Vector borne and zoonotic diseases最新文献

Background: As a natural accelerator of highly pathogenic avian influenza in wild birds, the H9 subtype of avian influenza poses a substantial threat to both humans and the poultry industry. A comprehensive meta-analysis is necessary to assess the current status of the global H9 outbreak. In this research, a literature review and meta-analysis are presented on the surveillance studies of the H9 subtype of avian influenza in wild birds worldwide up to 2024. Methods: A comprehensive search strategy was employed, utilizing the China Science and Technology Journal Database, China National Knowledge Infrastructure, PubMed, Google Scholar, and Scientific Direct databases. The exclusion criteria for this study included duplicate studies, reviews, other host studies, as well as research with inconsistent or insufficient data. An analysis was conducted on data obtained from a total of 31 publications. The rate-conversion analyses were conducted using a random-effects model in the "meta" package of the "R" software, with the PFT method implemented. Results: In the meta-analysis, the prevalence of wild bird H9 avian influenza virus (AIV) was found to be 0.02% (193 out of 365,972). Statistically significant higher prevalences of wild bird influenza A virus were observed in Norway and South Africa (0.87%, 21/2417 and 0.44%, 10/1155, respectively) in comparison with other regions. Within the Anseriformes family, the prevalence rate was much greater (0.17%, 80 out of 90,014) compared with other species. In addition, we performed subgroup analyses that included geographical variables. These assessments showed a higher prevalence of H9 in wild birds in cold regions (0.08%, 30/100,691). Conclusion: In summary, our results suggest that the occurrence of H9 AIV in avian populations differs among different geographical areas and species. Therefore, it is necessary to conduct further surveillance on the prevalence of AIV in wild birds to guide the creation of strong and efficient regulatory strategies targeted at eradicating the transmission of AIV across different species.

Background: DNA extraction from ticks is essential for research on tick-borne diseases, yet the methodologies currently employed exhibit significant variability in terms of yield and purity. This systematic review aims to consolidate existing literature on DNA extraction from ticks, evaluate the various methodologies, challenges, and research gap. Methodology: A systematic review of existing literature was conducted to assess the efficacy, yield, and purity of DNA extracted from various tick species using the aforementioned methods. Comparative analyses focused on factors such as extraction efficiency, contamination issues, and the impact of tick exoskeleton resilience. Results: Phenol-chloroform extraction achieved high DNA yields (50-100 ng/µL) but posed safety risks and was time-consuming. Silica-based methods provided yields of 40-80 ng/µL, effective for many species but less so for those with high microbial loads. Magnetic bead-based extraction offered rapid results with yields ranging from 20 to 70 ng/µL, although it faced challenges such as bead carryover and equipment requirements. Variability in extraction efficiency was noted across different tick species, necessitating method optimization. Conclusion: The review identified several critical research gaps in DNA extraction methods for tick-borne disease diagnostics and research. Currently, methods such as mechanical disruption combined with chemical lysis and column-based methods have shown effectiveness in extracting DNA from ticks, but they come with limitations, including high cost, labor intensity, and reduced efficiency under certain conditions. Despite their utility, these methods often face challenges in resource-limited settings or in varying environmental conditions. To address these issues, there is a need for standardized protocols, cost-effective extraction techniques, and longitudinal studies to evaluate performance under diverse conditions. By addressing these gaps, we can improve diagnostic accuracy, enhance our understanding of tick-borne diseases, and advance both research and public health efforts.

Background: Bats act as reservoirs for a variety of zoonotic viruses, sometimes leading to spillover into humans and potential risks of global transmission. Viral shedding from bats is an essential prerequisite to bat-to-human viral transmission and understanding the timing and intensity of viral shedding from bats is critical to mitigate spillover risks. However, there are limited investigations on bats' seasonal viral shedding patterns and their related risk factors. We conducted a comprehensive review of longitudinal studies on bat viruses with spillover potential to synthesize patterns of seasonal viral shedding and explore associated risk factors. Methods: We extracted data from 60 reviewed articles and obtained 1085 longitudinal sampling events. We analyzed viral shedding events using entropy values to quantitatively assess whether they occur in a consistent, pulsed pattern in a given season. Results: We found that clear seasonal shedding patterns were common in bats. Eight out of seventeen species-level analyses presented clear seasonal patterns. Viral shedding pulses often coincide with bats' life cycles, especially in weaning and parturition seasons. Juvenile bats with waning maternal antibodies, pregnant bats undergoing immunity changes, and hibernation periods with decreased immune responses could be potential risk factors influencing seasonal shedding patterns. Conclusion: Based on our findings, we recommend future longitudinal studies on bat viruses that combine direct viral testing and serological testing, prioritize longitudinal research following young bats throughout their developmental stages, and broaden the geographical range of longitudinal studies on bat viruses based on current surveillance reports. Our review identified critical periods with heightened viral shedding for some viruses in bat species, which would help promote efforts to minimize spillovers and prevent outbreaks.

