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ObjectivesLung cancer is one of the most common cancers in Shandong Province, China. Projecting future cancer trend is crucial for planning cancer control. We aimed to examine the trend of lung cancer incidence and mortality from 2012 to 2023, and predict the lung cancer burden to 2030 in Shandong.MethodsData of lung cancer incidence and mortality from 2012 to 2023 were obtained from the Shandong Cancer Registries. The average annual percentage change (AAPC) was used to quantify the trend of the lung cancer age-standardised rate using Joinpoint software. Bayesian age-period-cohort model was used to predict lung cancer incidence and mortality from 2024 to 2030.ResultsThe age-standardised incidence rate (ASIR) remained stable from 2012 to 2023. The ASIR in males decreased with an AAPC of -1.350%, while the ASIR in females increased with an AAPC of 2.429%. The age-standardised mortality rate (ASMR) decreased with an AAPC of -2.911%. This trend was also observed in males (AAPC=-2.513%), females (AAPC=-3.632%), urban areas (AAPC=-3.267%) and rural areas (AAPC=-2.603%). For our predictions, the ASIR will increase to 49.21 per 100,000 until 2030, with an AAPC of 1.873%. This upward trend is expected for females and urban areas, with an AAPC of 4.496% and 4.176%, while it is not observed for males and rural areas. The ASMR is expected to remain stable up to 2030, and this trend will maintain both in males and females. The ASMR will exhibit an upward trend (AAPC=1.100%) in urban areas and a downward trend (AAPC=-0.915%) in rural areas.ConclusionThe ASIR of lung cancer will increase until 2030, while the ASMR of lung cancer is expected to remain stable in Shandong. It is necessary to take further preventive measures such as strengthening tobacco control, enhancing health education and expanding screening efforts.

ObjectiveTo investigate the prevalence and genetic diversity of human astrovirus (HAstV) strains in untreated domestic sewage. MethodsWe collected six domestic sewage samples (one liter for each) at an inlet of an urban sewage treatment plant quarterly from January 2018 to June 2019 in Jining city, Shandong province. After concentrated via anion membrane adsorption elution method, the viral nucleic acid in the samples was extracted with MagMAX Pathogen RNA/DNA Kit and complete open reading frame 2 (ORF2) region of HAstV was amplified using real-time reverse transcription PCR (RT-PCR). Then the amplicons were subjected to next generation sequencing (NGS). Clean data of NGS were assembled de novo to form contigs using CLC Genomics Workbench 12.0 (QIAGEN, USA) with default parameters for homology and phylogenetic analysis. ResultsAll the six sewage samples were positive for HAstV. Totally 43 ORF2 sequences of HAstV were obtained and classified into 9 genotypes including classic HAstV-1 to HAstV-5 and novel MLB1 and VA1-3. HAstV-5 was the most common genotype (47.53%). Phylogenetic analysis revealed that local and foreign sequences clustered together in some branches, indicating the transmission of various genotypes of HAstV among different regions in the world. ConclusionThe analysis results demonstrates that NGS-based environmental surveillance could greatly improve the understanding on HAstV genetic diversity.

ObjectivesThe impact of climate change, especially extreme temperatures, on health outcomes has become a global public health concern. Most previous studies focused on the impact of disease incidence or mortality, whereas much less has been done on road traffic injuries (RTIs). This study aimed to explore the effects of ambient temperature, particularly extreme temperature, on road traffic deaths in Jinan city.MethodsDaily data on road traffic deaths and meteorological factors were collected among all residents in Jinan city during 2011–2020. We used a time-stratified case-crossover design with distributed lag nonlinear model to evaluate the association between daily mean temperature, especially extreme temperature and road traffic deaths, and its variation in different subgroups of transportation mode, adjusting for meteorological confounders.ResultsA total of 9,794 road traffic deaths were collected in our study. The results showed that extreme temperatures were associated with increased risks of deaths from road traffic injuries and four main subtypes of transportation mode, including walking, Bicycle, Motorcycle and Motor vehicle (except motorcycles), with obviously lag effects. Meanwhile, the negative effects of extreme high temperatures were significantly higher than those of extreme low temperatures. Under low-temperature exposure, the highest cumulative lag effect of 1.355 (95% CI, 1.054, 1.742) for pedal cyclists when cumulated over lag 0 to 6 day, and those for pedestrians, motorcycles and motor vehicle occupants all persisted until 14 days, with ORs of 1.227 (95% CI, 1.102, 1.367), 1.453 (95% CI, 1.214, 1.740) and 1.202 (95% CI, 1.005, 1.438), respectively. Under high-temperature exposure, the highest cumulative lag effect of 3.106 (95% CI, 1.646, 5.861) for motorcycle occupants when cumulated over lag 0 to 12 day, and those for pedestrian, pedal cyclists, and motor vehicle accidents all peaked when persisted until 14 days, with OR values of 1.638 (95% CI, 1.281, 2.094), 2.603 (95% CI, 1.695, 3.997) and 1.603 (95% CI, 1.066, 2.411), respectively.ConclusionThis study provides evidence that ambient temperature is significantly associated with the risk of road traffic injuries accompanied by obvious lag effect, and the associations differ by the mode of transportation. Our findings help to promote a more comprehensive understanding of the relationship between temperature and road traffic injuries, which can be used to establish appropriate public health policies and targeted interventions.

Abstract We aimed to analyse cancer survival and its spatial distribution in Shandong Province. A total of 609,861 cancer cases from 2014 to 2016 were included in the analysis. Survival analysis was performed using strs in Stata. Spatial analysis was performed with GeoDa to determine measures of global and local spatial autocorrelation. Hotspot analysis was used to identify spatial clusters of high values (hotspots) and low values (cold spots) through ArcGIS. The 5-year relative survival rates were 37.85% for all cancers combined, 29.29% for males and 48.88% for females. After age standardisation, the survival rates were 34.47% for all cancers, 28.43% for males and 41.56% for females. Cancers with higher survival rates included thyroid (78.80%), breast (69.52%), uterus (64.51%) and bladder (62.54%) cancers. However, cancers with lower survival rates included pancreatic (11.34%), liver (13.19%), lung (18.39%), bone (19.71%), gallbladder (19.78%), oesophagus (24.52%), and stomach (28.85%) cancers and leukaemia (26.30%). Cancer survival rates in urban areas (37.53%) were higher than those in rural areas (32.83%). From the geographic distribution of cancer survival, we observed that the survival rate displayed a downward trend from east to west and from north to south. The hotspot analysis revealed that some counties of Qingdao, Jinan, Zibo, Dongying and Yantai cities were hotspots, whereas almost all counties of Linyi city and some counties of Weifang, Heze, Rizhao, and Dezhou cities were cold spots. In conclusion, the cancer survival rate in Shandong is still lower than that in China overall. The early diagnosis and treatment of lung and digestive tract cancers need to be further strengthened. Nevertheless, our results reflect a critical first step in obtaining and reporting accurate and reliable estimates of survival in Shandong.

