BERLIN — When she returned to Germany last week from a vacation in Serbia, one of the first things Snjezana Kirstein did was to stop at a pop-up coronavirus testing center at Berlin’s Tegel Aiport.
Whereas such tests can be hard to find in the United States, with unpredictable costs and results two weeks in coming, Ms. Kirstein was on her way in a matter of minutes after having her nose and throat swabbed. She expected an answer in 24 to 48 hours. The test was not only swift, it was free.
“I think it is super,” Ms. Kirstein said. “It was so easy to find, and best of all, it didn’t cost me a thing.”
As of Saturday, Germany will require that same simple test for all citizens or residents, like Ms. Kirstein, and other travelers who enter the country from coronavirus “hot spots,” again making it a leader in using testing as a firewall against the spread of the virus.
“I am very aware that this is an intrusion in personal freedom,” Jens Spahn, Germany’s health minister, said at a news conference Thursday. “But freedom always comes with responsibility for myself and for others.”
As Europe reopens, cases have begun ticking up nearly everywhere, to a greater or lesser extent, leaving countries in a constant, seesaw battle to tamp down outbreaks before they undo months of hard-won progress made during costly lockdowns this spring.
Germany is no exception. This week it recorded 1,045 new coronavirus infections in a single day, part of a rising trend that has begun to worry officials as people return from trips abroad during the summer vacation season.
One of the biggest concerns in Germany and across the continent is that travelers will carry the virus with them. Until now, Germany, like other countries, has relied on quarantining newly arriving travelers. But such measures are not always enforced, or strictly followed.
Since the start of the pandemic, Germany has made testing a primary tool in its battle against the virus. Now it is turning to that approach again to head off a potential second wave of infections. Its capacity to make testing efficient, affordable and available has distinguished it among industrialized nations.
In January, doctors at the Charité research hospital in Berlin developed one of the world’s first diagnostic tests for the new coronavirus. They quickly made it available to the country’s public hospitals and research laboratories, as well as a nationwide network of about 200 privately owned labs. Everyone focused on making test kits.
The World Health Organization later approved the kits and distributed instructions for developing them worldwide. At that time, the Centers for Disease Control and Prevention were still struggling to develop test kits in the United States.
While nearly 90 percent of Germany’s population of 83 million is covered by public insurance, people can also opt for private insurance that either competes with the public system, or provides top-up coverage.
By May, the German authorities required all insurance companies to cover the cost of testing. Initially it was limited to those with symptoms, but today it is available to just about everyone, with the government agreeing to help cover the costs.
“We have had a very important principle since the beginning of the pandemic — that testing in Germany is not a question of money,” Mr. Spahn said. “That is a big difference to many other countries that have failed to test enough over many months.”
Early on, the government also ordered hospitals and labs to reduce all but necessary treatments to free resources to process coronavirus tests, earmarking millions to support the effort and ensuring speedy results.
These measures allowed Germany to ramp up testing at a pace that prevented the country’s hospitals — well equipped in any case, with one of the world’s highest ratios of intensive care beds per capita and a centralized system to transfer patients between them — from becoming overwhelmed.
By March, Germany was one of the highest testers per capita in the world. Other countries have since overtaken it, in part because Germany has been so effective in targeting tests and following up on positive results to isolate those infected and shut down chains of infection before they get out of control.
So while Germany can carry out as many as 1.2 million tests per week, according the health ministry, it is only currently testing half that many people. That gives it the bandwidth to easily expand testing to incoming travelers, while still maintaining readiness should a big second wave arrive.
The United States has a capacity of 4.5 million tests per week, according to the Rockefeller Foundation, but its population is also roughly four times the size of Germany’s, and results can take five to 14 days.
The United States also lacks comprehensive contract-tracing, another factor that has left it struggling to contain the spread of the virus. Germany has had fewer than 10,000 deaths attributed to the virus, the United States more than 150,000.
Those awaiting test results in Germany are required to self-quarantine, and are released from the obligation immediately if the result is negative. They must also leave contact information in case they have a positive result and need to be traced.
The speed of the results, then, is critical to the containment effort. People are more likely to abide isolation for two days than for two weeks, and even if they don’t they still have less time to wander around and potentially expose others. Germany’s shorter turnaround also reduces the time that healthy people are taken out of productive roles in society.
Those who refuse a test must remain in quarantine for two weeks, unless they can provide a negative test less than 72 hours old. Under current E.U. travel restrictions, foreigners from outside the bloc are allowed to enter the country only if they have the right to live and work in Germany, with few exceptions.
Germany’s wide availability of testing has not made everyone happy, however, and not all agree on the benefits.
Some experts warn that it could overwhelm laboratories and threaten the country’s readiness to deal with a resurgence of the virus when colder temperatures push people back indoors.
“It is questionable whether the general testing of travel returnees offers an appropriate balance between benefit and expense,” said Dr. Michael Müller, head of the Association of Medical Labs, which represents more than 200 labs across the country.
Others have questioned whether it is fair to saddle taxpayers with the burden of paying for the tests for those who willingly risk traveling outside Europe, despite warnings by government health authorities.
The requirement for travelers includes those coming from 130 countries and regions, including the United States and three districts in Spain, which the German authorities consider high-risk for spread of the virus.
But Mr. Spahn rejected the idea that only the wealthy were traveling, citing people with families in Turkey or elsewhere in Europe whom they visited.
“I know the saying, ‘Whoever can afford a ski trip can pay for their broken leg,’ but when you think that idea through, then especially in a pandemic, it compromises solidarity in society,” Mr. Spahn said. “So testing will remain cost-free.”
While Germans are normally quick to decry any encroachment on their personal privacy, the threat of the virus returning appears to frighten them more, and there has been little pushback to the proposed requirement for travelers.
On the second day after a testing station was set up at Tegel Airport, dozens of people pushing luggage trolleys stacked with suitcases or young children in strollers waited patiently for their turn to submit a voluntary test.
“It is an unbelievable hassle to set it up and organize it, but if it gives passengers back a sense of security when traveling, then it is worth it,” said Hannes Stefan Hönemann, spokesman for the airport’s operator.
The requirement for travelers include those coming over land as well if they have visited a hot zone. Health authorities in the southern state of Bavaria, the gateway for people returning by car from vacations on the Mediterranean coasts, set up test centers at three highway rest stops near the border, as well as at airports and major train stations.
Over the weekend, before the requirement went into effect this week, about 18,000 people were tested voluntarily, they said.
Bavaria made free testing available to all residents on July 1. The government invested 200 million euros, about $235 million, to expand laboratory capacity, both public and private, as well as personnel and working hours. Today it has the capacity for about 27,000 tests a day, state health minister, Melanie Huml, said.
“Test, test, test is the name of the game in Bavaria,” she said. “Our goal is to recognize infections as quickly as possible to stop chains of infection as early as early as possible.”
She estimates they can test as many as 2,000 travelers each day, the same capacity as expected in Berlin’s airports. Those who test positive will be alerted immediately, as will the public local health office, so it can follow up on care and contact tracing.
“Corona is not over and does not forgive any lack of vigilance,” Ms. Huml said. “We have to be careful to prevent a second wave from creeping up on us.”