Background

Infections with liver flukes (Clonorchis sinensis, Opisthorchis viverrini, and O. felineus) cause high burden. Mechanistic models have been employed to disentangle their transmission dynamics and guide the design of control strategies. However, no comprehensive review of these mechanistic models has yet been undertaken.

Methods

In this systematic review, we searched six major databases (PubMed, Web of Science, Korea Med, Cochrane, China National Knowledge Infrastructure [CNKI], and Wanfang Data) for studies published up to 14 May 2025, to identify and evaluate mechanistic models of liver fluke infections. We included all mechanistic transmission models for human liver flukes regardless of language or setting, while excluded non-mechanistic models, reviews, and empirical studies.

Results

Of the 533 records identified, 18 studies were eligible for analysis. Most studies focused on C. sinensis in China and O. viverrini in Lao People’s Democratic Republic, primarily employing population-based model with ordinary differential equations. Findings consistently identified humans as the central reservoir sustaining transmission, while the role of animal reservoir hosts (e.g. cats and dogs) in transmission was less explored (in 6 out of 18 studies) and divergent in different models. Models incorporating host heterogeneity demonstrated the superiority of integrated control strategies-combining mass drug administration, health education, and environmental improvements over single intervention. High frequency, coverage and adherence of measures were shown to be critical for achieving control or even elimination targets.

Conclusion

Results from mechanistic models support the implementation of One Health strategies to improve liver fluke control. This review identifies the need for integrative, data-driven One Health modeling frameworks that incorporate human, animal, and environmental transmission parameters, and address key sources of heterogeneity in host behavior, exposure, and transmission dynamics to support control targets.

Background

Lassa fever is a zoonotic disease, caused by Lassa virus (LASV), that was first reported in 1965. After 55 years, its research landscape remains largely underexplored. Therefore, a bibliometric study is needed to identify LASV research landscape.

Methods

Scopus database was searched and the resulting data was analyzed using VOSviewer (version 1.6.15) for Windows, bibliometrix (version 3.0.0) with Biblioshiny, and R (version 4.5.2) to reveal trends in LASV publications, including keywords, authors’ productivity over time, and collaboration among research institutions and universities.

Results

From Scopus, 1566 studies were retrieved, and the trend analysis indicated three distinct phases: a low productivity phase (1970–2002), consistent increase phase (2003–2014), and high productivity phase (2015–2025). The Journal of Virology included the most LASV publications (132 articles). Original research articles dominated the LASV publications with 1270 (81.10%), followed by reviews 296 (18.90%). Keyword analysis revealed evolution over time, with terms used to describe LASV forming the most dominant network across clusters. Factorial analysis revealed keywords absence linked to health and environment role in LASV spread. Among the top 50 authors, 20% were from Africa (Guinea, Mali, Nigeria, and Sierra Leone), indicating minimal locally driven research. Country collaboration network analysis revealed the dominance of the United States, Germany, France, and China, while Nigeria was prominently represented in Africa. The findings further indicate few studies on vaccines and therapeutics, and less involvement of authors from LASV-endemic regions.

Conclusion

Despite significant growth in LASV research, critical gaps in vaccines, therapeutics, and endemic region representation highlight the urgent need for locally driven One Health studies and equitable research partnerships.

The use of antimicrobial agents in animals contributes to the emergence and spread of bacterial antimicrobial resistance, posing risks to human, animal, and environmental health. Monitoring antimicrobial consumption in food-producing animals is a critical component of antimicrobial stewardship. This study describes the current state of antimicrobial use and resistance monitoring in animals in Brazil and compares it to systems implemented in the United Kingdom (UK) and the Netherlands, countries known for having well-established surveillance frameworks. Data were collected between July 2019 and November 2025 from official technical reports on veterinary antimicrobial sales and use, as well as policy documents and legislation. Findings show that the UK and the Netherlands have developed integrated systems based on mandatory data reporting and sector-specific metrics. These systems are supported by coordinated policies and high stakeholder engagement. In contrast, Brazil lacks a national system for monitoring antimicrobial use in animals. Sales data are not publicly available, and there is no standardized mechanism to track antimicrobial consumption on farms. Although policy frameworks exist, enforcement is limited, and access to surveillance data is fragmented. The absence of a centralized, transparent system hinders Brazil’s capacity to evaluate antimicrobial use patterns or inform targeted interventions. Given Brazil’s leading role in global animal protein production, addressing these gaps is essential to advancing national stewardship efforts and contributing to global strategies to contain bacterial antimicrobial resistance.

