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Emerging Infectious Diseases Sep 2023The SARS-CoV-2 Delta variant, first identified in October 2020, quickly became the dominant variant worldwide. We used publicly available data to explore the...
The SARS-CoV-2 Delta variant, first identified in October 2020, quickly became the dominant variant worldwide. We used publicly available data to explore the relationship between illness and death (peak case rates, death rates, case-fatality rates) and selected predictors (percentage vaccinated, percentage of the population >65 years, population density, testing volume, index of mitigation policies) in 45 high-income countries during the Delta wave using rank-order correlation and ordinal regression. During the Delta-dominant period, most countries reported higher peak case rates (57%) and lower peak case-fatality rates (98%). Higher vaccination coverage was protective against peak case rates (odds ratio 0.95, 95% CI 0.91-0.99) and against peak death rates (odds ratio 0.96, 95% CI 0.91-0.99). Vaccination coverage was vital to preventing infection and death from COVID-19 during the Delta wave. As new variants emerge, public health authorities should encourage the uptake of COVID-19 vaccination and boosters.
Topics: Humans; COVID-19; SARS-CoV-2; COVID-19 Vaccines; Developed Countries
PubMed: 37494699
DOI: 10.3201/eid2909.230142 -
Annual Review of Entomology Jan 2024Malaria is an infectious disease caused by parasites, transmitted by , , , and in China. In 2021, the disease was eliminated in China after more than 70 years of... (Review)
Review
Malaria is an infectious disease caused by parasites, transmitted by , , , and in China. In 2021, the disease was eliminated in China after more than 70 years of efforts implementing an integrated mosquito management strategy. This strategy comprised indoor residual spray, insecticide-treated bed nets, irrigation management, and rice-fish coculture based on an understanding of taxonomic status and ecological behaviors of vector species, in conjunction with mass drug administration and promotion of public education. However, China still faces postelimination challenges, including the importation of approximately 2,000-4,000 cases of malaria into the country each year, as well as widespread resistance to pyrethroid insecticides in ; these challenges require long-term vector surveillance to understand the distribution, population density, and development of resistance in vector mosquitoes to prevent local epidemics caused by imported malaria cases.
Topics: Animals; Malaria; Anopheles; Insecticides; Mosquito Vectors; China; Biology; Insecticide Resistance; Mosquito Control
PubMed: 38270986
DOI: 10.1146/annurev-ento-021323-085255 -
A pathogen's spatial range is not constrained by geographical features in the flax rust pathosystem.Ecology and Evolution Oct 2023Climate change and shifting environmental conditions can allow pathogens to spread into previously unburdened areas. For plant pathogens, this dynamic has the potential...
Climate change and shifting environmental conditions can allow pathogens to spread into previously unburdened areas. For plant pathogens, this dynamic has the potential to disrupt natural ecosystem equilibria and human agriculture, making predicting plant pathogen range shifts increasingly important. Although such predictions will hinge on an accurate understanding of the determinants of pathogen range-namely the environmental, geographical, and host range characteristics that modulate local pathogen habitation-few studies to date have probed these in natural plant populations. Here, we characterize range determinants for the model system of Lewis flax () and its pathogen, flax rust (), in the Rocky Mountains. Transect surveys were performed to assess three relationships: (i) the effect of geographical features-elevation, slope aspect, slope grade, and land cover-on flax presence and density, (ii) the effect of geographical features on flax rust presence and prevalence, and (iii) the effects of flax's local population density and metapopulation structure on flax rust presence and prevalence. We found that flax population density, but not host metapopulation structure, influences the distribution of flax rust. Additionally, we showed that, while the distribution of flax was broadly constrained to a relatively narrow range of geographical and resulting environmental features, flax rust was evenly distributed across the full range of settings measured. These results indicate that a warming environment, which is expected to modulate such features, may restrict the optimal range of the plant more than that of its pathogen. Importantly, our results also suggest that even if flax shifts its spatial range to escape increasing climatic pressures, flax rust will not face any significant barriers to track this movement.
