4% (7.1-28.5%) for yellow fever virus, 13.1% (6.4-21.7%) for Zika virus, 9.2% (6.5-12.3%) for Rift Valley fever virus and 6.0% (3.1-9.7) for Crimean-Congo haemorrhagic fever virus. Subgroup and meta-regression analyses showed that seroprevalence differed considerably between countries, study populations, specific age categories, sample sizes and laboratory methods.

CONCLUSION

This SRMA provides information on the significant circulation of various arboviruses in SSA, which is essential for the adoption and planning of vaccines. These findings suggest the need to invest in surveillance and research activities on arbovirus in SSA countries to increase our understanding of their epidemiology to prevent and respond to future epidemics.

Impact of urban greening on population health in sub-Saharan Africa: a scoping review protocol

INTRODUCTION

The rate of urbanisation in sub-Saharan Africa (SSA) has increased remarkably, with the urban population expected to double by 2050. This rapid urbanisation, industrialisation and climate change pose serious public health challenges resulting from increased heat waves and other environmental changes. Urban greening holds promise as a climate change mitigation and adaptation strategy, leading to biodiversity conservation and enhancing the physical, mental and social well-being of the population.

METHODS AND ANALYSIS

This scoping review aims to identify and synthesise studies that investigated the availability and utilisation of green spaces, the factors that affect the utilisation of green spaces as well as the health impacts of urban greening in SSA. A systematic search will be conducted across multiple databases (MEDLINE, PubMed, JSTOR, SCOPUS and Green FILE) and grey literature sources for papers published up to 2024, in line with established scoping review frameworks. The data will be charted and extracted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Extension for Scoping Reviews. We will further synthesise and use thematic analysis to fully understand the relationship between urban greening and population health in SSA.

ETHICS AND DISSEMINATION

Ethical approval will not be required because primary data will not be collected for the study. The results of this study come from published articles, which are publicly available. The results of the review will be submitted to a peer-reviewed journal for publication and presented at workshops and conferences.

REGISTRATION

The scoping review protocol has been registered on the Open Science Framework https://osf.io/nfh68.

Impacts of climate change on water-related mosquito-borne diseases in temperate regions: A systematic review of literature and meta-analysis

Mosquito-borne diseases are a known tropical phenomenon. This review was conducted to assess the mecha-nisms through which climate change impacts mosquito-borne diseases in temperate regions. Articles were searched from PubMed, Scopus, Web of Science, and Embase databases. Identification criteria were scope (climate change and mosquito-borne diseases), region (temperate), article type (peer-reviewed), publication language (English), and publication years (since 2015). The WWH (who, what, how) framework was applied to develop the research question and thematic analyses identified the mechanisms through which climate change affects mosquito-borne diseases. While temperature ranges for disease transmission vary per mosquito species, all are viable for temperate regions, particularly given projected temperature increases. Zika, chikungunya, and dengue transmission occurs between 18-34 °C (peak at 26-29 °C). West Nile virus establishment occurs at monthly average temperatures between 14-34.3 °C (peak at 23.7-25 °C). Malaria establishment occurs when the consecutive average daily temperatures are above 16 °C until the sum is above 210 °C. The identified mechanisms through which climate change affects the transmission of mosquito-borne diseases in temperate regions include: changes in the development of vectors and pathogens; changes in mosquito habitats; extended transmission seasons; changes in geographic spread; changes in abundance and behaviors of hosts; reduced abundance of mosquito predators; interruptions to control operations; and influence on other non-climate factors. Process and stochastic approaches as well as dynamic and spatial models exist to predict mosquito population dynamics, disease transmission, and climate favorability. Future projections based on the observed relations between climate factors and mosquito-borne diseases suggest that mosquito-borne disease expansion is likely to occur in temperate regions due to climate change. While West Nile virus is already established in some temperate regions, Zika, dengue, chikungunya, and malaria are also likely to become established over time. Moving forward, more research is required to model future risks by incorporating climate, environmental, sociodemographic, and mosquito-related factors under changing climates.

Assessing and correcting neighborhood socioeconomic spatial sampling biases in citizen science mosquito data collection

Climatic, ecological, and socioeconomic factors are facilitating the spread of mosquito-borne diseases, heightening the importance of vector surveillance and control. Citizen science is proving to be an effective tool to track mosquito populations, but methods are needed to detect and account for small scale sampling biases in citizen science surveillance. In this article we combine two types of traditional mosquito surveillance records with data from the Mosquito Alert citizen science system to explore the ways in which the socioeconomic characteristics of urban neighborhoods result in sampling biases in citizen scientists' mosquito reports, while also shaping the spatial distribution of mosquito populations themselves. We use Barcelona, Spain, as an example, and focus on Aedes albopictus, an invasive vector species of concern worldwide. Our results suggest citizen scientists' sampling effort is focused more in Barcelona's lower and middle income census tracts than in its higher income ones, whereas Ae. albopictus populations are concentrated in the city's upper-middle income tracts. High resolution estimates of the spatial distribution of Ae. albopictus risk can be improved by controlling for citizen scientists' sampling effort, making it possible to provide better insights for efficiently targeting control efforts. Our methodology can be replicated in other cities faced with vector mosquitoes to improve public health responses to mosquito-borne diseases, which impose massive burdens on communities worldwide.

