Chikungunya virus (CHIKV) poses an increasing global public health threat, as evidenced by the significant 2025 Foshan outbreak in China. Rapid, whole-genome sequencing (WGS) is critical for outbreak response but is challenged by primer mismatches across diverse lineages and a lack of direct sequencing platform comparisons. To address this, we developed a novel lineage-inclusive primer set and performed parallel WGS on 24 clinical samples from the outbreak using both Illumina (NGS) and Oxford Nanopore Technologies (TGS) platforms. Our lineage-inclusive primer set successfully amplified full-length CHIKV genomes across all samples. Comparisons revealed that Illumina NGS provided higher raw read accuracy, while Nanopore TGS achieved more complete coverage of terminal UTRs with a faster turnaround time. Crucially, after polishing, variant calls between the two platforms were 100% concordant. Phylogenetic analysis was consistent with a single introduction event, with all outbreak isolates forming a monophyletic clade within the ECSA lineage most closely related to contemporaneous strains from Réunion Island. This study validates a lineage-inclusive amplicon-based sequencing strategy and demonstrates that NGS and TGS offer complementary advantages. When integrated, they provide a robust framework for real-time genomic surveillance, enhancing preparedness and guiding public health interventions against CHIKV.

Zika virus (ZIKV), a single-stranded positive-sense RNA virus of the Flaviviridae family (Flavivirus genus), causes acute febrile illness and severe congenital anomalies. Serological cross-reactivity with Dengue virus (DENV) and Chikungunya virus (CHIKV) complicates diagnosis, underscoring the urgency of developing specific point-of-care tests for early detection, outbreak mitigation, and reduced misdiagnosis risks. This study established and optimized an RPA-CRISPR/Cas12a assay for the rapid, visual, and highly specific detection of ZIKV. Primers and crRNAs targeting the highly conserved capsid (C) gene were designed, and the assay was systematically evaluated for its specificity, sensitivity, reproducibility, and clinical applicability. The RPA-CRISPR/Cas12a assay enabled naked-eye detection under UV light within 35 min. It demonstrated single-copy sensitivity (1 copy/μL), no cross-reactivity with DENV 1-4, CHIKV, or Japanese encephalitis virus (JEV), and 100% concordance with RT-qPCR in clinical validation. Repeatability tests showed low variability (coefficient of variation (C.V.) < 15%), confirming robust reproducibility. This instrument-free platform integrates rapid visual detection, single-copy sensitivity, high specificity, and field-deployable features, making it particularly suitable for point-of-care testing (POCT) in resource-limited settings. The developed assay provides critical support for early outbreak containment and prenatal screening in ZIKV-endemic regions.

Background: Diarrheal disease remains a significant public health issue, particularly affecting young children and older adults. Despite efforts to control and prevent these diseases, their incidence continues to be a global concern. Understanding the trends in diarrhea incidence and the factors influencing these trends is crucial for developing effective public health strategies. Objective: This study aimed to explore the temporal trends in diarrhea incidence and associated factors from 1990 to 2019 and to project the incidence for the period 2020–2040 at global, regional, and national levels. We aimed to identify key factors influencing these trends to inform future prevention and control strategies. Methods: The eXtreme Gradient Boosting (XGBoost) model was used to predict the incidence from 2020 to 2040 based on demographic, meteorological, water sanitation, and sanitation and hygiene indicators. SHapley Additive exPlanations (SHAP) value was performed to explain the impact of variables in the model on the incidence. Estimated annual percentage change (EAPC) was calculated to assess the temporal trends of age-standardized incidence rates (ASIRs) from 1990 to 2019 and from 2020 to 2040. Results: Globally, both incident cases and ASIRs of diarrhea increased between 2010 and 2019. The incident cases are expected to rise from 2020 to 2040, while the ASIRs and incidence rates are predicted to slightly decrease. During the observed (1990–2019) and predicted (2020–2040) periods, adults aged 60 years and above exhibited an upward trend in incidence rate as age increased, while children aged < 5 years consistently had the highest incident cases. The SHAP framework was applied to explain the model predictions. We identified several risk factors associated with an increased incidence of diarrhea, including age over 60 years, yearly precipitation exceeding 3000 mm, temperature above 20 °C for both maximum and minimum values, and vapor pressure deficit over 1500 Pa. A decreased incidence rate was associated with relative humidity over 60%, wind speed over 4 m/s, and populations with above 80% using safely managed drinking water services and over 40% using safely managed sanitation services. Conclusions: Diarrheal diseases are still serious public health concerns, with predicted increases in the incident cases despite decreasing ASIRs globally. Children aged < 5 years remain highly susceptible to diarrheal diseases, yet the incidence rate in the older adults aged 60 plus years still warrants additional attention. Additionally, more targeted efforts to improve access to safe drinking water and sanitation services are crucial for reducing the incidence of diarrheal diseases globally.

