Porcine lung tissue slices: a culture model for PRCV infection and innate immune response investigations.

Respiratory coronaviruses (RCoVs) significantly threaten human health, necessitating the development of an ex vivo respiratory culture system for investigating RCoVs infection. Here, we successfully generated a porcine precision-cut lung slices (PCLSs) culture system, containing all resident lung cell types in their natural arrangement. Next, this culture system was inoculated with a porcine respiratory coronavirus (PRCV), exhibiting clinical features akin to humans who were infected by SARS-CoV-2. The results demonstrated that PRCV efficiently infected and replicated within PCLSs, targeting ciliated cells in the bronchioles, terminal bronchioles, respiratory bronchioles, and pulmonary alveoli. Additionally, through RNA-Seq analysis of the innate immune response in PCLSs following PRCV infection, expression levels of interferons, inflammatory cytokines and IFN stimulated genes were significantly upregulated. This ex vivo model may not only offer new insights into PRCV infection in the porcine respiratory tract but also serve as a valuable tool for studying human respiratory CoVs infection.

Transmissible gastroenteritis virus induces inflammatory responses via RIG-I/NF-κB/HIF-1α/glycolysis axis in intestinal organoids and in vivo.

Transmissible gastroenteritis virus (TGEV)-induced enteritis is characterized by watery diarrhea, vomiting, and dehydration, and has high mortality in newborn piglets, resulting in significant economic losses in the pig industry worldwide. Conventional cell lines have been used for many years to investigate inflammation induced by TGEV, but these cell lines may not mimic the actual intestinal environment, making it difficult to obtain accurate results. In this study, apical-out porcine intestinal organoids were employed to study TEGV-induced inflammation. We found that apical-out organoids were susceptible to TGEV infection, and the expression of representative inflammatory cytokines was significantly upregulated upon TGEV infection. In addition, retinoic acid-inducible gene I (RIG-I) and the nuclear factor-kappa B (NF-κB) pathway were responsible for the expression of inflammatory cytokines induced by TGEV infection. We also discovered that the transcription factor hypoxia-inducible factor-1α (HIF-1α) positively regulated TGEV-induced inflammation by activating glycolysis in apical-out organoids, and pig experiments identified the same molecular mechanism as the ex vivo results. Collectively, we unveiled that the inflammatory responses induced by TGEV were modulated via the RIG-I/NF-κB/HIF-1α/glycolysis axis ex vivo and in vivo. This study provides novel insights into TGEV-induced enteritis and verifies intestinal organoids as a reliable model for investigating virus-induced inflammation. IMPORTANCE: Intestinal organoids are a newly developed culture system for investigating immune responses to virus infection. This culture model better represents the physiological environment compared with well-established cell lines. In this study, we discovered that inflammatory responses induced by TGEV infection were regulated by the RIG-I/NF-κB/HIF-1α/glycolysis axis in apical-out porcine organoids and in pigs. Our findings contribute to understanding the mechanism of intestinal inflammation upon viral infection and highlight apical-out organoids as a physiological model to mimic virus-induced inflammation.

Hypoxia inducible factor-1α facilitates transmissible gastroenteritis virus replication by inhibiting type I and type III interferon production.

Transmissible gastroenteritis virus (TGEV) is characterized by watery diarrhea, vomiting, and dehydration and is associated with high mortality especially in newborn piglets, causing significant economic losses to the global pig industry. Hypoxia inducible factor-1α (HIF-1α) has been identified as a key regulator of TGEV-induced inflammation, but understanding of the effect of HIF-1α on TGEV infection remains limited. This study found that TGEV infection was associated with a marked increase in HIF-1α expression in ST cells and an intestinal organoid epithelial monolayer. Furthermore, HIF-1α was shown to facilitate TGEV infection by targeting viral replication, which was achieved by restraining type I and type III interferon (IFN) production. In vivo experiments in piglets demonstrated that the HIF-1α inhibitor BAY87-2243 significantly reduced HIF-1α expression and inhibited TGEV replication and pathogenesis by activating IFN production. In summary, we unveiled that HIF-1α facilitates TGEV replication by restraining type I and type III IFN production in vitro, ex vivo, and in vivo. The findings from this study suggest that HIF-1α could be a novel antiviral target and candidate drug against TGEV infection.

Different populations of A(H1N1)pdm09 viruses in a patient with hemolytic-uremic syndrome.