Epidemiological characteristics and transmission dynamics of dengue fever in China

China has experienced successive waves of dengue epidemics over the past decade. Nationwide data on 95,339 dengue cases, 89 surveillance sites for mosquito density and population mobility between 337 cities during 2013-20 were extracted. Weekly dengue time series including time trends and harmonic terms were fitted using seasonal regression models, and the amplitude and peak timing of the annual and semiannual cycles were estimated. A data-driven model-inference approach was used to simulate the epidemic at city-scale and estimate time-evolving epidemiological parameters. We found that the geographical distribution of dengue cases was expanding, and the main imported areas as well as external sources of imported cases changed. Dengue cases were predominantly concentrated in southern China and it exhibited an annual peak of activity, typically peaking in September. The annual amplitude of dengue epidemic varied with latitude (F = 19.62, P = 0.0001), mainly characterizing by large in southern cities and small in northern cities. The effective reproduction number Reff across cities is commonly greater than 1 in several specific months from July to November, further confirming the seasonal fluctuations and spatial heterogeneity of dengue epidemics. The results of this national study help to better informing interventions for future dengue epidemics in China.

Virus-like particle-based vaccines targeting the Anopheles mosquito salivary protein, TRIO

Malaria is a highly lethal infectious disease caused by Plasmodium parasites. These parasites are transmitted to vertebrate hosts when mosquitoes of the Anopheles genus probe for a blood meal. Sporozoites, the infectious stage of Plasmodium , transit to the liver within hours of injection into the dermis. Vaccine efforts are hindered by the complexity of the parasite's lifecycle and the speed at which the infection is established in the liver. In an effort to enhance immunity against Plasmodium , we produced a virus-like particle (VLP)-based vaccine displaying an epitope of TRIO, an Anopheles salivary protein which has been shown to enhance mobility and dispersal of sporozoites in the dermis. Previous work demonstrated that passive immunization with TRIO offered protection from liver infection and acted synergistically with a Plasmodium targeted vaccine. Immunization of mice with TRIO VLPs resulted in high-titer and long-lasting antibody responses that did not significantly drop for over 18 months post-immunization. TRIO VLPs were similarly immunogenic when combined with an anti-malaria vaccine targeting the L9 epitope of the Plasmodium falciparum circumsporozoite protein.However, when used in a malaria challenge mouse model, TRIO VLPs only provided modest protection from infection and did not boost the protection provided by L9 VLPs.

Current Status of Malaria Control and Elimination in Africa: Epidemiology, Diagnosis, Treatment, Progress and Challenges

The African continent carries the greatest malaria burden in the world. Falciparum malaria especially has long been the leading cause of death in Africa. Climate, economic factors, geographical location, human intervention and unstable security are factors influencing malaria transmission. Due to repeated infections and early interventions, the proportion of clinically atypical malaria or asymptomatic plasmodium carriers has increased significantly, which easily lead to misdiagnosis and missed diagnosis. African countries have made certain progress in malaria control and elimination, including rapid diagnosis of malaria, promotion of mosquito nets and insecticides, intermittent prophylactic treatment in high-risk groups, artemisinin based combination therapies, and the development of vaccines. Between 2000 and 2022, there has been a 40% decrease in malaria incidence and a 60% reduction in mortality rate in the WHO African Region. However, many challenges are emerging in the fight against malaria in Africa, such as climate change, poverty, substandard health services and coverage, increased outdoor transmission and the emergence of new vectors, and the growing threat of resistance to antimalarial drugs and insecticides. Joint prevention and treatment, identifying molecular determinants of resistance, new drug development, expanding seasonal malaria chemo-prevention intervention population, and promoting the vaccination of RTS, S/AS01 and R21/Matrix-M may help to solve the dilemma. China's experience in eliminating malaria is conducive to Africa's malaria prevention and control, and China-Africa cooperation needs to be constantly deepened and advanced. Our review aims to help the global public develop a comprehensive understanding of malaria in Africa, thereby contributing to malaria control and elimination.

An outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 associated with contaminated lettuce and the cascading risks from climate change, the United Kingdom, August to September 2022

Shiga-toxin producing Escherichia coli (STEC) O157 is a food-borne pathogen which causes gastrointestinal illness in humans. Ruminants are considered the main reservoir of infection, and STEC exceedance has been associated with heavy rainfall. In September 2022, a large outbreak of STEC O157:H7 was identified in the United Kingdom (UK). A national-level investigation was undertaken to identify the source of the outbreak and inform risk mitigation strategies. Whole genome sequencing (WGS) was used to identify outbreak cases. Overall, 259 cases with illness onset dates between 5 August and 12 October 2022, were confirmed across the UK. Epidemiological investigations supported a UK grown, nationally distributed, short shelf-life food item as the source of the outbreak. Analytical epidemiology and food chain analysis suggested lettuce as the likely vehicle of infection. Food supply chain tracing identified Grower X as the likely implicated producer. Independent of the food chain investigations, a novel geospatial analysis triangulating meteorological, flood risk, animal density and land use data was developed, also identifying Grower X as the likely source. Novel geospatial analysis and One Health approaches are potential tools for upstream data analysis to predict and prevent contamination events before they occur and to support evidence generation in outbreak investigations.

The association between climatic factors and waterborne infectious outbreaks with a focus on vulnerability in Pakistan: integrative review

Climate change affects the spread of waterborne infectious diseases, yet research on vulnerability to outbreaks remains limited. This integrative review examines how climate variables (temperature and precipitation) relate to human vulnerability factors in Pakistan. By 2060, mean temperatures are projected to rise from 21.68°C (2021) to 30°C, with relatively stable precipitation. The epidemiological investigation in Pakistan identified Diarrhea (119,000 cases/year), Malaria (2.6 million cases/year), and Hepatitis (A and E) as the most prevalent infections. This research highlighted vulnerability factors, including poverty (52% of the population), illiteracy (59% of the population), limited healthcare accessibility (55% of the population), malnutrition (38% of the population), dietary challenges (48% of the population), as well as exposure to water pollution (80% of the population) and air pollution (55% of the population). The findings suggest that the coordinated strategies are vital across health, environmental, meteorological, and social sectors, considering climatic variability patterns and population vulnerability determinants.

The Role of High-Level Isolation Units in Response to High-Consequence and Emerging Infectious Diseases: Experience of the German STAKOB Network

This case study describes the experience of the German Permanent Working Group of Competence and Treatment Centers for High Consequence Infectious Diseases, known as STAKOB (Ständiger Arbeitskreis der Kompetenz- und Behandlungszentren für Krankheiten durch hochpathogene Erreger). STAKOB brings together public health authorities (competence centers) and high-level isolation units (treatment centers) to collaborate on the clinical management of high-consequence infectious diseases (HCIDs) and emerging infectious diseases. The network is coordinated by the Robert Koch Institute, Germany's federal public health institute. The main tasks of STAKOB are to strengthen HCID clinical and public health management and increase expert knowledge on HCID and non-HCID emerging infectious diseases in Germany. STAKOB enables the exchange of knowledge and experiences; development of guidelines on infection prevention and control measures, clinical management, and therapy; and support for the World Health Organization and other outbreak responses internationally. The past years have shown how important the STAKOB network is for Germany-not only in providing critical care for HCID cases but also increasing capacity to support public health and clinical management of emerging infectious disease cases. However, maintaining several high-level isolation units in Germany requires a high commitment of financial, material, and human resources. Due to the rarity of HCID and emerging infectious disease events, maintaining the appropriate level of preparedness and ensuring sufficient investments is an ongoing struggle. Nevertheless, it is essential to have a network ready to react to HCID and non-HCID emerging infectious diseases in times of a changing biosecurity and infectious landscape.

One Health Ethics and the Ethics of Zoonoses: A Silent Call for Global Action

This paper presents a critical review of key issues related to the emergence of new networks for the spread of zoonotic diseases amid the mass extinction of species. Zoonotic and infectious diseases account for approximately 70% of new and existing diseases affecting humans and animals. The initial section argues that the term "zoonoses" should not be confined to single-cause events within veterinary medicine. Instead, zoonoses should be viewed as complex, systemic phenomena shaped by interrelated factors, including environmental, sociocultural, and economic elements, influenced by anthropogenic climate change. The second section presents bioethical principles and potential strategies for those engaged in zoonotic disease prevention. The third section uses the slaughter of animals in disaster settings as a case study to illustrate the need for further clarification of normative and interspecies justice conflicts in One Health ethics. This section concludes with an outlook on "zoonoethics". Section four develops the analysis of the interlinked elements that trigger zoonoses and examines antimicrobial resistance (AMR) from an ethical and political standpoint, concluding with policy recommendations for addressing AMR. Section five offers a critical reflection, integrating contributions from zoonoethics, human ecology, and the ecotheological turn. Finally, section six concludes with a call to action and policy recommendations for an inclusive, intercultural, and gender-sensitive One Health approach.