Objective:This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A (RVA) in the Pearl River Delta region of Guangdong Province, China.Methods:This study included individuals aged 28 days-85 years. A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens, including RVA, using a Gastrointestinal Pathogen Panel, followed by genotyping, virus isolation, and complete sequencing to assess the genetic diversity of RVA.Results:The overall RVA infection rate was 14.59% (103/706), with an irregular epidemiological pattern. The proportion of co-infection with RVA and other pathogens was 39.81% (41/103). Acute gastroenteritis is highly prevalent in young children aged 0-1 year, and RVA is the key pathogen circulating in patients 6-10 months of age with diarrhea. G9P[8] (58.25%, 60/103) was found to be the predominant genotype in the RVA strains, and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis. Recombination analysis showed that gene reassortment events, selection pressure, codon usage bias, gene polymorphism, and post-translational modifications (PTMs) occurred in the G9P[8] and G3P[8] strains.Conclusion:This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China, further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity. Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.

Objectives Dengue has been endemic in Southeast Asian countries for decades. There are few reports tracing the dynamics of dengue in real time. In this study, we generated hundreds of pathogen genomes to understand the genomic epidemiology of an outbreak in a hyper-endemic area of dengue. Methods We leveraged whole-genome short-read sequencing (PE150) to generate genomes of the dengue virus and investigated the genomic epidemiology of a dengue virus transmission in a mesoscale outbreak in Shantou, China, in 2019. Results The outbreak was sustained from July to December 2019. The total accumulated number of laboratory-confirmed cases was 944. No gender bias or fatalities were recorded. Cambodia and Singapore were the main sources of imported dengue cases (74.07%, n = 20). A total of 284 dengue virus strains were isolated, including 259 DENV-1, 24 DENV-2, and 1 DENV-3 isolates. We generated the entire genome of 252 DENV isolates (229 DENV-1, 22 DENV-2, and 1 DENV-3), which represented 26.7% of the total cases. Combined epidemiological and phylogenetic analyses indicated multiple independent introductions. The internal transmission evaluations and transmission network reconstruction supported the inference of phylodynamic analysis, with high Bayes factor support in BSSVS analysis. Two expansion founders and transmission chains were detected in CCH and LG of Shantou. Conclusions We observed the instant effects of genomic epidemiology in monitoring the dynamics of DENV and highlighted its prospects for real-time tracing of outbreaks of other novel agents in the future.

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.

Background Guangdong is a hyperepidemic area of dengue, which has over 0.72 million cumulative cases within the last four decades, accounting for more than 90% of cases in China. The local epidemic of dengue in Guangdong is suspected to be triggered by imported cases and results in consequent seasonal transmission. However, the comprehensive epidemiological characteristics of dengue in Guangdong are still unclear. Methods The epidemiology, seroprevalence, molecular evolution of dengue virus, and the development of policies and strategies on the prevention and control of dengue were analyzed in Guangdong, China from 1978 to 2017. Findings Seasonal transmission of dengue virus in Guangdong, China was mainly sustained from July to October of each year. August to September was the highest risk period of local dengue outbreaks. Most of the dengue cases in Guangdong were young and middle-aged adults. Five hundred and three fatal cases were recorded, which declined within the last two decades (n = 10). The serological test of healthy donors' serum samples showed a positive rate of 5.77%. Dengue virus 1–4 (DENV 1–4) was detected in Guangdong from 1978 to 2017. DENV 1 was the dominant serotype of dengue outbreaks from 1978 to 2017, with an increasing tendency of DENV 2 since 2010. Local outbreaks of DENV 3 were rare. DENV 4 was only encountered in imported cases in Guangdong, China. The imported cases were the main source of outbreaks of DENV 1–2. Early detection, management of dengue cases, and precise vector control were the key strategies for local dengue prevention and control in Guangdong, China. Interpretation Dengue has not become an endemic arboviral disease in Guangdong, China. Early detection, case management, and implementation of precise control strategies are key findings for preventing local dengue transmission, which may serve for countries still struggling to combat imported dengue in the west pacific areas.