Abstract Omono River virus (OMRV) is a newly reported, unclassified RNA virus in the family Totiviridae, which infects mosquitoes and bats. In this study, we report the isolation of an OMRV strain SD76 from Culex tritaeniorhynchus captured in Jinan city, China. The cytopathic effect was characterized by cell fusion on C6/36 cell line. Its complete genome was 7611 nucleotides in length, with 71.4–90.4% similarities with other OMRV strains. Phylogenetic analysis based on complete genomes showed all OMRV-like strains can be divided into 3 groups with between-group distances ranging from 0.254 to 0.293. These results revealed that the OMRV isolate had high genetic diversity with those identified previously, and enriched the genetic information of family Totiviridae.

Abstract Background Measles caused by measles virus (MeV) is a highly contagious viral disease which has also been associated with complications including pneumonia, myocarditis, encephalitis, and subacute sclerosing panencephalitis. The current study isolated 33 strains belonging to 2 groups, outbreak and sporadic strains, in 13 cities of Shandong province, China from 2013 to 2019. Comparison of genetic characterization among 15 outbreak strains and 18 sporadic strains was performed by analyzing nucleotide sequences of the C-terminal region of N protein gene (N-450). Results All 33 stains belonged to genotype H1. The outbreak strains and sporadic strains distributed crossly in phylogenetic tree. Sequences alignment revealed some interesting G to A transversion which changed the amino acids on genomic sites 1317, 1422, and 1543. The nucleotide and amino acid similarities among outbreak isolates were 98–100% (0–10 nucleotide variations) and 97.7–100%, respectively; They were 97.3–100% and 96.6–100%, respectively for sporadic isolates. Evolutionary genetics analysis revealed that the mean evolution rates of outbreak and sporadic isolates were 1.26 N 10− 3 and 1.48 N 10− 3 substitutions per site per year separately, which were similar with corresponding data before 2012. Local transmission analysis suggested that there were three transmission chains in this study, two of them originated from Japan. Outbreak cases and sporadic cases emerged alternatively and were reciprocal causation on the transmission chains. Conclusions Our study investigated the phylogeny and evolutional genetics of MeV during a 7-year surveillance, and compared epidemic and genetic characteristics of outbreak strains and sporadic strains. These results underscore the importance of evolutionary study alongside with sporadic cases in discovering and tracing possible outbreaks, especially in the stage of measles elimination.

Although hepatitis B virus (HBV) vaccination is recommended for hepatitis C virus (HCV)-infected individuals to avoid HBV superinfection, the persistence of their humoral and cell-mediated immunity responses to HBV vaccination is still under investigation. Patients with chronic hepatitis C (CHC) and matched healthy controls, who completed three doses of hepatitis B vaccine (HepB) in 2014, were followed up five years later. One booster dose of HepB was given to those with antibody against hepatitis B surface antigen (anti-HBs) lower than 10mIU/mL. Anti-HBs was tested at follow-up and on the 14th day after the booster dose, as well as HBsAg specific spot-forming cells of interferon γ and interleukin (IL) 2, 4, 5, and 6. At five years, only 56.58% of the CHC patients had sero-protective titers (≥10mIU/mL) of anti-HBs, compared to 70.83% in the controls (P .05). Multivariable analysis showed that HCV infection was an independent predictor factor to anti-HBs level at follow-up. HBsAg specific IL-6 was stronger in the CHC patients compared to the controls (P

Condyloma acuminatum (CA) is a sexually transmitted disease (STD) caused by human papillomavirus (HPV) infection. It is important to study the prevalence and distribution of HPV genotypes before implementing the HPV vaccination program. Therefore, the aim of this study was to evaluate the epidemiological characteristics of CA cases and the distribution of HPV genotypes in Shandong Province, China. One-to-one questionnaire surveys were conducted on all patients diagnosed with CA in sentinel hospitals from Shandong Province, China. HPV genotypes were determined using the polymerase chain reaction (PCR)-reverse dot blot hybridization method. The study enrolled 1185 patients (870 males and 315 females) and found that CA patients are mainly males and sexually active people between the ages of 20 and 40. Recurrence occurred in 34.7% patients. Among the 880 CA patients who underwent HPV typing, the HPV test positivity rate was 91.4%. In these cases, low-risk (LR) HPV infection was predominant, with an infection rate of 91.3%, while high-risk (HR) HPV genotypes were found in 53.5% patients. The most frequent HPV genotypes encountered were HPV6 (57.8%), HPV11 (37.2%), HPV16 (13.7%), and HPV42 (10.3%). HPV6 and/or HPV11 are the main infections in all patients, and more than half of the patients are coinfected with HR-HPV. However, unlike other regions, HPV42 has a higher prevalence rate among CA patients in Shandong Province and is a nonvaccine HPV genotype. Therefore, regular HPV typing helps to understand the characteristics of specific genotypes and the choice of the best type for vaccine coverage.

During the first quarter of 2020, a considerable increase in reports of symptomatic hepatitis A cases was noted in Yantai, a coastal city in eastern China. This study aimed to characterize the epidemic and identify the probable source. Serum samples from cases with onsets from 1 January to 31 March 2020 and suspected bivalve mollusk samples from the local seafood market were screened for hepatitis A virus (HAV) RNA by PCR amplification and sequencing of the VP1/2A region. We also analyzed the characteristics and risk exposures of these cases. In total, 110 confirmed cases were notified during the epidemic. Among the 103 cases investigated, the median age was 41 years (range: 25–70 years), and 74 (71.8%) were male. Eighty-eight cases (85.4%) reported having eaten shellfish and 72 (69.9%) specifically oysters. HAV RNA was detected and sequenced successfully in 80.2% (69/86) of the cases, as well as in one oyster out of 20 shellfish samples. Phylogenetic analysis revealed that all isolates belonged to a single genotype IA but presented the co-circulation of five distinct genomic sub-lineages. The oyster-derived HAV strain shared over 98.2% nucleotide identity with all clinical strains obtained during the epidemic, particularly 100% homology with the strains of seven cases. These data indicated that contaminated oyster consumption was probably a common source of this epidemic, although multiple HAV strains were involved. We recommend strengthening shellfish surveillance, changing dietary habits in seafood consumption, and encouraging vaccination for target adults in coastal areas with a high prevalence of hepatitis A.

