Spatial characteristics and driving factors of human brucellosis and plague infections in the Meriones unguiculatus plague focus in China.

BackgroundPlague is a life-threatening disease caused by the bacterium, Yersinia pestis. Madagascar is the leading country for human plague cases worldwide. Human plague is a serious disease, particularly in its septicaemic and pneumonic forms. We report a case of pneumonic plague co-infected by a MDR-Stenotrophomonas maltophilia.Case presentationA 24 year-old man originated from Soavinandriana, a plague focus, felt uneasy and developed high fever with chills. He started treatment by himself, by private medical care and by a traditional healer for nine days moving several times from place to place. His condition had deteriorated when he presented to a district hospital with a syndrome of dyspnea, bronchial rale and altered state of consciousness. Two days later, plague diagnosis, performed as a last resort, revealed a positive F1 antigen on rapid diagnostic test. Additional tests (pla PCR and plague serology) evidenced a Y. pestis infection. However, streptomycin treatment did not achieve a complete recovery as the course of disease was complicated by the presence of MDR-S. maltophilia in his lung. This opportunistic infection could have been favored by an immunosuppression due to Y. pestis pulmonary infection and probably been acquired during his stay at a District Hospital. He was treated with a combination of ciprofloxacin and gentamycin and recovered fully.ConclusionsPneumonic plague infection may promote another virulent or avirulent bacterial infection particularly when it is not initially suspected. However, coinfection is rarely described and its occurrence frequency is unknown. In middle or low resources areas, which is the case of most plague endemic countries, control and prevention of infections in health facilities is not optimal. Co-infection with an opportunistic pathogen agent, such as S. maltophilia, is a risk which must not be disregarded as demonstrated by this case report. When deciding of a national control strategy, it should be taken into account in the choice of the first line treatment.

Extreme climatic events and variability are on the rise around the world, with varying implications for populations across socio-economic conditions. Effective strategies for climate adaptation and development depend on understanding these differential sensitivities to climatic variability. This study focuses on a vulnerable population living in forest-fringe villages of central India, where seasonal migration is a common livelihood strategy for poor households to supplement their incomes with remittances. We quantify the relative sensitivity of a decision to migrate for the first time to climate and socio-economic variables and how the sensitivities vary for different segments of the population. We surveyed 5000 households in 500 forest-fringe villages to identify patterns of migration from 2013 to 2017. Using a mixed-effects logistic regression model, we predicted the probability of first-time migration of a household member based on climate variables and household- and district-level characteristics. We find that households in more agricultural and prosperous districts experience lower rates of migration but are more sensitive to climatic variability than households in poorer districts. The probability of first-time migration from a household in the most prosperous district increases by approximately 40% with one standard deviation in mean maximum temperature or rainfall from the 1981–2017 mean. However, the probability of migration does not vary as a function of climatic variability for households in the poorest district. We attribute this difference in sensitivities to the greater dependence on agriculture and irrigation in more prosperous districts and poverty-driven dependence on migration regardless of the climate in poorer districts. Households investing remittances from migration in agricultural intensification could become increasingly sensitive to climate variability, particularly with water shortages and projected increases in climate variability in the region. Promotion of non-agricultural livelihood options and climate-resilient agriculture could the reduce sensitivity of migration to climate variability in the study region.

Frontiers in climate change–disease research

To comprehensively understand the spatial characteristics and pollution hazards of heavy metals in rice in Fujian Province, the contents of Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn in 260 rice samples were measured based on the field investigation. Their spatial distribution patterns and clustering characteristics were explored by geostatistical methods, and their pollution-health risks were revealed by the pollution index method and exposure evaluation model. The results showed that the average contents of eight heavy metals in rice were below the food safety limits, but the excess rates of As, Cu, and Cd samples reached 33.08%, 22.69%, and 18.85%, respectively. In terms of spatial characteristics, the contents of Cd, Hg, and Ni were higher in the southeastern and northwestern regions, while the contents of As, Cu, and Cr were higher in the southwestern parts of Fujian Province. The hotspots of the corresponding heavy metals were also concentrated in the above-mentioned areas, showing an obvious spatial clustering effect. The pollution risk assessment showed that the single factor pollution index of heavy metals in rice decreased in the order of As (0.536) > Hg (0.505) > Cu (0.421) > Cd (0.378) > Cr (0.318) > Zn (0.304) > Pb (0.286) > Ni (0.116), and the Nemerow comprehensive pollution index was 0.623, which was generally at a safe level with low pollution risk. Furthermore, the non-carcinogenic risk index of heavy metals for adults and children were 3.558 and 6.014, and the carcinogenic risk index were 0.0050 and 0.0084, respectively, with extremely serious health hazards. In contrast, the health damage of heavy metals was higher in children than that in adults, with As and Cd in rice as the pivotal elements. Therefore, attention should be paid to the future monitoring and agricultural management of heavy metal pollution in rice in the region.