High-resolution mapping of urban Aedes aegypti immature abundance through breeding site detection based on satellite and street view imagery

Identification of Aedes aegypti breeding hotspots is essential for the implementation of targeted vector control strategies and thus the prevention of several mosquito-borne diseases worldwide. Training computer vision models on satellite and street view imagery in the municipality of Rio de Janeiro, we analyzed the correlation between the density of common breeding grounds and Aedes aegypti infestation measured by ovitraps on a monthly basis between 2019 and 2022. Our findings emphasized the significance (p ≤ 0.05) of micro-habitat proxies generated through object detection, allowing to explain high spatial variance in urban abundance of Aedes aegypti immatures. Water tanks, non-mounted car tires, plastic bags, potted plants, and storm drains positively correlated with Aedes aegypti egg and larva counts considering a 1000 m mosquito flight range buffer around 2700 ovitrap locations, while dumpsters, small trash bins, and large trash bins exhibited a negative association. This complementary application of satellite and street view imagery opens the pathway for high-resolution interpolation of entomological surveillance data and has the potential to optimize vector control strategies. Consequently it supports the mitigation of emerging infectious diseases transmitted by Aedes aegypti, such as dengue, chikungunya, and Zika, which cause thousands of deaths each year.

Complete Blood Count Values Over Time in Young Children During the Dengue Virus Epidemic in the Dominican Republic From 2018 to 2020

Background: Dengue fever (DF) is a mosquito-borne illness with substantial economic and societal impact. Understanding laboratory trends of hospitalized Dominican Republic (DR) pediatric patients could help develop screening procedures in low-resourced settings. We sought to describe laboratory findings over time in DR children with DF and DF severity from 2018 to 2020. Methods: Clinical information was obtained prospectively from recruited children with DF. Complete blood count (CBC) laboratory measures were assessed across Days 1-10 of fever. Participants were classified as DF-negative and DF-positive and grouped by severity. We assessed associations of DF severity with demographics, clinical characteristics, and peripheral blood studies. Using linear mixed-models, we assessed if hematologic values/trajectories differed by DF status/severity. Results: A total of 597 of 1101 with a DF clinical diagnosis were serologically evaluated, and 574 (471 DF-positive) met inclusion criteria. In DF, platelet count and hemoglobin were higher on earlier days of fever (p < = 0.0017). Eighty had severe DF. Severe DF risk was associated with thrombocytopenia, intraillness anemia, and leukocytosis, differing by fever day (p < = 0.001). Conclusions: In a pediatric hospitalized DR cohort, we found marked anemia in late stages of severe DF, unlike the typically seen hemoconcentration. These findings, paired with clinical symptom changes over time, may help guide risk-stratified screenings for resource-limited settings.

Climate-health risk (In)visibility in the context of everyday humanitarian practice

Nongovernmental migrant shelters in Mexico play a key role in documenting the factors that shape forced migration from Central America. Existing intake protocols in shelters are largely oriented to humanitarian legal frameworks that determine eligibility for international protection based on interpersonal violence and political persecution. This qualitative study calls attention to how existing humanitarian logics may obscure climate- and health-related disruptions as drivers of forced migration from Central America in the context of everyday humanitarian practice. In May 2022 we compared migrant's responses (n = 40) to a standardized intake protocol at a nongovernmental humanitarian migrant shelter in Mexico with responses to semi-structured interviews that focused on migrants' perceptions of climate change and health as drivers of forced displacement. We found that slow- and rapid-onset climatic disruptions; illness and disease; and various forms of violence and repression are often interrelated drivers of forced displacement. Comparing intake protocols and in-depth interview responses, we found that climate- and health-related drivers of forced displacement are rarely documented. These findings speak to the importance of critically examining everyday humanitarian practices in the context of ongoing advocacy that calls for climate-related disruptions to be integrated into existing humanitarian protection frameworks.

Adapting to the shifting landscape: Implications of climate change for malaria control: A review

Malaria, a global public health challenge, continues to affect millions of lives, particularly in regions where its transmission is endemic. The interplay between climate change and malaria dynamics has emerged as a critical concern, reshaping the landscape of this vector-borne disease. This review publication, titled "Adapting to the shifting landscape: Implications of climate change for malaria control," explores the multifaceted relationship between climate change and the control of malaria. The paper begins by dissecting the influence of climate change on malaria dynamics, including alterations in temperature, precipitation, and other climatic factors that impact the habitat and life cycle of malaria vectors. It delves into the evolving ecology and behavior of malaria vectors in response to changing climatic conditions, emphasizing the importance of understanding these adaptations. As a response to this shifting landscape, the review discusses adaptive strategies for malaria control, ranging from vector control measures to the utilization of climate data in early warning systems. Community engagement and education are highlighted as essential components of these strategies, recognizing the vital role of local communities in effective malaria control efforts. The paper also identifies future directions and research needs, underscoring the importance of staying ahead of the evolving climate-malaria relationship. This review underscores the urgency of adapting to the changing landscape of malaria transmission driven by climate change. It emphasizes the significance of proactively addressing climate-related challenges to enhance malaria control and protect the health and well-being of vulnerable populations.