In the process of online prediction of multivariable non-stationary time series by kernel extreme learning machine (KELM), the dynamic characteristics of the system which are difficult to determine have always posed a big problem. We propose an online sequential prediction model with an adaptive forgetting factor (AFF) for multivariable time series to solve this problem. The multivariable time series instead of variable itself is reconstructed firstly. AFF is introduced into the objective function and can be adjusted iteratively and adaptively with the system changes. As a result, higher weight can be allocated for the fresh and more important samples while the old failure samples can be quickly forgotten. The model sparsification uses a fast leave-one-out cross-validation (FLOO-CV) method to set a prediction error threshold so that samples can be selected conditionally to form a dictionary. Besides, the dictionary parameters, including AFF and kernel parameters, are recursively updated simultaneously without increasing calculation complexity. The experimental results show that, compared with four fashionable KLEM methods, the proposed AFF-OSKELM has a better dynamic tracking ability and adaptability. Moreover, compared with single variable prediction, the spatial reconstructed multivariable has higher prediction accuracy and stability.

Abstract Background The major infectious diseases of hepatitis B has constituted an acute public health challenge in China. An effective and affordable HBV control model is urgently needed. A national project of Community-based Collaborative Innovation HBV (CCI-HBV) demonstration areas has optimized the existing community healthcare resources and obtained initial results in HBV control. Methods Based on the existing community healthcare network, CCI-HBV project combined the community health management and health contract signing service for long-staying residents in hepatitis B screening. Moreover, HBV field research strategy was popularized in CCI-HBV areas. After screening, patients with seropositive results were enrolled in corresponding cohorts and received treatment at an early stage. And the uninfected people received medical supports including health education through new media, behavior intervention and HBV vaccinations. In this process, a cloud-based National Information Platform (NIP) was established to collect and store residents’ epidemiological data. In addition, a special quality control team was set up for CCI project. Results After two rounds of screening, HBsAg positive rate dropped from 5.05% (with 5,173,003 people screened) to 4.57% (with 3,819,675 people screened), while the rate of new HBV infections was 0.28 per 100 person-years in the fixed cohorts of 2,584,322 people. The quality control team completed PPS sampling simultaneously and established the serum sample database with 2,800,000 serum samples for unified testing. Conclusions CCI-HBV project has established a large-scale field research to conduct whole-population screening and intervention. We analyzed the HBsAg prevalence and new infection rate of HBV in the fixed population for the epidemic trend and intervention effect. The purpose of CCI-HBV project is to establish and evaluate a practical model of grid management and field strategy, to realize the new goal to control hepatitis B in China. To provide policymakers with a feasible model, our results are directly applicable. Trial registration The project was funded by the Major Projects of Science Research for the 11th and 12th five-year plans of China, entitled “The prevention and control of AIDS, viral hepatitis and other major infectious diseases”, Grant Nos. 2009ZX10004901, 2011ZX10004901, 2013ZX10004904, 2014ZX10004007 and 2014ZX10004008.

Abstract Background Herpes simplex virus type-2 (HSV-2) infection is the main cause of genital ulcer disease and increases the risk of HIV acquisition. Little information is available regards the epidemiological characteristics of HSV-2 among general population in China. The aim of this study was to explore seroprevalence and associated factors of HSV-2 and provide information for design of HSV-2 control strategy in Shandong, China. Methods In this cross-sectional study, a total of 8074 persons, 18–49 years of age, were selected using multi-stage probability sampling to represent the general population of Shandong in 2016. Demographic data were collected through face-to-face interviews. Other variables were obtained by self-administered questionnaire surveys. Blood was collected for HSV-2 IgG detection with ELISA. Results A total of 7256 sexually-active participants were included in the analysis. The weighted seroprevalence of HSV-2 infection was 4.2% (95% confidence interval [CI], 3.2–5.3) in females, which was significant higher than that in males (2.7%; 95% CI, 1.1–4.2) (P = 0.04). The seroprevalence of HSV-2 was higher in individuals from eastern region (6.4%; 95% CI, 5.9–6.9) and urban areas (4.3%; 95% CI, 2.6–6.0) of Shandong than those from other regions (P

Comparison of anti-HBs persistence after hepatitis B vaccination on two-dose schedule and three-dose schedule among adults is still controversial. In this study, adults were followed up at 12 years after the primary immunization. Three hundred and forty-one and 288 adults with age 15 through 40 years old were given anti-HBV vaccination on a 0-, 1-, and 6-month schedule or on a 0- and 6-month one, respectively (in 2003). Blood samples of 202 patients on 0-, 1- and 6-month schedule and 194 patients on 0- and 6-month regimen were collected at one month and twelve years (in 2015) after the primary series and anti-HBs levels were measured. The seroprotection rate for 3-dose schedule and 2-dose one was 71.78% (95%CI = 65.04%, 77.87%) and 53.61% (95%CI = 46.07%, 60.49%). The GMC of anti-HBs was 31 mIU/mL (95%CI = 24, 41) and 12 mIU/mL (95%CI = 9, 17), respectively. Participants using three doses had higher seroprotection rate and GMC (P

Background: We assessed immunogenicity of three-dose and two-dose immunization schedules with a Sabin-strain inactivated poliovirus vaccine (sIPV) produced by one Chinese vaccine manufacturer. Methods: This was an open label, randomized, controlled trial conducted in 16 vaccination clinics in Shandong province. Infants were allocated randomly to either a 3-dose study arm (sIPV administered at 2, 3, and 4 months of age) or a 2-dose arm (sIPV administered at 4 and 8–11 months of age). Poliovirus neutralizing antibodies were measured in sera collected prior to the first sIPV dose and one month after the last dose. Findings: We enrolled 560 infants; 536 (95.7%) completed the study. Final seropositivity rates were >98% for all three serotypes in both study arms. There were no statistically significant differences in seropositivity between the 2-dose and the 3-dose schedule. Final median reciprocal titres of polio antibodies were high overall (>1:768 for all serotypes) and statistically significantly higher in 2-dose recipients compared with 3-dose recipients (p