The oasis is the most important territorial system of human-earth relationships in the hyper-arid zone. With the socioeconomic development, increasingly serious environmental problems have occurred in the oases. But current research major focus on the soil water balance of oases while ignore the spatial characteristics and risks of heavy metals in soils. Therefore, taking Southern Xinjiang, a typical hyper-arid zone, as a case study site, we collected soil samples from 15 major oases in the region and analyzed the spatial characteristics and risks of eight heavy metals (Cr, Ni, Cu, Zn, As, Cd, Pb, Hg). Through spatial autocorrelation analysis, the contamination index method, the geoaccumulation index method, and risk assessment methods, the analysis results show that (1) the overall concentration of soil heavy metals in the oases of Southern Xinjiang is low and relatively uniformly distributed, and there is a small-scale aggregation. (2) The eight heavy metals in the study area exhibit significant spatial distribution differences, with varying concentrations, but none exceed the risk screening values. The content of 8 heavy metals in the soil of the Southern Xinjiang oasis ranges from 0.01 to 62.73mg/kg, in descending order of Zn > Cr > Ni > Cu > Pb > As > Cd > Hg. Among them, Zn, Cr, and Ni have the highest concentrations, while Cd, As, and Pb show significant deviations from background values. (3) Except for Cd and Hg, there is no overall ecological risk from soil heavy metals in the soils of most Southern Xinjiang oases. (4) None of the oasis soils in the study area have shown non-carcinogenic risks from heavy metals, but there are some carcinogenic risks for children, which are related to the accumulation of heavy metals and the specificity of the children's population. This study fills a key gap in soil heavy metal research in oasis areas, offering valuable data for future research and policy. Future work should focus on remediation technologies like phytoremediation and microbial treatments, along with targeted policies to reduce pollution risks, especially for vulnerable populations.

Type of the article: Research ArticleAbstractIn the context of growing pressure on forest ecosystems arising from agricultural area expansion and intensification, expanding population, and climate variability, this study aims to identify and quantify the impacts of these changes on forest coverage in the South Asian region. Using a balanced panel dataset for 1990–2023, the analysis employs a regularized fixed-effects estimation to identify the key drivers of forest area change and assess variable importance.The findings show that a 1% increase in agricultural value added is achieved at the cost of a 0.32% decrease in forest area, making it the most significant driver of forest loss. Use of inorganic fertilizer also exerts a strong negative influence, as forest cover is reduced by 0.18% for every additional percentage usage of fertilizer. Irrigation expansion has a similarly adverse effect, contributing to a 0.21% decline per 1% increase in irrigated area. Population density growth intensifies pressure on forests, with each additional 10 persons per km² corresponding to a 0.05% decrease in forest area. However, pasture share exhibits a positive association: a 1-percentage-point increase corresponds to a 0.14% rise in forest area, and cattle density also shows a modest but positive effect. The results indicate the presence of mixed livestock–forest systems and early forest-transition dynamics in some countries.Overall, the findings demonstrate that the pattern of agricultural practices determines forest trajectories in South Asia, and achieving sustainability will require country-specific strategies that balance productivity growth with integrated land-use planning and long-term conservation goals.

