BackgroundGuangdong, China is a critical epicenter for avian influenza virus (AIV) emergence, where H5N1 and highly pathogenic H7N9 were first identified. Monitoring AIV genotype distribution and genetic diversity in this region is essential for providing early warnings and mitigating the risk of human infections.MethodsIn May 2025, a cross-sectional study was conducted across 4 representative cities in Guangdong. We collected 500 environmental swabs and 45 wastewater samples from 23 live poultry markets (LPMs). Samples were screened for influenza A virus (IAV) and subtyped for H5, H7, and H9. Next generation sequencing (NGS) and phylogenetic analyses were employed to characterize viral diversity and zoonotic potential.ResultsAIV was detected in 49.2% (246/500) of environmental samples. H9 was the dominant subtype (38.2%), followed by H5 (3.2%) and H7 (0.8%); 2.4% of positive samples showed multi-subtype co-occurrence. “Non-restricted zone” markets (80.0%) and “waste storage areas” (68.4%) were identified as primary contamination hotspots. Phylogenetic analysis revealed that H5 and H9 viruses are accumulating mutations linked to enhanced human-type receptor affinity. Notably, H5 and H6 sequences exhibited long internal branches and clustered with isolates from other Asian countries rather than domestic strains, highlighting a significant gap in current domestic molecular surveillance and a lack of continuous evolutionary data for these genotypes.ConclusionsWidespread AIV contamination persists in Guangdong LPMs, dominated by H9 with low-level circulation of highly pathogenic subtypes. The identified surveillance gaps for H5/H6 and the presence of multi-subtype environments underscore the urgent need for strengthened, integrated molecular monitoring and stricter market regulation to mitigate public health risks.

BackgroundThe post-pandemic era has brought about marked shifts in the circulation patterns of respiratory pathogens. Nevertheless, comprehensive epidemiological data on acute respiratory infections (ARIs) covering both influenza-like illness (ILI) and severe acute respiratory infection (SARI) remain scarce for southern China. This study aimed to characterize the epidemiological profiles and pathogen spectra of ARIs in Guangzhou, China, from January 2024 to December 2025.MethodsRespiratory specimens were collected from ILI outpatients and SARI inpatients attending two sentinel hospitals in Guangzhou. All specimens were tested for 23 respiratory pathogens using the NxTAG™ Respiratory Pathogen Panel. Statistical analyses were conducted to explore pathogens distribution stratified by patients’ demographic characteristics.ResultsAmong 4,635 ARI cases, the overall pathogen detection rate was 47.96% (n = 2,223). Influenza virus (IFV, 14.5%) and human rhinovirus (HRV, 10.1%) were predominant. In ILI cases, IFV (19.1%) and HRV (10.9%) were most common; in SARI cases, HRV (8.5%) and respiratory syncytial virus (RSV, 8.2%) prevailed. Marked age-dependent variations were observed: RSV and bocavirus (BOV) primarily infected preschool children, whereas SARS-CoV-2 and IFV were more commonly detected in adults and older individuals. Seasonally, an earlier IFV peak occurring in December and an out-of-season RSV epidemic in 2025 characterized by a summer peak were observed. Co-infections occurred in 9.76% of positive cases, with IFV/HRV most frequent. Positivity rates were higher in ILI (54.1%) than SARI (34.5%). Logistic regression identified advanced age (≥60 years), RSV in children age < 5 years and MP were associated with SARI.ConclusionThese findings reveal that the spectrum of respiratory pathogens in Guangzhou is characterized by dynamic patterns of co-circulation and alternating predominance across different time periods and populations. Highlighting the need for age-specific and seasonally tailored interventions and comprehensive diagnostic tools.