Arthropod-borne viruses (arboviruses) are a taxonomically varied group of viruses that affect the health of many avian species, including the ruffed grouse (Bonasa umbellus), a popular upland game bird whose numbers are in decline in portions of its range. Hunter-harvested ruffed grouse tissue samples were tested for arboviruses during the 2018-2022 hunting seasons in Michigan, Minnesota, and Wisconsin, USA. A low percentage of harvested ruffed grouse were infected with West Nile virus (8/1892; 0.4%), eastern equine encephalitis virus (18/1892; 1.0%), and Highlands J virus (4/1892; 0.2%), and approximately half (16/30) of those infected had histologic cardiac lesions consistent with arboviral infection. Some ruffed grouse may be adversely affected following infection with these viruses, highlighting the need for increased awareness and continued surveillance, particularly in the face of additional stressors such as climate change, which may alter virus-vector-host dynamics, host susceptibility to arbovirus infections, and geographical distributions.

Objective: Severe fever with thrombocytopenia syndrome (SFTS) poses a significant public health concern in China and has the potential for severe morbidity and mortality. Previous studies on SFTS have focused primarily on analyzing its incidence under existing climate conditions, often overlooking the impacts of future climate change on the disease's distribution. Moreover, the key factors influencing SFTS transmission identified in prior research are limited and lack a comprehensive consideration of multiple environmental and socioeconomic factors in specific regions. Methods: In this study, by utilizing SFTS case data from Chuzhou city alongside multisource environmental variables, the maximum entropy ecological niche (MaxEnt) model was employed to identify the key climatic factors influencing the distribution of SFTS. Risk areas were projected for the present and future climate scenarios, including shared socioeconomic pathway (SSP)126, SSP245, SSP370, and SSP585. Results: The results indicate that (1) precipitation in the driest quarter, elevation, and precipitation in the wettest month are the most critical variables; (2) potential risk areas are situated predominantly in the central hilly region, with the total area of medium- and high-risk zones measuring 5731.86 km², which accounts for 42.67% of the total area; (3) in future climate scenarios, the central-south and southwestern regions emerge as high-risk areas, with the maximum area of future high-risk zones reaching 6417.8398 km², projected for the 2030s under the SSP585 scenario; and (4) the current epicenter of the SFTS risk area is located in Zhang Baling town (118°12'23″E, 32°28'56″N). Under the SSP126 and SSP370 scenarios, the epicenter exhibits minimal movement, whereas significant shifts occur under the SSP245 and SSP585 scenarios. Conclusion: These findings provide essential insights for formulating scientifically grounded prevention and control strategies against SFTS in Chuzhou city.

Background: Black flies (Diptera: Simuliidae) are a notorious group of blood-sucking insects acting as vectors of various diseases in humans and other animals, most notable being Onchocerciasis. Due to its medical and veterinary significance, accurate and quick species identification is of utmost importance in the field of black fly research. DNA barcoding is one such taxonomic tool, aiding in quick and efficient species identification using molecular methods. Despite sporadic reports of ocular and cutaneous Onchocerciasis, especially from North-East India, Indian Simuliidae has been understudied due to lack of expertise on morphological taxonomy and lack of genetic library. Materials and Methods: Blackflies were collected from eight distinct locations in the Central Himalayan region that are part of the West Bengal, India, districts of Kalimpong and Darjeeling. Various traps were used to collect the specimens, and they were kept it in 70% ethyl alcohol. Following the morphological identification of each fly specimen, genomic DNA was extracted from its dissected legs using the QIAmp DNA extraction kit (QIAGEN, Germany). The voucher specimen slide was deposited in the National Zoological collection, ZSI, Kolkata, India. Results: This is the first comprehensive DNA barcoding study of black flies (Feuerborni and Multistriatum species group) using mitochondrial cytochrome c oxidase subunit I (COI) gene sequences along with morphological identification from the Central Himalayan region of West Bengal involving four species: Simulium dentatum, Simulium digitatum, Simulium praelargum, and Simulium senile. DNA barcode approach through ML tree clearly distinguished all the species with supporting PTP, ASAP, and GMYC analysis. Interspecific genetic distances were also calculated where S. dentatum and S. digitatum showed minimum distances in the study area. Conclusion: Coupled with a robust morpho-taxonomic framework, the DNA barcodes generated here will help with accurate species identification, which will lead to better management and control strategies for these harmful vector species at the study site.

