JMIR Publications

ABSTRACT

Background:

Background In the post-coronavirus disease (COVID-19) pandemic era, many countries launched apps to trace contacts of COVID-19 infections. Each contact tracing application (CTA) faces a variety of issues owing to different national policies or technologies to trace contacts.

Objective:

Objective We aimed to investigate all CTAs used to trace contacts in various countries worldwide, including the technology used by each CTA, the availability of knowledge information from official websites, the interoperability of the CTAs in various countries, the infection detection rate and policies of the specific country, and to summarize the current problems of the application based on the information collected.

Methods:

Method We investigated CTAs launched in all countries through Google, Google Scholar, and PUBMED. After eliminating CTAs that did not meet the screening criteria, we experimented with all applications that could be installed and complemented with information about applications that could not be installed or used by consulting official websites and previous literature. We compared the collected information on CTAs with relevant previous literature to understand and analyze the data.

Results:

Result After screening 166 COVID-19 applications developed in 197 countries worldwide, we selected 98 applications from 95 countries, among these, 63 apps were usable. The methods of contact tracing are divided into three main categories: Bluetooth, geolocation, and QR codes. Each method is further categorized depending on the protocol. At the effectiveness level, CTAs face three problems. First, the distance and time for Bluetooth/geolocation-based CTAs to record contact are generally set to 2m/15min; however, this distance should be lengthened and the time should be shortened for more infectious variants. Second, Bluetooth/geolocation-based CTAs also face the problem of lack of accuracy, for which the ultrasonic technology adopted by CTA of United states (NOVID) has proven to be effective in improving the accuracy of CTA. Additionally, we investigated infection detection rates in 33 countries, 16 of which had significantly low detection rates and wherein CTAs could have lacked effectiveness in reducing virus propagation. Regarding policy, CTAs in all countries (except for that in Europe) can only be used in their own countries and lack interoperability among others countries. In addition, five countries have already discontinued CTAs, but we believe that it is too early to discontinue them. With regard to the user acceptance, 28 out of 98 CTAs had no official source of knowledge, which could reduce user acceptance of CTAs.

Conclusions:

Conclusion We surveyed all CTAs worldwide and identified their technical, effectiveness, policy, and acceptance issues in the post-COVID-19 pandemic era.