Objective To estimate the socio-economic burden caused by various types of hand-foot-mouth disease(HFMD)cases in Guangdong province from 2015 to 2023.Methods On the basis of the previous studies of disease economic burden and the data of HFMD reported in Guangdong from 2015 to 2023,the economic burdens of common cases(including outpatients and inpatients),severe cases,and death cases of HFMD were estimated.The per capita productivity loss caused by premature death of HFMD in different age groups was calculated by the human capital method.Results From 2015 to 2023,a total of 2 727 381 cases of HFMD were reported in Guangdong province,with 99.96%classified as common cases,932 severe cases,and 33 death cases.The annual economic loss attributable to HFMD in Guangdong province during this period remained stable at 357 million-523 million CNY,except for a notable decrease between 2020 and 2022,when it was estimated at 76 million-370 million CNY.The economic burden of common cases accounted for 99.38%.The economic burden of severe cases accounted for 0.59%,showing a fluctuating downward trend from 5 million CNY in 2015 to 0.756 3 million CNY in 2023.The economic burden associated with death cases accounted for 1.03%,exhibiting a declining trend from 6 million CNY in 2015 to no death in 2022-2023,with premature death losses constituting 98.41%-98.66%of total death losses.Conclusions The socio-economic burden caused by HFMD in Guangdong province has been generally stable from 2015 to 2023,apart from a decline in 2020-2022.The burden was mainly attributable to common cases,and the disease burden of severe and death cases decreased with fluctuations.It is recommended that we should closely monitor changes in the composition of the economic burden of HFMD and adjust prevention and control strategies accordingly.

Background The largest documented chikungunya fever (CF) outbreak in China occurred in Foshan, yet evidence on outbreak-wide epidemiological characteristics and intervention-associated effects has remained limited. Methods We conducted a longitudinal analysis from 16 June to 10 August 2025, integrating case and vector epidemiology, and generalised estimating equation (GEE) models. Results A total of 8,964 cases were reported, with no deaths. Females had a higher incidence than males (1,027.12 vs 919.71 per 100,000), and males had lower infection odds (OR 0.89, 95% CI = 0.86–0.93). Adults older than 60 years showed the highest incidence (2371.62 vs. <1402.00 per 100,000) and infection risk (OR < 1 in other age groups). Cases were concentrated in Shunde District (82.42%). The onset-to-diagnosis interval shortened after interventions. 2.60% were asymptomatic; fever, rash and arthralgia were the predominant symptoms. The effective reproduction number (\(\:{R}_{t}\)) rose rapidly (3.12, 95% CI = 0.08–11.51) and declined below 1 by 1 August (0.87, 95% CI = 0.80–0.94). Breteau index (BI) and adult mosquito density Index (ADI) were decreased and high in the border areas between districts. For non-lagged GEE, one-unit changes in ADI and BI were associated with 9.28% (95% CI= -13.40–37.92; P = 0.45) and 0.60% (95% CI =-1.48–2.73; p = 0.57) changes in case numbers. One-unit changes in ADI were associated with a 10.73% change in \(\:{R}_{t}\) (95% CI = 3.23–18.78; p = 0.004), and 7.50% in BI (95% CI =-5.15–21.84; p = 0.26). For lagged GEE, lagged ADI remained associated with \(\:{R}_{t}\) (8.74%, 95% CI = 1.14–16.91; p = 0.023), while lagged tOD showed no significant association with case numbers (2.68%, 95% =CI -8.21 to 14.86; p = 0.64) and \(\:{R}_{t}\) (2.17%, 95% CI= -1.70 to 6.20; p = 0.28). Conclusions This outbreak showed high transmissibility, concentration in Shunde, and elevated risk in females and older adults. The key area for vector control was the border of different districts. Prioritising routine and targeted adult-mosquito surveillance and control, while maintaining larval source management and accelerating case detection, not only for this outbreak but also for other non-endemic urban settings facing comparable arboviral threats.