Respiratory viral infections may have different impacts ranging from infection without symptoms to severe disease or even death though the reasons are not well characterized. A patient (age group 5-15 years) displaying symptoms of hemolytic uremic syndrome died one day after hospitalization. qPCR, next generation sequencing, virus isolation, antigenic characterization, resistance analysis was performed and virus replication kinetics in well-differentiated airway cells were determined. Autopsy revealed hemorrhagic pneumonia as major pathological manifestation. Lung samples harbored a large population of A(H1N1)pdm09 viruses with the polymorphism H456H/Y in PB1 polymerase. The H456H/Y viruses replicated much faster to high viral titers than upper respiratory tract viruses in vitro. H456H/Y-infected air-liquid interface cultures of differentiated airway epithelial cells did reflect a more pronounced loss of ciliated cells. A different pattern of virus quasispecies was found in the upper airway samples where substitution S263S/F (HA1) was observed. The data support the notion that viral quasispecies had evolved locally in the lung to support high replicative fitness. This change may have initiated further pathogenic processes leading to rapid dissemination of inflammatory mediators followed by development of hemorrhagic lung lesions and fatal outcome.

PEDV promotes the differentiation of CD4+T cells towards Th1, Tfh, and Treg cells via CD103+DCs.

Porcine epidemic diarrhea virus (PEDV) can infect all ages of pigs, particularly newborn piglets with a mortality almost reaching to 80-100%, causing significant economic losses to the global pig industry. The mucosal immune response is crucial for PEDV prevention, in which specific dendritic cells (DCs) and differentiated T cells play vital roles. In this study, CD103+DCs were differentiated successfully with retinoic acid (RA) treatment in vitro. PEDV could not replicate efficiently in differentiated CD103+DCs but could promote maturation of CD103+DCs by up-regulating the expression of SLA-DR, CD1a, CD86, and cytokines of IL-1ß and IL-10. In addition, PEDV-infected CD103+DCs and CD4+T cells were co-cultured, and the results showed that the differentiation of CD4+T cells toward Th1, Tfh, and Treg, but not Th2. These results demonstrate that PEDV-infected CD103+DCs could promote the differentiation of CD4+T cells, which provided the basis for further study of mucosal response induced by PEDV via CD103+DCs.

Damage Detection and Localization of Bridge Deck Pavement Based on Deep Learning.

Bridge deck pavement damage has a significant effect on the driving safety and long-term durability of bridges. To achieve the damage detection and localization of bridge deck pavement, a three-stage detection method based on the you-only-look-once version 7 (YOLOv7) network and the revised LaneNet was proposed in this study. In stage 1, the Road Damage Dataset 202 (RDD2022) is preprocessed and adopted to train the YOLOv7 model, and five classes of damage were obtained. In stage 2, the LaneNet network was pruned to retain the semantic segmentation part, with the VGG16 network as an encoder to generate lane line binary images. In stage 3, the lane line binary images were post-processed by a proposed image processing algorithm to obtain the lane area. Based on the damage coordinates from stage 1, the final pavement damage classes and lane localization were obtained. The proposed method was compared and analyzed in the RDD2022 dataset, and was applied on the Fourth Nanjing Yangtze River Bridge in China. The results shows that the mean average precision (mAP) of YOLOv7 on the preprocessed RDD2022 dataset reaches 0.663, higher than that of other models in the YOLO series. The accuracy of the lane localization of the revised LaneNet is 0.933, higher than that of instance segmentation, 0.856. Meanwhile, the inference speed of the revised LaneNet is 12.3 frames per second (FPS) on NVIDIA GeForce RTX 3090, higher than that of instance segmentation 6.53 FPS. The proposed method can provide a reference for the maintenance of bridge deck pavement.

Transmissible Gastroenteritis Virus Infection Promotes the Self-Renewal of Porcine Intestinal Stem Cells via Wnt/ß-Catenin Pathway.

