Transboundary and Emerging Diseases最新文献

Examining both long-term and short-term effects can enhance the precision and reliability of time series analysis. This study aimed to delve into the asymmetric effects of weather conditions on hemorrhagic fever with renal syndrome (HFRS) in the long and short terms and build a forecasting system. Data comprising monthly HFRS incidents and weather factors in Heilongjiang from January 2004 to December 2019 were extracted. Subsequently, the long- and short-term asymmetric impacts were examined using the autoregressive distributed lag (ARDL) and nonlinear ARDL (NARDL) models. Next, the samples were partitioned into training and testing subsets to evaluate the predictive potential of both models. From 2004 to 2019, HFRS exhibited a declining trend (average annual percentage change = −6.744%, 95% CI: −13.52%–0.563%) and a dual seasonal pattern, with a prominent peak in June and a secondary one in October–December. This study identified long-term asymmetric effects of rainfall (Wald long-run asymmetry (WLR) = 3.292, p = 0.001), wind velocity (WLR = −3.271, p = 0.001), and air pressure (WLR = −6.453, p < 0.001) on HFRS. Additionally, this study observed short-term asymmetric impacts of relative humidity (Wald short-run symmetry (WSR) = −1.547, p = 0.001), rainfall (WSR = −1.984, p = 0.049), and air pressure (WSR = −2.33, p = 0.021) on HFRS. A unit increase in relative humidity, sunshine hours, and air pressure resulted in about 10.9%, 1.9%, and 13.6% decreases in HFRS, respectively; a unit decrease in relative humidity, rainfall, and sunshine hours led to about 6.7%, 1.8%, and 2% decreases in HFRS, respectively. When temperature increased and decreased by one unit, the HFRS incidence increased by 11.6% and 22.5%, respectively. HFRS also varied significantly with the positive and negative changes in differenced (D) temperature, D (relative humidity), D (wind velocity), D (rainfall), D (air pressure), and D (sunshine hours) at 0−3-month delays over the short term. The NARDL model exhibited notably lower error rates in forecasting compared to the ARDL model. Meteorological parameters affect HFRS in both the long and short term, often showing asymmetric effects. The NARDL model, capable of incorporating various weather parameters, proves to be valuable in predicting HFRS epidemic and guiding strategies for prevention and control.

Lumpy skin disease (LSD) is an economically important and notifiable transboundary viral disease of cattle and water buffalo, predominantly transmitted by arthropod vectors. In recent times, LSD has emerged as a notable concern in Nepal, with the first outbreak reported in June 2020, in Morang district. In 2022, outbreaks of LSD were observed in several districts with Nawalpur district being the hard-hit district. The objective of this study is to provide insights into the epidemiological characteristics of LSD, to identify potential sources and associated risk factors for LSD outbreak in Nawalpur, and its financial impact. The overall morbidity rate was observed to be 28.02% (n = 431/1,538) and the mortality rate was 3.06% (n = 47/1,538), resulting in a case fatality rate of 10.90% (n = 47/431). The predominant clinical symptoms were skin nodules, lameness, and decreased milk production in milking animals. Dry cattle, including pregnant cows and cattle heifers were the most affected. Univariable logistic regression analysis identified factors linked to disease outbreaks, such as importing animals from disease prevalent regions, sharing feed and water, herd size, and the presence of clinical signs in neighboring farms. Multivariable analysis highlighted the significance of neighboring farms having sick animals in resulting disease outbreaks. Because of the substantial economic impact due to LSD, it is imperative to implement effective control and preventive measures. These include animal movement control and quarantine, following biosecurity protocols during nearby outbreaks, and targeted vaccination of susceptible populations to prevent further disease spread.