Background There have been few studies on the relationship between long‐term changes in sodium intake and blood pressure. A method of reducing sodium intake in a population that is known for high‐sodium intake based on homemade cooking is also needed. Methods and Results Our study was based on a baseline survey of 15 350 individuals aged 18 to 69 years with multistage random sampling and a 3‐year salt‐restriction campaign across Shandong Province, China. We included 339 individuals from six districts/counties in this cohort study, and the 24‐hour urinary sodium‐potassium ratio (Na+/K+) served as an indicator of sodium intake. The average change in ratio was 2.39 (95% CI, 2.17–2.61) from 6.81 (95% CI, 6.41–7.21) at baseline to 4.41 (95% CI, 4.18–4.64) during the resurvey. Following a reduction from low to high quartiles of urinary Na+/K+ ratio, the average increases were 10.9 (95% CI, 8.9–12.9), 9.2 (95% CI, 6.9–11.5), 6.3 (95% CI, 4.0–8.6), and 5.3 (95% CI, 2.9–7.7) mm Hg for systolic blood pressure (P for trend=0.019) and 3.8 (95% CI, 2.4–5.2), 2.9 (95% CI, 1.7–4.2), 1.6 (95% CI, 0.4–2.8), and −0.3 (95% CI, −1.4–0.8) mm Hg for diastolic blood pressure (P for trend=0.002), respectively. A reduction in salt intake was evident for people using a 2‐g salt‐restriction spoon for cooking (−3.49 versus −2.22; P=0.027) after adjustment of confounding factors, compared with nonusers. Similar findings were obtained for other salt‐restriction spoon–based indicators. Conclusions Our study indicated that using a salt‐restriction spoon for cooking was associated with reduced salt intake that led to a blunting of blood pressure deterioration. This finding further supports the salt‐restriction spoon–based strategy for people whose primary salt intake is from homemade cooking.

Background: The aim of this study was to investigate the immunogenicity and safety of the enterovirus 71 vaccine (EV71 vaccine) administered alone or simultaneously. Methods: A multi-center, open-label, randomized controlled trial was performed involving 1080 healthy infants aged 6 months or 8 months from Shandong, Shanxi, Shaanxi, and Hunan provinces. These infants were divided into four simultaneous administration groups and EV71 vaccine separate administration group. Blood samples were collected from the infants before the first vaccination and after the completion of the vaccination. This trial was registered in the Clinical Trials Registry (NCT03519568). Results: A total of 895 were included in the per-protocol analysis. The seroconversion rates of antibodies against EV71 in four simultaneous administration groups (98.44% (189/192), 94.57% (122/129), 99.47% (187/188) and 98.45% (190/193)) were non-inferior to EV71 vaccine separate administration group (97.93% [189/193]) respectively. Fever was the most common adverse event, the pairwise comparison tests showed no difference in the incidence rate of solicited, systemic or local adverse events. Three serious adverse events related to the vaccination were reported. Conclusions: The evidence of immunogenicity and safety supports that the EV71 vaccine administered simultaneously with vaccines need to be administered during the same period of time recommended in China.

Abstract Background A population-based study of Chlamydia trachomatis (CT) infections is essential in designing a specific control program; however, no large investigation of CT infections among the general population in mainland China has been conducted since 2000. We aimed to determine the prevalence, risk factors, and associated medical costs of CT among residents, 18–49 years of age, in Shandong, China. Methods From May to August 2016, a multistage probability sampling survey involving 8074 individuals was distributed. Data were collected via face-to-face interviews, followed by self-administered questionnaire surveys. First-void urines were collected and tested for CT and Neisseria gonorrhoeae (NG) using nucleic acid amplification. Results The weighted prevalence of CT infection was 2.3% (95% confidence interval [CI], 1.5–3.2) in females and 2.7% (1.6–3.8) in males. Women, 30–34 years of age, had the highest prevalence of CT infections (3.5%, 2.6–4.4), while the highest prevalence of CT infections in males was in those 18–24 years of age (4.3%, 0.0–8.8). Neisseria gonorrhoeae infection had a prevalence of 0.1% (0.0–0.3) in women and 0.03% (0.0–0.1) in men. Risk factors for CT infections among females included being unmarried, divorced, or widowed (odds ratio [OR], 95% CI 3.57, 1.54–8.24) and having two or more lifetime sex partners (3.72, 1.14–12.16). Among males, first intercourse before 20 years of age (1.83, 1.10–3.02) and having two or more lifetime sex partners (1.85, 1.14–3.02) were associated with CT infections. The estimated lifetime cost of CT infections in patients 18–49 years of age in Shandong was 273 million (range, 172–374 million) China Renminbi in 2016. Conclusions This study demonstrated a high burden of CT infections among females

Immune memory after hepatitis B vaccination among adults is still under investigation. In this study, adults who had normal and high antibody response to the primary series of hepatitis B vaccination (HepB) were followed up at 5 years after the primary immunization. A booster dose was given to those who had low hepatitis B surface antibody (anti-HBs) titers, defined as anti-HBs levels < 10 mIU/mL. Blood samples were collected at two weeks after the booster and anti-HBs levels were measured. We assumed those with ant-HBs levels > = 10 mIU/mL after the booster had anamnestic response. In total, 242 persons completed the booster and the anti-HBs test. The anamnestic response rate was 99.59% (241/242) and geometric mean concentration (GMC) of anti-HBs after the booster was 2989 mIU/mL (95% CI: 255, 35085). Anti-HBs titer after the booster dose had a positive correlation with anti-HBs titers measured right after the primary immunization as well as anti-HBs titers 5 years later just before the booster. After the booster, no significant difference was found in anti-HBs titers between participants who were immunized with the 10μg HepB vaccine and those with the 20μg vaccine. Multivariable analysis showed that 1) vaccine brand used for the primary vaccination, 2) anti-HBs titers after primary vaccination and 3) anti-HBs titers before the booster dose were independently associated with the anti-HBs titers after the booster 1) β = -0.21, 95% CI: -0.33, -0.09, P = 0.001; 2) β = 0.07, 95% CI: 0.05, 0.09, P < 0.001; 3) β = 0.04, 95% CI: 0.02, 0.07, P < 0.001). In summary, anamnestic response exists among almost all adults at five years after HepB primary immunization. Vaccine brand used for primary vaccination, initial anti-HBs titers after primary immunization and anti-HBs titers before the booster were the independent predictive factors of HepB anamnestic response titers.

Abstract Background Kadipiro virus (KDV) belongs to the Reoviridae family, which consists of segmented, non-enveloped, double-stranded RNA viruses. It has previously been isolated from Culex, Anopheles, Armigeres and Aedes mosquitoes in Indonesia and China. Here, we describe the isolation and characterization of SDKL1625 from Anopheles sinensis mosquitoes in Shandong province, China. Methods In this study, we isolated Kadipiro virus in Aedes albopictus C6/36 cell culture and the complete genome sequencing was made by next generation sequencing. Results We isolated and characterized a Kadipiro virus from Anopheles sinensis mosquitoes in 2016 in Shandong province, China. Nucleotide and amino acid homology analysis of SDKL1625 showed higher levels of sequence identity with QTM27331 (Odonata, China, 2016) than with JKT-7075 (Culex fuscocephalus, Indonesia, 1981). The SDKL1625 has 86–97% amino acid identity with the JKT-7075, 88–99% amino acid identity with the QTM27331. Among the 12 fragments, VP1, VP2, VP4, VP6, VP7, VP9 and VP12 showed high amino acid identity (> 90%) and VP5 showed the lowest identity (86% and 88%). Conclusions This is the first identification of KDV from mosquito in China. Virus morphology and genome organization were also determined, which will further enrich our understanding of the molecular biological characteristics of KDV and seadornaviruses.