目的 对感染性腹泻样本进行检测鉴定,并对轮状病毒A组进行病毒分离,研究2019年广东省部分地区感染性腹泻病原学及轮状病毒分子流行病学特征.方法 2019年1月1日至2020年1月12日,采集广东省广州市、东莞市和江门市临床感染性腹泻患者粪便样本,进行多重RT-PCR扩增和微球杂交技术检测鉴定,并对轮状病毒A组阳性样本进行分离后,采用半巢式PCR试验对阳性细胞培养物进行G/P基因分型.结果 共纳入706例合格病例,病原体总检出率43.06％,病毒检出率18.13％高于细菌检出率8.36％高于寄生虫检出率1.27％.病毒病原谱以轮状病毒A组G9P[8]和诺如病毒GII型感染为主,细菌病原谱以沙门菌和艰难梭菌为主,寄生虫以蓝氏贾第鞭毛虫为首.不同季度、不同年龄组病原谱构成各不相同.轮状病毒A组主要受累群体为≤5岁儿童,主要时间分布于1-4月,基因型呈现多样性,包括G2P[4]、G3P[8]和G9P[8].结论 2019年广东省部分地区感染性腹泻病毒类病原体高于细菌类高于寄生虫类,轮状病毒A组G9P[8]、诺如GII型、沙门菌和蓝氏贾第鞭毛虫是最主要的病原体,且G9P[8]型A组轮状病毒毒株在轮状病毒感染中占主导趋势.在防控病毒性和细菌性腹泻的同时,应警惕寄生虫所致腹泻并重视混合感染的病原学监测.

目的:了解广东省4城市高危职业人群布鲁氏菌感染状况,探讨其布鲁氏菌感染的相关因素.方法:2013年1—6月,采用整群抽样的方法从广东省广州、佛山、惠州和揭阳4个城市招募了1050名畜牧业从业人员为研究对象,对其进行问卷调查和血清学检查.结果:调查人群血清阳性率为1.5％(16/1050),其中牲畜交易市场从业人员阳性率最高(3.1％,6/195),其次是屠夫(2.2％,6/269)、农民或奶工(2.1％,4/191).多因素分析表明接触绵羊、山羊或其产品、过去12个月内有持续关节痛者和年龄小是职业人群中布鲁氏菌感染血清阳性的相关因素(校正OR=10.5、26.8、17.5).与接触牛或猪的工人相比,接触绵羊、山羊或其产品者的布鲁氏菌血清阳性率更高(分别为5.5％和0.6％,校正OR值=10.5;95％CI:3.3～33.7).结论:广东省4城市畜牧业从业人员布鲁氏菌感染血清阳性率相对较低,接触绵羊、山羊或其产品、过去12个月内有持续关节痛者和年龄小是主要的相关因素.

Objective:To detect blood samples from clinically confirmed cases infected with the 2019 novel coronavirus (2019-nCoV) by fluorescence immunochromatography, colloidal gold immunoassay and micro neutralization test and compare differences in result and provide useful approaches to clinical and epidemiological investigation.Methods:The 2019-nCoV IgG/IgM antibody kit (Fluorescent immuno-chromatography) and the 2019-nCoV antibody test kit (Colloidal gold immunoassay) from Guangzhou Wanfu biotechnology Limited by Share Ltd, and the micro neutralization test established by a 2019-nCoV strain isolated by the laboratory in Guangdong Provincial Center for Diseases Control and Prevention were used to detect serum samples of clinically confirmed patients, in the Guangdong Province Second People′s Hospital, China.Results:A total of 113 serum samples from clinically confirmed cases infected with the 2019-nCoV were collected in Guangdong 2 nd People′s Hospital. The median age of the patients was 47.50 (32.00, 57.00) years and the gender ratio was 2.77∶1; The highest neutralizing antibody titer of micro neutralization test was 1∶1 024; Taking the result of micro neutralization test as gold standard, the sensitivity for colloidal gold immunoassay was greater than that of fluorescence immunochromatography (94.74% vs 82.46%), and the Kappa value for colloidal gold immunoassay and fluorescence immunochromatography was 85.84% and 75.24% respectively; at the same time, the negative predictive value and the positive predictive value for them were 94.44%, 91.53% and 83.87%, 92.16% respectively. Conclusions:In the serological method for the detection of the 2019-nCoV infection, the sensitivity and Kappa value for colloidal gold immunoassay were higher than those of fluorescent immunochromatography when the result of micro neutralization test was taken as the gold standard, which was more suitable for rapid detection of cases with the 2019-nCoV infection.

