Vector borne and zoonotic diseases最新文献

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.

Background: Crimean-Congo hemorrhagic fever (CCHF) is a highly fatal, tick-borne zoonosis in humans for which no licensed vaccines exist. Camels are important hosts of Hyalomma ticks, yet data on their role in CCHF epidemiology in Nigeria are limited. This study assessed seroprevalence and risk factors of the CCHF virus (CCHFV) in camels from major livestock markets in northern Nigeria.

Materials and methods: From June 2023 to July 2024, 812 camels were sampled during 54 weekly visits to Maiduguri (Borno), Maigatari (Jigawa), and Illela (Sokoto) livestock markets. Epidemiological data (sex, age, origin, and tick infestation) were recorded for each sampled camel. Serum samples were tested using ID Screen CCHF double antigen Enzyme-linked immunosorbent assay (ELISA) kits. Descriptive statistics and logistic regression were applied to identify predictors of seropositivity (p < 0.05).

Results: CCHFV antibodies were detected in 89.4% of camels (95% CI: 87.1-91.4%). Prevalence was highest in Maiduguri (94.2%), followed by Maigatari (92.0%) and Illela (80.4%). Females (94.1%) had higher seropositivity than males (84.9%), and adults (>48 months) exceeded younger camels (94.3% vs. 81.7%). Tick infestation was strongly associated with seropositivity. Multivariable analysis showed younger age (OR = 0.35, 95% confidence intervals [CI]: 0.19-0.66), male sex (OR = 0.33, 95% CI: 0.18-0.60), and absence of ticks (OR = 0.45, 95% CI: 0.26-0.81) were significantly linked to reduced odds of seropositivity.

Conclusion: The very high seroprevalence observed in camels suggests that they may contribute to the epidemiology of CCHF in northern Nigeria. Although cultural practices such as consumption of raw camel milk and urine are common, their role in CCHFV transmission remains uncertain; therefore, further studies are recommended to investigate their potential epidemiological significance. Strengthening One Health-based surveillance, vector control, and public education is critical to reducing zoonotic transmission and protecting human and animal health.

Background: Chikungunya virus (CHIKV) outbreaks have affected the global population and demand effective antiviral strategies. Exploring the molecular mechanisms associated with its pathogenesis through modulation of host response is essential for the development of efficient antiviral interventions. Although CHIKV-encoded kinases are not perceived, the phosphorylation of CHIKV proteins in hosts is reported. Hence, elucidating the signaling cross-talks between host kinases and viral proteins provides opportunities for targeted therapeutic strategies.

Methods: Toward this, we predicted the phosphosites in CHIKV proteins and their potential host kinases using multiple prediction tools, followed by a human kinase substrate phosphomotif pattern analysis to identify putative kinase interactions. The phosphoproteome of CHIKV and CHIKV-infected host cells and further the host-viral interactome were analyzed in conjunction with kinase inhibition assays to identify host kinases associated with their infection. Subsequently, in silico protein-protein docking was performed between the selected kinases and viral proteins to identify potential interactions.

Results and conclusion: In silico analysis revealed Mitogen-activated protein kinase 1 (MAPK1), Protein kinase C alpha (PRKCA), and Eukaryotic elongation factor 2 kinase (EEF2K) as major host kinases of specific phosphosites in CHIKV proteins. Putative kinases were also predicted for the reported phosphorylation sites in the CHIKV phosphoproteome. This study reveals that host kinases may phosphorylate substrates critical to CHIKV persistence and pathogenesis and emphasizes the potential of targeting host kinases as an adjunct to antiviral strategies. Our approach demonstrates the utility of kinase substrate specificity modeling to identify host kinases that can interact with viral proteins for their selection as drug-repurposable targets, particularly for variants and viruses without efficient/approved vaccines.

Background: Vector-borne zoonotic diseases remain a major global public health concern, particularly at interfaces where humans, domestic animals, and wildlife interact closely. Conventional surveillance approaches often fail to detect early zoonotic spillover events, especially in farm and zoological settings. Blood-fed mosquitoes, which feed on diverse vertebrate hosts, offer a unique opportunity for non-invasive environmental surveillance through xenosurveillance. This study evaluates the feasibility of using blood-fed mosquitoes as biological samplers to assess zoonotic risk in managed animal settings in eastern India.

Methods: A total of 185 blood-fed female mosquitoes were collected from livestock farms and zoological enclosures in West Bengal, India, and grouped based on host association (cattle, buffalo, goat, poultry, zebra, and deer). Mosquito species were identified using mitochondrial cytochrome c oxidase I (COI) gene sequencing. Host-group-wise pooled DNA from mosquito heads and abdomens was subjected to shotgun metagenomic sequencing using Oxford Nanopore MinION technology. Taxonomic classification was performed using Kraken 2, and microbial diversity was analyzed through alpha and beta diversity metrics using phyloseq.

Results: Six mosquito species were identified, including Culex tritaeniorhynchus, Culex vishnui, and Mansonia uniformis, known vectors of zoonotic pathogens. Metagenomic analysis revealed diverse microbial communities dominated by Actinobacteria, Proteobacteria, and Firmicutes, with significant host-associated variation in microbial composition. Buffalo- and zebra-associated mosquitoes exhibited the highest microbial richness, while cattle-associated mosquitoes showed comparatively lower diversity. Genomic fragments corresponding to potential zoonotic and veterinary pathogens-including Plasmodium relictum, Babesia bigemina, and Clostridium botulinum-were detected across multiple host groups. Beta diversity analysis demonstrated clear host-driven clustering of mosquito-associated microbiomes.

