Epidemiological clustered characteristics of coronavirus disease 2019 (COVID-19) in three phases of transmission in Jilin Province, China.

The current epidemiological status of the new coronary pneumonia epidemic in China is being explored to prevent and control the localized dissemination of aggregated outbreaks. This study analyzed the characteristics of new outbreaks of coronavirus disease 2019 (COVID-19) at three stages of aggregated outbreaks in Jilin Province, China, to provide a reference for the prevention and control of aggregated outbreaks. Case information were collected from all patients in Jilin Province from January 12, 2020 to the present. The epidemic was divided into three stages according to the time of onset. The first stage comprised 97 cases reported from January 12, 2020 to February 19, 2020, during which 17 aggregated outbreaks occurred. The second comprised 43 cases reported from April 25, 2020 and May 23, 2020, involving one aggregated outbreak. The third comprised 435 cases reported on January 10, 2021 and February 9, 2021, involving one aggregated outbreak. The relationship between aggregated and non-aggregated cases in the first phase of the outbreak and the difference between imported and local cases during the aggregated outbreak were assess using statistical analysis, and the differences in the baseline information between the three phases were analyzed. The incubation periods of the three phases were 10 days, 8 days, and 5 days. The number of aggregated epidemic events in Jilin Province tended to increase and then decrease over time. The clustered events in Jilin Province were divided into four categories: household contact (14 times, 51 cases); household contact and public places (one time, three cases); household contact, public places, and gatherings (one time, six cases); and household contact, public places, gatherings, and work (three times, 495 cases). Clustered events occurred mainly between January 22, 2020, and February 4, 2020. Among all cases in the first phase of the outbreak, the method of detection and the time from diagnosis to discharge were longer in aggregated cases than in non-aggregated cases, and that the source of infection and renewal cases were more frequent and more likely to be detected in the outpatient clinics during aggregated outbreaks than the imported cases. The second phase of the epidemic showed significant spatial variability (Moran's I<0, P<0.05). The third stage of the epidemic occurred in a higher proportion of individuals aged 50-90 years and within a shorter incubation period compared with the first two stages. The current focus of prevention and control of the COVID-19 epidemic in Jilin Province is to strictly implement the restrictions on gatherings and to perform timely screening and isolation of close contacts of infectious sources while strengthening the supervision of the inflow of people from outside the region. Simultaneously, more targeted prevention and control measures can be implemented for different age groups and occupations.

Application of logistic differential equation models for early warning of infectious diseases in Jilin Province.

BACKGROUND: There is still a relatively serious disease burden of infectious diseases and the warning time for different infectious diseases before implementation of interventions is important. The logistic differential equation models can be used for predicting early warning of infectious diseases. The aim of this study is to compare the disease fitting effects of the logistic differential equation (LDE) model and the generalized logistic differential equation (GLDE) model for the first time using data on multiple infectious diseases in Jilin Province and to calculate the early warning signals for different types of infectious diseases using these two models in Jilin Province to solve the disease early warning schedule for Jilin Province throughout the year. METHODS: Collecting the incidence of 22 infectious diseases in Jilin Province, China. The LDE and GLDE models were used to calculate the recommended warning week (RWW), the epidemic acceleration week (EAW) and warning removed week (WRW) for acute infectious diseases with seasonality, respectively. RESULTS: Five diseases were selected for analysis based on screening principles: hemorrhagic fever with renal syndrome (HFRS), shigellosis, mumps, Hand, foot and mouth disease (HFMD), and scarlet fever. The GLDE model fitted the above diseases better (0.80 ≤ R2 ≤ 0.94, P <  0. 005) than the LDE model. The estimated warning durations (per year) of the LDE model for the above diseases were: weeks 12-23 and 40-50; weeks 20-36; weeks 15-24 and 43-52; weeks 26-34; and weeks 16-25 and 41-50. While the durations of early warning (per year) estimated by the GLDE model were: weeks 7-24 and 36-51; weeks 13-37; weeks 11-26 and 39-54; weeks 23-35; and weeks 12-26 and 40-50. CONCLUSIONS: Compared to the LDE model, the GLDE model provides a better fit to the actual disease incidence data. The RWW appeared to be earlier when estimated with the GLDE model than the LDE model. In addition, the WRW estimated with the GLDE model were more lagged and had a longer warning time.