Japan aims to establish an international hydrogen supply chain by utilizing low-cost and abundantly available hydrogen sources and liquid hydrogen carriers to realize a future hydrogen economy that will enhance energy security and help achieve carbon neutrality. While hydrogen does not emit CO₂ when used as a fuel to generate energy, CO₂ emissions can be attributed to hydrogen due to the energy and other resources required at each stage of the hydrogen supply chain. Therefore, from a life cycle perspective, if hydrogen is to contribute to the world’s carbon neutrality goal, the entire hydrogen supply chain must be low-carbon. This paper explores the life cycle CO₂ emissions of international hydrogen supply chains envisaged by Japan. The target supply chains involve hydrogen produced from renewable electricity via electrolysis, as well as from fossil fuels with carbon capture and storage, sourced from resource-rich countries and imported to Japan using liquid hydrogen carriers such as liquid hydrogen, methylcyclohexane (MCH), and ammonia (NH₃). In addition, this paper addresses potential options for reducing life cycle CO₂ emissions to effectively establish a low-carbon hydrogen supply chain.

A just energy transition (JET) to low-carbon fuels, such as green hydrogen, is critical for mitigating climate change. Countries with abundant renewable energy resources are well-positioned to meet the growing global demand for green hydrogen. However, to improve the volumetric energy density and facilitate transport and distribution over long distances, green hydrogen needs to be converted into an energy carrier such as green ammonia. This study conducted a comparative life cycle assessment (LCA) to evaluate the environmental impacts of green ammonia production, with a particular focus on greenhouse gas (GHG) emissions. The boundary of the study was from cradle-to-production gate, and the design was based on a coastal production facility in South Africa, which uses renewable energy to desalinate seawater, produce hydrogen, and synthesise ammonia. The carbon intensity of production was 0.79 kg CO₂-eq per kg of ammonia. However, if co-products of oxygen, argon and excess electricity are sold to market and allocated a portion of GHG emissions, the carbon intensity was 0.28 kg CO₂-eq per kg of ammonia. Further, without the sale of co-products but excluding the embodied emissions of the energy supply system, as defined in the recent international standard (ISO/TS 19870), the carbon intensity was 0.11 kg CO₂-eq per kg of ammonia. Based on the hydrogen content of ammonia, this is equivalent to 0.60 kg CO₂-eq per kg of hydrogen, which is well below the current threshold for certification as a low-carbon fuel. The process contributing most to the overall environmental impacts was electrolysis (68%), with particulate matter (55%) and global warming potential (33%) as the dominant impact categories. This reflects the energy intensity of electrolysis and the carbon intensity of the energy used to manufacture the infrastructure and capital goods required for green ammonia production. These findings support the adoption of green ammonia as a low-carbon fuel to mitigate climate change and help achieve net-zero carbon emissions by 2050. However, achieving this goal requires the rapid decarbonisation of energy supply systems to reduce embodied emissions from manufacturing infrastructure.

Hydrogen is a promising energy carrier that is expected to play a crucial role in helping Canada achieve its net-zero target by 2050. However, reducing the ambiguity in regulatory frameworks is essential to incentivize and facilitate international trade in hydrogen. To this end, regulators must agree on quantification methodologies that consider life cycle boundaries, process descriptions, co-product allocation, conversion constants, and certification units. Several studies have highlighted the importance of life cycle assessment (LCA) as a standardized, relevant method for estimating the carbon footprint associated with hydrogen production and evaluating its environmental sustainability. As such, LCA-based certification schemes could help create a transparent hydrogen market. The aim of this study is to validate the proposed harmonized LCA-based methodology for quantifying hydrogen production’s carbon intensity. This methodology follows a consistent scope and life cycle inventory (LCI) development criteria, alongside a rigorous data quality assessment. The well-to-gate carbon intensities of six hydrogen production pathways are compared, which range from 0.26 to 10.07 kg CO_2e per kg of hydrogen (kg CO_2e/kg H₂), against the hydrogen carbon intensity thresholds established by the Canadian Clean Hydrogen Investment Tax Credit (CHITC). For example, the biomass gasification with carbon capture (CC) pathway demonstrates the lowest carbon intensity, while thermochemical pathways, such as steam methane reforming of natural gas without CC, poses challenges to meeting the maximum CHTIC threshold of 4 kg CO_2e/kg H₂.