Objective:To deeply analyze the epidemiological characteristics and changing trends of intestinal infectious diseases in China, and provide scientific evidence for the prevention and control of intestinal infectious diseases.Methods:The incidence data of notifiable intestinal infectious diseases in China from 2013 to 2022 were collected from China Disease Prevention and Control Information System. Descriptive statistical method was used to analyze the distributions of intestinal infectious diseases in China, and the annual change rate and seasonal index were calculated.Results:During 2013-2022, intestinal infectious diseases were reported nationwide, with the cases accounting for 43.50% of all notifiable infectious disease cases. The average reported incidence rate was 224.50/100 000, showing a decreasing trend year by year (average annual percent change=-6.45%, t=-2.76, P=0.025). The top 5 intestinal infectious diseases were hand foot and mouth disease (HFMD) (130.40/100 000), other infectious diarrhea (80.18/100 000), dysentery (7.45/100 000), acute hemorrhagic conjunctivitis (2.49/100 000) and viral hepatitis E (1.92/100 000). The incidences of dysentery, HFMD, typhoid fever/paratyphoid fever, viral hepatitis A and acute hemorrhagic conjunctivitis all showed decreasing trends year by year (all P<0.05), while the incidences of hepatitis E and other infectious diarrhea showed no significant changes with year (both P>0.05). The incidence of intestinal infectious diseases was high during May to October, with the peak in June. The incidence rate of intestinal infectious diseases was significantly higher in men than in women (all P<0.05). The HFMD, other infectious diarrhea and dysentery cases were mainly children aged 0-5 years, while the cholera, hepatitis A, hepatitis E, typhoid fever/paratyphoid fever and acute hemorrhagic conjunctivitis cases were mainly farmers aged ≥20 years. The annual reported incidence rate of intestinal infectious diseases was higher in southern provinces (283.66/100 000) than in northern provinces (142.63/100 000), and the annual reported incidence rate of intestinal infectious diseases was higher in coastal provinces (279.52/100 000) than in inland provinces (181.78/100 000), the differences were all significant (both P<0.001). Conclusions:During 2013-2022, the incidence of intestinal infectious diseases decreased significantly in China, with HFMD and other infectious diarrhea as the main diseases. Strengthened surveillance for intestinal infectious diseases should be carried out in key groups, such as children living scatteredly and farmers, and targeted prevention and control measures should be taken according to the epidemiological characteristics of different diseases to effectively reduce the incidence of intestinal infectious diseases.

Objective:To analyze the epidemiological characteristics and trend of acute hemorrhagic conjunctivitis (AHC) in China from 2015 to 2022, and to provide evidence for the adjustment of prevention and control strategies and measures for AHC.Methods:The case data of AHC reported by national notifiable disease information system from 2015 to 2022 were collected, and descriptive analysis method were used to analyze the population distribution characteristics, temporal epidemiological trends and spatial clusters of AHC in China.Results:From 2015 to 2022, the incidence of AHC in China ranged from 1.85/100 000 to 2.97/100 000, with a fluctuating downward trend. The average annual percent change (AAPC) was -4.91 (95% CI: -7.74 to -2.00, P<0.05), with an annual percent change (APC) of 2.73 (95% CI: -2.34 to 8.06, P=0.189) for 2015—2019 and an APC of -14.23 (95% CI: -21.78 to -5.94, P<0.05). The age-specific incidence rate was highest in children aged 0-4 years (fluctuating between 4.69 and 5.67/100 000 from 2015 to 2019; It decreased significantly during 2020—2022, fluctuating between 1.93 and 2.72 per 100 000).The proportion of cases in children at 0-4 years of age showed a fluctuating downward trend from 8.68% in 2015 to 3.76% in 2020, with an increase in 2021—2022 to 5.74%. After 2020, the proportion of the population aged 60 years and above has increased, reaching 33.59% in 2022. Cases were mainly farmers, with a fluctuating upward trend of around 50% per year, with the highest percentage of 60.96% in 2020. The peak seasonal incidence of AHC was obvious from May to September from 2015 to 2019, but it was not obvious in 2020—2022. The cases were mainly distributed in Guangxi, Hainan and other provinces in the southwestern part of China. The high incidence counties were concentrated in Leye County of Guangxi, Maojian District of Hubei, Fuchuan Yao Autonomous County of Guangxi, Funing County of Yunnan, and Pulan County of Tibet every year. Conclusions:The overall epidemic rate of AHC in China showed a fluctuating downward trend from 2015 to 2022, with a pronounced decline observed between 2020 and 2022, potentially linked to non-pharmaceutical interventions during the COVID-19 pandemic. Increased attention needs to be given to farmers and people above 60 years of age to reduce the risk of morbidity. Moreover, prevention and control efforts should be strengthened in high-risk areas of southwestern China, and comprehensive measures should be implemented in counties with high incidence, including enhanced health education campaigns and improved allocation of sanitary facilities, to reduce the risk of AHC infection. This study is the first to highlight the potential impact of public health policies on AHC epidemiology, thereby offering a scientific foundation for population- and region-specific precision prevention strategies, particularly guiding the refinement of control measures in high-burden areas.