PubMed: 37818245
DOI: 10.1002/ece3.10577 -
Nutrients Dec 2023Santiago, Chile is a very segregated city, with higher childhood obesity rates observed in vulnerable areas. We compared the counts and proximity of unhealthy food...
Santiago, Chile is a very segregated city, with higher childhood obesity rates observed in vulnerable areas. We compared the counts and proximity of unhealthy food outlets (UFOs) around a 400 m buffer of 443 public schools (municipal and subsidized) located in socioeconomically diverse neighborhoods in 14 municipalities of Santiago. This was a cross-sectional study in which the socioeconomic status (SES) of the population living inside the buffer was classified as middle-high, middle, and low. We used the Kruskal-Wallis test for comparisons of density and proximity between type of school, SES, and population density. We used a negative binomial model (unadjusted and adjusted by population density) to determine the expected change in counts of UFOs by SES, which was compared to the reference (middle-high). Low SES neighborhoods had significantly more counts of UFOs, and these were located much closer to schools. Low and middle SES neighborhoods had an 88% and 48% higher relative risk of having UFOs compared to middle-high SES areas; (IRR = 1.88; 95% CI 1.59-2.23) and (IRR = 1.48; 95% CI 1.20-1.82), respectively. A socio-spatial segregation of UFOs associated with childhood obesity across public schools was observed in Santiago.
Topics: Child; Humans; Chile; Cross-Sectional Studies; Pediatric Obesity; Food; Schools
PubMed: 38201938
DOI: 10.3390/nu16010108 -
Ecology and Evolution May 2024Canid species are highly adaptable, including to urban and peri-urban areas, where they can come into close contact with people. Understanding the mechanisms of wild...
Canid species are highly adaptable, including to urban and peri-urban areas, where they can come into close contact with people. Understanding the mechanisms of wild canid population persistence in these areas is key to managing any negative impacts. The resource dispersion hypothesis predicts that animal density increases and home range size decreases as resource concentration increases, and may help to explain how canids are distributed in environments with an urban-natural gradient. In Australia, dingoes have adapted to human presence, sometimes living in close proximity to towns. Using a targeted camera trap survey and spatial capture-recapture models, we estimated spatial variation in the population density and detection rates of dingoes on Worimi Country in the Great Lakes region of the NSW coast. We tested whether dingo home range and population densities varied across a gradient of human population density, in a mixed-use landscape including, urban, peri-urban, and National Park environs. We found human population density to be a strong driver of dingo density (ranging from 0.025 to 0.433 dingoes/km across the natural-urban gradient), and to have a negative effect on dingo home range size. The spatial scale parameter changed depending on survey period, being smaller in the peak tourism period, when human population increases in the area, than in adjacent survey periods, potentially indicating reduced home range size when additional resources are available. Our study highlights the potential value of managing anthropogenic resource availability to manage carnivore densities and potential risk of human-carnivore interactions.
PubMed: 38779530
DOI: 10.1002/ece3.11404 -
ACS Omega Nov 2023Infectious diseases continue to pose an imminent threat to global public health, leading to high numbers of deaths every year and disproportionately impacting developing... (Review)
Review
Infectious diseases continue to pose an imminent threat to global public health, leading to high numbers of deaths every year and disproportionately impacting developing countries where access to healthcare is limited. Biological, environmental, and social phenomena, including climate change, globalization, increased population density, and social inequity, contribute to the emergence of novel communicable diseases. Rapid and accurate diagnoses of infectious diseases are essential to preventing the transmission of infectious diseases. Although some commonly used diagnostic technologies provide highly sensitive and specific measurements, limitations including the requirement for complex equipment/infrastructure and refrigeration, the need for trained personnel, long sample processing times, and high cost remain unresolved. To ensure global access to affordable diagnostic methods, loop-mediated isothermal amplification (LAMP) integrated clustered regularly interspaced short palindromic repeat (CRISPR) based pathogen detection has emerged as a promising technology. Here, LAMP-integrated CRISPR-based nucleic acid detection methods are discussed in point-of-care (PoC) pathogen detection platforms, and current limitations and future directions are also identified.
