Disease Reporting Information System Research Articles

Comparison of Three Influenza Surveillance Data Sources for Timely Detection of Epidemic Onset - Chengdu City, Sichuan Province and Beijing Municipality, China, 2017-2023.

The syndromic surveillance system, exemplified by the influenza-like illness (ILI) surveillance system, has long been crucial in providing early warnings of influenza epidemics. The analysis revealed that employing reported influenza case data from the nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS) enhanced the early detection of influenza epidemics, particularly within the context of multiple respiratory pathogens circulating concurrently. The NIDRIS, characterized by its extensive coverage, obligatory reporting, high specificity, and real-time data transmission, offers a valuable tool for the effective early detection of influenza epidemics. Utilizing this system could enhance preparedness and responses to such health crises, potentially mitigating their impact on public health.

Epidemiological Characteristics and Spatiotemporal Patterns of Visceral Leishmaniasis in Xinjiang, China, during 2004-2021.

The spread of visceral leishmaniasis (VL), a serious global zoonotic parasitic disease, is mostly under control; however, several cases have been reported in recent decades in Xinjiang, China. This study aimed to analyze the epidemiological status and spatiotemporal clustering characteristics of VL in Xinjiang, China, between 2004 and 2021 to provide a basis for the development and implementation of surveillance and response measures. Data on VL incidence during 2004-2021 were collected from the National Diseases Reporting Information System of China. Global spatial autocorrelation analysis, identification of local indicators of spatial association, and spatial-temporal clustering analysis were conducted to identify the distribution and high-risk areas. A total of 2034 VL cases were reported, with a mean annual incidence of 0.50 per 100,000. There was a general decreasing trend in the incidence of VL during our study period. The majority of the cases were reported from October to February of the following year, and fewer cases were reported from April to July. Spatial autocorrelation analysis revealed that the incidence of VL was spatially clustered within a few counties. Significant differences were observed during the study period (Moran's I = 0.74, Z = 4.900, p < 0.05). The male-to-female ratio was 1.37:1, and most patients were in the age group 0-3 years. Cases were primarily distributed in seven regions and two autonomous prefectures, and Kashgar reported the highest number of cases (1688, 82.98%). Spatial analysis revealed that the aggregation of VL was predominantly observed in southwest Xinjiang. This was in alignment with the high-risk areas identified by spatiotemporal clustering analysis. The H-H clustering region was primarily observed in Gashi, Atushi, Shufu, Injisha, Kashgar, Yepuhu, and Bachu. These findings indicate that integrated control measures must be taken in different endemic areas to strengthen the VL control program in Xinjiang, China.

Retrospective estimation of the time-varying effective reproduction number for a COVID-19 outbreak in Shenyang, China: An observational study.

The time-varying effective reproduction number Re(t) is essential for designing and adjusting public health responses. Retrospective analysis of Re(t) helps to evaluate health emergency capabilities. We conducted this study to estimate the Re(t) of the Corona Virus Disease 2019 (COVID-19) outbreak caused by SARS-CoV-2 Omicron in Shenyang, China. Data on the daily incidence of this Corona Virus Disease 2019 outbreak between March 5, 2022, and April 25, 2022, in Shenyang, China, were downloaded from the Nationwide Notifiable Infectious Diseases Reporting Information System. Infector-infectee pairs were identified through epidemiological investigation. Re(t) was estimated by R-studio Package "EpiEstim" based on Bayesian framework through parameter and nonparametric method, respectively. About 1134 infections were found in this outbreak, with 20 confirmed cases and 1124 asymptomatic infections. Fifty-four infector-infectee pairs were identified and formed a serial interval list, and 15 infector-infectee pairs were included in the generation time table. Re(t) calculated by parameter and nonparametric method all peaked on March 17, 2022, with a value of 2.58 and 2.54 and decreased to <1 after March 28, 2022. There was no statistical difference in the Re(t) distribution calculated using the 2 methods (t = 0.001, P > .05). The present study indicated that the decisive response of Shenyang, China, played a significant role in preventing the spread of the epidemic, and the retrospective analysis provided novel insights into the outbreak response to future public health emergencies.

Epidemiological characteristics of typhoid fever in Fujian Province, 2011-2022

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever in Fujian Province from 2011 to 2022, and understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The surveillance data of typhoid fever during 2011-2022 in Fujian Province were obtained from the National Disease Reporting Information System and analyzed with SAS 9.4. The spatial autocorrelation analysis of typhoid fever incidence at county/district levels was performed with ArcGlS 10.8. Results: A total of 5 126 cases of typhoid fever were reported in Fujian Province from 2011 to 2022, with an average annual incidence rate of 1.10/100 000. The average annual incidence rate was 0.96/100 000 from 2011 to 2015, 1.49/100 000 from 2016 to 2019, and 0.81/100 000 from 2020 to 2022. The disease occurred all the year round, with high epidemic season from May to September. A total of 23.59% (1 209/5 126) of the cases occurred at the age of 0-4, and 9.62% (493/5 126) at the age of 5-9. The male to female ratio of the cases was 0.97∶1 (2 524∶2 602) for the whole population, 1.19∶1 (925∶777) for people under 10 years old, 0.75∶1 (1 060∶1 404) for people between 10 and 54 years old, and 1.28∶1 (539∶421) for people over 55 years old. Cases in Ningde City accounted for 30.65% (1 571/5 126) of the total cases. Most hotspots were occurred in Ningde City. Recurrent and clustered cases were found in family members. Conclusions: Typhoid fever was prevalent at a low level in Fujian Province during 2011-2022, indicating that strengthening the prevention and control measures should target key areas and populations. The incidence of typhoid fever in Fujian Province showed spatial aggregation phenomenon, and most cases gathered in Ningde City. Intensive study for the influencing factors of spatial clustering should be conducted.