Background: The tick-borne pathogens, Bourbon virus (BRBV) and Heartland virus (HRTV) are the cause of febrile illnesses that may progress to severe and fatal diseases. Materials and Methods: As a preliminary effort to determine if these viruses were enzootic in Texas, ticks and blood samples were collected from feral swine (Sus scrofa) and white-tailed deer (Odocoileus virginianus) (WTD) killed by gunning as part of an abatement program during 2019-2021 in Travis County, Texas. Ticks were collected from these animals by hand and blood samples were obtained by cardiac puncture using 22-gauge needles and 5 mL syringes. Information was recorded for each animal, including date, sex, and location. The species of ticks were identified morphologically using a taxonomic key, and serum samples were tested for neutralizing antibodies to BRBV and HRTV. Results: A total of 83 Ixodes scapularis and 58 Amblyomma americanum ticks were collected from feral swine, and 196 I. scapularis and 11 Dermacentor albipictus from WTD. Although A. americanum, the implicated vector of both viruses was collected from feral swine, neutralizing antibody was not detected to BRBV, but 12% (9/75) had antibody to HRTV as evidence of a previous infection. Of the serum samples obtained from WTD, all were negative for BRBV neutralizing antibody, but 6.6%% (5/75) were positive for HRTV antibody. Conclusion: These preliminary results indicated that HRTV was enzootic in Travis, County, Texas and further studies are warranted to determine the specific tick vectors and the possible role of WTD and feral swine in the maintenance and transmission cycle of this virus.

Background: Enterocytozoon bieneusi is reported to be a common microsporidian of humans and animals in various countries. However, limited information on E. bieneusi has been recorded in cats (Felis catus) and dogs (Canis familiaris) in China. Here, we undertook molecular epidemiological investigation of E. bieneusi in cats and dogs in Shanghai, China. Methods: A total of 359 genomic DNAs were extracted from individual fecal samples from cats (n = 59) and dogs (n = 300), and then were tested using a nested PCR-based sequencing approach employing internal transcribed spacer (ITS) of nuclear ribosomal DNA as the genetic marker. Results: Enterocytozoon bieneusi was detected in 34 of 359 (9.5%) (95% confidence interval [6.7 - 13.0%]) fecal samples from cats (32.2%; 19/59) and dogs (5.0%; 15/300), including 24 stray cats and dogs (22.6%; 24/106), as well as 10 household/raised cats and dogs (4.0%; 10/253). Correlation analyses revealed that E. bieneusi positive rates were significantly associated with stray cats and dogs (p < 0.05). The analysis of ITS sequence data revealed the presence of five known genotypes, CD7, CHN-HD2, D, PtEb IX, and Type IV, and two novel genotypes, D-like1 and PtEb IX-like1. Zoonotic genotype D was the predominant type with percentage of 61.8% (21/34). Phylogenetic analysis of ITS sequence data sets showed that genotypes D, D-like1, and Type IV were clustered within Group 1, showing zoonotic potential. The others were assigned into Group 10 with host specificity. Conclusions: These findings suggested that cats and dogs in Shanghai harbor zoonotic genotype D of E. bieneusi and may have a significant risk for zoonotic transmission. Further insight into the epidemiology of E. bieneusi in other animals, water, and the environment from other areas in China will be important to have an informed position on the public health significance of microsporidiosis caused by this microbe.

Background: Bourbon virus (BRBV) is an emerging pathogen that can cause severe and fatal disease in humans. BRBV is vectored by Amblyomma americanum (lone star ticks), which are widely distributed across the central, southern, and eastern United States. Wildlife species are potentially important for the maintenance and transmission of BRBV, but little is known about which species are involved, and what other factors play a role in their exposure to BRBV. Methods: To assess the exposure risk to BRBV among wildlife in the St. Louis, Missouri, area, we collected sera from 98 individuals, representing 6 different mammalian species from two locations in St. Louis County: Tyson Research Center (TRC) and WildCare Park (WCP) from fall 2021 to spring 2023. The sera were used in a BRBV neutralization assay to detect neutralizing antibodies and RT-qPCR for viral RNA analysis. We also sampled and compared the abundance of A. americanum ticks at the two locations and modeled which factors influenced BRBV seropositivity across species. Results: In TRC, we observed a high rate of seropositivity in raccoons (Procyon lotor, 23/25), and white-tailed deer (Odocoileus virginianus, 18/27), but a low rate in opossums (Didelphis virginiana, 1/18). Neutralizing antibodies were also detected in sampled TRC bobcats (Lynx rufus, 4/4), coyotes (Canis latrans, 3/3), and a red fox (Vulpes vulpes, 1/1). The virological analysis did not detect BRBV RNA in any serum samples. In contrast to TRC, all sera screened from WCP were negative for BRBV-specific neutralizing antibodies, and significantly fewer ticks were collected at WCP (31) compared with TRC (2316). Conclusions: Collectively, these findings suggest that BRBV circulates in multiple wildlife species in the St. Louis area and that tick density and host community composition may be important factors in BRBV ecology.