Varicella zoster virus and cardiovascular diseases

A time series study of the association between extreme temperature and ozone on varicella incidence

This study aimed to discuss the effects of extreme temperatures and ozone on the incidence of varicella in Shijiazhuang City from 2014 to 2022, which provides new ideas for preventing public health events. METHODS We collected varicella cases in Shijiazhuang, China, from 2014 to 2022 and evaluated the relationship between temperature extremes and ozone on varicella incidence by building distributional lag nonlinear models. The analysis was stratified by age and sex, with 19,188 varicella cases reported. A nonlinear "J"-shaped relationship emerged between mean daily temperature and varicella incidence, where colder temperatures heightened risk, while hotter ones reduced it, particularly affecting females and adolescents. Additionally, ozone concentration displayed an "S"-shaped correlation, with low levels posing a risk and high levels protective against varicella, notably among females and adults. Our study results show a significant correlation between extreme temperatures and ozone concentrations on varicella incidence, and this study may help prevention and control authorities to create timely warnings of high-risk outbreaks, and assist the public in responding to varicella outbreaks.

Epidemiological Characteristics of Varicella under Different Immunisation Strategies in Suzhou Prefecture, Jiangsu Province

Background: The varicella vaccine is excluded from the Chinese national immunisation programme but is included in the local expanded programme on immunisation (EPI) in the Suzhou Prefecture. This study investigated the epidemiological characteristics of the varicella cases during the implementation of different immunisation strategies in the Suzhou Prefecture, Jiangsu Province. Methods: In this study, we used descriptive statistics. Information on reported instances from 2012 to 2021 was first retrieved. Data on varicella cases were collected from the China Information System for Disease Control and Prevention (CISDCP). Similarly, information on vaccinated children was obtained from the Jiangsu Province Vaccination Integrated Service Management Information System (JPVISMIS). The census data in this study was procured from the Suzhou Bureau of Statistics. Results: From 2012 to 2021, a total of 118,031 cases of varicella were reported in Suzhou, and the average annual reported incidence was 91.35 per 100,000. The average yearly incidence after implementing the two-dose varicella vaccination decreased by 41.57% compared with the implementation of one dose. This study demonstrates two annual incidence peaks, a small peak between April and July and a prominent peak between October and January. It is also possible that this seasonal distribution is related to the geography of Suzhou. The average annual reported incidence between districts with a statistically significant difference (χ2 = 98.077, p < 0.05). The one-dose varicella vaccination coverage gradually increased from 55.34% in 2012 to 89.06% in 2021 and the two-dose varicella vaccination coverage gradually increased from 0.27% in 2012 to 82.17% in 2021. Conclusions: Administering the varicella vaccine in the local EPI has significantly decreased the incidence rate and the total number of cases. A two-dose vaccination schedule is still the best vaccination strategy for varicella vaccine effectiveness.