Epidemiological Characteristics and Trends of Scarlet Fever in Zhejiang Province of China: Population-Based Surveillance during 2004-2022.

Over the past two decades, scarlet fever has resurged in some countries or areas. Nationwide nonpharmaceutical interventions changed the patterns of other infectious diseases, but its effects on the spread of scarlet fever were rarely studied. This study aimed to evaluate the changes in scarlet fever incidence in Zhejiang Province, China, before and during the COVID-19 pandemic periods and to provide references for scarlet fever prevention and control. Scarlet fever surveillance data in Zhejiang, China (2004-2022), were analyzed in three stages. Two-sample z test, ANOVA, and Tukey's test were used to compare and analyze the characteristics of disease spread at different stages. The ARIMA model was used to predict the overall trend. The data were obtained from the National Infectious Disease Reporting Information System. A total of 28,652 cases of scarlet fever were reported across Zhejiang Province during the study period, with the lowest average monthly incidences in 2020 (0.111/100,000). The predominant areas affected were the northern and central regions of Zhejiang, and all regions of Zhejiang experienced a decrease in incidence in 2020. The steepest decline in incidence in 2020 was found in children aged 0-4 years (67.3% decrease from 23.8/100,000 to 7.8/100,000). The seasonal pattern changed, with peak occurrences in April to June and November to January during 2004-2019 and 2021 and a peak in January in 2020. The median duration from diagnosis to confirmation was highest before COVID-19 (4 days); however, it decreased to 1 day in 2020-2022, matching the other two medians. In 2020, Zhejiang experienced an unprecedented decrease in scarlet fever, with the lowest incidence in nearly 18 years, but it rebounded in 2021 and 2022. The seasonal epidemiologic characteristics of scarlet fever also changed with the COVID-19 outbreaks. This suggested that nationwide nonpharmaceutical interventions greatly depressed the spread of scarlet fever. With the relaxation of non-pharmaceutical intervention restrictions, scarlet fever may reappear. Government policymakers should prioritize the control of future scarlet fever outbreaks for public health.

Epidemiological characteristics and temporal-spatial clustering analysis on human brucellosis in Jiangsu Province, 2006–2021

The marked increase in the incidence rate of brucellosis is a serious public health concern in Jiangsu Province. However, its temporal and spatial distribution has not been studied in depth. The main purpose of this study is to depict the demographic, temporal and spatial distribution patterns and clustering characteristics of brucellosis cases in Jiangsu Province, China, from 2006 to 2021 to develop and implement effective scientific prevention and control strategies. Data for human brucellosis cases in Jiangsu Province from 2006 to 2021 were obtained from the Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS). Spatial autocorrelation analysis and temporal-spatial scan statistics were used to identify potential changes in the spatial and temporal distributions of human brucellosis in Jiangsu Province. During the years 2006–2021, 1347 brucellosis cases were reported in Jiangsu Province, with an average annual incidence rate of 0.1036 per 100,000 individuals. Middle-aged and elderly individuals (aged 40–69 years) were the main infected populations, accounting for 69.72% (939/1347) of all reported cases. The incidence of brucellosis in Jiangsu showed a long-term increasing trend and displayed pronounced seasonal variations, with the peak occurring between April and June annually. The incidence gradually expanded from the northern and southern areas to the central areas between 2006 and 2021. Global spatial autocorrelation analysis demonstrated a positive correlation in the incidence of brucellosis between 2008 and 2012–2021. Temporal-spatial clustering analysis showed that the primary cluster was detected in the northern, highly endemic regions of Jiangsu, and the three secondary clusters were in areas where there had been outbreaks of brucellosis. Human brucellosis remains a serious public health issue in Jiangsu Province. Northern and southern Jiangsu regions, with high rates of brucellosis, may require special plans and measures to monitor and control the disease. Additionally, the capacity to respond to outbreaks in high-incidence areas should be improved to prevent further brucellosis outbreaks.

Annual incidence and fatality rates of notifiable infectious diseases in southeast China from 1950 to 2022 and relationship to socioeconomic development.