The H6N6 avian influenza virus (AIV) subtype is one of the most frequently isolated subtypes in poultry, and it has a broad host range. Some strains can overcome species barriers for transmission and infect humans. Increased affinity for human-type receptors is a key factor in this process. In this study, two H6N6 AIV strains originating from five different clades, in which amino acid 226 of hemagglutinin was mutated from glutamine to lysine, were isolated from ducks. The receptor-binding preference and pathogenicity of the two strains in poultry and mice were evaluated. The results indicated that the DK/GD/W3 strain can bind to both α-2,6 and α-2,3 receptors, whereas the DK/GD/L31 strain maintained affinity toward avian-origin α-2,3 receptors, highlighting differences in receptor tropism and pathogenicity to different hosts for two H6N6 strains with the same genetic background. These findings have revealed the complex recombination characteristics and molecular characteristics of H6N6 circulating strains in the environment and underscored the importance of continuous surveillance of this subtype for livestock and poultry health as well as human safety.

In 2021, a pregnant Rottweiler dog living on a sheep farm was diagnosed with clinical bluetongue (BT) infection. This study reports on the investigation of this farm where bluetongue virus (BTV) infection was diagnosed in this atypical host species. Samples were collected during farm visits 14, 28, 60, and 89 days after the onset of clinical signs in the pregnant Rottweiler. Blood was collected from all farm dogs (n = 6) and tested for BTV genome using a reverse-transcriptase quantitative PCR (RT-qPCR) assay and BTV antibodies with the competitive ELISA (cELISA) and dogs positive by RT-qPCR were further tested using virus neutralization (VN) serological testing. Blood was also collected from 16 sick sheep and tested using RT-qPCR. Midges were trapped on the study farm using an Onderstepoort UV light trap placed above a sheep pen for 36 hr at the first farm (14 days) visit. Parous/gravid midges were tested by BTV RT-qPCR in batches of up to 200 midges per species. Blood-fed midges (n = 308) were tested using a PCR species probe (KAPA Multiplex Master Mix) to identify the host species on which the midge had fed. Three dogs (n = 3/6) had detectable BTV RNA with RT-qPCR and high VN antibody titers to BTV. All RT-qPCR-positive dogs and one additional dog tested cELISA seropositive (n = 4/6). Bluetongue virus RNA was detected in 5/16 sheep tested. The most abundant midge species was Culicoides imicola (99.3%) and BTV was only detected in this species (n = 3/4 batches of 200 parous midges). Dog blood was not detected in any blood-fed midges tested. The occurrence of natural BT viraemia in exposed dogs creates a potential risk of BTV entry into BT-free countries through dog importation. It remains unclear whether BT viremia in dogs is capable of onward transmission.

The global outbreak of highly pathogenic avian influenza (HPAI) H5N1 Eurasian lineage goose/Guangdong clade 2.3.4.4b virus that was detected in North America in 2021 is the largest in history and has significantly impacted wild bird populations and domestic poultry across the continent. Synanthropic birds may play an important role in transmitting the virus laterally to other wild bird species and domestic poultry. Understanding the dynamics of HPAI in atypical, or nonreservoir, wild bird hosts may help inform management decisions and potential risk factors to both wild and domestic bird populations. Following the confirmation of infections of HPAI H5N1 in domestic poultry at two commercial premises in Indiana, United States, we sampled and tested 266 Columbiformes and Passeriformes birds and found no detections of the virus at either location. We further queried laboratories within the National Animal Health Laboratory Network for avian influenza (AI) virus diagnostic test results for wild birds submitted from morbidity/mortality events, for a total of 9,368 birds tested across eight orders and 1,543 avian influenza virus detections between February 2022 and March 2023. Query results were assessed for viral prevalence by taxonomic group and suggested that the virus most often was observed in predatory and scavenging birds. The highest prevalence was observed in raptors (0.2514), with prevalence rates in exclusively scavenging Cathartidae reaching up to 0.5333. There is evidence that the consumption of infected tissues is a key pathway for transmission of AI viruses in predatory and scavenging birds. Although detections were found in nonpredatory synanthropic birds, including orders Columbiformes and Passeriformes, the risk of transmission from and between these groups appears comparatively low. Understanding the dynamics of AI viruses in synanthropic bird orders during the global HPAI H5N1 outbreak in wild bird populations can provide pertinent information on viral transmission, disease ecology, and risk to humans and agriculture.

