Transboundary and Emerging Diseases最新文献

Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally endemic, costly swine arterivirus with wide genetic and antigenic variations, leading to the frequent appearance of novel virulent strains that hampers PRRSV control. Recently, NADC30-like (lineage 1C, L1C) and NADC34-like (lineage 1A, L1A) PRRSV strains were reported to be prevalent in mainland South Korea and became the main epidemic strains persistently attributed to PRRSV outbreaks nationwide, raising great concern in the domestic pork industry. Although the genotypic and pathotypic variability of NADC30- and NADC34-like viruses has been explored in the United States and China, their genomic and biological characteristics have been scarcely studied in South Korea. Here, NADC34-like GNU-2353 and NADC30-like GNU-2377 strains were independently identified from vaccinated swine herds experiencing high piglet mortality. Whole-genome sequencing and phylogenetic analysis revealed that GNU-2353 and GNU-2377 clustered into sublineages L1A (NADC34-like) and L1C (NADC30-like), respectively, sharing high genomic homology with their corresponding lineage-representative strains and harboring the same molecular signatures of continuous 100 and discontinuous 131 amino acid deletions in the nsp2-coding region, respectively. Recombination detection indicated that GNU-2353 and GNU-2377 were recombinants and evolved through natural interlineage recombination between NADC34-like (L1A, major parent) or NADC30-like (L1C, major parent) and RespPRRS modified live virus (MLV)–like (lineage 5, minor parent) strains, respectively. Both viruses displayed homogenous growth kinetics but replicated faster than the prototype VR-2332 in a porcine alveolar macrophage cell line (PAM-KNU). The transcriptional profiles of immune response genes in infected PAM-KNU cells varied between the isolates and VR-2332; particularly, interleukin-10 expression was dramatically upregulated in cells infected with GNU-2353 and GNU-2377. Piglets with GNU-2353 and GNU-2377 infection had high fever; weight loss; increased viremia and nasal shedding; viral distribution in various tissues; thymic atrophy; and apparent macroscopic and microscopic lung lesions, including interstitial pneumonia and viral colonization, compared with control piglets, suggesting that both isolates were virulent to pigs. Remarkably, GNU-2353 caused higher fever, mortality rate (40%) with cyanosis, viremia, and viral shedding within 2 weeks and significantly higher viral loads in several organs than GNU-2377 infection. Thus, NADC34-like GNU-2353 was more pathogenic than NADC30-like GNU-2377. Our findings provide insights into the current epizootic circumstance of NADC30- and NADC34-like PRRSV in South Korea and can aid in tailoring improved control strategies.

Given the growing threat posed by viral hemorrhagic fevers, the development of surveillance tools is crucial to provide accurate and rapid solutions. Public health response involves risk assessment as well as effective and sustainable surveillance to ensure downstream communication and preparedness. A serological approach that offers high precision and throughput, cost efficiency, and multiplexing capacity is critical. In this work, we evaluated a Luminex-based multiplex microsphere immunoassay for five hemorrhagic fever viruses (HFVs) among the World Health Organization (WHO) blueprint. This five-plex MagPix immunoassay confirmed the presence of Rift Valley fever and Crimean–Congo hemorrhagic fever, but also revealed the exposure of human populations to hantaviruses in Senegal, underscoring the importance of regular serosurveillance in the identification of HFV hotspots.