Abstract Stomach cancer is common in the Chinese population. The present study aimed to analyze the incidence and mortality as a result of stomach cancer in Shandong Province, in order to provide a reference for cancer prevention and control. We analyzed the incidence and mortality data of stomach cancer collected from 15 cancer registries in 2012. We calculated the crude, age‐standardized, and truncated incidence and mortality rates for the registered population, and estimated the numbers of new cases and deaths that might have occurred in the total provincial population by applying the age‐specific rates to the corresponding populations. The estimated numbers of new cases and deaths of stomach cancer were 36 796 and 25 343, respectively, among the total Shandong population in 2012. Both the incidence and mortality rates were higher in men than in women. The incidence in rural areas was similar with that in urban areas, whereas mortality was markedly higher in rural than in urban areas. Age‐specific incidence and mortality of stomach cancer increased with age, particularly after 40 years‐of‐age and peaked at 80–84 or ≥85 years‐of‐age. Stomach cancer is common in Shandong province, particularly among men and residents in rural areas. Targeted prevention, early detection, and treatment programs should be carried out.

Abstract Background Persons with chronic hepatitis B (CHB) infection were reported to suffer severe disease after hepatitis E virus (HEV) superinfection, but the studies regarding HEV seroprevalence in this population were limited. A recent study in Vietnam found higher HEV seroprevalence among CHB patients compared with healthy controls. Methods A community-based case-control study was conducted in two counties of Shandong province, China, where hepatitis E incidence was at the highest (Rushan) and lowest (Zhangqiu) in the province based on data from routine public health surveillance. Four townships were selected randomly from each county and all residents in these townships were tested for hepatitis B surface antigen (HBsAg). Those tested positive for HBsAg (CHB group) and the 1:1 age and sex-matched HBsAg-negative residents (control group) were included. Anti-HEV IgM and IgG were tested and positive rates of IgG and IgM were compared between the CHB group and the control group. Results In total, 2048 CHB participants and 2054 controls were included in the study. In the CHB group, HEV IgG seroprevalence was 9.16% (95% CI: 7.47–11.09) in Zhangqiue and 38.06% (95% CI: 35.07–41.19) in Rushan (P

Background: Tremendous progress has been made in hepatitis B virus (HBV) prevention and control in the last 30 years in China, but it continues to be a major public health problem. The most recently reported population-based seroepidemiological survey on HBV in Shandong Province in China was published in 2006, and an updated baseline for HBV prevalence was badly needed in the province to identify the change in HBV epidemiology in the last decade. Methods: Two population-based cross-sectional serosurveys were performed among the population aged 1–59 years in the same sample areas in Shandong Province, China in 2006 and 2014, respectively. Data on demographic characteristics were collected. A blood sample was obtained from each person and was tested for hepatitis B surface antigen (HBsAg), antibody against HBsAg (anti-HBs), and antibody against hepatitis B core antigen (anti-HBc). Results: Overall, the prevalence rates of HBsAg, anti-HBs, and anti-HBc were 3.39% (95% confidence interval (CI) 2.51–4.26), 44.96% (95% CI 41.34–48.57), and 24.45% (95% CI 22.19–26.71), respectively, among the population aged 1–59 years in the 2006 serovsurvey; the corresponding prevalence rates were 2.49% (95% CI 1.81–3.17), 48.27% (95% CI 45.63–50.92), and 22.56% (95% CI 20.14–24.97), respectively, in 2014. The prevalence rates of HBsAg and anti-HBc were lower in 2014 than in 2006. Conversely, the prevalence of anti-HBs showed an increase. However, none of these differences were statistically significant (all p > 0.05). The prevalence of HBsAg showed an increase among persons aged 20–24 years in 2014 (3.83%) compared with 2006 (2.98%) (t = 0.45, p = 0.67). Among all occupation groups, the prevalence of HBsAg was lower in 2014 than in 2006, while the prevalence of anti-HBc showed moderate increases in students and farmers (all p > 0.05). The prevalence of HBsAg decreased more obviously in urban areas (65.49%) than rural areas (7.07%) from 2006 to 2014. Conclusions: The epidemiology of HBV infection has changed in Shandong Province, China over the last decade. More attention should be paid to HBV infection among students and farmers.

Abstract Limited information is available about the temporal trend in the prevalence and evolution of hepatitis B virus (HBV) S-gene mutations in the post-immunization era in China. From 2005 to 2013, 1077 hepatitis B cases under 15 years of age reported through Chinese National Notifiable Disease Reporting System (NNDRS) were successfully sequenced of S-gene in Shandong province, China. A total of 97 (9.01%) cases had amino acid (aa) substitution in the “α” determinant of HBsAg. The yearly prevalence from 2005 to 2013 maintained at a relatively stable level, and showed no significant change (P > 0.05). Multivariate logistic regression analysis demonstrated that the prevalence of “α” mutations was independently associated with the maternal HBsAg status (P 0.05). The hottest mutation position was aa126 (I126S/N and T126A, 29.63%), and aa 145 (G145R/A, 25.93%). Mutated residue 126 tended to occur less frequent, while that of residue 145 was more frequent with increasing year. Our data showed that there was no increase in the frequency of HBV “α” mutations over time during the post-immunization period. However, long-term vaccination might enhance the change of HBV mutational pattern, and G145 mutation was becoming dominant.

Abstract This study aimed to detect the spatial distribution and high-risk clusters of female breast cancer mortality for the years 2011 to 2013 in Shandong Province, China. The urban-rural difference in the spatial distribution and clusters of disease mortality were also examined. Breast cancer mortality data were obtained from the Shandong Death Registration System (SDRS) during 2011 to 2013 and were adjusted for the underreporting rate. The purely spatial scan Statistics method was performed using Discrete Poisson model. Seven significant spatial clusters for high mortality of female breast cancer were detected in Shandong Province at the county level; these clusters were mainly located in the eastern, southern, southwestern, central and northern regions. The spatial distributions differed significantly between urban and rural populations. Population ageing influenced the distribution of breast cancer clusters for the urban eastern residents. This study provided evidence for the presence of clusters of breast cancer mortality in Shandong, China and found urban-rural difference in the clusters, which is helpful for developing effective strategies to control breast cancer in different areas.