BackgroundThe COVID-19 pandemic has reshaped the global epidemiology of respiratory infectious diseases, posing new challenges for influenza forecasting. Existing studies are often limited by reliance on single data sources, poor interpretability, or failure to account for nonlinear relationships among variables, which restricts their ability to balance prediction accuracy and practical utility for public health decision-making. This study aimed to develop and validate a multisource data-integrated generalized additive model (GAM) to forecast influenza activity in Shenzhen, China.MethodsUsing surveillance and auxiliary data from 2023 to 2025, we developed GAM models incorporating local and Hong Kong influenza surveillance, cross-boundary mobility metric, meteorological factors, and Baidu Search Index data. The predictive performance of the GAM was compared with Seasonal Autoregressive Integrated Moving Average with Exogenous Variables (SARIMAX) model. Model accuracy was evaluated using root mean square error (RMSE), mean absolute percentage error (MAPE), and R2.ResultsThe multisource data-driven GAM exhibited high predictive accuracy across short-term forecasting horizons. For 1-week ahead forecasts, the model achieved an R2 of 0.85 (95% CI: 0.74–0.92). Notably, performance remained robust for 2- and 3-week forecasts, with R2 values of 0.80 (95% CI: 0.69–0.87) and 0.74 (95% CI: 0.62–0.83), respectively. The GAM demonstrated superior overall performance compared with SARIMAX.ConclusionThe multisource data-integrated GAM provides robust and stable influenza forecasts for Shenzhen up to 3 weeks in advance. This approach provides a valuable tool to support cross-boundary public health collaboration between Hong Kong and Shenzhen, and might serve as a reference for the development of broader regional public health strategies in future research.

Background:Psittacosis is a non-statutory infectious disease and receives relatively low attention in China. Since 2019, the incidence of psittacosis in Guangdong Province has been continuously increasing. Therefore, it is necessary to understand the epidemiological characteristics, providing a basis for optimizing psittacosis prevention and control. Methods:This study included psittacosis cases reported in Guangdong Province from 2019 to 2024. Data were collected and a retrospective survey was conducted. The spatiotemporal distribution, clinical manifestations and epidemiological exposure histories were analyzed. Logistic regression model was used to explored the risk factors for psittacosis pneumonia. Results:A total of 435 psittacosis cases were reported in Guangdong Province. It demonstrated an overall increasing trend in the incidence rate, with cases predominantly occurring in winter and spring. Nansha District in Guangzhou (p < 0.001), Boluo in Huizhou (p < 0.001) and Shunde in Foshan (p = 0.001) were identified as hotspots for psittacosis. The incidence rate of psittacosis was higher in males (χ2 = 17.26, p < 0.001) and in the 50-79 age group (χ2 = 123.45, p < 0.001). Univariate regression analysis showed that underlying diseases are a risk factor for psittacosis pneumonia [OR (95% CI) = 2.47(1.42, 3.31), p = 0.01]. There were 162 cases with a history of epidemiological exposure, but only 42 cases (25.93%) used protective measures. Conclusion:The incidence of psittacosis has been increasing in Guangdong Province recently, posing a threat to individuals with poultry exposure. In the future, it is suggested to enhance the monitoring of individuals with daily contact with poultry, particularly for the older adult, in winter and spring.

BackgroundThis study aims to evaluate the health economics of hand-foot-mouth disease enterovirus 71 (EV71) vaccination for the population of appropriate age in Guangdong Province.MethodsA SEIR model was constructed, and a group of differential equations was established. The incidence data of HFMD in Guangdong from January to June 2017 were used to fit the model and the basic reproduction value (R0) of this disease was simulated. Then, the incidence of HFMD under different vaccination coverage rate (0, 40, 70, and 90%) was simulated in four scenarios. Cost-effectiveness analysis was used to evaluate the health economics.ResultsThe self-funded voluntary EV71 vaccination strategy implemented in Guangdong Province has effectively reduced the disease economic burden of EV71-type HFMD, and the disease economic burden saved during the peak seasonal segment of HFMD in 2017 was $1,080,000. Meanwhile, Scenario 2, 3, and 4 would each result in a cumulative reduction of 6,525, 9,556, and 10,989 confirmed cases, respectively, with net monetary benefits of approximately $6.55 million, $9.59 million, and $11.2 million. The study results show that the current vaccine pricing is not cost-effectiveness, while the vaccine price is lower than $13.15, EV71 vaccination in Guangdong Province has a cost-effectiveness advantage.ConclusionVaccination can reduce the incidence of HFMD caused by EV71, which helps to improve the status of HFMD and decreases the disease burden.