Since a resurgence occurred in 1993, malaria has remained an endemic disease in the Republic of Korea (ROK). A major challenge is the inaccessibility of current vector mosquito abundance data due to a 2-week reporting delay, which limits timely implementation of control measures. We aimed to nowcast mosquito abundance and assess its utility by evaluating the predictive value of mosquito abundance for malaria epidemic peaks. We used machine learning models to nowcast mosquito abundance, employing gradient boosting models (GBMs), extreme gradient boosting (XGB), and an ensemble model combining both. Various meteorological factors served as predictors. The models were trained with data from mosquito collection sites between 2009 and 2021 and tested with data from 2022. To evaluate the utility of nowcasting, we calculated the effective reproduction number (R_t), which can indicate malaria epidemic peaks. Generalized linear models (GLMs) were then used to assess the impact of vector mosquito abundance on R_t. The ensemble models demonstrated the best performance in nowcasting mosquito abundance, with a root mean square error (RMSE) of 0.90 and R-squared value (R²) value of 0.85. The GBM model showed an RMSE of 0.91 and R² of 0.84, while the XGB model had an RMSE of 0.92 and R² of 0.85. Additionally, the R² of the GLMs predicting R_t using mosquito abundance 2 weeks in advance was >0.72 for all provinces. The mosquito abundance coefficients were also significant. We constructed reliable models to nowcast mosquito abundance. These outcomes could potentially be incorporated into a malaria early warning system. Our study provides evidence to support the development of malaria management strategies in regions where malaria remains a public health challenge.

Cutaneous leishmaniasis (CL) represents a significant vector-borne disease in Iran. Our study examined the status of zoonotic CL (ZCL) in the country and forecasted the influence of global climate change on the monthly activity of Phlebotomus papatasi, the main vector of ZCL in the country. To predict the impact of climate change on the monthly activity of Ph. papatasi, we obtained the monthly average minimum and maximum temperatures for both the reference and future periods, using the MIROC6 model and two different shared socioeconomic pathway (SSP) scenarios. Based on our analysis, we found that Ph. papatasi can be active in Iran from March to November, although this may vary depending on the region. Our predictions suggest that the duration of Ph. papatasi’s activity may change following future changes in weather patterns. In different scenarios, the duration of the active season in various regions of the country extends by at least 1–2 months. This extension is likely more pronounced in the southern provinces. Additionally, our findings indicate a notable correlation between ZCL incidence, the presence of Ph. papatasi, and environmental factors in Ardestan, Esfahan Province. This study focuses on the impact of temperature on the activity and distribution of Ph. papatasi in Iran, which is a significant vector for transmitting ZCL. The study predicts that with future climate scenarios, especially SSP5-8.5, the activity of this vector will start earlier, last longer, and might even occur throughout the year by the 2050s, thereby increasing the risk of ZCL transmission. Although temperature plays a dominant role in shaping the activity of Ph. papatasi, its influence is not consistent across Iran. The variation in different regions emphasizes the importance of implementing targeted public health approaches to address the changing risks of ZCL transmission due to evolving climate conditions. However, it acknowledges that certain factors such as land use and humidity have not been taken into account and requests additional research in these areas. It also calls for enhanced environmental monitoring and public health interventions.

H9N2 avian influenza virus (AIV) is one of the main pathogens causing respiratory disease in chicken; however, differentiating this virus from infectious bronchitis virus (IBV) and newcastle disease virus (NDV) only using clinical signs is difficult. In this study, 492 tracheal and lung tissue samples were collected from chicken farms in Shandong reporting respiratory symptoms and tested using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for the presence of H9N2 AIVs, IBVs, and NDVs. The H9N2 AIVs positive samples were inoculated with chicken embryos. Whole-genome sequences of the positive strains were obtained using Illumina MiSeq and analyzed for genetic evolution and key amino acid sites mutation. Seventy-two samples were positive for H9N2 subtype AIV, with a positive rate of 14.63%, while the positive rates of IBV and NDV were 6.10% and 0.41%, respectively. Thirty-four strains of H9N2 AIVs were obtained from positive samples. Phylogenetic tree analysis of HA and NA genes revealed that the 34 H9N2 AIV strains belonged to Y280-like and F/98-like branches, respectively. Clear temporalphylogenetic branching was observed, with some strains found in the “pre-2013 isolates” clade and others in the “post-2013 isolates” clade, which raised the possibility that strains in the former clade may have undergone recombination with viral strains from 10 years ago. Among the internal amino acid sites that are key to mammalian adaptation, all strains had an I368V mutation in the PB1 gene that enhanced viral transmissibility in mammals, and the PB2 genes of some strains were mutated to enhance the mammalian adaptation of I292V and A588V. Thus, the H9N2 AIV gene segments in Shandong have different degrees of recombination and gene variation, necessitating vigilant monitoring of virus variation.