Over the past 70 years, China has advanced significantly in the prevention and treatment of infectious diseases while simultaneously undergoing a socioeconomic transformation, making it a useful source of data for analysing relationships between public health policy and the control of infectious diseases. We collected data on the incidence of notifiable infectious diseases and associated fatalities in Jiangsu province in southeast China from the Provincial Center for Disease Control and Prevention, Provincial Institute of Parasitic Diseases, and the Nationwide Notifiable Infectious Diseases Reporting Information System. We compared data from different historical periods using descriptive statistical methods, joinpoint regression, and correlation analysis. During 1950-2022, 75 754 008 cases of 46 notifiable infectious diseases were reported in Jiangsu, with an average annual incidence was 1679.49 per 100 000 population and a fatality rate of 1.82 per 1000 persons. The incidence of classes A-B decreased (average annual percent change (AAPC) = -2.1) during the entire study period, while the incidence of class C increased (AAPC = 10.8) after 2004. The incidence of intestinal diseases (AAPC = -4.4) and vector-borne and zoonotic diseases (AAPC = -8.1) decreased rapidly, while the incidence of sexually transmitted and blood-borne diseases (AAPC = 1.8) increased. The number of medical and health institutions and the per capita gross domestic product correlated negatively with the annual incidence of diseases in classes A-B, but not with fatality rates. Although the annual incidence of many severe infectious diseases has decreased in Jiangsu since 1950, the incidence of sexually transmitted and blood-borne diseases increased. Socioeconomic growth and sustainable investment in health systems are associated with better control of infectious diseases.

Incidence and trends of 17 notifiable bacterial infectious diseases in China, 2004–2019

BackgroundCertain bacterial infectious diseases are categorized as notifiable infectious diseases in China. Understanding the time-varying epidemiology of bacterial infections diseases can provide scientific evidence to inform prevention and control measures.MethodsYearly incidence data for all 17 major notifiable bacterial infectious diseases (BIDs) at the province level were obtained from the National Notifiable Infectious Disease Reporting Information System in China between 2004 and 2019. Of them 16 BIDs are divided into four categories, respiratory transmitted diseases (RTDs, 6 diseases), direct contact/fecal-oral transmitted diseases (DCFTDs, 3 diseases), blood-borne/sexually transmitted diseases (BSTDs, 2 diseases), and zoonotic and vector-borne diseases (ZVDs, 5 diseases), and neonatal tetanus is excluded in the analysis. We characterized the demographic, temporal, and geographical features of the BIDs and examined their changing trends using a joinpoint regression analysis.ResultsDuring 2004‒2019, 28 779 thousand cases of BIDs were reported, with an annualized incidence rate of 134.00 per 100 000. RTDs were the most commonly reported BIDs, accounting for 57.02% of the cases (16 410 639/28 779 000). Average annual percent changes (AAPC) in incidence were − 1.98% for RTDs, − 11.66% for DCFTDs, 4.74% for BSTDs, and 4.46% for ZVDs. Females had a higher incidence of syphilis than males, and other BIDs were more commonly reported in males. Among 0-5-year-olds, the diseases with the largest increases in incidence were pertussis (15.17% AAPC) and scarlet fever (12.05%). Children and students had the highest incidence rates of scarlet fever, pertussis, meningococcal meningitis, and bacillary dysentery. Northwest China had the highest incidence of RTDs, while South and East China had the highest incidences of BSTDs. Laboratory confirmation of BIDs increased from 43.80 to 64.04% during the study period.ConclusionsRTDs and DCFTDs decreased from 2004 to 2019 in China, while BSTDs and ZVDs increased during the same period. Great attention should be paid to BSTDs and ZVDs, active surveillance should be strengthened, and timely control measures should be adopted to reduce the incidence.

Epidemiological characteristics of typhus in China, 1950-2021

Objective: To analyze the epidemiological characteristics of typhus in China from 1950 to 2021, and discuss the challenges in typhus prevention and control in China and suggest future prevention and control strategies. Methods: Based on the reported data of typhus from 1950 to 2021 in China from the Infectious Disease History Database of China Public Health Science Data Center and the National Notifiable Infectious Disease Reporting Information System of Chinese Center for Disease Control and Prevention, we conducted a descriptive statistical analysis. Mann-Kendall test and circular distribution method were used to analyze the incidence, mortality and case fatality of typhus to reveal the temporal, spatial and population distributions and diagnosis of typhus in China. Results: From 1950 to 2021, a total of 452 965 typhus cases and 7 339 typhus deaths were reported in China, with the cases numbers exceeding 10 000 in 14 years of the 1950s, 1960s and 1980s, respectively. Since 1990s, the reported cases and incidence rate of typhus have decreased dramatically and the most cases were sporadic. However, the reported typhus cases in Anhui, Hubei, Hunan Provinces showed significant uptrends. Although typhus could occur all the year round, but the seasonality was observed with the incidence mainly in summer and autumn. For different provinces from the north to the south, the peaks of typhus' monthly incidence tended to shift to earlier dates. The male to female ratio of the cases was 1.01∶1 (18 529∶18 366). However, more cases occurred in women in recent years. The cases aged ≤9 years accounted for the highest proportion (18.9%), but the number of cases aged ≥50 years showed an upward trend. Most cases were farmers with the proportion increasing year by year. Moreover, the cases in students and scattered-living children also accounted for relatively higher proportions. The median of the interval between onset and diagnosis of typhus was 6 days. Most cases were clinically diagnosed, while the proportion of laboratory-confirmed cases was low and most laboratory cases were confirmed by Well-Felix reaction. Conclusions: Although the incidence and mortality of typhus in China has decreased significantly, the risk for local typhus outbreaks still exists. The prevention and control of typhus still face many challenges. It is indispensable to strengthen the pathogen detection and surveillance for typhus in China.