Acute respiratory infections are caused by a diverse range of pathogens. The study aims to elucidate the epidemic characteristics of acute respiratory pathogens in Guangdong Province during the first year after the COVID-19 pandemic. We collected sentinel surveillance data of 12 respiratory pathogens from multi-pathogen surveillance among acute respiratory infections from August 2023 to July 2024 in Guangdong Province, China. We also collected surveillance data on hospitalized pneumonia as a supplementary. We calculated the test positivity for each pathogen and performed pairwise correlation analysis. Multi-pathogen surveillance revealed that over half of acute respiratory infections tested positive for at least one pathogen. The most commonly detected pathogens were influenza virus (19.70

Here, we report on a case of human infection with the H3N8 avian influenza virus. The patient had multiple myeloma and died of severe infection. Genome analysis showed multiple gene mutations and reassortments without mammalian-adaptive mutations. This suggests that avian influenza (A/H3N8) virus infection could be lethal for immunocompromised persons.

Q fever is a zoonotic disease caused by infection with Coxiella burnetii (C. burnetii). Due to its atypical symptoms and the absence of specific detection methods, Q fever is underdiagnosed commonly. Herein, we report a case of Q fever confirmed by metagenomic next-generation sequencing (mNGS) in March 2024 in Guangdong Province, China. The patient initially experienced fever and was admitted to hospital six days later. Despite a series of laboratory tests conducted at the hospital, the pathogen remained undetermined. Ten days after admission, mNGS revealed that the patient was infected with C. burnetii. The patient subsequently underwent treatment with doxycycline and recovered well. Epidemiological investigation revealed that the patient had been exposed to sheep infected with C. burnetii without any protective measures in Jiangxi Province, China. Based on the comprehensive results of mNGS, exposure history, clinical manifestations and treatment response, the patient was confirmed as a Q fever case. As a neglected and underestimated illness, Q fever necessitates an elevation in awareness among medical staff and the public. The public should be encouraged to take personal protective measures when exposed to livestock. Further research is needed to explore the rational application of mNGS in the diagnosis of uncommon and unknown diseases.

The electrical output and force-electric mapping characteristics of the trapezoidal piezoelectric cantilever beam are theoretically analyzed.According to the obtained force-electric mapping characteristic curve, the structure of the piezoelectric vibrator is optimized, so as to improve the output voltage.Firstly, the distributed parameter modeling of trapezoidal piezoelectric cantilever beam is carried out, and the theory resolution of output voltage is obtained, and theoretical resolution are compared with the finite element simulation results and verified.The trapezoidal piezoelectric beam and rectangular piezoelectric beam are compared and analyzed.The results show that the trapezoidal piezoelectric beam is more suitable for piezoelectric vibrator.The effects of the mechanical parameters of the trapezoidal piezoelectric cantilever beam on output voltage are investigated respectively, and the force-electric mapping relationship of the trapezoidal piezoelectric beam is obtained, which provides a good theoretical basis for the optimization design of the trapezoidal piezoelectric cantilever beam.

Dengue remains an important public health issue in South China. In this study, we aim to quantify the effect of climatic factors on dengue in nine cities of the Pearl River Delta (PRD) in South China. Monthly dengue cases, climatic factors, socio-economic, geographical, and mosquito density data in nine cities of the PRD from 2008 to 2019 were collected. A generalized additive model (GAM) was applied to investigate the exposure–response relationship between climatic factors (temperature and precipitation) and dengue incidence in each city. A spatio-temporal conditional autoregressive model (ST-CAR) with a Bayesian framework was employed to estimate the effect of temperature and precipitation on dengue and to explore the temporal trend of the dengue risk by adjusting the socioeconomic and geographical factors. There was a positive non-linear association between the temperature and dengue incidence in the nine cities in south China, while the approximate linear negative relationship between precipitation and dengue incidence was found in most of the cities. The ST-CAR model analysis showed the risk of dengue transmission increased by 101.0

为拓宽压电能量采集器的有效频带,通过在附有末端磁铁的压电悬臂梁上增加一对移动磁铁,设计了一种频率可调、单-双稳态模式可快速切换的非线性磁式压电能量采集器.首先,对采集器进行分布参数动力学分析,基于Euler-Bernoulli理论推导了系统动力学方程,根据Lagrange函数分析系统动能、势能和电能表达式,利用磁偶极子模型得到系统的磁力表达式,通过Galerkin离散方法和泰勒展开得到系统的一阶降阶模型,利用谐波平衡法得到方程的解析表达式.随后,利用仿真软件分别对采集器的单-双稳态特性进行研究,分析了磁铁间距、阻尼、负载等参数对系统输出电压和功率的影响,并通过实验进行验证.实验结果表明:通过移动磁铁引进的非线性磁力有效增加了采集器的输出电压和输出功率;通过改变磁铁间距改变能量采集器的谐振频率,较好地拓宽了采集器的工作频带;系统可通过调节磁铁间距实现单稳态模式与双稳态模式之间的切换,能够分别利用单稳态模式和双稳态模式收集高频和低频环境下的振动能量.