Intestinal stem cells (ISCs) play an important role in tissue repair after injury. A recent report delineates the effect of transmissible gastroenteritis virus (TGEV) infection on the small intestine of recovered pigs. However, the mechanism behind the epithelium regeneration upon TGEV infection remains unclear. To address this, we established a TGEV infection model based on the porcine intestinal organoid monolayer. The results illustrated that the porcine intestinal organoid monolayer was susceptible to TGEV. In addition, the TGEV infection initiated the interferon and inflammatory responses following the loss of absorptive enterocytes and goblet cells. However, TGEV infection did not disturb epithelial integrity but induced the proliferation of ISCs. Furthermore, TGEV infection activated the Wnt/ß-catenin pathway by upregulating the accumulation and nuclear translocation of ß-catenin, as well as promoting the expression of Wnt target genes, such as C-myc, Cyclin D1, Mmp7, Lgr5, and Sox9, which were associated with the self-renewal of ISCs. Collectively, these data demonstrated that the TGEV infection activated the Wnt/ß-catenin pathway to promote the self-renewal of ISCs and resulted in intestinal epithelium regeneration. IMPORTANCE The intestinal epithelium is a physical barrier to enteric viruses and commensal bacteria. It plays an essential role in maintaining the balance between the host and intestinal microenvironment. In addition, intestinal stem cells (ISCs) are responsible for tissue repair after injury. Therefore, prompt self-renewal of intestinal epithelium will facilitate the rebuilding of the physical barrier and maintain gut health. In the manuscript, we found that the transmissible gastroenteritis virus (TGEV) infection did not disturb epithelial integrity but induced the proliferation of ISCs and facilitated epithelium regeneration. Detailed mechanism investigations revealed that the TGEV infection activated the Wnt/ß-catenin pathway to promote the self-renewal of ISCs and resulted in intestinal epithelium regeneration. These findings will contribute to understanding the mechanism of intestinal epithelial regeneration and reparation upon viral infection.

xImpact: Intelligent Wireless System for Cost-Effective Rapid Condition Assessment of Bridges under Impacts.

Bridge strikes by over-height vehicles or ships are critical sudden events. Due to their unpredictable nature, many events go unnoticed or unreported, but they can induce structural failures or hidden damage that accelerates the bridge's long-term degradation. Therefore, always-on monitoring is essential for deployed systems to enhance bridge safety through the reliable detection of such events and the rapid assessment of bridge conditions. Traditional bridge monitoring systems using wired sensors are too expensive for widespread implementation, mainly due to their significant installation cost. In this paper, an intelligent wireless monitoring system is developed as a cost-effective solution. It employs ultralow-power, event-triggered wireless sensor prototypes, which enables on-demand, high-fidelity sensing without missing unpredictable impact events. Furthermore, the proposed system adopts a smart artificial intelligence (AI)-based framework for rapid bridge assessment by utilizing artificial neural networks. Specifically, it can identify the impact location and estimate the peak force and impulse of impacts. The obtained impact information is used to provide early estimation of bridge conditions, allowing the bridge engineers to prioritize resource allocation for the timely inspection of the more severe impacts. The performance of the proposed monitoring system is demonstrated through a full-scale field test. The test results show that the developed system can capture the onset of bridge impacts, provide high-quality synchronized data, and offer a rapid damage assessment of bridges under impact events, achieving the error of around 2 m in impact localization, 1 kN for peak force estimation, and 0.01 kN·s for impulse estimation. Long-term deployment is planned in the future to demonstrate its reliability for real-life impact events.

Genomic characterization and pathogenicity analysis of a porcine deltacoronavirus strain isolated in western China.

Porcine deltacoronavirus (PDCoV) is an enteric virus that was first identified in 2012. Although PDCoV has been detected worldwide, there is little information about its circulation in western China. In this study, fecal samples were collected from piglets with watery diarrhea in western China between 2015 and 2018 for the detection of PDCoV. The positive rate was 29.9%. A PDCoV strain (CHN/CQ/BN23/2016, BN23) was isolated and selected for further investigation. Phylogenetic analysis showed that this strain formed an individual cluster between the early Chinese lineage and the Chinese lineage. RDP4 and SimPlot analysis demonstrated that strain BN23 is a recombinant of Thailand/S5015L/2015 and CHN-AH-2004. The pathogenicity of BN23 was evaluated in 3-day-old piglets. Challenged piglets developed serious clinical signs and died at 3 days post-inoculation. Our data show that PDCoV is prevalent in western China and that strain BN23 is highly pathogenic to newborn piglets. Therefore, more attention should be paid to emerging PDCoV strains in western China.

Preparation and identification of monoclonal antibodies against porcine CD103.

