Vector borne and zoonotic diseases最新文献

Background: Leptospirosis is a globally important zoonosis maintained by chronically infected animal reservoirs, yet its long-term eco-epidemiological dynamics remain poorly understood. Southeast China has historically been an endemic region, but changing climate and land use may be reshaping Leptospira transmission.

Methods: We conducted 15-year longitudinal surveillance (2009-2024) in Pan'an County, Zhejiang Province, integrating field sampling of rodents and other hosts, serogroup identification, multilocus sequence typing, and experimental mouse infection. Annual rainfall, host data, and molecular analyses were combined to assess temporal trends, serogroup turnover, and virulence differences between classical and emerging lineages.

Results: Rodent Leptospira positivity persisted annually (1.2-18%) with peaks during heavy-rainfall years, while human cases declined after 2015. The host range narrowed from multispecies detection to rodent dominance after 2020. Serological and phylogenetic analyses revealed a post-2020 emergence of serogroup 56601, which replaced historical O1/O6 lineages and formed a genetically compact cluster, suggesting recent clonal expansion. In mice, the 56601 strain caused higher renal bacterial loads, more severe tubular injury, and stronger cytokine responses than O1.

Conclusions: Long-term surveillance demonstrates rapid ecological and genetic turnover of Leptospira and identifies 56601 as an emerging lineage with increased pathogenic potential in endemic regions.

Background: Tick-borne diseases caused by spotted fever group (SFG) Rickettsia and members of the family Anaplasmataceae are important public health concerns. Given that previous studies on SFG in Hokkaido, the northernmost prefecture of Japan, have been limited by small sample sizes or limited to specific pathogens or tick species, the epidemiology of tick-borne bacteria remains unclear. This study investigated the prevalence of SFG Rickettsia and Anaplasmataceae bacteria in multiple tick species in Hokkaido.

Methods: DNA was extracted from 1,115 questing ticks representing six species (548 Ixodes ovatus, 368 Ixodes persulcatus, 95 Haemaphysalis concinna, 74 Haemaphysalis japonica, 28 Haemaphysalis megaspinosa, and 2 Haemaphysalis longicornis) collected from six districts in Hokkaido. Samples were screened using PCR assays targeting the gltA gene of SFG Rickettsia species and the groEL gene of Anaplasmataceae. Amplicons were sequenced for species identification.

Results: SFG Rickettsia DNA was found only in I. persulcatus (48.9%, 180/368), including R. helvetica (32.1%) and Candidatus R. tarasevichiae (16.8%). Anaplasmataceae DNA was detected in 3.9% (44/1,115) of ticks, including I. persulcatus, I. ovatus, H. japonica, and H. megaspinosa. In I. persulcatus, Ehrlichia muris, Candidatus Neoehrlichia mikurensis, and Anaplasma phagocytophilum were detected in 4.6%, 3.3%, and 0.3%, respectively. Ehrlichia japonica was found in I. ovatus (0.9%), while unclassified Ehrlichia spp. were detected in H. japonica (1.4%) and H. megaspinosa (3.6%). Seventeen I. persulcatus (4.6%) carried both SFG Rickettsia and Anaplasmataceae.

Conclusions: The findings showed that questing ticks in Hokkaido harbor zoonotic bacteria. While I. persulcatus appears to be the principal vector, the detection of pathogens in I. ovatus, H. japonica, and H. megaspinosa suggests the potential for additional vectors in the region. These findings underscore the importance of continuous surveillance and heightened clinical awareness of tick-borne diseases in northern Japan.

Introduction: Arboviral diseases, transmitted by hematophagous arthropods such as mosquitoes and ticks, represent an escalating global public health challenge. The resurgence and geographic spread of arboviruses particularly dengue virus, Zika virus, chikungunya virus (CHIKV), and West Nile virus are closely linked to environmental change, urbanization, and increased human mobility. Understanding their evolutionary mechanisms, host-vector interactions, and emerging control strategies is critical to effective disease mitigation.