Objective:To deeply analyze the epidemiological characteristics and changing trends of intestinal infectious diseases in China, and provide scientific evidence for the prevention and control of intestinal infectious diseases.Methods:The incidence data of notifiable intestinal infectious diseases in China from 2013 to 2022 were collected from China Disease Prevention and Control Information System. Descriptive statistical method was used to analyze the distributions of intestinal infectious diseases in China, and the annual change rate and seasonal index were calculated.Results:During 2013-2022, intestinal infectious diseases were reported nationwide, with the cases accounting for 43.50% of all notifiable infectious disease cases. The average reported incidence rate was 224.50/100 000, showing a decreasing trend year by year (average annual percent change=-6.45%, t=-2.76, P=0.025). The top 5 intestinal infectious diseases were hand foot and mouth disease (HFMD) (130.40/100 000), other infectious diarrhea (80.18/100 000), dysentery (7.45/100 000), acute hemorrhagic conjunctivitis (2.49/100 000) and viral hepatitis E (1.92/100 000). The incidences of dysentery, HFMD, typhoid fever/paratyphoid fever, viral hepatitis A and acute hemorrhagic conjunctivitis all showed decreasing trends year by year (all P<0.05), while the incidences of hepatitis E and other infectious diarrhea showed no significant changes with year (both P>0.05). The incidence of intestinal infectious diseases was high during May to October, with the peak in June. The incidence rate of intestinal infectious diseases was significantly higher in men than in women (all P<0.05). The HFMD, other infectious diarrhea and dysentery cases were mainly children aged 0-5 years, while the cholera, hepatitis A, hepatitis E, typhoid fever/paratyphoid fever and acute hemorrhagic conjunctivitis cases were mainly farmers aged ≥20 years. The annual reported incidence rate of intestinal infectious diseases was higher in southern provinces (283.66/100 000) than in northern provinces (142.63/100 000), and the annual reported incidence rate of intestinal infectious diseases was higher in coastal provinces (279.52/100 000) than in inland provinces (181.78/100 000), the differences were all significant (both P<0.001). Conclusions:During 2013-2022, the incidence of intestinal infectious diseases decreased significantly in China, with HFMD and other infectious diarrhea as the main diseases. Strengthened surveillance for intestinal infectious diseases should be carried out in key groups, such as children living scatteredly and farmers, and targeted prevention and control measures should be taken according to the epidemiological characteristics of different diseases to effectively reduce the incidence of intestinal infectious diseases.