Abstract Background Hand hygiene is an important element of the WHO multimodal strategy for healthcare-associated infection control, whereas compliance of hand hygiene among healthcare workers (HCWs) remains a challenge to sustain. In order to increase the hand hygiene compliance of HCWs, a quality control circle (QCC) program was carried out in our hospital, and the plan-do-check-act (PDCA) method was applied for 12 months. Findings Hand hygiene compliance rates improved over time, with significant improvement between preintervention (60.1%) and postintervention (97.2%) periods (P

Objective: This study aimed to assess the seroprevalence of hepatitis E virus (HEV) infection and the potential risk factors for acquiring HEV infection in the seafood processing factories in Yantai City of Shandong Province, China. Methods: A cross-sectional study was conducted in five randomly selected seafood processing factories in Yantai City. Subjects were 15–66 years of age and were raw seafood processing workers, semi-finished products processing workers, and administrative staff, etc. Each participant completed a structured questionnaire and agreed to blood drawing. Anti-HEV IgG antibody was detected in the blood samples by ELISA method. Results: A total of 1028 of 1044 eligible workers were tested for HEV IgG antibody (response rate 98.5%). The prevalence of HEV IgG seropositivity was found to be 22.20%. Occupation was significantly associated with anti-HEV IgG antibody seropositivity (p

Background High sodium intake elevates blood pressure and thereby raises cardiovascular diseases (CVDs). Sodium intake is high in northern China, including Shandong province where the SMASH (Shandong‐Ministry of Health Action on Sodium and Hypertension) is currently underway. Methods and Results Blood pressure values and sodium intake measurements using 24‐hour urinary excretion were collected from the 2011 SMASH baseline survey, which was conducted in 20 counties/districts using a multistage stratified cluster random sampling method. We derived cause‐specific mortality from the Shandong Death Registration System (SDRS) during the same year and used population‐attributable fraction to estimate annual CVDs deaths attributable to high sodium intake (mediated through elevated systolic blood pressure) and CVD deaths averted by achieving different sodium‐reduction targets. Overall, 16 100 (95% uncertainty intervals, 11 000–22 600) CVD deaths among adults aged 25 to 69 years, including 5600 (4000–6500) for ischemic heart disease and 9000 (6700–11 600) for stroke, were attributable to higher sodium intake (2000 mg/day or 5.0 g/day of salt as a reference) in Shandong in 2011, accounting for 19.9% (13.7–25.0%) of total CVD deaths. The benefit of CVD deaths from sodium reduction is considerable with 8800 (6400–13 600), 6700 (4900–11 600), and 8500 (6000–10 800) averted, respectively, if sodium intake was reduced from the 2011 baseline to 3500 mg/day, 4000 mg/day, or reduced by 30%. Conclusions Nearly 20% of CVD deaths among adults aged 25 to 69 years could be attributable to the systolic blood pressure–raising effect of high sodium intake in Shandong in 2011. Potential benefits from population reduction of sodium intake are considerable.

Underreporting is a quality concern in mortality statistics. The purpose of this study was to assess and adjust underreporting in the population-based cause-of-death statistics. The total population (96 million) in Shandong, China was divided into 262 subcounty level populations geographically and by residence type (urban/rural). For each subpopulation, the total number of deaths during the years 2011-2013 was determined using data from the Household Registration System (HRS), and was used as a reference to assess the underreporting rate (UR) in the cause-of-death data from the Shandong Death Registration System (SDRS). It was estimated that 454,615 deaths, or 21.5% (95% CI: 21.4-21.5%) were unreported. Underreporting was more pronounced in rural (22.1%) versus urban communities (20.0%), in economically underdeveloped regions (32% versus 16% in least disadvantaged areas), and in newly included sites with no prior experience in cause-of-death reporting (24% versus 17%). Geographic variation was large with a UR at the prefectural level ranging from 11.2% to 43.7%. A stratified analysis showed that UR was higher in rural populations in high-income regions, but in middle- and low-income regions, was higher in urban communities. An adjustment factor (AF) was calculated for each of the 262 subpopulations (ranging from 0.9 to 2.5 with an average of 1.27). The total morality rate was adjusted from 6.03 to 7.67 deaths per 1000 persons. Underreporting in the SDRS varies greatly between areas and populations and is related to residence type, prior experience and local economy. Correcting underreporting at a local level is needed especially for comparative analyses across geographical areas or populations.

BACKGROUND:Industrialization and demographic transition generate nonstationary dynamics in human populations that can affect the transmission and persistence of infectious diseases. Decades of increasing vaccination and development have led to dramatic declines in the global burden of measles, but the virus remains persistent in much of the world. Here we show that a combination of demographic transition, as a result of declining birth rates, and reduced measles prevalence, due to improved vaccination, has shifted the age distribution of susceptibility to measles throughout China. METHODS AND FINDINGS:We fit a novel time-varying catalytic model to three decades of age-specific measles case reporting in six provinces in China to quantify the change in the age-specific force of infection for measles virus over time. We further quantified the impact of supplemental vaccination campaigns on the reduction of susceptible individuals. The force of infection of measles has declined dramatically (90%-97% reduction in transmission rate) in three industrialized eastern provinces during the last decade, driving a concomitant increase in both the relative proportion and absolute number of adult cases, while three central and western provinces exhibited dynamics consistent with endemic persistence (24%-73% reduction in transmission rate). The reduction in susceptible individuals due to supplemental vaccination campaigns is frequently below the nominal campaign coverage, likely because campaigns necessarily vaccinate those who may already be immune. The impact of these campaigns has significantly improved over time: campaigns prior to 2005 were estimated to have achieved less than 50% reductions in the proportion susceptible in the target age classes, but campaigns from 2005 onwards reduced the susceptible proportion by 32%-87%. A limitation of this study is that it relies on case surveillance, and thus inference may be biased by age-specific variation in measles reporting. CONCLUSIONS:The age distribution of measles cases changes in response to both demographic and vaccination processes. Combining both processes in a novel catalytic model, we illustrate that age-specific incidence patterns reveal regional differences in the progress to measles elimination and the impact of vaccination controls in China. The shift in the age distribution of measles susceptibility in response to demographic and vaccination processes emphasizes the importance of progressive control strategies and measures to evaluate program success that anticipate and react to this transition in observed incidence.