Background. Brucellosis is a major worldwide public health problem with economic and zoonotic implications. Despite the importance of vaccines in preventing brucellosis, no previous systematic evaluation of vaccination in sheep has been conducted. Materials and Methods. Articles were searched in databases such as PubMed, Science Direct, Cochrane, VIP, Wan Fang, and CNKI by screening the articles, and articles reporting Brucella vaccination in sheep were included in the study. Meta-analysis was performed using random effects models to calculate pooled risk ratios for vaccines and to calculate vaccine effectiveness. Results. A total of 2,605 articles were retrieved, and 17 articles were obtained through screening for analysis. The effectiveness of vaccination was 65% (RR = 0.35, 95% CI: 0.27–0.36; VE = 65%), with the M5 vaccine being significantly more effective at 84% (RR = 0.1587, 95% CI: 0.0256–0.9858; VE = 84%) than the other vaccines, and intramuscular injection could be the best route of immunization. Rev.1 was indicated for female sheep, especially for pregnant ewes (RR = 0.2016, 95% CI: 0.1139–0.3569; VE = 80%), and for reduced abortions (RR = 0.0978, 95% CI: 0.0459–0.2085). Conclusion. This meta-analysis was conducted to identify the relevant factors affecting vaccine efficacy. We recommend that sheep be inoculated intramuscularly with Rev.1, different inoculation protocols be adopted for sheep of different ages, and pregnant ewes be inoculated with Rev.1 to prevent abortion.

Erysipelothrix rhusiopathiae is responsible for erysipelas infection in pigs. Outbreaks of E. rhusiopathiae have increased in several countries, including China, over the past two decades. An E. rhusiopathiae strain (ML101) was isolated and characterized from dead pig tissue sample collected from a farm experiencing an outbreak of E. rhusiopathiae, which was responsible for the deaths of 146 sows and 308 fattening pigs within a week. Spleen swelling, gastric and bladder mucosa bleeding, and submandibular lymph node swelling and bleeding were observed through necropsy. ML101 was identified as serotype 1a via molecular analysis and immunological assays. Studies in mice demonstrated that the minimal lethal dose per animal was less than 10 colony-forming units (CFU). Notably, the minimal lethal dose in piglets was also less than 10 CFU, which is lower than that of any E. rhusiopathiae strain reported to date. The challenged piglets showed typical acute erysipelas symptoms, such as pyrexia, hemorrhage, depression, complete inappetence, reddening, and purpling skin on the buttock. Evidence of efficient horizontal transmission was observed, as healthy pigs were infected and died when cohoused with challenged piglets. Whole-genome sequencing revealed that ML101 contained a 77 kb genomic island (GI), carrying a Tn916 transposon and a multidrug resistance gene cluster (aadE-apt-spw-lsa(E)-lnu(B)-aadE-sat4–aphA3). A retrospective analysis of E. rhusiopathiae isolates via PCR indicated that the GI has been widely distributed since 2010, when outbreaks were more frequently reported in China. This study demonstrated that the highly virulent E. rhusiopathiae is responsible for the erysipelas outbreak and indicates that relevant genes located within the transmissible genetic elements may play roles in virulence. Therefore, epidemiological monitoring needs to be emphasized to better prevent and control erysipelas in the swine industry, and live attenuated vaccines should be used with caution.