Objective:To analyze the epidemiological characteristics and trend of acute hemorrhagic conjunctivitis (AHC) in China from 2015 to 2022, and to provide evidence for the adjustment of prevention and control strategies and measures for AHC.Methods:The case data of AHC reported by national notifiable disease information system from 2015 to 2022 were collected, and descriptive analysis method were used to analyze the population distribution characteristics, temporal epidemiological trends and spatial clusters of AHC in China.Results:From 2015 to 2022, the incidence of AHC in China ranged from 1.85/100 000 to 2.97/100 000, with a fluctuating downward trend. The average annual percent change (AAPC) was -4.91 (95% CI: -7.74 to -2.00, P<0.05), with an annual percent change (APC) of 2.73 (95% CI: -2.34 to 8.06, P=0.189) for 2015—2019 and an APC of -14.23 (95% CI: -21.78 to -5.94, P<0.05). The age-specific incidence rate was highest in children aged 0-4 years (fluctuating between 4.69 and 5.67/100 000 from 2015 to 2019; It decreased significantly during 2020—2022, fluctuating between 1.93 and 2.72 per 100 000).The proportion of cases in children at 0-4 years of age showed a fluctuating downward trend from 8.68% in 2015 to 3.76% in 2020, with an increase in 2021—2022 to 5.74%. After 2020, the proportion of the population aged 60 years and above has increased, reaching 33.59% in 2022. Cases were mainly farmers, with a fluctuating upward trend of around 50% per year, with the highest percentage of 60.96% in 2020. The peak seasonal incidence of AHC was obvious from May to September from 2015 to 2019, but it was not obvious in 2020—2022. The cases were mainly distributed in Guangxi, Hainan and other provinces in the southwestern part of China. The high incidence counties were concentrated in Leye County of Guangxi, Maojian District of Hubei, Fuchuan Yao Autonomous County of Guangxi, Funing County of Yunnan, and Pulan County of Tibet every year. Conclusions:The overall epidemic rate of AHC in China showed a fluctuating downward trend from 2015 to 2022, with a pronounced decline observed between 2020 and 2022, potentially linked to non-pharmaceutical interventions during the COVID-19 pandemic. Increased attention needs to be given to farmers and people above 60 years of age to reduce the risk of morbidity. Moreover, prevention and control efforts should be strengthened in high-risk areas of southwestern China, and comprehensive measures should be implemented in counties with high incidence, including enhanced health education campaigns and improved allocation of sanitary facilities, to reduce the risk of AHC infection. This study is the first to highlight the potential impact of public health policies on AHC epidemiology, thereby offering a scientific foundation for population- and region-specific precision prevention strategies, particularly guiding the refinement of control measures in high-burden areas.

Objective:To analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) in cases of febrile respiratory syndrome in China from 2010 to 2020.Methods:Based on the sub-project of the National Science and Technology Major Project for Infectious Disease Prevention and Control "Infectious Disease Monitoring Technology Platform", active monitoring of febrile respiratory syndrome cases was conducted in sentinel hospitals in 31 provinces across China (excluding Hong Kong, Macau, and Chinese Taiwan) from January 2010 to December 2020, resulting in the inclusion of 191 441 cases. Clinical specimens of monitored cases were screened for HRSV nucleic acid, and the differences in HRSV detection rates among different age groups, regions, and time periods were analyzed using the χ 2 test/Fisher exact probability method. Results:Among the 191 441 cases of febrile respiratory syndrome in China from 2010 to 2020, the age group M ( Q1, Q3) was 9 (2, 40) years old, with 83 773 cases (43.8%) in the <5 years old group. There were 113 660 males, with a male-to-female ratio of 1.5∶1.0. There were as many as 105 508 cases (55.2%) of scattered children and preschool children. About 70 565 cases (36.9%) lived in the northern region. There were 13 858 HRSV positive cases, with a total positive rate of 7.2%. The positive rate of HRSV detection in the northern population was 5.7% (4 004/70 565), which was lower than that in the southern population (8.2%, 9 854/120 876), and the difference was statistically significant (χ 2=407.4, P<0.001). HRSV was detected in all age groups, with the highest positive rate of 23.9% in the <6 months age group. The month with the highest positive rate was December, and autumn and winter were the main epidemic seasons. Both northern and southern HRSV subtypes were mainly infected with type A, with a low proportion of mixed infections of type A and type B. Conclusion:HRSV is a common pathogen causing respiratory infections in children from 2010 to 2020. It can be detected throughout the year and shows the main peak of prevalence in autumn and winter. The HRSV strain is mainly classified as a type A infection.