Materials and methods: This systematic review employed a comprehensive multidatabase search (PubMed, Scopus, Web of Science, Google Scholar) from 2000 to 2025 using MeSH terms and Boolean logic to identify studies on arbovirus evolution, transmission, and control. From 16,320 initial records, 12 high-quality, peer-reviewed studies met the final inclusion criteria based on relevance, methodology, and publication standards. The review followed PRISMA guidelines and adopted an integrative analytical framework, including genomic analysis, meta-epidemiological synthesis, and predictive modeling.

Results: The review highlights that arboviruses possess high genomic plasticity, enabling rapid adaptation through mutations (e.g., CHIKV A226V), recombination, and immune evasion. Key molecular mechanisms include subversion of RNA interference (RNAi) and Toll/IMD pathways, and saliva-assisted transmission in vectors. Environmental and anthropogenic driver's climate change, urban sprawl, and globalization are expanding arbovirus endemicity into new regions. Novel control strategies such as CRISPR gene drives, Wolbachia-based interventions, and RNAi antivirals offer promising alternatives to conventional vector control, with mRNA vaccine platforms showing significant potential.

Discussion: The findings emphasize the importance of a multidisciplinary approach integrating virology, vector biology, synthetic biology, and environmental modeling. Real-time genomic surveillance, predictive analytics, and eco-adaptive vector control strategies are essential for proactive response. However, ethical, ecological, and regulatory concerns around gene editing and microbial interventions warrant careful consideration. The evolving interplay between virus, vector, host, and environment necessitates dynamic public health strategies and sustained international collaboration.

Background: Zoonotic diseases represent a major concern for global public health with marked variation in their burden observed across different regions and population groups.

Methods: This study investigated the global distribution and determinants of zoonotic diseases using datasets from the 2021 Global Burden of Disease study and the WHO Global Health Observatory databases. We evaluated the roles of sex, age, and the sociodemographic index (SDI) on zoonotic disease burden by examining incidence, prevalence, disability-adjusted life years, and mortality data across 201 nations. The statistical approach incorporated Spearman correlation, multivariate regression models, and stratified time-series forecasting to 2040.

Results: The results showed a higher disease burden in Africa, South Asia, and parts of Southeast Asia, particularly among older males in low-SDI regions. A strong inverse association was observed between SDI and zoonotic disease burden, with improved health coverage and physician density linked to lower morbidity and mortality. Predictive models indicated a gradual global decline in disease burden, although progress varied significantly by region.

Conclusion: These results underscore the urgency of implementing equity-oriented interventions and inform strategic resource allocation that gives precedence to prioritizing vulnerable populations in low- and middle-income regions.

Background: Small mammals can carry and transmit various virulent pathogens. Xinjiang Uygur Autonomous Region (Xinjiang), with its rich diversity of small mammal species, represents a high-risk region for pathogen transmission. Epidemiological analysis and genetic sequencing of these pathogens are crucial for strengthening public health interventions.

Methods: This study examined the analysis of effects of region, habitat, host genus, and climatic factors on pathogen infection rates in small mammals using spleen and lung tissue samples collected between May and September 2024. Categorical variables were assessed using Pearson ${\chi }^2$ test/Monte Carlo ${\chi }^2$ test, while continuous variables were analyzed with the Wilcoxon rank-sum test. Principal component analysis was applied to extract key influence factors, followed by binary logistic regression modeling. Pathogens were detected in 43 host animals, including Anaplasma phagocytophilum (n = 27) and Spotted fever group rickettsiae (SFGR; n = 15), with infection rate comparisons conducted under different conditions (α = 0.05). Positive samples were sequenced and subjected to phylogenetic analysis.

Results: The overall pathogen infection rate in small mammals from Xinjiang border ports was 40.19%, comprising A. phagocytophilum (25.23%) and SFGR (14.02%). High temperature, low relative humidity, the Huoerguosi Port, and grassland habitats were associated with a reduced infection rate of pathogenic microorganisms (odds ratio = 0.71, 95% confidence interval = 0.51-0.93, p = 0.021). Spatially, A. phagocytophilum showed the highest infection rate in the Dulata Port, desert habitats, and Meriones spp., whereas SFGR predominated in the Takeshiken Port, alpine meadow steppes, and Marmota spp. Genetic homology analysis revealed maximum sequence similarities of 99.15% for A. phagocytophilum and 98.35% for SFGR.