Climate-driven scrub typhus incidence dynamics in South China: A time-series study

Background: Scrub typhus (ST) is a climate-sensitive infectious disease. However, the nonlinear relationship between important meteorological factors and ST incidence is not clear. The present study identified the quantitative relationship between ST incidence and meteorological factors in southern China.Methods: The weekly number of ST cases and simultaneous meteorological variables in central Guangdong Province from 2006 to 2018 were obtained from the National Notifiable Infectious Disease Reporting Information System and the Meteorological Data Sharing Service System, respectively. A quasi-Poisson generalized additive model combined with a distributed lag nonlinear model (DLNM) was constructed to analyze the lag-exposure-response relationship between meteorological factors and the incidence of ST.Results: A total of 18,415 ST cases were reported in the study area. The estimated effects of meteorological factors on ST incidence were nonlinear and exhibited obvious lag characteristics. A J-shaped nonlinear association was identified between weekly mean temperature and ST incidence. A reversed U-shaped nonlinear association was noted between weekly mean relative humidity and ST incidence. The risk of ST incidence increased when the temperature ranged from 24°C to 28°C, the relative humidity was between 78% and 82%, or the precipitation was between 50 mm and 150 mm, using the medians as references. For high temperatures (75th percentile of temperature), the highest relative risk (RR) was 1.18 (95% CI: 1.10–1.27), with a lag effect that lasted 5 weeks. High relative humidity (75th percentile of relative humidity) and high precipitation (75th percentile of precipitation) could also increase the risk of ST.Conclusion: This study demonstrated the nonlinear relationship and the significant positive lag effects of temperature, relative humidity, and precipitation on the incidence of ST. Between particular thresholds, temperature, humidity, and levels of precipitation increased the risk of ST. These findings suggest that relevant government departments should address climate change and develop a meteorological conditions-depend strategy for ST prevention and control.

Epidemiological characteristics of severe fever with thtrombocytopenia syndrome in China, 2011-2021

Objective: To analyze the epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) in China from 2011 to 2021, and provide evidence for the prevention and control of SFTS. Methods: The incidence data of SFTS were collected from the National Disease Reporting Information System of Chinese Center for Disease Control and Prevention for a descriptive epidemiological analysis and Cochran-Armitage trend test was used to evaluate the association between age and the morbidity rate and case fatality rate (CFR) of SFTS. Results: From 2011 to 2021, a total of 18 902 laboratory confirmed cases of SFTS, including 966 deaths, were reported in 533 counties (districts) of 154 prefecture-level cities in 27 provinces. The annual average morbidity rate was 0.125/100 000, and the annual average CFR was 5.11%. From 2011 to 2021 the overall morbidity rate of SFTS was in increase with an average annual percentage change (AAPC) of 14.80% (P=0.001). Most cases (99.23%) occurred in 7 provinces, including Shandong, Henan, Anhui, Hubei, Liaoning, Zhejiang and Jiangsu, with 70.28% of the cases in 11 prefecture-level cities. The average annual CFRs in the 7 provinces varied greatly from 1.30% to 11.27%. In 2011, SFTS cases were reported in 108 counties (districts) of 51 prefecture-level cities in 13 provinces, but SFTS cases were reported in 277 counties (districts) of 88 prefecture-level cities in 19 provinces in 2021, the disease spread from central area to the northeast and from the west and the south. SFTS mainly occurred in summer and autumn in both southern and northern China, and 96.63% of the cases were reported from April to October, and the incidence peak was during May-June. The cases mainly occurred in age group 50-74 years (69.46%), and the deaths mainly occurred in age group ≥60 years (79.71%). Both the morbidity rate and the CFR increased with age. The morbidity rate increased from 0.040/100 000 in age group 0-4 years to 4.480/100 000 in age group ≥80 years in males (χ²=13 185.21, P<0.001) and from 0.038/100 000 in age group 0-4 years to 3.318/100 000 in age group ≥80 years in females (χ²=12 939.83, P<0.001); the CFR increased from 0.70% in age group 30-34 years to 11.58% in age group ≥80 years in males (χ²=115.70, P<0.001) and from 1.56% in age group 35-39 years to 8.98% in age group ≥80 years in females (χ²=103.42, P<0.001). Conclusion: From 2011 to 2021, the incidence of SFTS increased in China, and the spread and obvious spatiotemporal distribution of SFTS were observed. The reported CFR varied greatly with area, and both the morbidity and mortality risk were high in the elderly.