Objective To analyze the epidemiological characteristics of leptospirosis in China from 2010 to 2022, so as to provide insights into formulation of the leptospirosis control strategy. Methods All data pertaining to clinically diagnosed cases and confirmed cases of leptospirosis reported in China from January 1, 2010 to December 31, 2022 was collected from Chinese Disease Prevention and Control Information Management System. The spatial, temporal and population distributions, and report and diagnosis institutions of leptospirosis cases were analyzed using a descriptive epidemiological method. Results A total of 4 559 leptospirosis cases were reported in China from 2010 to 2022, with an annual average number of 351 cases, and the number of reported leptospirosis cases reduced from 679 cases in 2010 to 158 cases in 2018. A total of 4 276 leptospirosis cases were reported in Sichuan Province, Yunnan Province, Guangdong Province, Hunan Province, Fujian Province, Zhejiang Province, Guangxi Zhuang Autonomous Region, Anhui Province, Jiangxi Province and Guizhou Province, accounting for 93.79% of the total number of leptospirosis cases in China. The number of leptospirosis cases had recently appeared a remarkable decline in Yunnan Province, while a significant rise was seen in the number of leptospirosis cases in two provinces of Zhejiang and Guangdong. No leptospirosis cases were reported in Henan Province from 2010 to 2020; however, there were 5 cases and 2 cases reported in 2021 and 2022, respectively. There was only one leptospirosis case reported in Shaanxi Province from 2010 to 2017; however, leptospirosis cases were reported in the province for 5 consecutive years since 2018. Leptospirosis cases were reported throughout the year in China from 2010 to 2022, with the peak of incidence found during the period between August and October, and the peak of leptospirosis incidence varied in provinces. A higher number of leptospirosis cases was seen among men than among women, with a male to female ratio of 2.3:1, and the median age of leptospirosis cases was 50 years (interquartile range, 23 years), with the highest proportion of leptospirosis cases reported at ages of 51 to 60 years (23.21%). Among all reported leptospirosis cases, 53.28% were confirmed cases, and the proportion of confirmed cases increased from 35.05% in 2010 to 61.66% in 2022. In addition, there were 67.22% of leptospirosis cases (2 937 cases) reported by comprehensive hospitals, 20.44% (893 cases) by disease control and prevention institutions, 7.23% (316 cases) by grassroots healthcare institutions and 5.10% (223 cases) by other healthcare and medical institutions, and the mortality of reported leptospirosis cases was 1.07% in China from 2010 to 2022, with a higher mortality seen among men than among women (1.39% vs. 0.36%; χ² = 9.52, P = 0.002). Conclusions The incidence of leptospirosis remained at a low level in China from 2010 to 2022, and southern China was still the main endemic area for leptospirosis. The epidemiological characteristics of leptospirosis cases varied in endemic provinces, and leptospirosis cases had been continued to be reported in Shaanxi and Henan provinces, which should be paid much attention to. Intensified surveillance of leptospirosis, improved diagnosis and treatment capability of leptospirosis cases and leptospirosis control with adaptations to local circumstance are recommended.

Visceral leishmaniasis is a zoonotic parasitic disease caused by viscerotropic Leishmania species and transmitted by bites of infected phlebotomine sandflies, which is predominantly prevalent in the Indian subcontinent, eastern Africa and South America. Currently, visceral leishmaniasis is the second most fatal parasitic disease in the world. Because of climate changes, urban development and individual conditions, there are changes in the density of visceral leishmaniasis vector sandflies and the likelihood of contact with humans, resulting in a visceral leishmaniasis transmission risk. The review summarizes natural, social and biological factors affecting the transmission of visceral leishmaniasis, so as to provide insights into formulation of targeted control measures for visceral leishmaniasis.