Conclusion: Xinjiang border ports have a high diversity of small mammal species with elevated pathogen infection rates. These findings underscore the necessity for sustained and enhanced surveillance of small mammal-borne diseases in this region.

Introduction: Brucellosis is a zoonotic infection caused by Brucella species, which have been identified in various hosts and are associated with significant economic losses. The control of bovine brucellosis in Türkiye has primarily relied on the administration of the Brucella abortus S19 vaccine via the conjunctival route. The present study investigates the humoral immune response induced by the administration to cattle of the vaccine produced in Türkiye, with the Rose Bengal Plate Test (RBPT), an enzyme-linked immunosorbent assay (ELISA), and a complement fixation test (CFT), and evaluates cellular immunity through flow cytometry methods.

Materials and methods: For the purpose of the study, blood samples were collected from 20 nonvaccinated calves aged 3-6 months housed at the Eastern Anatolian Agricultural Research Institute, and from 20 vaccinated calves on days 0, 14, and 28, and months 3, 6, 9, and 12 following vaccination. RBPT, iELISA, and CFT were used to evaluate humoral immunity, and the flow cytometric analysis for the evaluation of cellular immunity included the measurement of CD4⁺, CD8⁺ and CD14⁺ cell populations, as well as CD4⁺IFN-γ⁺, CD8⁺IFN-γ⁺, and CD14⁺IL-12⁺ levels.

Results: The study revealed an increase in CD4⁺ and CD8⁺ T cell populations, along with elevated IFN-γ⁺ and IL-12⁺ cytokine levels in vaccinated animals, which are critically important for the development of cellular immunity. Also observed was a very low rate of vaccine-associated antibody positivity.

Conclusions: The study showed that conjunctival vaccination of calves with locally produced B. abortus S19 enhanced cellular immunity (CD4⁺, CD8⁺, CD14⁺, IL-12, IFN-γ) but induced minimal detectable antibody responses.

Background: Zoological parks offer unique opportunities to monitor arthropod vectors and assess risks to native and exotic animal populations.

Methods: From August to December 2023, a prospective surveillance initiative was conducted at Riverbanks Zoo & Gardens, South Carolina's largest zoological park. Adult mosquitoes were collected near animal enclosures using CO₂-baited CDC miniature light traps. Pools of Culex spp. were screened for West Nile virus with rapid analyte measurement platform assays.

Results: A total of 597 mosquitoes representing 17 species were collected. All Culex pools tested negative for West Nile virus.

Conclusions: Despite routine mosquito abatement, a diverse assemblage of species was documented. Continued surveillance in zoological settings can clarify vector-borne disease dynamics and emerging threats to both humans and animals. Future studies should assess insecticide resistance and expand arboviral testing to strengthen prevention and mitigation strategies.

Background: Vesicular stomatitis is endemic in southern Mexico, Central America, and northern South America. The causative agent, vesicular stomatitis virus (VSV; Rhabdoviridae: Vesiculovirus), includes two serotypes-New Jersey (VSNJV) and Indiana (VSIV)-both present in Costa Rica. Transmission occurs via direct contact, fomites, and insect vectors. Occupational exposure, particularly in livestock workers, is a known risk, and high human seroprevalence has been reported elsewhere in Central America. Some cases present with a self-limited febrile illness, occasionally with vesicular lesions. No studies have assessed human VSV seropositivity in Costa Rica.

Methods: A cross-sectional survey was conducted in two dairy cantons of Costa Rica: Poás (n = 174) and Tilarán (n = 84). Serum samples were tested for neutralizing antibodies against VSNJV and VSIV using microseroneutralization in Vero-E6 cells. The seroprevalence with 95% confidence intervals was estimated. Associations with occupation and cattle contact were evaluated using chi-square tests and relative risk (RR). No clinical data were collected, as the study was focused solely on serological evidence of exposure.

