Background: Although a vaccination campaign has been conducted since 2004, Japanese encephalitis (JE) is still a public health problem in Guizhou, one of the provinces with the highest incidence of JE in China. The aim of this study was to understand the spatiotemporal distribution of JE and its relationship with environmental factors in Guizhou Province in the post-vaccination era, 2004–2016. Methods: We collected data on human JE cases in Guizhou Province from 2004 to 2016 from the national infectious disease reporting system. A Poisson regression model was used to analyze the relationship between JE occurrence and environmental factors amongst counties. Results: Our results showed that the incidence and mortality of JE decreased after the initiation of vaccination. JE cases were mainly concentrated in preschool and school-age children and the number of cases in children over age 15 years was significantly decreased compared with the previous 10 years; the seasonality of JE before and after the use of vaccines was unchanged. JE incidence was positively associated with cultivated land and negatively associated with gross domestic product (GDP) per capita, vegetation coverage, and developed land. In areas with cultivated land coverage < 25%, vegetation coverage > 55%, and urban area coverage > 25%, the JE risk was lower. The highest JE incidence was among mid-level GDP areas and in moderately urbanized areas. Conclusions: This study assessed the relationship between incidence of JE and environmental factors in Guizhou Province. Our results highlight that the highest risk of JE transmission in the post-vaccination era is in mid-level developed areas.

To explore epidemiological changes of Japanese encephalitis (JE) in a long-time span and evaluate the impact of mass immunisation. Data on JE cases from hospitals and the county Centers for Disease Control and Prevention in Guizhou Province was collected between 2005 and 2021. Epidemiological changes were analyzed according to a series of policy implementations and the coronavirus disease 2019 (COVID-19) pandemic. A total of 5138 JE cases and 152 deaths were reported in Guizhou Province during 2005–2021. The average incidence and case fatality rates were 0.83/100,000 and 2.96%, respectively. The JE prevalence showed a declining trend over the years with the reduced incidence gap between age groups and narrowing of the high-epidemic regions. During the COVID-19 pandemic, the JE activity reached its nadir in 2020. The inclusion in the Expanded Program on Immunization of the JE vaccine and catch-up immunisations showed a significant impact on the JE declining incidence rate. The implementation of JE immunisation programs has played a crucial role in controlling its spread. Continued efforts should be made to maintain high coverage of the JE vaccine and strengthen disease surveillance systems, ensuring JE effective control and eventual elimination.

Infant hepatitis B vaccine coverage in China is high, with over 95% of infants immunized; however, high vaccine coverage can often mask low timeliness. The vaccination interval between the second and third dose is not clearly defined by immunization guidelines in China. This retrospective cohort study assessed the time interval distribution of hepatitis B vaccination among a cohort of randomly selected live births from Centers for Disease Control and Prevention across four provinces or municipalities in China between January 2017 and December 2021. Among the infants analyzed, 163,224 received the first dose of hepatitis B vaccine with 146,905 (90.0%) and 135,757 (83.2%) infants receiving the second and third doses, respectively. A total of 132,577 (90.2%) infants received the second dose between 28–61 days after the first dose. Of the 119,437 (88.0%) infants that completed the hepatitis B series between 61–214 days after the second dose, 87,067 (64.1%) infants were vaccinated with the third dose between 151–180 days after the second dose. The time interval distribution for the three doses of hepatitis B vaccine varied across the four provinces or municipalities (P<0.001). Of the 58,077 infants who completed the hepatitis B vaccine series, 36,377 (62.6%) infants used the same type of hepatitis B vaccine for all three doses. Overall, the timeliness of hepatitis B vaccination for infants was lower than expected, with regional disparities observed. This highlights the need for improved timeliness through the introduction of a defined timeframe for the last two doses of vaccine, and training for obstetricians and related personnel.

Background: Tetanus has a high mortality rate and remains a major public health threat in low- and middle-income countries. Although neonatal tetanus has been eliminated in China, the burden of non-neonatal tetanus is still heavy. This study analyzed the case characteristics, outcomes, and hospitalization expenses of non-neonatal tetanus inpatients in Guizhou Province, China, and provided a basis for reducing the disease burden. Methods: One tertiary medical institution was randomly selected from each of the nine cities (states) in the province, and the data of non-neonatal tetanus hospitalized cases from 2021 to 2025 were collected. Descriptive epidemiological methods, the simple seasonal index method, and multiple linear regression were used in the analysis. Results: A total of 92 cases were included. Males accounted for 65.22% (60/92); farmers accounted for 86.96% (80/92); the median age was 60 (55–69) years; the incubation period ranged from 1 to 27 days; and cases peaked in summer. 95.65% (88/92) were not vaccinated with tetanus toxoid-containing vaccine (TTCV), and only 21.74% (20/92) received standardized treatment within 24 h after injury. The case fatality rate was 15.22% (14/92). None of the non-survivors were inoculated with TTCV, no standardized treatment was performed within 24 h after injury, the severity was severe or above, and the family members gave up treatment on their own. The median hospitalization cost was 55,724 yuan (equivalent to 8,359 US Dollars); the highest was 239,365 yuan (equivalent to 35,905 US Dollars); and the number of hospitalization days was the main influencing factor ( t = 5.751, p < 0.001). Conclusion: Non-neonatal tetanus in Guizhou Province was mainly in middle-aged and older male farmers, with a high incidence in summer, and most of them were not vaccinated with TTCV. The non-survivors were not vaccinated with TTCV and did not receive standard treatment within 24 h after injury. The disease had a high case fatality rate and was a serious economic burden. It is recommended to strengthen TTCV vaccination and standardized post-exposure disposal in high-risk groups, enhance medical financial support to prevent abandonment of treatment for economic reasons, and ensure that patients receive timely and comprehensive clinical care.