Acute hepatitis E infection could induce severe outcomes among chronic hepatitis B (CHB) patients. Between 2016 and 2017, an open-label study was conducted to evaluate the immunogenicity and safety of hepatitis E vaccine (HepE) in CHB patients, using healthy adults as parallel controls in China. Eligible participants who were aged ≥30 y were enrolled in the study. The CHB group included participants who had ever developed symptoms of hepatitis because of CHB but was currently at a clinically stable stage, which was defined as ALT ≤ 1.5 times of upper limit of the normal range (ULN) in this study. The control group included healthy adults who had hepatitis B surface antigen (HBsAg) negative. HepE was administered for 0, 1, 6 months for all participants. At 1 month after the third-dose vaccination (month 7), the seroconversion rates of anti-HEV IgG were >97% in both groups. The geometric mean concentration (GMC) of anti-HEV IgG in the CHB group was non-inferior to the healthy adult group (0.69 WU/mL, 95% CI 0.55–0.85). The proportion of the participants with adverse events ≥ grade 3 was similar in both groups (p = .99), and no vaccine-associated severe adverse events were identified. Changes in the liver function indicators were not of clinical significance. The HepE was highly immunogenic and well tolerated among clinically stable CHB patients and healthy adults.

In preparation for the introduction of human papillomavirus (HPV) vaccine, we investigated awareness and knowledge of HPV/HPV vaccine and potential acceptability to HPV vaccine among mothers with a teenage daughter in Weihai, Shandong, China. A cross-sectional survey was conducted in 2013 with a sample of 1850 mothers who had a daughter (aged 9-17 years) attending primary, junior and senior high schools. In the final sample (N = 1578, response rate 85.30%), awareness of HPV was reported by 305 (19.32%) mothers. Awareness varied significantly by daughter's age (P

To determine the cause of a 2008 outbreak of aseptic meningitis in Shandong Province, China, we analyzed samples from outbreak patients and coxsackievirus B3 samples collected during 1990–2010 surveillance. The cause of the outbreak was coxsackievirus B3, genogroup D. Frequent travel might increase importation of other coxsackievirus B3 genogroups.

Objectives To estimate the incidence of serious suicide attempts (SSAs, defined as suicide attempts resulting in either death or hospitalisation) and to examine factors associated with fatality among these attempters.Design A surveillance study of incidence and mortality. Linked data from two public health surveillance systems were analysed.Setting Three selected counties in Shandong, China.Participants All residents in the three selected counties.Outcome measures Incidence rate (per 100 000 person-years) and case fatality rate (%).Methods Records of suicide deaths and hospitalisations that occurred among residents in selected counties during 2009–2011 (5 623 323 person-years) were extracted from electronic databases of the Disease Surveillance Points (DSP) system and the Injury Surveillance System (ISS) and were linked by name, sex, residence and time of suicide attempt. A multiple logistic regression model was developed to examine the factors associated with a higher or lower fatality rate.Results The incidence of SSAs was estimated to be 46 (95% CI 44 to 48) per 100 000 person-years, which was 1.5 times higher in rural versus urban areas, slightly higher among females, and increased with age. Among all SSAs, 51% were hospitalised and survived, 9% were hospitalised but later died and 40% died with no hospitalisation. Most suicide deaths (81%) were not hospitalised and most hospitalised SSAs (85%) survived. The fatality rate was 49% overall, but was significantly higher among attempters living in rural areas, who were male, older, with lower education or with a farming occupation. With regard to the method of suicide, fatality was lowest for non-pesticide poisons (7%) and highest for hanging (97%).Conclusions The incidence of serious suicide attempts is substantially higher in rural areas than in urban areas of China. The risk of death is influenced by the attempter's sex, age, education level, occupation, method used and season of year.

The association of microalbuminuria and elevated 24 h urinary microalbumin excretion (UAE) with metabolic syndrome (MetS) has not been well examined in Chinese Adults. In the present study, a population-based cross-sectional study was conducted among Chinese adults aged 18-69 years in Shandong province in 2011 to determine the relationship between them. Data on 24 h UAE and other variables were obtained and components of MetS were examined. The prevalence of MetS and mean 24 h UAE was 24.7% and 6.7 mg, respectively. Compared with participants with normoalbuminuria, the odds of MetS and its components including central obesity, elevated blood pressure and elevated fasting glucose, but not the odds of low HDL cholesterol and elevated triglycerides, significantly increased in those with microalbuminuria. Additionally, the odds of MetS and its three components significantly increased across increasing quartiles of 24 h UAE within normal range (1.00, 1.11, 1.02 and 1.58, respectively, for MetS; 1.00, 1.14, 1.21, and 1.68, respectively, for central obesity; 1.00, 1.35, 1.26 and 1.68, respectively, for elevated blood pressure; and 1.00, 1.32, 1.06 and 1.47, respectively, for elevated triglycerides; p for linear trend ≤0.05 for all). Furthermore, for each increment of 10 mg 24 h UAE within normal range, the odds of MetS and its components including central obesity, elevated blood pressure, and elevated triglycerides significantly increased by 53%, 65%, 55%, and 41%, respectively. These findings suggest that both microalbuminuria and elevated 24 h UAE within normal range might be important risk factors for MetS in Chinese adults.

BackgroundHuman enteroviruses (HEVs) are common causes of acute meningitis. However, there is limited information about HEV associated with aseptic meningitis in mainland China because it has not been classified as a notifiable disease.ObjectivesTo characterize the HEVs associated with sporadic aseptic meningitis in China and to analyze their genetic features.Study designCerebrospinal fluid, throat swab and feces specimens were collected from patients with aseptic meningitis in 5 sentinel hospitals in Shandong Province, China between 2006 and 2012. Virological investigation (viral isolation and molecular identification) and phylogenetic analysis were performed.ResultsA total of 437 hospitalized patients were reported, and enteroviruses were detected in the specimens from 84 patients (19.2%) and were identified into 17 serotypes. The nine main serotypes were echovirus (E) 30 (27.4%), EV71 (13.1%), coxsackievirus (CV) B1 (9.5%), CVB3 (7.1%), CVB5 (7.1%), E6 (7.1%), E9 (7.1%), CVA9 (6.0%), and CVA10 (3.6%). Monthly distribution of isolated enteroviruses revealed a major peak in summer-fall season and a small second peak in winter constituted totally by EV71. Sequence analysis on VP1 coding region suggested Shandong strains had great genetic divergence with isolates from other countries.ConclusionsMultiple serotypes were responsible for enterovirus meningitis in mainland China. Aseptic meningitis caused by EV71 and coxsackie A viruses-the predominant pathogens for the hand, foot, and mouth disease-is currently an important concern in mainland China.