African horse sickness (AHS) is an acute infectious disease of equids caused by the AHS virus (AHSV), which can cause up to 90% mortality in naive horses. Reliable and rapid diagnosis is crucial for the surveillance and control of AHSV. As one of the AHSV detection methods recommended by World Organization for Animal Health (WOAH), the RT-qPCR assay has the drawbacks such as complex operation, expensive instruments, and long detecting time, which limit its application in simple laboratories or outdoors. In this study, a real-time reverse transcription multienzyme isothermal rapid amplification (RT-MIRA) assay was established to detect AHSV. Primers and exo-probes were designed, synthesized, and screened based on the conserved regions of the AHSV Seg-7 gene. A series of experiments were conducted to evaluate the performances of the established real-time RT-MIRA for detecting AHSV. The valid testing results showed that this method was highly specific for the detection of AHSV, without exhibiting any cross-reactivity towards other equine viruses or other Orbivirus; its limit of detection (LOD) was 10 copies/μL, which was consistent with that of RT-qPCR, meaning it had good sensitivity for detecting AHSV. Furthermore, the real-time RT-MIRA for AHSV performed good repeatability, and its standard curve exhibited good linearity with a correlation coefficient of R² = 0.9898, which indicated that the established method could be used for the quantitative detection of ASHV. As no AHS infection cases have been reported in China, 120 simulated clinical samples were tested by the real-time RT-MIRA and RT-qPCR for AHSV, which results showed there was a significant correlation between the two assays, with a κ value of 0.966 and an R² value of 0.9576. Parallel detection of 396 equine blood samples and 1760 Culicoides by this method and the RT-qPCR showed that all samples were negative for AHSV. Furthermore, the results of the real-time RT-MIRA could be judged by naked eyes under a portable equipment with blue light (480 nm). In conclusion, the real-time RT-MIRA for AHSV was specific and sensitive and had the advantages of convenient operation, visualization, no need for special equipment, and could be a reliable tool for rapid screening and detection of AHSV in field or border ports.

Bluetongue (BT) is a viral infection caused by the bluetongue virus (BTV) that affects domestic and wild ruminants worldwide. It is primarily transmitted by Culicoides spp. midges, and its infection is highly prevalent across temperate and tropical regions. However, significant changes in the global distribution of BTV have been observed in recent years. We aimed to evaluate the national BTV seroprevalence and risk factors among domestic ruminants (cattle, sheep, and goat species) in Peru. Serum samples were collected from 3452 cattle of 453 districts, 2786 sheep of 408 districts, and 1568 goats of 271 districts using a cross-sectional study in two stages (at the district and animal level) from 2017 to 2019 and analyzed by competitive enzyme-linked immunosorbent assay (cELISA). The national BTV true seroprevalences at animal level for cattle, sheep, and goats were 20.34% (95% CI: 17.76–20.82), 7.63% (95% CI: 7.17–9.56), and 8.58% (95% CI: 7.52–10.85), while the true districts-level seroprevalences were 31.53% (95% CI: 24.06–33.77), 24.41% (95% CI: 18.06–27.53), and 13.35% (95% CI: 8.59–17.98), respectively. In addition, we found that altitude and maximum temperature were identified as important factors influencing the seroprevalence of BTV in cattle, sheep, and goats. Higher altitudes above 3000 m above sea level (masl) played a protective role, reducing the BTV seroprevalence. In conclusion, antibodies against BTV were detected in Peruvian domestic ruminants without clinical signs. The seroprevalence was low in the South (<10.0%), varied in the Center and North, and high (>30%) in the East (Amazon rainforest). This study lays the groundwork for identifying BTV serotypes and Culicoides spp. in different regions, including altitudes above 3000 masl, to enhance BTV surveillance in Peru.