Biosensors for Public Health and Environmental Monitoring: The Case for Sustainable Biosensing

Climate change is a profound crisis that affects every aspect of life, including public health. Changes in environmental conditions can promote the spread of pathogens and the development of new mutants and strains. Early detection is essential in managing and controlling this spread and improving overall health outcomes. This perspective article introduces basic biosensing concepts and various biosensors, including electrochemical, optical, mass-based, nano biosensors, and single-molecule biosensors, as important sustainability and public health preventive tools. The discussion also includes how the sustainability of a biosensor is crucial to minimizing environmental impacts and ensuring the long-term availability of vital technologies and resources for healthcare, environmental monitoring, and beyond. One promising avenue for pathogen screening could be the electrical detection of biomolecules at the single-molecule level, and some recent developments based on single-molecule bioelectronics using the Scanning Tunneling Microscopy-assisted break junctions (STM-BJ) technique are shown here. Using this technique, biomolecules can be detected with high sensitivity, eliminating the need for amplification and cell culture steps, thereby enhancing speed and efficiency. Furthermore, the STM-BJ technique demonstrates exceptional specificity, accurately detects single-base mismatches, and exhibits a detection limit essentially at the level of individual biomolecules. Finally, a case is made here for sustainable biosensors, how they can help, the paradigm shift needed to achieve them, and some potential applications.

Development and validation of Mayaro virus with luciferase reporter genes as a tool for antiviral assays

Arboviruses are etiological agents in an extensive group of emerging diseases with great clinical relevance in Brazil, due to the wide distribution of their vectors and the favorable environmental conditions. Among them, the Mayaro virus (MAYV) has drawn attention since its emergence as the etiologic agent of Mayaro fever, a highly debilitating disease. To study viral replication and identify new drug candidates, traditional antiviral assays based on viral antigens and/or plaque assays have been demonstrating low throughput, making it difficult to carry out larger-scale assays. Therefore, we developed and characterized two DNA-launched infectious clones reporter viruses based on the MAYV strain BeAr 20290 containing the reporter genes of firefly luciferase (FLuc) and nanoluciferase (NLuc), designated as MAYV-firefly and MAYV-nanoluc, respectively. The viruses replicated efficiently with similar properties to the parental wild-type MAYV, and luminescence expression levels reflected viral replication. Reporter genes were also preserved during passage in cell culture, remaining stably expressed for one round of passage for MAYV-firefly and three rounds for MAYV-nanoluc. Employing the infectious clone, we described the effect of Rimantadine, an FDA-approved Alzheimer's drug, as a repurposing agent for MAYV but with a broad-spectrum activity against Zika virus infection. Additionally, we validated MAYV-nanoluc as a tool for antiviral drug screening using the compound EIDD-2749 (4'-Fluorouridine), which acts as an inhibitor of alphavirus RNA-dependent RNA polymerase.

Space-time distribution of intestinal infectious diseases and their association with socioeconomic variables in Ecuador

Background

Intestinal infectious diseases are a global concern in terms of morbidity, and they are closely linked to socioeconomic variables such as quality of life, weather and access to healthcare services. Despite progress in spatial analysis tools and geographic information systems in epidemiology, studies in Ecuador that evaluate temporal trends, specific geographic groups, and their correlation with socioeconomic variables are lacking. The absence of such information makes it challenging to formulate public health policies. This study sought to identify the spatial and temporal patterns of these diseases in Ecuador, along with their correlation with socioeconomic variables.

Methods

In Ecuador, the study was carried out in a continental territory, focusing on data related to intestinal infectious diseases collected from the National Institute of Statistics and Census (Instituto Nacional de Estadística y Censos) during the period from 2014 to 2019. This study involved spatial and temporal analyses using tools such as the global Moran's index and Local Indicators of Spatial Association to identify spatial clustering patterns and autocorrelation. Additionally, correlations between morbidity rates and socioeconomic variables were examined.

