EbolApp – A digital tool for smart contact tracing in infectious diseases (HCID) outbreaks

Abstract

Background: Outbreaks due to infectious diseases like Ebola virus disease require quick and proper epidemiological responses to implement effective countermeasures. Traditional epidemiological tools are often not easy to apply. PC-based digital tools can be cumbersome in field work. As smart phone adoption is very high in many parts of the world, smartphone-based tools could be an alternative. An app was developed for this purpose and tested in a proof-of-principle study. Methods and materials: EbolApp is an Android-based application that assigns identifiers to smartphones after installation and stores GSM/GPS tracking data on the mobile. With activated Bluetooth function any further device within a defined distance is recorded. If a user contracts a disease, ID-based user profiles are synchronized on a server by an alarm function, which informs any detected contact person and recommends a doctor's visit. Server data will be completely deleted afterwards. Individual movement profiles can be read out by authorized persons. A proof-of-principle analysis regarding compatibility and functionality was carried out by health care workers from a clinic for infectious diseases and tropical medicine. Results: On a total of 16 smartphones with Android version 6, 7 and 8, the app (Version 0.9) was installed without any problems. The complete app functionality was given for 13/16 smartphones (81.3%), no tracking was recorded in two, in one the app crashed while reading profiles. Battery consumption with continuously activated Bluetooth was significantly increased in 50% of users. Thirteen users were able to use the secure alarm function receiving corresponding contact warnings. Graphic mapping and temporal assignment of the motion profiles confirmed the correctness of the alarms. Conclusion: EbolApp is promising digital tool for contact tracing in infectious diseases. It allows fast track detection of contacts and can provide information as well as instructions to those which are at risk. This also may allow timely use of post-expositional vaccinations or medical therapies. The prerequisite is the adequate distribution of appropriate telephones within risk populations and compliance with corresponding data protection laws. In the updated Version 2.0, compatibility of the app has been improved again. A field trial in the Republic of Liberia is on the way.