Brucellosis is a zoonotic infectious disease caused by bacteria of the genus Brucella. In recent years, the prevalence of brucellosis in animals and humans has been increasing in China despite the considerable efforts taken to date. Dynamic model serves as an influential and promising approach for offering guidance and recommendations for the prevention and control of the disease. At this pivotal moment, it is time to provide a comprehensive and timely examination of the existing achievements derived from the mathematical dynamical modeling studies, highlight the key development trends, delve into identifying the limitations of the studies, and offer valuable perspectives and insights for potential future research directions. Through a review of 49 articles (22 articles utilizing data while 27 articles did not use data), this study focuses on analyzing the differences in model structure, research data and areas, characterization of prevention and control measures, and main results. Meanwhile, quantitative results such as the reproduction number and critical parameter values are extracted. The study points out that the limitations of existing models are manifested in the lack of heterogeneity in the research and the absence of the results on the scale of herd/flock. The primary reason is the lack of relevant data, indicating the necessity to advance interdisciplinary, multidisciplinary, and transdisciplinary collaboration across multiple departments. Therefore, it is encouraged that the future models should be established from the holistic approach of One Health.

Carbapenems are considered one of the most important last-resort classes of antibiotics, and the spread of carbapenem-resistant Enterobacterales (CRE) is a serious concern worldwide. From a One Health point of view, reports on CRE in companion animals are increasing, requiring attention regarding their role in maintenance and direct transmission to humans. The aim of this study was to assess the frequency of detection at admission and the in-hospital acquisition of CRE from perirectal swabs in dogs and cats hospitalized in an Italian Veterinary Teaching Hospital (VTH). Of the 150 patients sampled, 11.3% (n = 17) were CRE carriers at admission, 25.6% (n = 34) acquired CRE in their commensal microbiota during their hospital stay, and 2% (n = 3) developed an infection caused by CRE. Genotypical analysis showed that in 100% (78/78) of the CRE isolates (44 Escherichia coli, 33 Klebsiella pneumoniae, and 1 Klebsiella aerogenes) carbapenem resistance was conferred by the carbapenemase gene bla_NDM, suggesting an endemic presence of such gene within the hospital. Co-occurrent β-lactamase-encoding genes were found in most of the isolates. Risk factors associated with CRE acquisition were length of hospitalization (p = 0.0002) and treatment with piperacillin–tazobactam (PTZ; p = 0.0380), indicating potential cross-selection of CRE. These results reinforce the suspicion that companion animals could silently contribute to the maintenance and dissemination of CRE in the local community, posing a threat to global health.

The H5N6 avian influenza virus (AIV) is constantly undergoing recombination and evolution with other subtypes of AIV, resulting in various types of recombinant H5N6 viruses. However, the risk to human public health of different recombinant types of H5N6 viruses remains unclear. Recently, two types of different recombinant H5N6 viruses were isolated from chickens. One of the viruses possessed six internal genes originating from H9N2, named A/Chicken/Hubei/112/2020 (H5N6) (abbreviated 112); the other virus possessed PB2, PB1, PA, and NP originating from H5N1, while the M and NS genes were derived from H9N2, named A/Chicken/Hubei/125/2020 (H5N6) (abbreviated 125). Here, we investigated the receptor binding properties, pathogenicity, and transmissibility of the two H5N6 AIVs. The results showed that 112 and 125 could bind α-2,3-linked sialic acid receptor (avian-like receptor) and α-2,6-linked sialic acid receptor (human-like receptor). However, 125 and 112 showed different pathogenicity in mice. Mice infected with 125 lost only a slight body weight and all survived, while mice infected with 112 lost weight rapidly and all died within a week of infection. Furthermore, in the transmission experiment, 125 could only transmit through direct contact, while 112 could transmit not only by direct contact but also by aerosol. The above results indicated that 112 exhibited enhanced pathogenicity and transmissibility compared to 125, suggesting that the H5N6 virus, whose internal genes were derived from H9N2, could pose a greater threat to human health. Therefore, continuous monitoring of different recombinant H5N6 viruses in poultry should be carried out to prevent their transmission to humans.