PubMed: 38027359
DOI: 10.1021/acsomega.3c04422 -
Scientific Reports Aug 2023Reliable information on population size is fundamental to the management of threatened species. For wild species, mark-recapture methods are a cornerstone of abundance...
Reliable information on population size is fundamental to the management of threatened species. For wild species, mark-recapture methods are a cornerstone of abundance estimation. Here, we show the first application of the close-kin mark-recapture (CKMR) method to a terrestrial species of high conservation value; the Christmas Island flying-fox (CIFF). The CIFF is the island's last remaining native terrestrial mammal and was recently listed as critically endangered. CKMR is a powerful tool for estimating the demographic parameters central to CIFF management and circumvents the complications arising from the species' cryptic nature, mobility, and difficult-to-survey habitat. To this end, we used genetic data from 450 CIFFs captured between 2015 and 2019 to detect kin pairs. We implemented a novel CKMR model that estimates sex-specific abundance, trend, and mortality and accommodates observations from the kin-pair distribution of male reproductive skew and mate persistence. CKMR estimated CIFF total adult female abundance to be approximately 2050 individuals (95% CI (950, 4300)). We showed that on average only 23% of the adult male population contributed to annual reproduction and strong evidence for between-year mate fidelity, an observation not previously quantified for a Pteropus species in the wild. Critically, our population estimates provide the most robust understanding of the status of this critically endangered population, informing immediate and future conservation initiatives.
Topics: Humans; Animals; Male; Female; Conservation of Natural Resources; Endangered Species; Population Density; Ecosystem; Mammals; Chiroptera
PubMed: 37532795
DOI: 10.1038/s41598-023-38639-z -
Scientific Reports Jul 2023Isolation of wildlife populations represents a key conservation challenge in the twenty-first century. This may necessitate consideration of translocations to ensure...
Isolation of wildlife populations represents a key conservation challenge in the twenty-first century. This may necessitate consideration of translocations to ensure population viability. We investigated the potential population and genetic trajectory of a small, isolated tiger (Panthera tigris) population in Thailand's Dong Phayayen-Khao Yai forest complex across a range of scenarios. Using an individual-based, spatially-explicit population modelling approach, we simulate population and genetic trajectories and evaluate the relative impact of translocations from a related population. Population and genetic trajectories in our study were most sensitive to sex and number of individuals translocated and translocation frequency. Translocation of females produced consistently higher population, allelic richness, and heterozygosity compared to equal numbers of males. Despite population increases, declines in allelic richness and heterozygosity across simulations were stark, with simulations predicting a mean decline of allelic richness and heterozygosity of 46.5% and 53.5% without intervention, respectively. Translocations of four females every generation or every other generation were required to prevent substantial heterozygosity declines. While translocations could increase population size, they may fail to prevent long-term loss of genetic diversity in small populations unless applied frequently. This reinforces the importance of incorporating realistic processes of genetic inheritance and gene flow in modelling small populations.
Topics: Humans; Male; Animals; Female; Population Density; Tigers; Gene Rearrangement; Translocation, Genetic; Alleles
PubMed: 37433862
DOI: 10.1038/s41598-023-36849-z -
JAMA Network Open May 2024There are limited data on whether the vulnerabilities and impacts of social isolation vary across populations.
IMPORTANCE
There are limited data on whether the vulnerabilities and impacts of social isolation vary across populations.
OBJECTIVE
To explore the association between social isolation and mortality due to all causes, cardiovascular diseases (CVD), and malignant neoplasms focusing on heterogeneity by sociodemographic factors.
