Graduate School of Human Sciences, Waseda University, Tokorozawa, Japan.
School of Public Health, HangZhou Normal University, HangZhou, China.
JMIR Public Health Surveill. 2022 Oct 27;8(10):e40233. doi: 10.2196/40233.
In the post-COVID-19 pandemic era, many countries have launched apps to trace contacts of COVID-19 infections. Each contact-tracing app (CTA) faces a variety of issues owing to different national policies or technologies for tracing contacts.
In this study, we aimed to investigate all the CTAs used to trace contacts in various countries worldwide, including the technology used by each CTA, the availability of knowledge about the CTA from official websites, the interoperability of CTAs in various countries, and the infection detection rates and policies of the specific country that launched the CTA, and to summarize the current problems of the apps based on the information collected.
We investigated CTAs launched in all countries through Google, Google Scholar, and PubMed. We experimented with all apps that could be installed and compiled information about apps that could not be installed or used by consulting official websites and previous literature. We compared the information collected by us on CTAs with relevant previous literature to understand and analyze the data.
After screening 166 COVID-19 apps developed in 197 countries worldwide, we selected 98 (59%) apps from 95 (48.2%) countries, of which 63 (66.3%) apps were usable. The methods of contact tracing are divided into 3 main categories: Bluetooth, geolocation, and QR codes. At the technical level, CTAs face 3 major problems. First, the distance and time for Bluetooth- and geolocation-based CTAs to record contact are generally set to 2 meters and 15 minutes; however, this distance should be lengthened, and the time should be shortened for more infectious variants. Second, Bluetooth- or geolocation-based CTAs also face the problem of lack of accuracy. For example, individuals in 2 adjacent vehicles during traffic jams may be at a distance of ≤2 meters to make the CTA trace contact, but the 2 users may actually be separated by car doors, which could prevent transmission and infection. In addition, we investigated infection detection rates in 33 countries, 16 (48.5%) of which had significantly low infection detection rates, wherein CTAs could have lacked effectiveness in reducing virus propagation. Regarding policy, CTAs in most countries can only be used in their own countries and lack interoperability among other countries. In addition, 7 countries have already discontinued CTAs, but we believe that it was too early to discontinue them. Regarding user acceptance, 28.6% (28/98) of CTAs had no official source of information that could reduce user acceptance.
We surveyed all CTAs worldwide, identified their technological policy and acceptance issues, and provided solutions for each of the issues we identified. This study aimed to provide useful guidance and suggestions for updating the existing CTAs and the subsequent development of new CTAs.
在后 COVID-19 大流行时代，许多国家推出了用于追踪 COVID-19 感染接触者的应用程序。每个接触者追踪应用程序（CTA）都因各国不同的追踪接触者的政策或技术而面临各种问题。
本研究旨在调查全球各国用于追踪接触者的所有 CTA，包括每个 CTA 使用的技术、官方网站提供的有关 CTA 的知识、各国 CTA 的互操作性，以及推出 CTA 的特定国家的感染检测率和政策，并根据收集到的信息总结应用程序存在的问题。
我们通过谷歌、谷歌学术和 PubMed 调查了所有国家推出的 CTA。我们对所有可以安装的应用程序进行了实验，并通过咨询官方网站和之前的文献，编译了无法安装或使用的应用程序的信息。我们将我们收集到的有关 CTA 的信息与相关的先前文献进行比较，以了解和分析数据。
在筛选了全球 197 个国家/地区开发的 166 个 COVID-19 应用程序后，我们从 95 个（48.2%）国家中选择了 98 个（59%）应用程序，其中 63 个（66.3%）应用程序可用。接触追踪方法分为 3 大类：蓝牙、地理位置和 QR 码。在技术层面上，CTA 面临 3 大问题。首先，基于蓝牙和地理位置的 CTA 记录接触的距离和时间通常设置为 2 米和 15 分钟；然而，对于更具传染性的变异株，这个距离应该延长，时间应该缩短。其次，基于蓝牙或地理位置的 CTA 也存在准确性问题。例如，交通拥堵时相邻车辆中的两个人可能在≤2 米的距离内进行 CTA 接触追踪，但实际上这两个人可能被车门隔开，这可能会阻止传播和感染。此外，我们调查了 33 个国家的感染检测率，其中 16 个（48.5%）国家的感染检测率明显较低，表明 CTA 可能在降低病毒传播方面缺乏有效性。关于政策，大多数国家的 CTA 只能在本国使用，缺乏与其他国家的互操作性。此外，有 7 个国家已经停止使用 CTA，但我们认为现在停止还为时过早。关于用户接受度，98 个 CTA 中有 28.6%（28 个）没有官方信息来源，这可能会降低用户接受度。
我们调查了全球所有的 CTA，确定了它们的技术政策和接受度问题，并为我们发现的每个问题提供了解决方案。本研究旨在为更新现有的 CTA 和后续开发新的 CTA 提供有用的指导和建议。