Dendritic cells (DCs) play an important role in activating, regulating, and maintaining the immune response. CD103+ DCs, one of the DC subpopulations, mainly function in the mucosal immune response. They are responsible for capturing and carrying antigens to the relevant lymph nodes to activate the downstream immune responses. However, there is limited available information regarding the function of CD103+ DCs in the porcine mucosal immune response. In this study, two monoclonal antibodies (mAbs) against porcine CD103 were prepared, and their applications were evaluated by enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and flow cytometry. The produced mAbs (7F3 and 9H3) were both IgG1 subtype with κ chains in the light chain. The 7F3 recognizes a linear epitope (PDLRPRAQVYFSDLE) while 9H3 recognizes another linear epitope (QILDEGQVLLGAVGA). The prepared mAbs could be used in vivo to detect the cells expressing CD103 molecules, giving wide applications of both mAbs. In conclusion, this study successfully prepared 2 mAbs against CD103 protein, and they showed applicability in vivo experiments, which will provide the basis for the study of porcine mucosal immunity. KEY POINTS: • Preparation of monoclonal antibodies against porcine CD103 molecule • Analysis of the distribution of CD103 protein on different cells is possible • Exploration of the CD103+ DCs function in porcine mucosal immunity is possible.

Isolation, pathogenesis, and genetic evolution of a porcine bocavirus PBoV/HB/30/2018 strain in China.

Porcine bocavirus (PBoV) was first identified in Sweden in 2009. Due to its association with healthy as well as diseased pigs, its role in clinical disease has not been reported yet. In the present study, bocavirus was identified from the intestinal content of a 30-day-old piglet and its whole genome was constructed and phylogenetic analysis was carried on. The pathogenesis of bocavirus was investigated following orogastric inoculation of the colostrum-deprived newborn piglet with bacteria free intestinal content. The bocavirus-inoculated piglets developed diarrhea, shed virus in the rectal swabs from 18 h post inoculation and developed macroscopic and microscopic lesions in small intestine with virus confirmed by conventional PCR. This study experimentally confirmed pathogenicity and characterized bocavirus as the etiological agent of diarrhea in the colostrum-deprived newborn piglets. On phylogenetic analysis, it was observed that this virus has long evolutionary history with subsequent mutation as well as better host adaptation. This study highlights the importance of identifying bocavirus as the etiological agent of viral diarrhea that could threaten livestock, public health as well as economic loss.

Infection of polarized bovine respiratory epithelial cells by bovine viral diarrhea virus (BVDV).

Bovine viral diarrhea virus (BVDV) is affecting cattle populations all over the world causing acute disease, immunosuppressive effects, respiratory diseases, gastrointestinal, and reproductive failure in cattle. The virus is taken up via the oronasal route and infection of epithelial and immune cells contributes to the dissemination of the virus throughout the body. However, it is not known how the virus gets across the barrier of epithelial cells encountered in the airways. Here, we analyzed the infection of polarized primary bovine airway epithelial cells (BAEC). Infection of BAEC by a non-cytopathogenic BVDV was possible via both the apical and the basolateral plasma membrane, but the infection was most efficient when the virus was applied to the basolateral plasma membrane. Irrespective of the site of infection, BVDV was efficiently released to the apical site, while only minor amounts of virus were detected in the basal medium. This indicates that the respiratory epithelium can release large amounts of BVDV to the environment and susceptible animals via respiratory fluids and aerosols, but BVDV cannot cross the airway epithelial cells to infect subepithelial cells and establish systemic infection. Further experiments showed that the receptor, bovine CD46, for BVDV is expressed predominantly on the apical membrane domain of the polarized epithelial cells. In a CD46 blocking experiment, the addition of an antibody directed against CD46 almost completely inhibited apical infection, whereas basolateral infection was not affected. While CD46 serves as a receptor for apical infection of BAEC by BVDV, the receptor for basolateral infection remains to be elucidated.

Infection of bovine well-differentiated airway epithelial cells by Pasteurella multocida: actions and counteractions in the bacteria-host interactions.

Pasteurella (P.) multocida is a zoonotic pathogen, which is able to cause respiratory disorder in different hosts. In cattle, P. multocida is an important microorganism involved in the bovine respiratory disease complex (BRDC) with a huge economic impact. We applied air-liquid interface (ALI) cultures of well-differentiated bovine airway epithelial cells to analyze the interaction of P. multocida with its host target cells. The bacterial pathogen grew readily on the ALI cultures. Infection resulted in a substantial loss of ciliated cells. Nevertheless, the epithelial cell layer maintained its barrier function as indicated by the transepithelial electrical resistance and the inability of dextran to get from the apical to the basolateral compartment via the paracellular route. Analysis by confocal immunofluorescence microscopy confirmed the intactness of the epithelial cell layer though it was not as thick as the uninfected control cells. Finally, we chose the bacterial neuraminidase to show that our infection model is a sustainable tool to analyze virulence factors of P. multocida. Furthermore, we provide an explanation, why this microorganism usually is a commensal and becomes pathogenic only in combination with other factors such as co-infecting microorganisms.