Piezoelectric energy harvesting is commonly considered to be a promising field of development for microelectronic devices due to its potential to address a variety of key supply problems. However, due to their geometric designs, traditional piezoelectric energy harvesters (PEHs) tend to only be able to cultivate energy from vibrations flowing in one direction. The results of PEHs only capable of harvesting mono-directional vibrations are that they suffer from narrow resonance frequency bands and low energy conversion efficiency. To overcome these difficulties, this paper proposes a PEH inspired by a line tooth (PEH-ILT) with the ability to collect three-dimensional stochastic vibrations. To do so, the PEH-ILT possesses a nonlinear geometric shape which can, in theory, be designed arbitrarily. An example PEH-ILT is illustrated in this paper as well corresponding nonlinear piezoelectric constitutive equations. The cylindrical spiral curve is inspired by the line tooth design and is intended to replicate a nonlinear electro-mechanical model and its electrical output. Furthermore, the PEH-ILT is evaluated in this study by interacting with the four basic vibrations such devices are expected to encounter. In addition, the broadband piezoelectric energy harvesting conditions of the PEH-ILT are parsed and determined through the Melnikov theory, providing a theoretical explanation to the broadband conditions of the harvester. And this study can lay the theoretical basis for practical applications.

On April 23, 2022, an international flight KQ880 from Nairobi, Kenya arrived at Guangzhou Baiyun International Airport, Guangzhou City, Guangdong Province. All passengers were transferred to the quarantine hotel for routine 14-day medical observation and regular tested of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid. One of the patients, a 27-year-old Chinese male, reported positive SARS-CoV-2 nucleic acid on April 27, 2022. The patient had a history of full coronavirus disease 2019 (COVID-19) vaccination and denied exposure to other COVID-19 cases in the past 14 days. After diagnosis, he was transferred to Guangzhou Eighth People’s Hospital for treatment. On April 30, 2022, a nasal swab sample from the patient was sequenced using the Illumina MiniSeq platform (Illumina, San Diego, CA, USA), and genotyping results showed that the patient was infected with Omicron subvariant BA.2.12.1. A total of 33 amino acid mutation sites (T19I, A27S, G142D, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, L452Q, S477N, T478K, E484A, Q493R, Q498R, N501Y, Y505H, D614G, H655Y, N679K, P681H, S704L, N764K, D796Y, Q954H, N969K and L24del, P25del, P26del) were detected on the spike gene, two of which (L452Q and S704L) were key sites defining the signature of sublineage BA.2.12.1 (1-2) (Figure 1). The sequence has been submitted to the National Genomics Data Center (under the accession number WGS025539). On May 4, 2022, the World Health Organization reminded to closely monitor BA.2.12.1 subvariants (2). Compared to other Omicron variants, BA.2.12.1 subvariants shows stronger immune escape, even after having been vaccinated with booster dose (3). Several studies have shown that the transmissibility of BA.2.12.1 is about 23% to 27% faster than that of BA.2. Omicron BA 2.12.1 subvariants spread very fast, which led to the resurgence of the epidemic in many parts of the United States, and cases have been reported in at least 17 countries (4). Public health officials are focusing on this subvariant and trying to learn more. Author Affiliations

The SARS-CoV-2 Delta variant has spread rapidly worldwide. To provide data on its virological profile, we here report the first local transmission of Delta in mainland China. All 167 infections could be traced back to the first index case. Daily sequential PCR testing of quarantined individuals indicated that the viral loads of Delta infections, when they first become PCR-positive, were on average ~1000 times greater compared to lineage A/B infections during the first epidemic wave in China in early 2020, suggesting potentially faster viral replication and greater infectiousness of Delta during early infection. The estimated transmission bottleneck size of the Delta variant was generally narrow, with 1-3 virions in 29 donor-recipient transmission pairs. However, the transmission of minor iSNVs resulted in at least 3 of the 34 substitutions that were identified in the outbreak, highlighting the contribution of intra-host variants to population-level viral diversity during rapid spread.