The present study investigates the spatial-temporal patterns of Tulipa greigii distribution across the heterogeneous landscapes of the Turkistan Region, southern Kazakhstan. As a flagship species with high conservation and ecotourism value Tulipa greigii is increasingly affected by climate variability and landscape fragmentation. The aim of the research is to identify the ecological parameters governing tulip distribution and to assess the potential for sustainable ecotourism based on floral landscape dynamics. The methodology integrates field ecological surveys, multi-seasonal remote sensing (Sentinel-2 and Landsat 8), and geospatial modeling using NDVI and NDMI indices. Additionally, public interest and ecotourism potential were assessed through digital footprint analysis on social media platforms (Instagram and TikTok), as well as national visitation statistics. Geostatistical tools were employed to analyze spatial trends and vegetation stress patterns across six key study locations selected for their landscape diversity. Findings reveal a strong correlation between seasonal soil moisture levels and the spatial presence of Tulipa greigii. Higher vegetation indices were observed in slope-adjacent piedmonts and montane meadow belts, which also correspond with increased social media activity during the blooming season. The results confirm the role of geomorphological position, hydrological balance, and digital visibility in determining ecotourism hotspots. This study demonstrates the value of interdisciplinary methods in understanding plant distribution and promoting nature-based tourism. By integrating biophysical indicators with geospatial technologies and public engagement metrics, the research provides a holistic framework for identifying ecologically significant zones under pressure from climate change and human activity. Moreover, the proposed approach highlights the utility of coupling traditional ecological monitoring with digital analytics to track spatial interest trends and ecological vulnerabilities. The study contributes to the scientific basis for the development of adaptive conservation strategies, fostering synergies between biodiversity protection and regional ecotourism planning. It provides regionally grounded and practically oriented recommendations for harmonizing biodiversity conservation efforts with the development of digital ecotourism strategies, tailored specifically to the ecological and socio-spatial characteristics of Central Asia’s dryland landscapes.

Human plague risks (Yersinia pestis infection) are greatest when epizootics cause high mortality among this bacterium's natural rodent hosts. Therefore, health departments in plague-endemic areas commonly establish animal-based surveillance programs to monitor Y. pestis infection among plague hosts and vectors. The primary objectives of our study were to determine whether passive animal-based plague surveillance samples collected in Colorado from 1991 to 2005 were sampled from high human plague risk areas and whether these samples provided information useful for predicting human plague case locations. By comparing locations of plague-positive animal samples with a previously constructed GIS-based plague risk model, we determined that the majority of plague-positive Gunnison's prairie dogs (100%) and non-prairie dog sciurids (85.82%), and moderately high percentages of sigmodontine rodents (71.4%), domestic cats (69.3%), coyotes (62.9%), and domestic dogs (62.5%) were recovered within 1 km of the nearest area posing high peridomestic risk to humans. In contrast, the majority of white-tailed prairie dog (66.7%), leporid (cottontailed and jack rabbits) (71.4%), and black-tailed prairie dog (93.0%) samples originated more than 1 km from the nearest human risk habitat. Plague-positive animals or their fleas were rarely (one of 19 cases) collected within 2 km of a case exposure site during the 24 months preceding the dates of illness onset for these cases. Low spatial accuracy for identifying epizootic activity prior to human plague cases suggested that other mammalian species or their fleas are likely more important sources of human infection in high plague risk areas. To address this issue, epidemiological observations and multi-locus variable number tandem repeat analyses (MLVA) were used to preliminarily identify chipmunks as an under-sampled, but potentially important, species for human plague risk in Colorado.

Susceptibility studies were undertaken to determine the response of some South African wild rodent species to experimental plague (Yersinia pestis) infection. A degree of plague resistance was found in three gerbil species captured in the plague enzootic region of the northern Cape Province, these being the Namaqua gerbil, Desmodillus auricularis, (LD50 1 X 10(6) organisms), the bushveld gerbil, Tatera leucogaster, (LD50 9.1 X 10(5)) and the highveld gerbil, T. brantsii (LD50 4 X 10(2)). Animals from a population of the four-striped mouse, Rhabdomys pumilio, captured in the plague area of Port Elizabeth, proved moderately resistant to experimental plague infection (LD50 1.3 X 10(4)) while those from another population of the same species captured in a plague-free area of the Orange Free State were extremely susceptible (LD50, 5 organisms). The response of both populations however was a heterogeneous one. Marked differences in susceptibility were also found between two populations of multimammate mice, Mastomys natalensis (2n = 32) although both originated from areas outwith the known distribution of plague in southern Africa. The 50% infectious dose was relatively high in T. leucogaster (3.2 X 10(2)) and D. auricularis (1.7 X 10(3)), but was low (2-16 organisms) in the other rodent species tested. The plague antibody response, determined by enzyme-linked immunosorbent assay (ELISA), was extremely short-lived in T. leucogaster, only 10% of inoculated animals remaining seropositive at low titres after 11 weeks. Antibodies persisted for only slightly longer in the sera of T. brantsii which were reinoculated with 2 X 10(3) plague organisms 6 weeks after initial challenge. The demonstration of the existence of both susceptible and resistant populations of R. pumilio and M. natalensis indicates that these species must be considered as potential plague reservoir hosts in parts of South Africa. The results suggest that resistance to plague infection in previously epizootic hosts in the northern Cape Province such as Tatera sp. and D. auricularis has arisen through continual selective pressure of the organism. If the findings are applicable to gerbil populations in other plague enzootic regions of South Africa it is probable that acquired plague resistance has been responsible for the absence of gerbil epizootics and consequently for the dramatic decline in human plague outbreaks in South Africa since 1950.