Development of Synchronized High-Sensitivity Wireless Accelerometer for Structural Health Monitoring.

The use of digital accelerometers featuring high sensitivity and low noise levels in wireless smart sensors (WSSs) is becoming increasingly common for structural health monitoring (SHM) applications. Improvements in the design of Micro Electro-Mechanical System (MEMS) based digital accelerometers allow for high resolution sensing required for SHM with low power consumption suitable for WSSs. However, new approaches are needed to synchronize data from these sensors. Data synchronization is essential in wireless smart sensor networks (WSSNs) for accurate condition assessment of structures and reduced false-positive indications of damage. Efforts to achieve synchronized data sampling from multiple WSS nodes with digital accelerometers have been lacking, primarily because these sensors feature an internal Analog to Digital Converter (ADC) to which the host platform has no direct access. The result is increased uncertainty in the ADC startup time and thus worse synchronization among sensors. In this study, a high-sensitivity digital accelerometer is integrated with a next-generation WSS platform, the Xnode. An adaptive iterative algorithm is used to characterize these delays without the need for a dedicated evaluation setup and hardware-level access to the ADC. Extensive tests are conducted to evaluate the performance of the accelerometer experimentally. Overall time-synchronization achieved is under 15 µs, demonstrating the efficacy of this approach for synchronization of critical SHM applications.

Rapid and efficient detection methods of pathogenic swine enteric coronaviruses.

Porcine enteric coronaviruses (CoVs) cause highly contagious enteric diarrhea in suckling piglets. These COV infections are characterized by clinical signs of vomiting, watery diarrhea, dehydration, and high morbidity and mortality, resulting in significant economic losses and tremendous threats to the pig farming industry worldwide. Because the clinical manifestations of pigs infected by different CoVs are similar, it is difficult to differentiate between the specific pathogens. Effective high-throughput detection methods are powerful tools used in the prevention and control of diseases. The immune system of piglets is not well developed, so serological methods to detect antibodies against these viruses are not suitable for rapid and early detection. This paper reviews various PCR-based methods used for the rapid and efficient detection of these pathogenic CoVs in swine intestines. KEY POINTS: 1. Swine enteric coronaviruses (CoVs) emerged and reemerged in past years. 2. Enteric CoVs infect pigs at all ages with high mortality rate in suckling pigs. 3. Rapid and efficient detection methods are needed and critical for diagnosis.

Epidemiological characteristics of imported malaria in Shandong Province, China, from 2012 to 2017.

Shandong Province, China, has been implementing a malaria elimination program. In this study, we analyzed the epidemiological characteristics of malaria imported into Shandong Province between 2012 and 2017 to provide scientific data for the elimination of malaria. In this epidemiological study, we examined the status of malaria in 2012-2017 in Shandong Province, China. Data on all cases of malaria were collected from the online Infection Diseases Monitor Information System to describe and statistically analyze the sources of infection, species of parasite, populations affected, regional distributions, incidence, and temporal distributions of malaria. In total, 1053 cases of malaria were reported in 2012-2017, and all of them were imported. Plasmodium falciparum was the predominant species (77.6%) in Shandong Province; P. vivax malaria accounted for 10.9% of the total number of cases, P. ovale malaria for 2.9%, and P. malariae malaria for 8.2%. Most patients were male (96.8%), most were aged 21-50 years (87.2%), and migrant laborers (77.2%) and workers (6.6%) were at highest risk. The origin of the largest number of imported cases was Africa (93.4%), followed by Asia (5.9%) and Oceania (0.4%). Most cases of imported malaria occurred in June each year and 70% of cases were recorded in six cities during the period of 2012-2017. It is necessary to strengthen malaria surveillance among workers returning home from Africa and Southeast Asia, and to conduct timely blood tests to diagnose and treat imported infections.

A Reflective Framework for Performance Management (REFORM) of Real-Time Hybrid Simulation.

