On Tuesday Germany reported 21,832 Covid-19 infections within 24 hours and 169 deaths, while the 7-day incidence rose to 213.7 Covid cases per 100,000 people – the highest rate since the pandemic began.

The surge in Covid infections means people are more exposed to the virus – and there’s a higher chance of seeing an alert in the Corona-Warn-App. Here’s what that means – and what you have to do.

What happens if I see a red alert? Do I have to quarantine?

People who have downloaded Germany’s Corona-Warn-app (Covid warning app) are urged to check it regularly.

The app scans for exposures to Covid-19 (which it calculates anonymously) and shows a risk status. 

Note that you don’t receive a real-time warning if you come within two metres of a person with Covid-19 for data protection reasons. 

Twitter user Charlotte Voß recently put together a thread to show what happens if you receive an increased risk ‘red’ alert, and her experience of finding out she was infected with Covid. 

Voß pointed out that many people in Germany are not aware of the current rules for quarantine when coming into contact with people who’ve contracted Covid-19. Covid rules can vary slightly across regions. Voß details her experience with Cologne health officials.

If you receive a status showing you have an increased risk of infection, the app will recommend that you contact either your doctor, the German medical assistance hotline at 116 117 or your local health authorities.

READ ALSO: What you need to know about Covid testing when you visit Germany

They will likely say that you need to quarantine and get a Covid test – either antigen or PCR. The test will be free of charge.

Voß said she was double-vaccinated, and had visited a restaurant where her vaccination certificate was checked under 3G rules.

“Without the app and the PCR test, I would not have noticed the infection. My self-tests are/were all negative, I hardly have any symptoms,” she said.

Voß reiterated what lots of health experts say – that many people who’ve been vaccinated don’t notice their Covid infection because they may have few or no symptoms, which is likely due to protection from the jabs.

A good thread on what to do if you get a Red Alert from the Corona Warn App (OP is in Cologne, but it's a similar process in Berlin from what I understand) https://t.co/oTba4zSLYP

— nathan ma (@nthnashma) November 8, 2021

Voß said it was possible for her to get a test again after five days.

She said: “Those who are symptomless can be tested again five days after the positive test. If the result is negative, you are released from quarantine.”

Voß said that she was told the second test is generally not free.

“Anyone who cannot take the test after five days, or who has symptoms, remains in quarantine for the full 14 days (calculated from the day of the first official positive test),” she said. “At the end of the 14 days you have to take a test, for which the costs are covered.”

Voß said the Cologne health department where she lives asked about the people she “met on the two days before the positive test”.

Cologne officials do not contact these people, instead you enter their details into a digital contact management system, said Voß.

“The registered contact people then receive a “voucher” for an antigen test,” said Voß.

Under Germany’s rules, vaccinated people, and those who’ve recovered from Covid in the last six months who are identified as contacts generally do not have to quarantine unless they have symptoms, or after a positive Covid test.

For unvaccinated people, the health office will let you know if you need to quarantine (depending on the risk). 

You should also report on the Covid warning app that you have received a positive test. The information is anonymous. 

On November 9th, Voß reported that after five days she was able to do another PCR test – which was in this case free of charge – at her family doctor.

“That was negative,” she said. “I emailed the result to the Cologne health department and was informed by phone the next morning that the quarantine was over.”

Germany has federal-level guidelines for the rules on quarantines and being a contact person. As we mentioned above, health offices across Germany can have varying processes on track and trace, but this gives an idea of what to expect and what to look out for in the coming months. 

READ ALSO: Germany divided over Covid restrictions for the unvaccinated

What is the Corona-Warn-app anyway?

Back in June 2020, the German government launched the Corona-Warn-App to help monitor the Covid situation. The aim was to make tracking and tracing more efficient to keep the Covid spread down. 

The app was downloaded via the Apple Store and the Google Play Store 34.4 million times up to September 30th 2021.

The number of active users of the warning app is difficult to estimate, firstly because downloaded apps are not necessarily used and secondly because many people with a second or new mobile phone have downloaded the app several times.

The app is currently available in German, English, Romanian, Bulgarian, Polish and Turkish.

READ MORE: Who can still get free Covid tests in Germany?

How does the app work?

The app detects encounters with other smartphones in public spaces via Bluetooth by exchanging randomly generated crypto keys. The signal strength provides information about the distance between the people.

If an app user has tested positive for Covid-19, they can (voluntarily) enter this into the app. All users who have been in the vicinity of the affected person will then receive a notification about the possible risk.

If you see a risk alert from the warning app, you are being informed that the close proximity and duration of an encounter with a person who has reported a positive test result via the app means that there is an increased risk of infection – and that’s why you’re urged to take action by isolating and arranging for a Covid test. 

The app also now includes a check-in function and a digital vaccination record. It can also include proof of test results.