Objective The coronavirus disease 2019（COVID-19） pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody（NAb） responses to severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）.Methods In total, 605 serum samples from 125 COVID-19 patients（from January 1 to March 14, 2020）varying in age, sex, severity of symptoms, and presence of underlying diseases were collected, and antibody titers were measured using a micro-neutralization assay with wild-type SARS-CoV-2.Results NAbs were detectable approximately 10 days post-onset（dpo） of symptoms and peaked at approximately 20 dpo. The NAb levels were slightly higher in young males and severe cases, while no significant difference was observed for the other classifications. In follow-up cases, the NAb titer had increased or stabilized in 18 cases, whereas it had decreased in 26 cases, and in one case NAbs were undetectable at the end of our observation. Although a decreasing trend in NAb titer was observed in many cases, the NAb level was generally still protective.Conclusion We demonstrated that NAb levels vary among all categories of COVID-19 patients. Longterm studies are needed to determine the longevity and protective efficiency of NAbs induced by SARS-CoV-2.

探讨巨细胞病毒感染与住院严重急性呼吸道感染(SARI)肺炎的相关性.以67例符合严重急性呼吸系统感染临床诊断标准的住院病例为研究对象,同时以81例流感样门诊病例作为对照,使用荧光定量PCR方法检测所有研究对象的巨细胞病毒感染情况.采用二分类logistic回归模型分析巨细胞感染与住院严重急性呼吸道感染肺炎病例的关联.巨细胞病毒在呼吸道感染病例中有较高的阳性率,阳性率随年龄呈下降趋势.80％以上巨细胞病毒阳性病例存在与其他常见呼吸道病原共感染情况.Logistic回归分析表明:年龄和多病原共感染是SARI肺炎发生的危险因素,单独CMV阳性与SARI肺炎的发生没有显著相关性.SARI肺炎中CMV与其他呼吸道病原共感染概率高,临床上应加强对呼吸道感染病例的巨细胞病毒检测.

目的 本研究旨在评估登革热NS1抗原、病毒RNA和IgM抗体检测在登革热病毒感染早期实验室诊断中的应用.方法 2014年6-11月,连续采集广东省疑似登革热患者432份血清样本,所有样本同时进行了4项商用诊断试验,包括NS1快速诊断试验(RDT)、NS1酶联免疫吸附试验(ELISA)、实时定量RT-PCR(qRT-PCR)试验和IgM/IgG ELISA试验.结果 361例(83.6％)样本被检出登革病毒NS1抗原或病毒RNA或IgM抗体阳性,其中317例(87.8％)和43例(11.9％)为原发性和继发性登革热病例.NS1抗原总阳性率最高(358份,82.9％),其次是病毒RNA(268份,74.3％)和IgM抗体(179份,49.5％).在采集标本时,本研究观察到疾病早期NS1抗原和病毒RNA呈阳性、而IgM抗体是逐渐出现阳性的时间变化.NS1 RDT(97.0％)和NS1 ELISA试验(98.6％)对急性期和急性后期标本的敏感性均显著高于qRT-PCR(88.9％)和IgM-ELISA(59.3％)试验(P＜0.01).NS1 RDT和NS1ELISA的检测结果相似,具有较好的一致性(κ=0.363,P＜0.001),qRT-PCR对急性期标本的敏感性高于IgM-ELISA(P＜0.01).结论 在以原发性感染为主的非登革热疫区国家,应重视高灵敏度的NS1抗原检测.病毒RNA检测对登革热早期诊断仍有价值,而IgM抗体检测最适合作为第5天或第5天以上患者的辅助诊断方法.为了从诊断角度及时做出适当的疫情反应,迫切需要这些信息和进一步的调查.