Developing countries, Kenya included are mostly affected by food problems and poverty as a result of high dependence on agriculture. In Kenya agriculture contributes to 27.3% of the Gross Domestic Product. Agriculture in Kenya is dominated by smallholder farmers, whose production is hampered by climate variability, declining land sizes and low agricultural technologies. Agricultural intensification is aimed at solving the problem of low agricultural productivity and poverty through increasing farm output per unit land area. Makueni and Nyando Sub-County were considered as hotspots of climate change by CCAFS. A total of 320 households were sampled from the two sub-counties. From the scope farmers were engaged in 16 agricultural intensification practices, some practices were substitutes others complementary so they were highly correlated. Principal Component Analysis (PCA) was then used to group them into clusters called principal components. PCA helped in creating levels of agricultural intensifications. From the results, the number of components (Levels of agricultural intensification) of users was ranging from one to five. That is from low users of strategy 1, partial users of 2, 3 and 4 to full users of 5. The result revealed that 56% of farmers used 5 sets of strategies while 31%, 8%, 3% and 1% of farmers’ used 4, 3, 2 and 1 levels of agricultural intensification practices respectively. The results implied that there was need for smallholder farmers to increase agricultural intensification which leads to improved smallholder farmers livelihood outcomes and helps in building their resilience to harsh climatic conditions. Keywords: Agricultural intensification practices, Kenya, Principal Component Analysis, Smallholder farmer DOI : 10.7176/JESD/10-18-04 Publication date :September 30 th 2019

Unraveling the impacts of droughts and agricultural intensification on the Altiplano water resources

Quantifying overheating risk in English schools: A spatially coherent climate risk assessment

An improved understanding of population-level consequences of grazing on plants can be facilitated by an assessment of grazing effects on all stages in the life-cycle. In this study, 6 years of demographic data for three populations of the perennial herb Geranium sylvaticum were analysed. We examined the effects of sheep grazing (high sheep density, low sheep density and no sheep) and interannual climatic variability on vital rates and population growth rates (λ). Grazing did not affect survival or flowering rates, but reduced rates of growth and increased rates of clonal reproduction. At the population level, high contributions from retrogression and clonal reproduction buffered reduced rates of growth and stasis, and no consistent differences in λ between populations exposed to different sheep densities were found. Instead, large between-year variability in λ, independent of sheep density, was detected, related to variation in the local summer climate. The results indicated, however, that grazing effects on λ were more severe in unfavourable than in normal years. Our study highlights that increased clonal reproduction rates functioned as a tolerance mechanism towards grazing in this herb, which forms a mechanism to explain how moderate population responses to grazing in some herbs can arise.

Characterization of systemic and pneumonic murine models of plague infection using a conditionally virulent strain

The plague agent, Yersinia pestis, employs a type III secretion system (T3SS) to selectively destroy human immune cells, thereby enabling its replication in the bloodstream and transmission to new hosts via fleabite. The host factors responsible for the selective destruction of immune cells by plague bacteria were not known. Here we show that LcrV, the needle cap protein of the Y. pestis T3SS, binds N-formylpeptide receptor (FPR1) on human immune cells to promote the translocation of bacterial effectors. Plague infection in mice is characterized by high mortality, however N-formylpeptide receptor deficient animals exhibit increased survival and plague-protective antibody responses. We identified FPR1 p.R190W as a candidate human resistance allele that protects neutrophils from Y. pestis T3SS. These findings reveal the plague receptor on immune cells and show that FPR1 mutations provide for plague survival, which appears to have shaped human immune responses towards other infectious diseases and malignant neoplasms.