Conclusion: This pilot study demonstrates that blood-fed mosquitoes can serve as effective non-invasive biological samplers for detecting environmental DNA signatures of potential zoonotic pathogens in managed animal settings. While the detection of pathogen-associated genomic fragments does not confirm active infection or transmission, the findings highlight the utility of mosquito-based metagenomic surveillance as an early warning and risk-detection tool within a One Health framework. Integrating such approaches with targeted diagnostics and epidemiological surveillance may strengthen preparedness for emerging vector-borne zoonotic threats.

Introduction: Borrelia bavariensis, a causative agent of Lyme disease, was first reported in South Korea in 2018, yet no complete genome sequence has been described. Here, we present the first whole-genome characterization of B. bavariensis strain KW3, isolated from Ixodes granulatus in the Kangwon region of South Korea. Methods: Genome assembly was achieved using a hybrid approach combining PacBio and Illumina sequencing. Results: The KW3 genome consists of a linear chromosome and 12 plasmids, totaling 1.33 Mbp comprising 1,310 annotated genes. Comparative analyses revealed that strain KW3 is most closely related to Japanese strains NT24 and JAASAAF1029. In multiple phylogenetic trees, strain KW3 consistently clustered within the Japanese clade but formed a distinct subbranch, suggesting regional diversification. Several plasmids showed evidence of fusion or divergence, including lp32-10_lp28-4, lp32-10_lp36, and cp32-6_cp32-12, which displayed partial similarity to plasmids of European Borrelia garinii strains PBes (Germany) and 20047 (France). Key plasmid-borne virulence genes (ospA, ospB, ospC, dbpA, dbpB) were fully conserved in strain KW3 and closely matched those of Japanese strains. In contrast, the vlsE locus, typically located on lp28-8 in B. bavariensis, was absent, possibly due to plasmid loss during in vitro culture. Conclusions: This study provides the first complete genome sequence of B. bavariensis isolate from South Korea and highlights its close relationship to Japanese isolates while revealing unique plasmid features and virulence gene profiles. These findings underscore the importance of continued genomic surveillance to monitor the circulation, evolution, and pathogenic potential of this tick-borne pathogen across East Asia.

Introduction: Coxiella burnetii, the causative agent of Q fever, remains poorly understood in Pakistan, despite its clinical relevance in both humans and ruminants. This study aimed to determine the seroprevalence of C. burnetii in rodents. Methods: Rodents were captured in urban settings across three districts of Punjab, Pakistan. A total of 300 serum samples were collected from rodents belonging to the Muridae family (n = 268) and the Sciuridae family (n = 32). Samples were screened for C. burnetii antibodies using an indirect enzyme-linked immunosorbent assay. Results: An overall seroprevalence of 12.7% (38/300) was observed, with a higher prevalence in males compared with females (p < 0.05). Using multiple logistic regression, age was identified as a potential risk factor for C. burnetii in rodents, with 14.1% (37/262) of adult rodents testing positive for C. burnetii antibodies, compared with a 2.6% (1/38) detection rate in juvenile rodents. Coxiella burnetii antibodies were detected in five rodent species, Tatera indica, Mus musculus, Millaria meltada, Rattus rattus, and Rattus norvegicus with seroprevalence ranging from 7.8% to 23.3%, depending on the species. Conclusion: This detection of C. burnetii in rodents residing in populated regions of Punjab, Pakistan indicates pathogen exposure. Additional studies, including molecular testing are needed to confirm their role as pathogen reservoirs.

Background: Campylobacter jejuni typically causes gastrointestinal illness but may lead to severe systemic infection in immunocompromised hosts. Resistance to macrolides, fluoroquinolones, and tetracyclines is increasingly reported. Case Presentation: A 27-year-old male with X-linked agammaglobulinemia developed recurrent right foot cellulitis after local trauma. Following application of a non-sterile herbal ointment and sheepskin, the lesion progressed, and the patient developed fever and chills. Blood cultures repeatedly yielded multidrug-resistant C. jejuni, while wound culture grew Citrobacter braakii. The C. jejuni isolates showed high MICs to macrolides, fluoroquinolones, and tetracycline. Given persistent bacteremia despite broad-spectrum therapy, meropenem was initiated, resulting in rapid defervescence and clinical improvement. Conclusion: This case highlights the potential for transdermal acquisition of C. jejuni in immunodeficient patients, the clinical challenges posed by multidrug-resistant strains, and the need for education regarding traditional practices that may increase infection risk.

Reactive arthritis is defined as a sterile inflammation of the joint space, following a remote infection, which can be bacterial or viral in origin. Although leptospirosis is not a frequent cause, it has been reported as a potential trigger. We herein report an 11-year-old boy who presented with fever, jaundice, and acute onset of right hip pain with restricted movement. Laboratory investigations were done to evaluate for infectious causes. IgM antibodies for Leptospira were equivocal, suggesting the possibility of an acute infection. This case highlights that reactive arthritis can develop early in the course of leptospiral infection, as early as within 3 days of symptom onset, and may coincide with active systemic illness. Early recognition of this rare association is essential for the diagnosis and management.