Epidemiology of influenza virus reinfection in Guangxi, China: a retrospective analysis of a nine-year influenza surveillance data: Characteristics of influenza virus reinfection

BackgroundEpidemiological characteristic profile of the reinfection of the influenza virus has not been well described. MethodsThis study included all influenza cases of Guangxi, China from January 2011–December 2019 that were recorded in the National Notifiable Infectious Disease Reporting Information System (NIDRIS) within 24 hours after diagnosis. ResultsA total of 53,605.6 person-months and the median time of 8.7 months were observed for reinfection. The median age at the first influenza virus infection was 4.5 (interquartile range=2.0–7.5) years. The cumulative reinfection incidence was 2% at 6 months, 4% at 12 months, 5% at 24 months, and 7% after 59 months. Living in the rural area (hazard ratio [HR]=1.37 [95% confidence interval (CI), 1.29-1.45]), age ≤6 years (HR=11.43 [95% CI, 9.47–13.80]) were independent risk factors associated with influenza reinfection. Among 49 patients experiencing two laboratory tests, 32 patients (65.3%) were found to be infected with different virus types. The interval between two consecutive laboratory-confirmed episodes of the four groups differed (p=0.148): the maximum was 72.9 months and the minimum was 1.2 months. ConclusionsThe reinfection of the influenza virus in Guangxi was independently and positively associated with living the rural area and younger age. The unusually high frequency of reinfection points to a need for further prospective longitudinal studies to better investigate the sufficient impact on different subtypes.

Epidemiological characteristics and temporal-spatial analysis of overseas imported dengue fever cases in outbreak provinces of China, 2005\u20132019

BackgroundOverseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China. To better prevent and control such local outbreaks, the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provincial-level administrative divisions (PLADs) where dengue fever is outbreak in the mainland of China were explored.MethodsUsing the Chinese National Notifiable Infectious Disease Reporting Information System (CNNDS), we identified overseas imported dengue fever cases in dengue fever outbreak areas in the mainland of China from 2005 to 2019 to draw the epidemic curve and population characteristic distribution of overseas imported cases in each PLAD. Based on spatial autocorrelation analysis of ArcGIS 10.5 and temporal-spatial scanning analysis of SaTScan 9.5, we analyzed the temporal-spatial distribution of overseas imported dengue fever in dengue fever outbreak areas in the mainland of China.ResultsA total of 11,407 imported cases, mainly from Southeast Asia, were recorded from 2005 to 2019 in these 13 PLADs. Of which 62.1% were imported into Yunnan and Guangdong Provinces. Among the imported cases, there were more males than females, mainly from the 21–50 age group. The hot spots were concentrated in parts of Yunnan, Guangdong and Fujian Provinces. We found the cluster of infected areas were expanding northward.ConclusionsBased on the analysis of overseas imported dengue cases in 13 PLADs of the mainland of China from 2005 to 2019, we obtained the epidemiological characteristics and spatial distribution of imported dengue cases. Border controls need to pay attention to key population sectors, such as 21–50 years old men and education of key populations on dengue prevention. There is a need to improve the awareness of the prevention and control of imported cases in border areas. At the same time, northern regions cannot relax their vigilance.Graphical

Study on epidemic trend of hemorrhagic fever with renal syndrome in Zhejiang province, 2005-2020

Objective: To analyze the epidemiological characteristics and spatiotemporal distribution of hemorrhagic fever with renal syndrome (HFRS) in Zhejiang province from 2005 to 2020, and provide scientific information for the precise prevention and control of HFRS. Methods: Data on HFRS cases in Zhejiang province during 2005-2020 were collected from the China National Notifiable Infectious Disease Reporting Information System (NNDS) for a descriptive analysis, and software ArcGIS 10.2 was used for global autocorrelation and local autocorrelation analyses. Spatiotemporal clusters were scanned with SaTScan 9.4.4 and visualized with ArcGIS 10.2. Results: A total of 7 724 HFRS cases were reported in Zhejiang province from 2005 to 2020, including 25 deaths. There were two incidence peaks each year, in late spring and early summer (May-June) and in winter (November-January). The top three areas with high cumulative cases were Ningbo (1 875, 24.27%), Taizhou (1 642, 21.25%), and Shaoxing (1 123, 14.54%). Among the reported cases, with a male to female ratio of 2.73∶1(5 656∶2 068). The majority of HFRS cases were middle-aged and elderly people, with cases aged 41-70 years accounting for 60.95%. Most HFRS cases were farmers, accounting for 69.89% (5 398/7 724). The spatial distribution of HFRS in most years was correlated. SaTScan was used for retrospective spatiotemporal scanning and three clusters were detected: the first type clusters were in 21 counties in eastern Zhejiang province and central Zhejiang province, among which 4 were in Ningbo, Shaoxing and Jinhua, 8 were in Taizhou, and 1 was in Lishui (RR=13.69, LLR=5 522.60, P<0.001); the second type clusters were in Longquan and Qingyuan counties (RR=31.20, LLR=1 232.46, P<0.001); the third types of clusters were in Changxing and Anji counties of Huzhou in northern Zhejiang province (RR=3.42, LLR=23.93, P<0.001). Conclusions: HFRS mainly occurred in middle-aged,elderly and male farmers in Zhejiang province. The incidence was high in late spring, early summer and winter in eastern Zhejiang province. Precise prevention and control measures are needed for populations at high risk before the epidemic season.