Results: In Poás, VSNJV seroprevalence was 40.8% and VSIV 16.7%. Agricultural work was associated with higher VSNJV (RR = 2.28, p = 0.0001) and VSIV seropositivity (RR = 4.78, p = 0.0004). Direct cattle contact correlated with VSIV seropositivity (RR = 4.22, p = 0.0050). In Tilarán, VSNJV seroprevalence was 26.2% and VSIV 3.6%; only direct cattle contact was significantly associated with VSNJV (RR = 6.14, p = 0.0191). Prevalence was higher in Poás for both VSNJV (RR = 1.56, p = 0.022) and VSIV (RR = 4.67, p = 0.0028).

Conclusions: This first report of human VSV seropositivity in Costa Rica shows a predominance of VSNJV. Higher prevalence among agricultural workers and those with cattle contact highlights occupational risk. Findings align with bovine seroprevalence and historical Central American human data, underscoring the need to consider VSV in febrile illnesses and to strengthen integrated "One Health" surveillance.

As a zoonotic protozoan, Pentatrichomonas hominis has been implicated in gastrointestinal diseases, typically residing in the cecum or colon of diverse vertebrate hosts. Nevertheless, information regarding its prevalence and genotypic distribution in farmed foxes (Vulpes lagopus) remains limited. Fresh fecal samples (n = 352) from farmed foxes in northern China were analyzed for P. hominis via nested PCR. The overall prevalence was 15.62% (55/352). Infection rates were 12.09% (22/182) in adults and 19.41% (33/170) in juveniles. The prevalence exhibited seasonal fluctuations, ranging from 10.90% to 25.24%, with the highest prevalence observed in autumn. Foxes with diarrhea exhibited a significantly higher infection rate (33.78%, 25/74) than those without (10.79%, 30/278). Prevalence varied across regions, with the highest rates in Jilin (30.00%, 12/40), followed by Shandong (26.88%, 25/93), Hebei (12.90%, 12/93), Liaoning (6.33%, 5/79), and Heilongjiang (2.13%, 1/47). All positive samples were grouped into the zoonotic CC1 genotype based on phylogenetic analysis. This study offers novel epidemiological insights into P. hominis occurrence among farmed foxes in northern China and underpins the advancement of specific approaches for its detection and control.

Background: There is limited understanding of the replication and transmission of bandaviruses and the influence of host genotype in successful infection. An in vitro Bandavirus model, such as Lone Star virus (LSV, Bandavirus amblyommae), capable of propagating in standard cell lines, could provide some of this critical information. In this study, we sequenced the genome of LSV and profiled its relationship with a key host viral-interacting protein, Synaptogyrin-2 (SYNGR2), known to influence the replication of another Bandavirus, Bandavirus dabieense.Materials and Methods:The genome of the LSV TMA 1381 strain was sequenced and assembled using Oxford Nanopore Technology. The expression of SYNGR2 was profiled and annotated in Vero cells. SYNGR2 knockout (KO) Vero clones were obtained via CRISPR-Cas9 gene editing of the first exon, present in all SYNGR2 isoforms. Following LSV infection, expression of SYNGR2 and LSV titer was measured in SYNGR2-KO and wild-type cell lines.

Results and conclusions: Sequence variation and evidence of viral heterogeneity were detected across all segments of the LSV TMA 1381 strain (4 missense substitutions out of 7 single-nucleotide polymorphisms identified, q > 16). Important amino acid sequence differences for the nonstructural protein, known to directly interact with host SYNGR2, were observed between LSV and other bandaviruses (15.5-47.4%). The change in SYNGR2 expression in wild-type Vero cells was limited following LSV infection (1.77-fold). No difference in estimated LSV titer was detected between wild-type and SYNGR2-KO Vero cells (p > 0.16). Our data illustrate key distinctions from previous Bandavirus reports and underline the need for future studies to explore the mechanisms of LSV replication and pathogenesis.