Currently, the lack of (1) a sufficiently integrated, adaptive, and reflective framework to ensure the safety, integrity, and coordinated evolution of a real-time hybrid simulation (RTHS) as it runs, and (2) the ability to articulate and gauge suitable measures of the performance and integrity of an experiment, both as it runs and post-hoc, have prevented researchers from tackling a wide range of complex research problems of vital national interest. To address these limitations of the current state-of-the-art, we propose a framework named Reflective Framework for Performance Management (REFORM) of real-time hybrid simulation. REFORM will support the execution of more complex RTHS experiments than can be conducted today, and will allow them to be configured rapidly, performed safely, and analyzed thoroughly. This study provides a description of the building blocks associated with the first phase of this development (REFORM-I). REFORM-I is verified and demonstrated through application to an expanded version of the benchmark control problem for real-time hybrid simulation.

Development of a multiplex RT-PCR for the detection of major diarrhoeal viruses in pig herds in China.

The major enteric RNA viruses in pigs include porcine epidemic diarrhoea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine rotavirus A (PRV-A), porcine kobuvirus (PKV), porcine sapovirus (PSaV) and porcine deltacoronavirus (PDCoV). For differential diagnosis, a multiplex RT-PCR method was established on the basis of the N genes of TGEV, PEDV and PDCoV, the VP7 gene of PRV-A, and the polyprotein genes of PKV and PSaV. This multiplex RT-PCR could specifically detect TGEV, PEDV, PDCoV, PRV-A, PKV and PSaV without cross-reaction to any other major viruses circulating in Chinese pig farms. The limit of detection of this method was as low as 100 -101  ng cDNA of each virus. A total of 398 swine faecal samples collected from nine provinces of China between October 2015 and April 2017 were analysed by this established multiplex RT-PCR. The results demonstrated that PDCoV (144/398), PSaV (114/398), PEDV (78/398) and PRV-A (70/398) were the main pathogens, but TGEV was not found in the pig herds in China. In addition, dual infections, for example, PDCoV + PSaV, PDCoV + PRV-A, PRA-V + PSaV and PEDV + PDCoV, and triple infections, for example, PDCoV + PRV-A + PSaV and PEDV + PDCoV + PKV, were found among the collected samples. The multiplex RT-PCR provided a valuable tool for the differential diagnosis of swine enteric viruses circulating in Chinese pig farms and will facilitate the prevention and control of swine diarrhoea in China.

Infection Studies in Pigs and Porcine Airway Epithelial Cells Reveal an Evolution of A(H1N1)pdm09 Influenza A Viruses Toward Lower Virulence.

We analyzed the virulence of pandemic H1N1 2009 influenza A viruses in vivo and in vitro. Selected viruses isolated in 2009, 2010, 2014, and 2015 were assessed using an aerosol-mediated high-dose infection model for pigs as well as air-liquid interface cultures of differentiated airway epithelial cells. Using a dyspnea score, rectal temperature, lung lesions, and viral load in the lung as parameters, the strains from 2014-2015 were significantly less virulent than the strains isolated in 2009-2010. In vitro, the viruses from 2009-2010 also differed from the 2014-2015 viruses by increased release of infectious virus, a more pronounced loss of ciliated cells, and a reduced thickness of the epithelial cell layer. Our in vivo and in vitro results reveal an evolution of A(H1N1)pdm09 viruses toward lower virulence. Our in vitro culture system can be used to predict the virulence of influenza viruses.

Sudden Event Monitoring of Civil Infrastructure Using Demand-Based Wireless Smart Sensors.

Wireless smart sensors (WSS) have been proposed as an effective means to reduce the high cost of wired structural health monitoring systems. However, many damage scenarios for civil infrastructure involve sudden events, such as strong earthquakes, which can result in damage or even failure in a matter of seconds. Wireless monitoring systems typically employ duty cycling to reduce power consumption; hence, they will miss such events if they are in power-saving sleep mode when the events occur. This paper develops a demand-based WSS to meet the requirements of sudden event monitoring with minimal power budget and low response latency, without sacrificing high-fidelity measurements or risking a loss of critical information. In the proposed WSS, a programmable event-based switch is implemented utilizing a low-power trigger accelerometer; the switch is integrated in a high-fidelity sensor platform. Particularly, the approach can rapidly turn on the WSS upon the occurrence of a sudden event and seamlessly transition from low-power acceleration measurement to high-fidelity data acquisition. The capabilities of the proposed WSS are validated through laboratory and field experiments. The results show that the proposed approach is able to capture the occurrence of sudden events and provide high-fidelity data for structural condition assessment in an efficient manner.