COVID-19 Super Spreading Event Amongst Elderly Individuals - Jilin Province, China, January 2021.

SUMMARY: What is already known on this topic? Clusters of COVID-19 cases often happened in small settings (e.g., families, offices, school, or workplaces) that facilitate person-to-person virus transmission, especially from a common exposure. What is added by this report? On January 10 and 11, 2021, an individual gave three product promotional lectures in Tonghua City, Jilin Province, that ultimately led to a 74-case cluster of COVID-19. Our investigation determined the outbreak to be an import-related COVID-19 superspreading cluster event in which elderly, retired people were exposed to the infected individual during his promotional lectures, which were delivered in a confined space and lasted several hours. What are the implications for public health practice? Routine activities, such as attending a lecture in a classroom, can provide an environment conducive to COVID-19 superspreading events because respiratory viruses can spread easily and widely. We suggest local government to strengthen infection control management, reduce unnecessary indoor large gathering activities, and promote wearing of masks, especially during wintertime in the north of China. Health education for elderly people should promote use of effective personal protection and emphasize the importance of wearing masks.

Index and First-Generation Cases in a COVID-19 Outbreak - Jilin Province, China, 2021.

What is already known on this topic? Contact tracing and testing with isolated medical care of identified cases is a key strategy for interrupting chains of transmission of COVID-19 and reducing mortality associated with COVID-19. At the early phases of the COVID-19 pandemic, due to test capacity limitations, case finding often started from suspected cases. What is added by this report? The index patient infected 74 individuals who were close contacts that were identified through contact tracing, and exposed individuals were monitored in quarantine with daily polymerase chain reaction (PCR) testing. All individuals were asymptomatic initially, but all PCR-positive individuals eventually developed symptoms. Infectivity was documented up to 8 days before being confirmed as a symptomatic case, approximately 4 days before turning PCR positive. What are the implications for public health practice? During an outbreak, we suggest tracing close contacts from both PCR-positive individuals and suspected cases, rather than from suspected cases alone. Due to the long period of infectivity before turning PCR positive or developing symptoms, close contacts that had contact with a newly PCR positive case within 4 days should be judged as at risk of being infected; close contacts that had contact within 8 days of a newly symptomatic case should be judged as at risk being infected.

Effect of temperature and its interaction with other meteorological factors on bacillary dysentery in Jilin Province, China.

Bacterial dysentery (BD) brings a major disease burden to developing countries. Exploring the influence of temperature and its interaction with other meteorological factors on BD is significant for the prevention and early warning of BD in the context of climate change. Daily BD cases and meteorological data from 2008 to 2018 were collected in all nine prefecture-level cities in Jilin Province. A one-stage province-level model and a two-stage city-specific multivariate meta-pooled level distributed lag non-linear model were established to explore the correlation between temperature and BD, then the weather-stratified generalised additive model was used to test the interaction. During the study period, a total of 26 971 cases of BD were developed. The one-stage and two-stage cumulative dose-response 'J' curves overlapped, and results showed a positive correlation between temperature and BD with a 1-6 days lag effect. Age group ⩾5 years was found to be more sensitive to the effects. Moreover, there was a significant interaction between temperature, humidity and precipitation (P = 0.004, 0.002, respectively) on BD under high temperature (>0 °C), reminding residents and policymakers to pay attention to the prevention of BD in situations with both high temperature and humidity, high temperature and precipitation during the temperate monsoon climate.

Evaluating the effectiveness of measures to control the novel coronavirus disease 2019 in Jilin Province, China.