Results

During the investigated period, Ecuador registered 209,668 cases of these diseases. Notable variations in case numbers were identified, with a 9.2% increase in 2019 compared to the previous year. The most impacted group was children under 5 years old, and the highest rates were centered in the southern and southwestern regions of the country, with Limón Indanza and Chunchi being the cantons with the highest rates, notably showing a significant increase in Limón Indanza. Additionally, there were significant correlations between morbidity rates and socioeconomic variables, school dropout rates, low birth weight, and access to water services.

Conclusion

This study emphasizes the importance of considering socioeconomic variables when addressing these diseases in Ecuador. Understanding these correlations and geospatial trends can guide the development of health policies and specific intervention programs to reduce the incidence in identified high-risk areas. More specific research is needed to understand the underlying causes of variability in morbidity and develop effective prevention strategies.

Resurgence of Clinical Malaria in Ethiopia in the Era of Anopheles stephensi Invasion

Background

The invasion of Anopheles stephensi into Africa poses a potential threat to malaria control and elimination on the continent. However, it is not clear if the recent malaria resurgence in Ethiopia has linked to the expansion of An. stephensi. We aimed to summarize the major achievements and lesson learnt in malaria control in Ethiopia from 2001 to 2022, to assess the new challenges and prospects for the control of An. stephensi.

Methods and findings

We obtained the clinical malaria case reports, antimalarial drug treatment records, insecticide-treated and long-lasting insecticidal net (ITN/LLIN) distribution and utilization records, and indoor residual spraying (IRS) coverage data from the Ethiopian Ministry of Health (MoH) for the period 2001-2022. We analyzed clinical malaria hotspots using spatially optimized hotspot analysis. We investigated malaria outbreaks in 2022 and examined the potential role of An. stephensi in the outbreaks.Clinical malaria cases in Ethiopia decreased by 80%, from 5.2 million cases (11% confirmed) in 2004 to 1.0 million cases (92% confirmed) in 2018; however, cases increased steadily to 2.6 million confirmed cases (98% confirmed) in 2022. Plasmodium vivax cases and proportion have increased significantly in the past 5 years. Clinical malaria hotspots are concentrated along the western Ethiopian border areas and have grown significantly from 2017 to 2022. Major malaria outbreaks in 2022/23 were detected in multiple sites across Ethiopia, and An. stephensi was the predominant vector in some of these sites, however, it was absence from many of the outbreak sites.

Conclusions

The malaria burden has been significantly reduced in Ethiopia in the past two decades, but in recent years it has increased substantially, and the cause of such increase is a subject of further investigation. Major gaps exist in An. stephensi research, including vector ecology, surveillance, and control tools, especially for adult mosquito control.

Zika virus infection suppresses CYP24A1 and CAMP expression in human monocytes

Monocytes are the primary targets of Zika virus (ZIKV) and are associated with ZIKV pathogenesis. Currently, there is no effective treatment for ZIKV infection. It is known that 1,25-dihydroxy vitamin D3 (VitD3) has strong antiviral activity in dengue virus-infected macrophages, but it is unknown whether VitD3 inhibits ZIKV infection in monocytes. We investigated the relationship between ZIKV infection and the expression of genes of the VitD3 pathway, as well as the inflammatory response of infected monocytes in vitro. ZIKV replication was evaluated using a plaque assay, and VitD3 pathway gene expression was analyzed by RT-qPCR. Pro-inflammatory cytokines/chemokines were quantified using ELISA. We found that VitD3 did not suppress ZIKV replication. The results showed a significant decrease in the expression of vitamin D3 receptor (VDR), cytochrome P450 family 24 subfamily A member 1 (CYP24A1), and cathelicidin antimicrobial peptide (CAMP) genes upon ZIKV infection. Treatment with VitD3 was unable to down-modulate production of pro-inflammatory cytokines, except TNF-α, and chemokines. This suggests that ZIKV infection inhibits the expression of VitD3 pathway genes, thereby preventing VitD3-dependent inhibition of viral replication and the inflammatory response. This is the first study to examine the effects of VitD3 in the context of ZIKV infection, and it has important implications for the role of VitD3 in the control of viral replication and inflammatory responses during monocyte infection.

Control of companion animal parasites and impact on One Health

The last decades have witnessed an increase in the global population and movements of companion animals, contributing to changes in density and distribution of pet parasites. Control of companion animal parasites (CAPs) becomes increasingly relevant because of the intensifying human-animal bond. Parasites impact on the health of humans and their pets, but also of wildlife and the environment. We conducted a qualitative review on the current advancements, gaps and priorities for the monitoring and treatment of CAPs with a focus on securing public health. There is a need to raise awareness, coordinate global surveillance schemes and better quantify the impact of companion animal parasites on One Health.