On April 29, 2022, a flight arrived at Baiyun International Airport, Guangzhou City, Guangdong Province, from Amsterdam Schiphol Airport, Netherlands. After the first test of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid at the airport, all passengers were admitted to a quarantine hotel for a routine 14-day medical observation. On April 30, one of the passengers (a 20-year-old Chinese female) was reported positive for coronavirus disease 2019 (COVID-19), and then a nasopharyngeal swab sample was immediately retested on May 1 and reported positive. The patient was fully vaccinated against COVID-19 and completed 14 days of quarantine before flying to China. She denied any history of exposure to COVID-19 cases. After diagnosis, the patient was sent to Foshan Fourth People’s Hospital for treatment. On May 4, 2022, the viral genomic sequence of the patient was obtained using the Illumina MiniSeq platform (Illumina, San Diego, CA, USA), and genotyping results showed that the genome belonged to the Omicron/variant of concern (VOC) sublineage BA.4, with a total of 30 amino acid mutations (V3G, T19I, A27S, G142D, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, L452R, S477N, T478K, E484A, F486V, Q498R, N501Y, Y505H, D614G, H655Y, N679K, P681H, N764K, D796Y, Q954H, N969K) and 5 deletions (L24del, P25del, P26del, H69del, V70del) in the Spike protein gene. The phylogenetic tree indicates that the sequenced BA.4 has high similarity to the genome detected in Denmark on May 4, 2022 (GISAID: EPI_ISL_12648960) (Figure 1). The sequence has been deposited in the National Genomics Data Center (under the accession number WGS025540). On May 4, 2022, the World Health Organization reminded to closely monitor Omicron BA.4 subvariants (1). BA.4 is driving the upsurge in South Africa and has rapidly replaced BA.2, with over 50% of sequenced cases since the first week of April 2022 (2). Compared to BA.2, the BA.4 subvariants also showed stronger immune escape to the plasma of 3-dose vaccinees, even vaccinated BA.1 convalescent plasma (3-4). Cases of BA.4 infection have been reported in at least 20 countries, mainly from South Africa (62.39%) (5-6). Researchers are focusing on this subvariant and trying to learn more.

The piezoelectric energy harvester (PEH) has shown important practical value in numerous fields including, but not limited to communication, transportation, and military industrialization. However, the efficiency of piezoelectric energy harvesting is greatly limited due to its narrow frequency bandwidth. To harvest the vibration energy from a wider frequency range, this paper proposes a variant power generator array that is designed by using an arc-shaped piezoelectric cantilever beam (APCB) array. Five APCBs with different radii are arrayed parallel to each other with the energy harvesting circuit being connected in continuum by a rectifier bridge. The mathematical model and values of the APCB are depicted in this paper so to elucidate its low stiffness characteristic. The finite element analysis of the APCB is similarly recorded and the simulation result indicated that the APCB have better output performance than the corresponding flat-plat piezoelectric cantilever beam (FPCB). In addition, output voltage of the APCB can be increased while increasing the resonance frequency by increasing the width. Finally, the result of finite element simulation shows that the piezoelectric energy harvester using five APCBs arrayed in parallel series can be 14 times more efficient than that of the PEH with single APCB.

What is already known about this topic? The Omicron variant has been listed as a variant of concern, but the characteristics still remain unclear. What is added by this report? The vaccinated proportion of 65 imported coronavirus disease 2019 cases that were infected with Omicron variant in this study was 89.23%, which was higher than Delta cases. Most imported cases infected with Omicron were tested positive using polymerase chain reaction after entering Guangdong within 3 days, a shorter period than Delta. What are the implications for public health practice? Under this observation, the international travelers infected with Omicron variant were detected positive earlier after entry than those infected with Delta variant. Breakthrough infections occurred in most Omicron cases in this study, but vaccination was still effective to reduce the incidence of severe illness. Omicron surveillance should be strengthened.