Objective:To analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) in cases of febrile respiratory syndrome in China from 2010 to 2020.Methods:Based on the sub-project of the National Science and Technology Major Project for Infectious Disease Prevention and Control "Infectious Disease Monitoring Technology Platform", active monitoring of febrile respiratory syndrome cases was conducted in sentinel hospitals in 31 provinces across China (excluding Hong Kong, Macau, and Chinese Taiwan) from January 2010 to December 2020, resulting in the inclusion of 191 441 cases. Clinical specimens of monitored cases were screened for HRSV nucleic acid, and the differences in HRSV detection rates among different age groups, regions, and time periods were analyzed using the χ 2 test/Fisher exact probability method. Results:Among the 191 441 cases of febrile respiratory syndrome in China from 2010 to 2020, the age group M ( Q1, Q3) was 9 (2, 40) years old, with 83 773 cases (43.8%) in the <5 years old group. There were 113 660 males, with a male-to-female ratio of 1.5∶1.0. There were as many as 105 508 cases (55.2%) of scattered children and preschool children. About 70 565 cases (36.9%) lived in the northern region. There were 13 858 HRSV positive cases, with a total positive rate of 7.2%. The positive rate of HRSV detection in the northern population was 5.7% (4 004/70 565), which was lower than that in the southern population (8.2%, 9 854/120 876), and the difference was statistically significant (χ 2=407.4, P<0.001). HRSV was detected in all age groups, with the highest positive rate of 23.9% in the <6 months age group. The month with the highest positive rate was December, and autumn and winter were the main epidemic seasons. Both northern and southern HRSV subtypes were mainly infected with type A, with a low proportion of mixed infections of type A and type B. Conclusion:HRSV is a common pathogen causing respiratory infections in children from 2010 to 2020. It can be detected throughout the year and shows the main peak of prevalence in autumn and winter. The HRSV strain is mainly classified as a type A infection.

The studies on infectiousness of person infected with SARS-CoV-2 at different stages of illness are an important basis for making effective prevention and control measures such as investigating the infectious source, determining the scope of close contacts and the timing of case isolation. This review discusses the infectiousness of cases infected with SARS-CoV-2 in the incubation period, symptomatic period and convalescent period by reviewing national and international literatures, technical and professional guidelines. Existing researches suggest that the infectious viruses could be isolated at the end of the incubation period as well as since illness onset, and viral load in upper respiratory tract swabs reached the peak on day 4-6 after illness onset and thereafter began to decline, implying the infectiousness was relatively strong at the end of incubation period and within one week after illness onset. Although there were a few cases who tested positive for SARS-CoV-2 after recovery, no evidence was found to indicate these cases can cause the transmission.

Objective:To analyze the incidence of acute respiratory infection (ARI) and related healthcare seeking behaviors in population in the period of COVID-19 epidemic in China.Methods:According to the province specific cumulative incidence rates of COVID-19 reported as of March 31, 2020, the low, medium and high-risk areas were classified. In these areas, a stratified two stage cluster random sampling method was used to select participants for face-to-face questionnaire surveys. Data on the incidence of ARI and related healthcare seeking behaviors in community residents during COVID-19 epidemic period were collected to calculate the attack rate of ARI and related healthcare seeking rate. Logistic regression method was used to explore the influencing factors for ARI incidence and healthcare seeking behavior.Results:A total of 34 857 community residents were surveyed, in whom 647 (1.9%) reported that they had ARI symptoms during the COVID-19 epidemic period, and 241 (37.2%) had healthcare seeking behaviors. In terms of the incidence of COVID-19-related ARI, in high-risk area, the risk of COVID-19-related ARI was 1.36 times (95% CI: 1.12-1.65) than that in low-risk area; among different age groups, the risk of COVID-19-related ARI in age groups 20-39 years, ≥60 years was 1.80 times (95% CI: 1.29-2.59) and 1.63 times (95% CI: 1.14-2.40) than that in age group 1-9 years; the risk of COVID-19-related ARI in people with underlying diseases was 1.53 times (95% CI: 1.23-1.89) than that in those without underlying diseases; the risk of COVID-19-related ARI in people with contacts with confirmed cases of COVID-19 and people with fever or respiratory symptoms was 1.53 times (95% CI: 1.01-2.27) and 6.60 times (95% CI: 5.05-8.53) than those in people without these contacts. The healthcare seeking rate in COVID-19-related ARI patients with exposures to those with fever or respiratory symptoms was 1.68 times (95% CI: 1.05-2.70) than that in such patients without the exposures. Conclusions:The attack rate of COVID-19-related ARI was affected by the local epidemic level of COVID-19, and in high-risk area, the attack rate of COVID-19-related ARI was also high. The healthcare seeking rate in patients with COVID-19-related ARI was low. Therefore, it is necessary to encourage the healthcare seeking in people with ARI in COVID-19 pandemic period.