Epidemiological features and spatial\u2013temporal distribution of visceral leishmaniasis in mainland China: a population-based surveillance study from 2004 to 2019

BackgroundAlthough visceral leishmaniasis (VL) was largely brought under control in most regions of China during the previous century, VL cases have rebounded in western and central China in recent decades. The aim of this study was to investigate the epidemiological features and spatial–temporal distribution of VL in mainland China from 2004 to 2019.MethodsIncidence and mortality data for VL during the period 2004–2019 were collected from the Public Health Sciences Data Center of China and annual national epidemic reports of VL, whose data source was the National Diseases Reporting Information System. Joinpoint regression analysis was performed to explore the trends of VL. Spatial autocorrelation and spatial–temporal clustering analysis were conducted to identify the distribution and risk areas of VL transmission.ResultsA total of 4877 VL cases were reported in mainland China during 2004–2019, with mean annual incidence of 0.0228/100,000. VL incidence showed a decreasing trend in general during our study period (annual percentage change [APC] = −4.2564, 95% confidence interval [CI]: −8.0856 to −0.2677). Among mainly endemic provinces, VL was initially heavily epidemic in Gansu, Sichuan, and especially Xinjiang, but subsequently decreased considerably. In contrast, Shaanxi and Shanxi witnessed significantly increasing trends, especially in 2017–2019. The first-level spatial–temporal aggregation area covered two endemic provinces in northwestern China, including Gansu and Xinjiang, with the gathering time from 2004 to 2011 (relative risk [RR] = 13.91, log-likelihood ratio [LLR] = 3308.87, P < 0.001). The secondary aggregation area was detected in Shanxi province of central China, with the gathering time of 2019 (RR = 1.61, LLR = 4.88, P = 0.041). The epidemic peak of October to November disappeared in 2018–2019, leaving only one peak in March to May.ConclusionsOur findings suggest that VL is still an important endemic infectious disease in China. Epidemic trends in different provinces changed significantly and spatial–temporal aggregation areas shifted from northwestern to central China during our study period. Mitigation strategies, including large-scale screening, insecticide spraying, and health education encouraging behavioral change, in combination with other integrated approaches, are needed to decrease transmission risk in areas at risk, especially in Shanxi, Shaanxi, and Gansu provinces.Graphical abstract

The distribution of hepatitis C virus infection in Shanghai, China: a time-spatial study

BackgroundShanghai, as a pilot city of China to achieve the goal of eliminating hepatitis C, its strategy of allocating medical resources is a pressing problem to be solved. This study aims to infer the time-spatial clustering patterns of HCV-infected cases, and grasp the dynamic genotype distribution of HCV, thereby inform elimination strategies of HCV with efficacy and efficiency.MethodsReported HCV cases including their demographic information in Shanghai city from 2005 to 2018 were released from the National Infectious Disease Reporting Information System, population data at community scale, geographical layers of hospitals, communities and districts were gathered from former research. Blood samples of HCV-infected individuals were collected during 2014–2018 from 24 sentinel hospitals, HCV-antibody test, qualitative nucleic acid test and NS5B/5’UTR gene amplification were performed accordingly to determine the genotypes of the specimen. Furthermore, global and local spatial self-correlation analysis of both acute and chronic HCV infections were conducted at community scale year by year, then time-spatial clusters of acute and chronic HCV infections and HCV genotype distribution of specimen collected from sentinel hospitals by districts were mapped by using Arcmap10.1.ResultsA total of 2631 acute HCV cases and 15,063 chronic HCV cases were reported in Shanghai from 2005 to 2018, with a peak in 2010 and 2017, respectively. The mean age of chronic HCV patients was 49.70 ± 14.55 years, 3.34 ± 0.32 years older than the acute (t = 10.55, P-value < 0.01). The spatial distribution of acute HCV infection formed one primary cluster (Relative Risk = 2.71), and the chronic formed one primary cluster and three secondary clusters with Relative Risk ranged from 1.94 to 14.42, meanwhile, an overlap of 34 communities between acute and chronic HCV clusters were found with time period spans varied from 6 to 12 years. Genotype 1 (N = 257, 49.71%) was the most prevalent HCV genotype in Shanghai, genotype 3 infections have increased in recent years. Baoshan district presented cluster of acute HCV and the highest proportion of genotype 2, Pudong new area was the cluster of chronic HCV and occupied the highest proportion of genotype 3.ConclusionsDespite the low prevalence of HCV infection, it is still needed to push forward the elimination process in Shanghai, as there is a certain amount of HCV infected people waiting to be treated. The time-spatial clustering patterns and the dynamic of HCV genotype distribution together indicated a changing constitution of different transmission routes of HCV infection, thus, a focused strategy may be needed for high-risk population related to genotype 3 infection like drug users, in addition to an enforcement of the existing measures of preventing the iatrogenic and hematogenic transmission of HCV.

Spatiotemporal distribution and sociodemographic and socioeconomic factors associated with primary and secondary syphilis in Guangdong, China, 2005-2017.

