ABSTRACT
Objective To analyze the epidemic characteristics of varicella in Chongqing from 2014 to 2020, and to provide evidence for the development of scientific and effective varicella control strategies. Methods Data on the outbreak of varicella and vaccination in Chongqing from 2014 to 2020 were collected through the China Disease Prevention and Control Information System, and descriptive epidemiological methods were used for statistical analysis. Results A total of 181 551 cases of varicella were reported in Chongqing from 2014 to 2020, with an average annual incidence rate of 83.79 per 100 000. The incidence rate of varicella increased from 39.95 per 100 000 in 2014 to 81.88 per 100 000 in 2020 (P < 0.001). The incidence of varicella was seasonal, with the peak periods occurring from May to June and from October to December each year. The average annual incidence rate in municipal districts was 88.90/100 000, higher than 67.42/100 000 in counties and 82.50/100 000 in autonomous counties. The average annual incidence rate of varicella in males (87.13/100 000) was higher than that in females (80.38/100 000). The incidence of varicella was mainly distributed in people under 15 years old, with 143 508 cases (79.10%) reported, and the highest incidence age was 5-9 years old (37.00%). Among the affected occupations , 133 733 cases (62.6%) were students , 39 274 cases (18.40%) were children in nursery care, and 17 963 cases (8.4%) were scattered children. The actual number of doses of varicella vaccine from 2014 to 2020 was 2 302 522 doses, with the coverage rates of one-dose and two-dose vaccines being 75.56% and 32.17%, respectively. ARIMA predicted that there would be 2 604, 811, 756, 1 226, 2 405, 3 904, 2 410, 1 211, 2 034, 6 878, 10 887, and 8 955 cases of varicella from January to December 2021. Conclusion The incidence of varicella in Chongqing is on the rise, with obvious seasonal, regional and population distribution characteristics. It is necessary to strengthen the prevention and control of varicella epidemic, strengthen the prevention and control measures of key groups and key institutions in the high incidence season, strengthen the publicity of varicella vaccine, and improve the vaccination rate of two-doses of varicella vaccine for eligible children.