Ticks and tick-borne diseases from Mallorca Island, Spain

Ixodid ticks are obligate blood-feeding arthropods and important vectors of pathogens. In Mallorca, almost no data on the tick fauna are available. Herein, we investigated ticks and tick-borne pathogens in ticks collected from dogs, a cat and humans in Mallorca as result of a citizen science project. A total of 91 ticks were received from German tourists and residents in Mallorca. Ticks were collected from March to October 2023 from dogs, cat and humans, morphologically and genetically identified and tested for pathogens by PCRs. Six tick species could be identified: Ixodes ricinus (n = 2), Ixodes ventalloi (n = 1), Hyalomma lusitanicum (n = 7), Hyalomma marginatum (n = 1), Rhipicephalus sanguineus s.l. (n = 71) and Rhipicephalus pusillus (n = 9). Rhipicephalus sanguineus s.l. adults were collected from dogs and four females from a cat and the 16S rDNA sequences identified it as Rh. sanguineus s.s. Hyalomma lusitanicum was collected from 1 human, 1 dog and 5 specimens were collected from the ground in the community of Santanyi, together with one H. marginatum male. This is the first report of Hyalomma marginatum in Mallorca. Both I. ricinus were collected from humans and I. ventalloi female was collected from a dog. All ticks tested negative for Anaplasma phagocytophilum, Coxiella spp., Francisella spp., and piroplasms. In 32/71 (45%) specimens of Rh. sanguineus s.s., Rickettsia spp. could be detected and in 18/32 (56.2%) sequenced tick DNAs R. massiliae was identified. Ixodes ventalloi female and both I. ricinus tested positive in the screening PCR, but the sequencing for the identification of the Rickettsia sp. failed.

Continuous epileptiform discharges are associated with worse neurodevelopmental findings in a congenital Zika syndrome prospective cohort

PURPOSE

This study aimed to identify continuous epileptiform discharges (CEDs) on electroencephalograms (EEG) and to determine their clinical significance in children with congenital Zika syndrome (CZS).

METHODS

This prospective cohort study included 75 children diagnosed with CZS born from March 2015 and followed up until September 2018 (age up to 36 months). EEG was performed to detect CEDs up to 24 months old. Data on obstetric, demographic, and clinical signs; cranial computed tomography (CT); ophthalmology examination; anti-seizure medication; growth; and motor development were collected. Fisher's exact test was used to verify the associations between categorical variables, and the T- test was used to compare the mean z-scores of anthropometric measurements between the groups with and without CED.

RESULTS

CEDs were identified in 41 (54.67 %) children. The mean age of CEDs identification was 12.24 ± 6.86 months. Bilateral CEDs were shown in 62.89 % of EEGs. CEDs were associated with severe congenital microcephaly, defined by z-score >3 standard deviation of head circumference (HC) below the mean for sex and age (p = 0.025), and worse outcomes, including first seizure before 6 months (p = 0.004), drug-resistant epilepsy (p < 0.001), chorioretinal scarring or mottling (p = 0.002), and severe CT findings (p = 0.002). The CED group had lower mean z-scores of HC up to 24 months of age.

CONCLUSION

This is the first description of the prevalence and significance of CEDs that also remains during wakefulness in patients with CZS. New investigations may suggest that it is more appropriate to classify the EEG not as a CED, but as a periodic pattern. Anyway, CEDs may be a marker of neurological severity in children with CSZ.

Assessing the Vulnerability and Adaptation Needs of Mozambique's Health Sector to Climate: A Comprehensive Study

Climate change poses severe consequences, particularly in sub-Saharan Africa, where poverty rates may escalate by 2050 without significant climate and development action. The health impacts are diverse, encompassing communicable and non-communicable diseases. Mozambique, a climate-vulnerable nation, has experienced significant natural disasters in the past 42 years, impacting its health system. This study aims to assess Mozambique's health sector's vulnerability and adaptation needs to climate change. Following a methodology proposed by the World Health Organization and the Intergovernmental Panel for Climate Change, a six-step vulnerability and adaptation assessment was conducted to conduct the Health Vulnerability Index (HVI) for Mozambique's regions (n=161). The HVI integrates historical climate, epidemiological, and socio-economic data at the district level, and was computed using exposure, sensitivity, and adaptive capacity dimensions. The results revealed spatial patterns in exposure to climate variables, extreme weather events, and variations in sensitivity and adaptive capacity across the country. The HVI mirrored the exposure findings. Notably, high vulnerability was observed in several districts, while major urban centers displayed lower vulnerability. These findings highlight the country's vulnerability to climate change and underscore the potential for adverse impacts on livelihoods, the economy, and human health. The study provides a foundation for developing strategies and adaptation actions.