BACKGROUND: Based on differences in populations and prevention and control measures, the spread of new coronary pneumonia in different countries and regions also differs. This study aimed to calculate the transmissibility of coronavirus disease 2019 (COVID-19), and to evaluate the effectiveness of measures to control the disease in Jilin Province, China. METHODS: The data of reported COVID-19 cases were collected, including imported and local cases from Jilin Province as of March 14, 2019. A Susceptible-Exposed-Infectious-Asymptomatic-Recovered/Removed (SEIAR) model was developed to fit the data, and the effective reproduction number (Reff) was calculated at different stages in the province. Finally, the effectiveness of the measures was assessed. RESULTS: A total of 97 COVID-19 infections were reported in Jilin Province, among which 45 were imported infections (including one asymptomatic infection) and 52 were local infections (including three asymptomatic infections). The model fit the reported data well (R2 = 0.593, P < 0.001). The Reff of COVID-19 before and after February 1, 2020 was 1.64 and 0.05, respectively. Without the intervention taken on February 1, 2020, the predicted cases would have reached a peak of 177,011 on October 22, 2020 (284 days from the first case). The projected number of cases until the end of the outbreak (on October 9, 2021) would have been 17,129,367, with a total attack rate of 63.66%. Based on the comparison between the predicted incidence of the model and the actual incidence, the comprehensive intervention measures implemented in Jilin Province on February 1 reduced the incidence of cases by 99.99%. Therefore, according to the current measures and implementation efforts, Jilin Province can achieve good control of the virus's spread. CONCLUSIONS: COVID-19 has a moderate transmissibility in Jilin Province, China. The interventions implemented in the province had proven effective; increasing social distancing and a rapid response by the prevention and control system will help control the spread of the disease.

Incidence trend and age-period-cohort analysis of reported hepatitis C among residents aged 30 to 79 in northeastern China, 2008 to 2017.

The purpose of this study was to acquire the epidemic trend of age-standardized reported incidence and to analyze the age effect, period effect, and cohort effect on the reported incidence of hepatitis C in Jilin Province, China.We collected the annual reported incidence data of hepatitis C by gender (2008-2017). Annual percentage change and annual average percentage change were calculated by joinpoint Poisson regression analysis. The age effect, period effect, and cohort effect on the incidence of hepatitis C were estimated by an age-period-cohort model, and the relative risk was determined.Joinpoint regression analysis showed that the age-standardized reported incidence of hepatitis C indicated a declining trend integrally. Among people aged 30 to 44 (youth), the incidence trend declined the fastest, while trends declined the slowest among women and the overall population aged over 66 (elderly people) and men aged 45 to 65 (middle-aged group). The results of the age-period-cohort model showed that the reported incidence increased first and then decreased with age. Throughout the period, the risk of hepatitis C also increased first and then decreased. Compared with the median birth cohort of the same age group, the birth cohort of the patients with the highest incidence of hepatitis C was in the 1930s, followed by the 1940s and 1950s. The birth cohort of the patients with the lowest incidence was in the 1980s, followed by the 1970s and 1960s.Although the overall reported incidence trend of hepatitis C is declining and the risk of the young birth cohort is low, many factors affecting infection and testing with hepatitis C still exist in China. We should focus on high-risk population management and formulate corresponding public health strategies to accelerate the implementation of the global health strategy to eliminate hepatitis C published by the World Health Organization.

Effectiveness of Interventions to Control Transmission of Reemergent Cases of COVID-19 - Jilin Province, China, 2020.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: COVID-19 has a high transmissibility calculated by mathematical model. The dynamics of the disease and the effectiveness of intervention to control the transmission remain unclear in Jilin Province, China. WHAT IS ADDED BY THIS REPORT?: This is the first study to report the dynamic characteristics and to quantify the effectiveness of interventions implemented in the second outbreak of COVID-19 in Jilin Province, China. The effective reproduction number of the disease before and after May 10 was 4.00 and p<0.01, respectively. The combined interventions reduced the transmissibility of COVID-19 by 99% and the number of cases by 98.36%. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: The findings of this study would add data on the transmission of COVID-19 and provide evidence to prepare the second outbreak transmission of the disease in other areas of China even in many other countries.

Epidemiological Characteristics and Spatial Analysis of Tick-Borne Encephalitis in Jilin Province, China.