ObjectivesThe aim was to understand persistence of the virus in body fluids the and immune response of an infected host to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), an agent of coronavirus disease 2019 (COVID-19).MethodsWe determined the kinetics of viral load in several body fluids through real time reverse transcription polymerase chain reaction, serum antibodies of IgA, IgG and IgM by enzyme-linked immunosorbent assay and neutralizing antibodies by microneutralization assay in 35 COVID-19 cases from two hospitals in Guangdong, China.ResultsWe found higher viral loads and prolonged shedding of virus RNA in severe cases of COVID-19 in nasopharyngeal (1.3 × 106 vs 6.4 × 104, p < 0.05; 7∼8 weeks) and throat (6.9 × 106 vs 2.9 × 105, p < 0.05; 4∼5 weeks), but similar in sputum samples (5.5 × 106 vs 0.9 × 106, p < 0.05; 4∼5 weeks). Viraemia was rarely detected (2.8%, n = 1/35). We detected early seroconversion of IgA and IgG at the first week after illness onset (day 5, 5.7%, n = 2/35). Neutralizing antibodies were produced in the second week, and observed in all 35 included cases after the third week illness onset. The levels of neutralizing antibodies correlated with IgG (rs = 0.85, p < 0.05; kappa = 0.85) and IgA (rs = 0.64, p < 0.05; kappa = 0.61) in severe, but not mild cases (IgG, rs = 0.42, kappa = 0.33; IgA, rs = 0.32, kappa = 0.22). No correlation with IgM in either severe (rs = 0.17, kappa = 0.06) or mild cases (rs = 0.27, kappa = 0.15) was found.DiscussionWe revealed a prolonged shedding of virus RNA in the upper respiratory tract, and evaluated the consistency of production of IgG, IgA, IgM and neutralizing antibodies in COVID-19 cases.

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2 infection and was first reported in central China in December 2019. Extensive molecular surveillance in Guangdong, China's most populous province, during early 2020 resulted in 1,388 reported RNA-positive cases from 1.6 million tests. In order to understand the molecular epidemiology and genetic diversity of SARS-CoV-2 in China, we generated 53 genomes from infected individuals in Guangdong using a combination of metagenomic sequencing and tiling amplicon approaches. Combined epidemiological and phylogenetic analyses indicate multiple independent introductions to Guangdong, although phylogenetic clustering is uncertain because of low virus genetic variation early in the pandemic. Our results illustrate how the timing, size, and duration of putative local transmission chains were constrained by national travel restrictions and by the province's large-scale intensive surveillance and intervention measures. Despite these successes, COVID-19 surveillance in Guangdong is still required, because the number of cases imported from other countries has increased.

The Asian musk shrew (shrew) is a new reservoir of a rat hepatitis E virus (HEV) that has been classified into genotype HEV-C1 in the species Orthohepevirus C. However, there is no information regarding classification of the new rat HEV based on the entire genome sequences, and it remains unclear whether rat HEV transmits from shrews to humans. We herein inoculated nude rats (Long-Evans rnu/rnu) with a serum sample from a shrew trapped in China, which was positive for rat HEV RNA, to isolate and characterize the rat HEV distributed in shrews. A rat HEV strain, S1129, was recovered from feces of the infected nude rat, indicating that rat HEV was capable of replicating in rats. S1129 adapted and grew well in PLC/PRF/5 cells, and the recovered virus (S1129c1) infected Wistar rats. The entire genomes of S1129 and S1129c1 contain four open reading frames and share 78.3–81.8% of the nucleotide sequence identities with known rat HEV isolates, demonstrating that rat HEVs are genetically diverse. We proposed that genotype HEV-C1 be further classified into subtypes HEV-C1a to HEV-C1d and that the S1129 strain circulating in the shrew belonged to the new subtype HEV-C1d. Further studies should focus on whether the S1129 strain infects humans.

目的 建立一种肠道病毒通用型微滴式数字PCR(ddPCR)的定量检测方法,以实现肠道病毒的量化检测.方法 利用肠道病毒标准品对ddPCR反应中的探针浓度、退火温度进行优化,并确定ddPCR的检测范围.利用已优化好的反应条件对28份临床样本进行病毒载量检测.结果 本研究确定ddPCR的最佳探针浓度为0.4 μmol/L,退火温度为51.0℃,核酸检测范围为3.02～3.59×106 copies/μL,检出限为3.02 copies/μL.ddPCR方法线性相关系数为0.993 8,呈良好的线性关系.结论 本研究建立基于ddPCR肠道通用型的定量方法,可有效地对临床样本中不同血清型的肠道病毒临床样本进行拷贝数定量分析,为临床研究病毒载量的测定提供一种技术.