Environmental surveillance of poliovirus on sewage has been conducted in Shandong Province, China since 2008. A type 2 vaccine-derived poliovirus (VDPV) with 7 mutations in VP1 coding region was isolated from the sewage collected in the city of Jinan in December 2012. The complete genome sequencing analysis of this isolate revealed 25 nucleotide substitutions, 7 of which resulted in amino acid alteration. No evidence of recombination with other poliovirus serotypes was observed. The virus did not lose temperature sensitive phenotype at 40°C. An estimation based on the evolution rate of the P1 coding region suggested that evolution time of this strain might be 160-176 days. VP1 sequence analysis revealed that this VDPV strain is of no close relationship with other local type 2 polioviruses (n=66) from sewage collected between May 2012 and June 2013, suggesting the lack of its circulation in the local population. The person who excreted the virus was not known and no closely related virus was isolated in local population via acute flaccid paralysis surveillance. By far this is the first report of VDPV isolated from sewage in China, and these results underscore the value of environmental surveillance in the polio surveillance system even in countries with high rates of OPV coverage.

BACKGROUND: Reduction of measles incidence and mortality has been encouraging in China. However, it remains an important public health concern among infants. This study aimed to examine the space-time distribution pattern of infant measles occurrence for the period of 1999-2008 in Shandong, China. METHODS AND FINDINGS: Measles cases among infants aged younger than 1 year were obtained from the national infectious diseases reporting information system. A spatiotemporal analysis using population attributable risk percent (PAR%) was used to distinguish between multiple geographic clusters of potential interest. The analysis detected 29 statistically significant space-time clusters with the most likely cluster in Zaozhuang City from 2006 to 2008. Of the 28 secondary clusters, 22 were found in 2008. The map of PAR%, relative risk (RR) and space-time cluster analysis indicated that the clusters were generally unchanged, and were found south-west and north-west of Shandong. The Lanshan District in Linyi had the highest PAR%, while highest RR was in the Yicheng District in Zaozhuang. CONCLUSION: There were significant space-time clusters of infant measles in Shandong over the study period. PAR% is an effective way to analyze multiple clusters from their application like RR. Interrupting measles circulation and maintaining routine coverage over 95% may be the only effective strategy to achieve measles elimination.

BACKGROUND: The rubella vaccine was introduced into the immunization program in 1995 in the Shandong province, China. A series of different rubella vaccination strategies were implemented at different stages of measles control in Shandong province. METHODOLOGY/PRINCIPAL FINDINGS: The average reported incidence rate of rubella cases remained at a low level in Shandong province after 1999. However, rubella epidemics occurred repeatedly in 2001/2002, 2006, and 2008/2009. The age of the onset of rubella cases gradually increased during 1999-2010, which showed that most cases were found among the 10 years old in 1999 and among the 17 years old in 2010. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All rubella viruses isolated in Shandong province were divided into 4 genotypes: 1E, 1F, 2A, and 2B. Genotype 1E viruses accounted for the majority (79%) of all these viruses. The similarity of nucleotide and amino acid sequences among genotype 1E viruses was 98.2-100% and 99.1-100%, respectively. All Shandong genotype 1E strains, differed from international genotype 1E strains, belonged to cluster 1 and interdigitated with the viruses from other provinces in mainland China. The effective number of infections indicated by a bayesian skyline plot remained constant from 2001 to 2009. CONCLUSIONS/SIGNIFICANCE: The gradual shift of disease burden to an older age group occurred after a rubella-containing vaccine was introduced into the childhood immunization schedule in 1995 in Shandong province. Four genotypes, including 1E, 1F, 2A, and 2B, were found in Shandong province during 2000-2009. Genotype 1E, rather than genotype 1F, became the predominant genotype circulating in Shandong province from 2001. All Shandong genotype 1E viruses belong to the genotype 1E/cluster 1; they have constantly circulated, and co-evolved and co-circulated, with those from other provinces.

BACKGROUND: Large-scale outbreaks of hand, foot, and mouth disease (HFMD) occurred repeatedly in the Central Plain of China (Shandong, Anhui, and Henan provinces) from 2007 until now. These epidemics have increased in size and severity each year and are a major public health concern in mainland China. PRINCIPAL FINDINGS: Phylogenetic analysis was performed and a Bayesian Markov chain Monte Carlo tree was constructed based on the complete VP1 sequences of HEV71 isolates. These analyses showed that the HFMD epidemic in the Central Plain of China was caused by at least 5 chains of HEV71 transmission and that the virus continued to circulate and evolve over the winter seasons between outbreaks. Between 1998 and 2010, there were 2 stages of HEV71 circulation in mainland China, with a shift from evolutionary branch C4b to C4a in 2003-2004. The evolution rate of C4a HEV71 was 4.99×10(-3) substitutions per site per year, faster than the mean of all HEV71 genotypes. The most recent common ancestor estimates for the Chinese clusters dated to October 1994 and November 1993 for the C4a and C4b evolutionary branches, respectively. Compared with all C4a HEV71 strains, a nucleotide substitution in all C4b HEV71 genome (A to C reversion at nt2503 in the VP1 coding region, which caused amino acid substitution of VP1-10: Gln to His) had reverted. CONCLUSIONS: The data suggest that C4a HEV71 strains introduced into the Central Plain of China are responsible for the recent outbreaks. The relationships among HEV71 isolates determined from the combined sequence and epidemiological data reveal the underlying seasonal dynamics of HEV71 circulation. At least 5 HEV71 lineages circulated in the Central Plain of China from 2007 to 2009, and the Shandong and Anhui lineages were found to have passed through a genetic bottleneck during the low-transmission winter season.

Abstract Background Culexflavivirus (CxFV) is an insect specific virus that has been isolated from Culexpipiens, Culexquinquefasciatus, Culextritaeniorhynchus and other Culex mosquitoes. It is a novel flavivirus isolated in Asia, North America, Central America and Africa. Phylogenetic analysis indicates that, based on the envelope gene (E gene) sequence, the worldwide CxFV strains can be divided into two genotypes. Result A virus (SDDM06-11) was isolated from Culexpipiens collected in Shandong Province, China in 2006. The strain caused cytopathic effect (CPE) in Aedesalbopictus (C6/36) cells by 3 days post-infection and immunofluorescence assay (IFA) showed a reaction with Japanese encephalitis virus (JEV) polyclonal antibodies. Phylogenetic analysis of the E gene sequence showed CxFV formed two genotypes with the SDDM06-11 strain assigned to genotype 1. Analysis of the E gene nucleotide homology showed the virus possessed characteristic amino acids at specific sites. The nucleotide homology of the open reading frame (ORF) was 94.8%-95.1% between SDDM06-11 and isolates from Japan, Iowa and Texas, and 90.2%-90.5% between SDDM06-11 and isolates from Uganda and Mexico. Conclusion In this paper we report the first isolation and identification of an isolate of CxFV in mainland China. Phylogenetic analysis indicates the isolate belongs to genotype 1. Our findings provide insight into the occurrence of CxFV in Culex mosquito populations and its distribution on a global scale.