Outbreaks of zoonotic Streptococcus equi subsp. zooepidemicus (SEZ) have caused severe epidemics in the pig sector since the 1970s in Southeastern Asia, China, and more recently North America. Cases of high mortality caused by peracute septicaemia were all attributed to strains of a highly virulent clonal lineage belonging to the sequence type (ST) 194. In Europe, only two outbreaks have been reported with similar features, caused by other sequence types. In August 2023, a febrile disease followed by abortion and subsequent death was observed among sows kept in a small-scale organic pig farm in West Hungary. Symptoms, pathological lesions, and microbiological findings were suggestive of septicaemia from bacterial origin caused by SEZ. According to the results of the routine laboratory testing, no other relevant infectious agents were involved. Whole-genome sequence analysis assigned the examined strains to ST138, unrelated to any of the European isolates. It also revealed a few common SEZ virulence genes, compared to the highly virulent ST194 strains. A sudden weather change and subsequent extremely high average daily temperature before the outbreak could be identified as the only predisposing factor. The immediate antibiotic treatment and applied biosecurity measures might have helped to restrict and terminate the outbreak. To our knowledge, this is the first report on abortion and lethal septicaemia in sows from Central and Eastern Europe. The results call attention to the potential of non-ST194 SEZ strains to cause outbreaks in pig farms.

Understanding timing and distribution of virus spread is critical to global commercial and wildlife biosecurity management. A highly pathogenic avian influenza virus (HPAIv) global panzootic, affecting ~600 bird and mammal species globally and over 83 million birds across North America (December 2023), poses a serious global threat to animals and public health. We combined a large, long-term waterfowl GPS tracking dataset (16 species) with on-ground disease surveillance data (county-level HPAIv detections) to create a novel empirical model that evaluated spatiotemporal exposure and predicted future spread and potential arrival of HPAIv via GPS tracked migratory waterfowl through 2022. Our model was effective for wild waterfowl, but predictions lagged HPAIv detections in poultry facilities and among some highly impacted nonmigratory species. Our results offer critical advance warning for applied biosecurity management and planning and demonstrate the importance and utility of extensive multispecies tracking to highlight potential high-risk disease spread locations and more effectively manage outbreaks.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most impactful viruses in swine production worldwide. Early detection of PRRSV outbreaks is the first step in rapid disease response. A syndromic surveillance system can be implemented to detect early signs of PRRSV activity in breeding herds. This study aimed to integrate multiple data sources and test univariate and multivariate statistical process control charts to identify early indicators associated with PRRSV outbreaks in sow farms. From March 2022 until May 2023, 16 breed-to-wean swine farms were enrolled in the study. The following key clinical and productivity indicators associated with PRRSV outbreaks were investigated: number of abortions, number of dead sows, number of off-feed events, preweaning mortality rate (PWM), and percentage of neonatal losses. The PRRSV status for the herd was determined by reverse transcriptase polymerase chain reaction testing using processing fluid samples, and it was considered as the reference to calculate the performance of the surveillance system. The exponentially weighted moving average (EWMA), cumulative sum (CUSUM), multivariate exponentially weighted moving average (MEWMA), and multivariate cumulative sum (MCUSUM) were the methods used to detect significant changes in the aforementioned parameters following the PRRSV outbreaks. Using the EWMA model, the indicators with the highest early detection rates were PWM followed by the abortions (71% and 64%, respectively), with the models raising alarms 4 weeks earlier on average than the processing fluids, respectively. For the CUSUM model, the weekly number of PWM, followed by abortions, were the indicators with the highest early detection rates (71% and 64%, respectively), with the models raising alarms 4 weeks earlier on average than the processing fluids for both indicators. Concerning the multivariate models, the MEWMA model with higher early detection used the PWM and neonatal losses (86%), with the models raising alarms 4 weeks earlier on average than the processing fluids, with the models raising alarms 3.5 weeks earlier on average than the processing fluids. For the MCUSUM, the model with higher early detection used PWM and neonatal losses (86%), with the models raising alarms 4.3 weeks earlier on average than the processing fluids. The models with the earliest time to detect signs associated with a PRRSV outbreak and with the lowest false negative and false positive were the multivariate models, MEWMA and the MCUSUM, using the combination of PWM and neonatal losses. Thus, monitoring multiple indicators outperformed the univariate models. With that, using multivariate models is the best option for disease surveillance using indicators, and it allows the decision-makers to investigate potential outbreaks earlier.