High temperatures and low humidity promote the occurrence of microsporidians (Microsporidia) in mosquitoes (Culicidae)

BACKGROUND

In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing temperatures. In the present study, we used a mosquito-microsporidian model to determine the impact of environmental factors such as temperature, humidity, wind and rainfall on the occurrence rates of opportunistic obligate microparasites (Microsporidia) in hosts from a family that includes important disease vectors (Culicidae).

METHODS

In our study, 3000 adult mosquitoes collected from the field over 3 years were analysed. Mosquitoes and microsporidia were identified using PCR and sequencing of the hypervariable V5 region of the small subunit ribosomal RNA gene and a shortened fragment of the cytochrome c oxidase subunit I gene, respectively.

RESULTS

DNA metabarcoding was used to identify nine mosquito species, all of which were hosts of 12 microsporidian species. The prevalence of microsporidian DNA across all mosquito samples was 34.6%. Microsporidian prevalence in mosquitoes was more frequent during warm months (> 19 °C; humidity < 65%), as was the co-occurrence of two or three microsporidian species in a single host individual. During warm months, microsporidian occurrence was noted 1.6-fold more often than during the cold periods. Among the microsporidians found in the mosquitoes, five (representing the genera Enterocytospora, Vairimorpha and Microsporidium) were positively correlated with an increase in temperature, whereas one (Hazardia sp.) was significantly correlated with a decrease in temperature. Threefold more microsporidian co-occurrences were recorded in the warm months than in the cold months.

CONCLUSIONS

These results suggest that the susceptibility of mosquitoes to parasite occurrence is primarily determined by environmental conditions, such as, for example, temperatures > 19 °C and humidity not exceeding 62%. Collectively, our data provide a better understanding of the effects of the environment on microsporidian-mosquito interactions.

An optical system to detect, surveil, and kill flying insect vectors of human and crop pathogens

Sustainable and effective means to control flying insect vectors are critically needed, especially with widespread insecticide resistance and global climate change. Understanding and controlling vectors requires accurate information about their movement and activity, which is often lacking. The Photonic Fence (PF) is an optical system that uses machine vision, infrared light, and lasers to identify, track, and interdict vectors in flight. The PF examines an insect's outline, flight speed, and other flight parameters and if these match those of a targeted vector species, then a low-power, retina-safe laser kills it. We report on proof-of-concept tests of a large, field-sized PF (30 mL × 3 mH) conducted with Aedes aegypti, a mosquito that transmits dangerous arboviruses, and Diaphorina citri, a psyllid which transmits the fatal huanglongbing disease of citrus. In tests with the laser engaged, < 1% and 3% of A. aegypti and D. citri, respectfully, were recovered versus a 38% and 19% recovery when the lacer was silenced. The PF tracked, but did not intercept the orchid bee, Euglossa dilemma. The system effectively intercepted flying vectors, but not bees, at a distance of 30 m, heralding the use of photonic energy, rather than chemicals, to control flying vectors.

Climate change and its impact on infectious diseases in Asia

ABSTRACT

Climate change, particularly increasing temperature, changes in rainfall, extreme weather events and changes in vector ecology, impacts the transmission of many climate-sensitive infectious diseases. Asia is the world's most populous, rapidly evolving and diverse continent, and it is already experiencing the effects of climate change. Climate change intersects with population, sociodemographic and geographical factors, amplifying the public health impact of infectious diseases and potentially widening existing disparities. In this narrative review, we outline the evidence of the impact of climate change on infectious diseases of importance in Asia, including vector-borne diseases, food- and water-borne diseases, antimicrobial resistance and other infectious diseases. We also highlight the imperative need for strategic intersectoral collaboration at the national and global levels and for the health sector to implement adaptation and mitigation measures, including responsibility for its own greenhouse gas emissions.

The importance, benefits, and future of nanobiosensors for infectious diseases

Infectious diseases, caused by pathogenic microorganisms such as bacteria, viruses, parasites, or fungi, are crucial for efficient disease management, reducing morbidity and mortality rates and controlling disease spread. Traditional laboratory-based diagnostic methods face challenges such as high costs, time consumption, and a lack of trained personnel in resource-poor settings. Diagnostic biosensors have gained momentum as a potential solution, offering advantages such as low cost, high sensitivity, ease of use, and portability. Nanobiosensors are a promising tool for detecting and diagnosing infectious diseases such as coronavirus disease, human immunodeficiency virus, and hepatitis. These sensors use nanostructured carbon nanotubes, graphene, and nanoparticles to detect specific biomarkers or pathogens. They operate through mechanisms like the lateral flow test platform, where a sample containing the biomarker or pathogen is applied to a test strip. If present, the sample binds to specific recognition probes on the strip, indicating a positive result. This binding event is visualized through a colored line. This review discusses the importance, benefits, and potential of nanobiosensors in detecting infectious diseases.