Objective To compare two multi-pathogen detection assays for respiratory pathogens detection.Methods A total of 62 nasopharyngeal swab samples were collected from acute respiratory infection cases in the sentinel hospitals of Guangdong Provincial Center for Disease Control and Prevention from April to June,2018.The samples were tested in parallel by a single-tube nucleic acid assay for multiple respiratory pathogens (RespiFinder 2SMART,assay 1) and a microfluidic chip assay for respiratory pathogens (RESP_TRIAL CARD V l,assay 2).The detection rates,consistency rates and kappa values of both methods were compared.Results The positive rates of assay 1 and 2 were 70.97％and 80.65％,respectively.The difference was caused by different detection spectrum of pathogens.For the pathogens detected by both assays,the positive rates were 70.97％ and 66.31％ for assay 1 and 2,respectively.The detection performance of both assays for bocavirus,coronavirus,influenza virus,parainfluenza virus,respiratory syncytial virus,adenovirus and metapneumovirus were similar,with the overall consistency rates of 93.5％-100.00％,and all kappa values were ＞0.6.The consistency of detection for Mycoplasma pneumoniae,Bacillus pertussis and Legionella pneumophila by the two assays were rather poor.Conclusions The performance of the two assays was similar.Both assays would be used based on targeted respiratory pathogens.

We previously reported in this Journal that, 1 Sun J. Wu D. Zhong H. Guan D. Zhang H. Tan Q. et al. Returning ex-patriot Chinese to Guangdong, China, increase the risk for local transmission of Zika virus. J Infect. 2018; 75: 356-367 Google Scholar in early 2016, the public authority of China enforced the detection of imported zika cases in international airports regarding to the continuing global transmission of Zika virus (ZIKV). During February to September, 2016, 28 imported ZIKV infection cases were detected in China, of which 15 were imported from Venezuela, Suriname and Guatemala to Enping County, Guangdong, China (Fig. 1) where is the hometown of more than 450,000 Guangdong residents work and live in South America and South Pacifica countries. Most of these residents maintain their permanent home and travel frequently between Enping County and ZIKV endemic countries in South America or South Pacifica. Therefore, Enping was considered as the most threaten area by ZIKV in Guangdong, China due to high incidence of importation of zika cases. Additionally, Guangdong Province is a hyper-endemic areas of arboviruses located in Southern China, where both Aedes albopictus and aegypti mosquitoes are encountered simultaneously. Dengue occurred annually. Chikungunya were also occasionally imported and caused an local outbreak in 2010. 2 Wu D. Wu J. Zhang Q. Zhong H. Deng X. Ke C. et al. Chikungunya outbreak in Guangdong Province, China, 2010. Emerg Infect Dis. 2012; 18: 493-495 Google Scholar ,3 Sun J. Wu D. Zhou H. Zhang H. Guan D. He X. et al. The epidemiological characteristics and genetic diversity of dengue virus during the third largest historical outbreak of dengue in Guangdong, China, in 2014. J Infect. 2016; 72: 80-90 Google Scholar However, whether there were previously importation of ZIKV within returned ex-patriot Chinese in Enping, Guangdong, China and result in unware local transmission before 2016 in naïve population is still remained unknown.

Objective In this study, phage display technology was used to construct the human anti-Zika virus(ZIKV), phage antibody library and to obtain and express the monoclonal antibody. The aim was to master the preparation and expression of human phage antibody library screening method for highly specific antibodies. Methods The whole blood samples of Zika patients were collected and the lymphocytes were isolated. The RT-PCR method was used to amplify the antibody light chain and heavy chain Fab gene from lymphocyte Ig mRNA. The pComb3H system was used to construct the gene with genetic diversity Preparation of human anti-ZIKV phage antibody library. The purified antibody library was screened by using the purified ZIKV and the obtained ZIKV E protein antigen. Results The monoclonal antibody Fab fragment gene was successfully obtained for the ZIKV E protein antigen. The gene can be efficiently expressed in Escherichia coli. Conclusions According to the sequence analysis, this study showed that the monoclonal antibody was a new human genetically engineered antibody against ZIKV, which laid the foundation for the early diagnosis of ZIKV, and obtain a specific monoclonal antibody to ZIKV for human treatment of ZIKV infection. Key words: Human genetically engineered antibody; ZIKV; Phage display; Fab fragment