BERLIN (Reuters) - Germany’s health minister on Wednesday urged users of a smartphone app to help trace coronavirus infections to upload positive test results into the system, so that others at risk get a timely warning. The Corona Warn App, launched 100 days ago, has been downloaded more than 18 million times - more than all other similar apps across Europe combined that use Bluetooth technology to assess an individual’s risk of catching COVID-19. Yet only 5,000 app users who have tested positive - or half the total - have actually taken the steps needed to trigger exposure notifications to their contacts, Health Minister Jens Spahn told a news conference. Most are calling a hotline, while few are directly uploading their results via their phone - reflecting lingering fears that people’s identity will be revealed despite the app’s privacy protections. “Please use the app, if you test positive, to inform those you have been in touch with,” Spahn told reporters. Despite the relatively high public support for the app, designed by Deutsche Telekom and SAP, there is little evidence so far that it has contributed meaningfully to curbing the pandemic. Still, the government is backing the Corona Warn App as a supplement to manual contact tracing to contain infection numbers that are rising in Germany, albeit more slowly than in other European countries. Work is continuing to digitally automate the task of uploading of lab test results, with the consent of users. A symptom tracker to help users figure out whether they may have COVID-19 will be added in October, said Juergen Mueller, chief technology officer at SAP.