Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, China.
Yunnan Center for Disease Control and Prevention, Yunnan, China.
J Med Internet Res. 2023 May 16;25:e44186. doi: 10.2196/44186.
Chickenpox is an old but easily neglected infectious disease. Although chickenpox is preventable by vaccines, vaccine breakthroughs often occur, and the chickenpox epidemic is on the rise. Chickenpox is not included in the list of regulated communicable diseases that must be reported and controlled by public and health departments; therefore, it is crucial to rapidly identify and report varicella outbreaks during the early stages. The Baidu index (BDI) can supplement the traditional surveillance system for infectious diseases, such as brucellosis and dengue, in China. The number of reported chickenpox cases and internet search data also showed a similar trend. BDI can be a useful tool to display the outbreak of infectious diseases.
This study aimed to develop an efficient disease surveillance method that uses BDI to assist in traditional surveillance.
Chickenpox incidence data (weekly from January 2017 to June 2021) reported by the Yunnan Province Center for Disease Control and Prevention were obtained to evaluate the relationship between the incidence of chickenpox and BDI. We applied a support vector machine regression (SVR) model and a multiple regression prediction model with BDI to predict the incidence of chickenpox. In addition, we used the SVR model to predict the number of chickenpox cases from June 2021 to the first week of April 2022.
The analysis showed that there was a close correlation between the weekly number of newly diagnosed cases and the BDI. In the search terms we collected, the highest Spearman correlation coefficient was 0.747. Most BDI search terms, such as "chickenpox," "chickenpox treatment," "treatment of chickenpox," "chickenpox symptoms," and "chickenpox virus," trend consistently. Some BDI search terms, such as "chickenpox pictures," "symptoms of chickenpox," "chickenpox vaccine," and "is chickenpox vaccine necessary," appeared earlier than the trend of "chickenpox virus." The 2 models were compared, the SVR model performed better in all the applied measurements: fitting effect, R=0.9108, root mean square error (RMSE)=96.2995, and mean absolute error (MAE)=73.3988; and prediction effect, R=0.548, RMSE=189.1807, and MAE=147.5412. In addition, we applied the SVR model to predict the number of reported cases weekly in Yunnan from June 2021 to April 2022 using the same period of the BDI. The results showed that the fluctuation of the time series from July 2021 to April 2022 was similar to that of the last year and a half with no change in the level of prevention and control.
These findings indicated that the BDI in Yunnan Province can predict the incidence of chickenpox in the same period. Thus, the BDI is a useful tool for monitoring the chickenpox epidemic and for complementing traditional monitoring systems.
水痘是一种古老但容易被忽视的传染病。尽管水痘可以通过疫苗预防，但疫苗突破时有发生，水痘疫情呈上升趋势。水痘并未被列入必须报告和控制的法定传染病名单，因此，在早期快速识别和报告水痘疫情至关重要。百度指数（BDI）可以补充中国布鲁氏菌病和登革热等传统传染病监测系统。报告的水痘病例数和互联网搜索数据也显示出类似的趋势。BDI 可以成为一种有用的工具，用于显示传染病的爆发情况。
本研究旨在开发一种利用 BDI 辅助传统监测的高效疾病监测方法。
获取云南省疾病预防控制中心报告的 2017 年 1 月至 2021 年 6 月每周的水痘发病率数据，评估水痘发病率与 BDI 之间的关系。我们应用支持向量机回归（SVR）模型和包含 BDI 的多元回归预测模型来预测水痘的发病率。此外，我们还使用 SVR 模型预测了 2021 年 6 月至 2022 年 4 月第一周的水痘病例数。
分析表明，新诊断病例数与 BDI 之间存在密切关联。在我们收集的搜索词中，最高的斯皮尔曼相关系数为 0.747。大多数 BDI 搜索词，如“水痘”、“水痘治疗”、“水痘的治疗”、“水痘症状”和“水痘病毒”，趋势一致。一些 BDI 搜索词，如“水痘图片”、“水痘症状”、“水痘疫苗”和“是否需要接种水痘疫苗”，比“水痘病毒”的趋势出现得更早。对这两个模型进行比较，SVR 模型在所有应用的测量指标中表现更好：拟合效果，R=0.9108，均方根误差（RMSE）=96.2995，平均绝对误差（MAE）=73.3988；预测效果，R=0.548，RMSE=189.1807，MAE=147.5412。此外，我们应用 SVR 模型，使用同一时期的 BDI 预测 2021 年 6 月至 2022 年 4 月云南省每周报告的病例数。结果表明，2021 年 7 月至 2022 年 4 月的时间序列波动与过去一年半的情况相似，防控水平没有变化。
这些发现表明，云南省的 BDI 可以预测同期的水痘发病率。因此，BDI 是监测水痘疫情和补充传统监测系统的有用工具。