Tick-borne encephalitis (TBE) is a viral infectious disease and has become a reemerging public health threat in recent years in northeastern China. However, no studies has characterized the epidemiologic features and explored the spatial dynamics and environmental factors of TBE cases in Jilin Province. In this study, we have described the epidemiological features of 846 reported human TBE cases from 2006 to 2016 in Jilin Province. There was an obvious single peak pattern of TBE cases from May to July in Jilin Province. More than 60% of TBE cases occurred in farmers, and the people in 50- to 59-year-old group had the high incidence of the disease. The results of Getis-Ord Gi* statistics demonstrated that the human TBE cases were more clustered in the northeastern border including Dunhua and Yanji cities and Antu and Wangqing counties, and southern areas including Huinan, Jingyu, Jiangyuan, and Liuhe counties in Jilin Province. We demonstrated that the temporal dynamics of TBE in Jilin was significantly associated with the dynamics of meteorological factors especially after 2009. The results from the auto-logistic regression analysis showed that the percentage coverage of forest, temperature, and autoregressive term were significantly associated with the occurrence of human TBE cases in Jilin Province. Our findings will provide a scientific evidence for the targeted prevention and control programs.

Effects of climate factors on hemorrhagic fever with renal syndrome in Changchun, 2013 to 2017.

Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease caused by hantaviruses (HVs). Climate factors have a significant impact on the transmission of HFRS. Here, we characterized the dynamic temporal trend of HFRS and identified the roles of climate factors in its transmission in Changchun, China.Surveillance data of HFRS cases and data on related environmental variables from 2013 to 2017 were collected. A principal components regression (PCR) model was used to quantify the relationship between climate factors and transmission of HFRS.During 2013 to 2017, a distinctly declining temporal trend of annual HFRS incidence was identified. Four principal components were extracted, with a cumulative contribution rate of 89.282%. The association between HFRS epidemics and climate factors was better explained by the PCR model (F = 10.050, P <.001, adjusted R = 0.456) than by the general multiple regression model (F = 2.748, P <.005, adjusted R = 0.397).The monthly trends of HFRS were positively correlated with the mean wind velocity but negatively correlated with the mean temperature, relative humidity, sunshine duration, and accumulative precipitation of the different previous months. The study results may be useful for the development of HFRS preventive initiatives that are customized for Changchun regarding specific climate environments.

A Chinese Creutzfeldt-Jakob disease patient with E196K mutation in PRNP.

Genetic Creutzfeldt-Jakob disease (gCJD) is caused by a range of mutations in the prion protein gene (PRNP) and account for approximately 10-15% of overall human prion diseases worldwide. They are different with disease onset, disease duration, clinical signs and diagnostic findings. Here we reported a 71 year-old female with an E196K mutation in one PRNP allele, while the codon 129 was a methionine homozygous genotype. The patient started with non-specific symptoms, but displayed rapidly progressive disturbances of speech, memory, cognitive and physical movement. No periodic activity was recorded at electroencephalography (EEG) during the entire disease course. Retrospective investigation of her family members did not reveal similar neurological disorders. Total clinical course was about seven months.

Isolation and genetic characterization of hantaviruses carried by Microtus voles in China.

To gain more insights into hantavirus distribution in China, Microtus fortis were caught in Jilin province and M. maximowiczii in the Inner Mongolia Autonomous Region. Hantavirus specific RNA was detected by RT-PCR in 3 out of 26 M. fortis and 5 out of 64 M. maximowiczii. Two hantaviruses (Fusong-Mf-682 and Yakeshi-Mm-59) were isolated successfully in cell culture and their S and M segment nucleotide sequences were determined. Phylogenetic analysis of the S and M segment sequences revealed that the Mf-originated strains from Fusong were closely related to Vladivostok hantavirus (VLAV) with 99% nucleotide identity, but differed from the Yakeshi-Mm strains, with an amino acid divergence of more than 8.8% for the N protein and 11.8% for the GnGc proteins. Yakeshi-Mm strains were closely related to the Khabarovsk hantavirus (KHAV) isolated earlier from M. fortis in Khabarovsk, with an amino acid sequence identity of more than 98.4% for the S segment and 95.6% for the M segment. On phylogenetic trees, Yakeshi-Mm strains clustered together with KHAV and Topografov virus (TOPV) carried by Lemmus sibiricus. The results suggest that the hantavirus carried by M. fortis in China belongs to VLAV type and should be considered as a distinct hantavirus species. They also suggest that M. fortis is the natural host of VLAV (including Fusong-Mf strains), whereas M. maximowiczii is the natural host of KHAV including Yakeshi-Mm strains. Thus, in addition to Hantaan, Seoul, Dabieshan and Puumala-like Hokkaido viruses, at least two other hantaviruses, namely KHAV and VLAV, are circulating in China.