Previous studies exploring the factors associated with the incidence of syphilis have mostly focused on individual-level factors. However, recent evidence has indicated that social-level factors, such as sociodemographic and socioeconomic factors, also affect the incidence of syphilis. Studies on the sociodemographic and socioeconomic factors associated with syphilis incidence are scarce, and they have rarely controlled for spatial effects, even though syphilis shows spatial autocorrelation. Syphilis data from 21 cities in Guangdong province between 2005 and 2017 were provided by the National Notifiable Infectious Disease Reporting Information System. The incidence time series, incidence map, and space-time scanning data were used to visualize the spatiotemporal distribution. The spatial panel data model was then applied to explore the relationship between sociodemographic factors (population density, net migration rate, male:female ratio, and the number of health institutions per 1,000 residents), socioeconomic factors (gross domestic product per capita, the proportion of secondary/tertiary industry), and the incidence of primary and secondary syphilis after controlling for spatial effects. The incidence of syphilis increased slowly from 2005 (11.91 per 100,000) to 2011 (13.42 per 100,000) and then began to decrease, reaching 6.55 per 100,000 in 2017. High-risk clusters of syphilis tended to shift from developed areas to underdeveloped areas. An inverted U-shaped relationship was found between syphilis incidence and gross domestic product per capita. Moreover, syphilis incidence was significantly associated with population density (β = 2.844, P = 0.006), the number of health institutions per 1,000 residents (β = -0.095, P = 0.007), and the net migration rate (β = -0.219, P = 0.002). Our findings suggest that the incidence of primary and secondary syphilis first increase before decreasing as economic development increases further. These results emphasize the necessity to prevent syphilis in regions at the early stages of economic growth.

Epidemiological characteristics and spatiotemporal clusters on measles of infants under 1 year old in Henan Province from 2015 to 2019

Objective To analyze the spatial and temporal characteristics on measles of infants under 1 year old in Henan Province during 2015-2019, to provide evidence for the prevention and control of measles. Methods Data were collected from the Infection Disease Reporting Information System in China and the National Measles Surveillance System. The epidemiological characteristics on measles of infants under 1 year old in Henan Province during 2015-2019 were described. Spatiotemporal distribution and clustering were analyzed by using the ArcGIS 10.7 software and SaTScan 9.4 software. Results A total of 2 757 measles infants under 1 year old were found in Henan Province from 2015-2019 with an average annual incidence of 42.82/100 000. Most cases aged between 6-8 months old, accounting for 49.40% of the total number of cases. The epidemic peak was between January and May. The trend surface analysis found that the incidence of measles decreased gradually from the southern to northern parts, which showed an inverted U type curve. The spatiotemporal scan found three spatiotemporal aggregation areas, and the strongest areas were located in Pingdingshan and Nanyang Districts, which including 28 counties in 2015. Conclusion The incidence rate of measles infants under 1 year old was decreasing year by year and showing obviously seasonal rule in Henan Province, 2015-2019. Infants aged 6-8 months old are the main group of patients. The main clustering areas were located in the south central part of Henan Province, suggesting that the prevention and control measures should be further strengthened in these areas.

Epidemiological characteristics of imported malaria in Mianyang, Sichuan, 2009-2019

Objective To analyze the epidemiological characteristics of imported malaria in Mianyang during the 20092019 period, and we provide scientific basis for the control of imported malaria. Methods The epidemic situation was collected from the infectious disease reporting information system and the epidemiological investigation data of imported malaria during 2009–2019 in Mianyang. The data were analyzed by descriptive epidemiological. Results A total of 169 imported malaria cases were reported during 2009–2019 in Mianyang, all were laboratory confirmed cases, with an average annual incidence rate of 0.43/100 000. There were 64 cases (37.876%) of vivax malaria, 91 cases (53.85%) of falciparum malaria, 5 cases (2.96%) of ovale malaria, 1 case (0.59%) of quartan malaria and 8 cases (4.73%) of mixed infections. Imported cases were reported all the year round, June and July had the most cases, with 22 cases each, accounting for 26.04% of the whole year. There were 10 cases (5.92%) imported from other province in China, 38 cases (22.49%) imported from 6 countries in Asia, 121 cases (71.60%) imported from 24 countries in Africa. Imported malaria cases have been reported in 10 counties. The average age of the cases was (38.45±11.74) years. Malaria cases were majorly young men working as peasant and migrant workers. The average time from symptom appearing to being diagnosed was 4.18 d, 39.05% and 56.21% of the patients were diagnosed in municipal and county medical treatment units, respectively. Conclusion The situation of imported malaria from overseas is still serious in Mianyang. It is important to improve the malaria diagnosis and treatment, and strengthen the health education of migrant workers and their families in order to achieve better prevention and control of imported malaria in the area and put an end to secondary cases. 摘要:目的 分析 2009—2019 年四川省绵阳市输人性疟疾的流行病学特征, 为进一步加强输人性疟疾防治工作提 供科学依据。 方法 通过法定传染病报告信息管理系统, 收集绵阳市 2009—2019 年疟疾病例流行病学资料和病例个 案调査资料。采用描述性流行病学方法对这些资料进行统计学分析。 结果 2009—2019 年绵阳市共有 169 例输人性 疟疾病例, 均为实验室确诊病例, 年均发病率 0.43/10 万。其中间日疟64 例 (37.87%)、恶性疟 91 例(53.85%)、三日疟1 例 (0.59%)、卵型疟 5 例 (2.96%)、混合感染 8 例 (4.73%)。输人性病例全年均有分布, 6 月和 7 月最多, 均为 22 例, 占全年 的26.04%。169例输人性疟疾病例中, 10 例 (5.92%)来自国内其他省份, 38 例 (22.49%)来自亚洲 6 个国家, 121 例 (71.60%)来自非洲 24 个国家。全市10 个县市区均有输人性疟疾病例报告。病例平均年龄 (38.45±11.74) 岁, 主要为男 性青壮年, 职业以农民、工人为主。发病至诊断时间平均为 4.18d, 39.05%、56.21% 的病例分别在县级、市级医疗机构确 诊。 结论 绵阳市输人性疟疾疫情仍然严峻, 应引起高度重视, 需进一步加强输人性疟疾防控;提高医务人员疟疾诊 治能力, 完善疟疾监测体系, 加强对重点地区重点人群尤其是出境人员和高疟区回归人员的健康教育, 防止继发病例 发生。

