Abstract:
Objective To analyze the epidemiological and clinical characteristics of pertussis in Taizhou City of Zhejiang Province in 2024, and to explore the local prevention and control strategy.
Methods Case data and population data were obtained from the China Disease Prevention and Control Information System. Epidemiological case investigation data were collected from the Zhejiang Vaccine Clinical Research and Application Effectiveness Evaluation System and the Immunization Service Information System. Descriptive epidemiological methods were used to analyze the temporal, regional, and population distributions, and SaTScan 9.7 software was applied for spatiotemporal cluster scanning.
Results In 2024, a total of 3 090 pertussis cases were reported in Taizhou City, with no deaths. The number of reported cases increased significantly compared with previous years, and the peak occurred in April. Spatiotemporal scanning identified three clusters: a most likely cluster centered on Tantou Town in Tiantai County, covering 16 streets/towns; a second most likely cluster centered on Taiping Subdistrict in Wenling City, covering 11 streets/towns; and a third most likely cluster centered on Ganjiang Town in Yuhuan City, covering 6 streets/towns. The three clusters together accounted for 31.04% of the total scanned cases. The majority of cases were in the 6-10 years age group (55.02%), and students accounted for the highest proportion by occupation (44.17%). The most common clinical manifestations were cough (97.58%) and aggravated nocturnal cough (52.10%), while typical symptoms were less frequent. Among the cases, 82.49% had completed the full 4-dose vaccination schedule, and their complication rate (10.47%) was lower than that of the unvaccinated group (20.56%).
Conclusion The number of reported pertussis cases surged in Taizhou City in 2024, showing significant spatiotemporal clustering, with school-aged children being the high-risk group. Vaccination could reduce the risk of complications. It is recommended to further enhance surveillance sensitivity, with a focus on strengthening immunization strategies for high-risk groups such as school-aged children aged 6-10 years old, and to reinforce targeted protection for infants under 1 year old who have not completed primary vaccination, along with their families. In addition, prevention and control resources should be deployed in advance for the cluster areas identified through spatiotemporal analysis and for the spring peak season, to interrupt local transmission chains.