DESIGN, SETTING, AND PARTICIPANTS
This cohort study used a moderator-wide approach to examine the heterogeneity in the association of social isolation with all-cause, CVD, and malignant neoplasm mortality using baseline data from the Japan Gerontological Evaluation Study in 2010 and 2011. Eligible participants were adults aged 65 years or older without heart disease, stroke, cancer, or impaired activity of daily living across 12 Japanese municipalities. Follow-up continued until December 31, 2017, identifying 6-year all-cause, cardiovascular disease (CVD), and malignant neoplasm mortality. Logistic regression assessed effect modification by age, gender, education, income, population density, marital status, and employment on mortality associations. Data analysis was performed from September 13, 2023, to March 17, 2024.
EXPOSURE
Social isolation, determined by a 3-item scale (scores of 2 or 3 indicating isolation) was the primary exposure variable.
MAIN OUTCOMES AND MEASURES
Six-year all-cause, CVD, and malignant neoplasms mortality.
RESULTS
This study included 37 604 older adults, with a mean (SD) age of 73.5 (5.9) years (21 073 women [56.0%]). A total of 10 094 participants (26.8%) were classified as experiencing social isolation. Social isolation was associated with increased all-cause (odds ratio [OR], 1.20 [95% CI, 1.09-1.32]), CVD (OR, 1.22 [95% CI, 0.98-1.52]), and malignant neoplasm mortality (OR, 1.14 [95% CI, 1.01-1.28]). Stratified analysis showed associations of social isolation with all-cause and malignant neoplasm mortality among people with high income (highest tertile all cause: OR, 1.27 [95% CI, 1.06-1.53]; malignant neoplasm: OR, 1.27 [95% CI, 1.02-1.60]), living in areas with high population density (highest tertile all cause: OR, 1.47 [95% CI, 1.26-1.72]; malignant neoplasm: OR, 1.38 [95% CI, 1.11-1.70]), not married (all cause: OR, 1.33 [95% CI, 1.15-1.53]; malignant neoplasm: OR, 1.25 [95% CI, 1.02-1.52]), and retirees (all cause: OR, 1.27 [95% CI, 1.14-1.43]; malignant neoplasm: OR, 1.27 [95% CI, 1.10-1.48]). Formal testing for effect modification indicated modification by population density and employment for all-cause mortality and by household income and employment for neoplasm mortality.
CONCLUSIONS AND RELEVANCE
Social isolation was associated with increased risks of all-cause, CVD, and malignant neoplasm mortality, with associations varying across populations. This study fills an important gap in research on social isolation, emphasizing its varied associations across demographic and socioeconomic groups.
Topics: Humans; Social Isolation; Female; Male; Aged; Cardiovascular Diseases; Neoplasms; Japan; Aged, 80 and over; Cohort Studies; Cause of Death; Sociodemographic Factors; Mortality; Socioeconomic Factors
PubMed: 38787557
DOI: 10.1001/jamanetworkopen.2024.13132 -
Scientific Reports Jul 2023The Peleng tarsier (Tarsius pelengensis) is poorly known primate, with a range limited to Banggai island-group, Central Sulawesi, Indonesia. It was classified as...
The Peleng tarsier (Tarsius pelengensis) is poorly known primate, with a range limited to Banggai island-group, Central Sulawesi, Indonesia. It was classified as "Endangered" by IUCN in 2017 based on extremely limited demographic and distributional data. The aim of this study was to collect and analyze data on the population and distribution of Peleng tarsiers. Surveys were conducted over approximately 5 months in 2017 and 2018 across Peleng and the neighboring islands of Banggai, Labobo, and Bangkurung. We determined that tarsiers only occur on Peleng and Banggai Island. The average population density in Peleng and Banggai was estimated to be 234 individuals/km. This is comparable to the broad ranges of tarsier densities throughout Sulawesi and offshore islands. Peleng tarsiers were found in all elevations (0-937 m above sea level) and nearly all vegetated habitats in Peleng island. Using the IUCN criteria for determining conservation status, in conjunction with our new data, we believe that the Peleng tarsier population should be classified as "Vulnerable".
Topics: Animals; Tarsiidae; Indonesia; Ecosystem; Population Density
PubMed: 37454197
DOI: 10.1038/s41598-023-30049-5