Detection of phylogenetically distinct Puumala-like viruses from red-grey vole Clethrionomys rufocanus in China.

In order to investigate whether Puumala virus (PUUV) or PUUV-like virus is present in China, Clethrionomys rufocanus and C. rutilus were captured in the Jilin province during the spring and autumn of 2002-2003 for detection of PUUV viral RNA by RT-PCR and confirmation of PUUV-positive antigens by an immunofluorescence assay. PUUV-positive RNA was identified in six out of 121 C. rufocanus but not in any of the 41 C. rutilus. Complete S and partial M sequences (nt 1,316-1,598 and 2,687-3,089) were amplified by RT-PCR directly from some of the antigen positive lung tissues and subjected to nucleic acid sequencing. It was found that the Chinese PUUV-like viruses were related most closely with the PUUV strains with 77.7-81.7% identity at the nucleotide level and 91.7-97% identity at the amino acid level for S segment, and with 77-78.8% identity at the nucleotide level and 91.5-92.6% identity at the amino acid level for the partial M segment (nt 1,316-1,598). Genetic analysis indicated that the Chinese PUUV-like viruses shared the highest level of identity with the viruses which circulate in C. rufocanus in the Far East region of Russia with 85.1-87.4% identity at the nucleotide level and 95.9% identity at the amino acid level for the partial M segment (nt 2,687-3,089), respectively. Phylogenetic analysis revealed that the Chinese PUUV-like viruses are distinct from those identified from Japan, South Korea, Europe or Russia. These results indicate that PUUV-like virus is present in China in addition to Hantaan, Seoul and Dabieshan viruses.

Isolation and characterization of hantavirus carried by Apodemus peninsulae in Jilin, China.

To provide a better understanding of hantavirus epidemiology in China, Korean field mice (Apodemus peninsulae) and striped field mice (Apodemus agrarius) were captured in Jilin province, China, where haemorrhagic fever with renal syndrome (HFRS) is endemic. Hantavirus antigens were detected in eight of the 130 A. peninsulae individuals and in four of the 193 A. agrarius individuals by using an immunofluorescence assay. Partial S and M segments were amplified from all of the antigen-positive samples. Furthermore, two hantaviruses (CJAp89 and CJAp93) were isolated successfully in cell culture and the entire S and M segments were amplified from one of them (CJAp93). Phylogenetic analysis of these sequences (partial or complete) showed that hantaviruses carried by A. peninsulae and A. agrarius form two distinct lineages, although viruses carried by A. peninsulae are similar to those isolated previously from A. agrarius in China and from HFRS patients in Russia. However, the viruses detected in A. peninsulae in China are genetically different from those detected in A. peninsulae in other countries. These data suggest that A. peninsulae is also a natural host for HTNV in north-eastern China.

[Identification of Puumala like viruses in China].

BACKGROUND: To confirm if Puumala like viruses exist in China. METHODS: RNA was extracted from lungs of bank voles captured in the Northeast China, partial S segments genome of Puumala viruses were amplified and sequenced. RESULTS: 926 bp cDNA of S segments of Puumala like virus was amplified and sequenced. The phylogenetic analysis revealed that the Puumala like viruses found in China were most close to that found in Far East region of Russia. CONCLUSIONS: Puumala like virus does exist in Northeast China, and the nucleotides sequence of the viruses have high homolog to Puumala viruses found in Russia.