Epidemic characteristics of imported malaria in Hubei, 2015-2019

Objective To understand the malaria epidemic characteristics in Hubei Province from 2015 to 2019, so as to provide the evidence for adjusting the strategies in the post-elimination stage. Methods The data from the Disease Reporting Information System of Chinese Center for Disease Control and Prevention were analyzed, with the descriptive epidemiological method for the epidemiological characteristics of malaria in Hubei Province from 2015 to 2019. Results During 2015 to 2019, a total of 645 malaria cases were reported in Hubei Province, all reported cases were imported from overseas, 456 were infected with falciparum malaria (70.7%), 78 with vivax malaria (12.1%), 88 with ovale malaria (13.6%), 20 with quartan malaria (3.1%) and 3 with mixed infection (0.5%). The top 5 cities with highest number of imported malaria cases were Wuhan (222, 34.4%), Yichang (85, 13.2%), Huangshi (60, 9.3%), Huanggang (46, 7.1%), Xiangyang (45, 7.0%). The peak of disease onset mainly occurred in January to February, in July and in November. 84.3% (544/645) of the whole cases were concentrated in 20-<50 age groups. There were 621 male cases and 24 female cases, with a sex ratio of 25.9:1. The patients first selected diagnosis units were mainly concentrated in medical institutions, 452 (70.1%) cases were diagnosed with malaria at initial doctor visited. 43.9% of the cases were diagnosed as malaria within 24 hours after seeing a doctor. The proportion of cases with a time interval of ≥4 d from initial diagnosis to confirmed showed a decreasing trend. Imported malaria cases were mainly confirmed by prefecture-level medical institutions, accounting for 33.6%. During 2015-2019, all imported malaria cases of Hubei province were came from 39 countries distributed Africa, Asia, Oceania and South America. The imported cases came mainly from Congo-Kinshasa (118), Nigeria (73), Angola (53), Ethiopia (48) and Republic of Congo (39). Conclusions During 2015-2019, the imported malaria cases were reported in Hubei Province every year, therefore the surveillance system of malaria must be continue to work for strengthen the achievement of malaria elimination in Hubei Province. 摘要:目的 分析2015—2019年湖北省输人性疟疾流行特征,为湖北省消除疟疾后监测工作提供科学依据。 方法 在传染病报告信息管理系统中收集2015—2019年湖北省网报疟疾病例资料,对2015—2019年湖北省输人性疟 疾疫情的流行病学特征进行分析。 结果 2015—2019年湖北省共报告输人性疟疾病例645例。其中,恶性疟456例 (占70.7%)、间日疟78例（占12.1%)、卵形疟88例（占13.6%)、三日疟20例（占3.1%)和混合感染3例（占0.5%)。输人性 疟疾病例主要分布在武汉(222例,占34.4%)、宜昌（85例,占13.2%)、黄石(60例,占9.3%)、黄冈(46例,占7.1%)和襄阳 (45例,占7.0%)。2015—2019年每月均有输人性疟疾病例报告,其中1—2月、7月和11月为病例报告的3个髙峰期。 发病以20 ~ <50岁组居多,占84.3%(544/645)。男性621例,女性24例,性别比25.9:1。全省输人性疟疾病例初诊单位 主要集中在医疗机构,452例病例初诊被诊断为疟疾,初诊正确率为70.1%。病例就诊后24 h内确诊占43.9%,病例初 诊到确诊时间间隔≥4 d的占比呈现下降趋势。输人性疟疾病例主要由地市级医疗机构确诊,占33.6%。2015—2019 年,湖北省所有疟疾病例从非洲、亚洲、大洋洲和南美洲的39个国家输人。主要从非洲刚果民主共和国（118例）、尼日 利亚(73例）、安哥拉(53例）、埃塞俄比亚(48例）、刚果共和国（39例）等国家输人。 结论 2015—2019年湖北省每年均 有输人性疟疾病例报告,为固巩全省消除疟疾成果,必须持续加强对输人性疟疾疫情的监测工作。