Ali Miladi doesn't like hospitals. He's hardly been to the doctor's office since he was 15. But on a recent Tuesday afternoon, the 31-year-old was sitting in a room at the so-called Covisan center in Aubervilliers, a Paris suburb located in France's poorest department of Seine-Saint-Denis. Miladi, the owner of a kebab shop, had been suffering for several days from sore muscles, strong headaches, vertigo, nausea and diarrhea.

"When I was told at the medical hotline that I probably had COVID-19, I immediately understood the urgency of coming here — this illness is extremely dangerous," he told DW. "The fact that I could come to this municipal building and didn't have to go to an anonymous hospital helped me make that decision."

Miladi is one of about 400 people Aubervilliers' Covisan team has already tested. The center is part of France's plan to fight the pandemic — and prevent a further lockdown. But critics say that end doesn't justify all of the planned means.

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'Individual solutions'

"We want to find individual solutions for every contaminated household to stop the propagation of the virus," Aubervilliers' project coordinator Anaïs Anthonioz told DW. Infected people are also being redirected to the center by GPs and pharmacists. If deemed necessary, and if the concerned people agree, Covisan teams then visit the sick person's home.

"We want to see if people can self-isolate in separate rooms and who's in charge at the household. It wouldn't make sense, for example, to send the person in charge into isolation at a hotel," said Anthonioz, adding that her teams also try to identify contact persons to recommend they get tested.

The team in Aubervilliers is part of a pilot project launched on April 23 by the hospital group AP-HP that includes a further seven centers. About 4,000 people have already been advised and roughly half of them been tested. Mobile teams have visited more than 860 households.

Read more: Human contact tracing provides valuable clues to COVID-19 infections

Proven effectiveness in Haiti

The project is based on a system used in Haiti to eradicate cholera, said Jean-Sebastien Molitor. He's Haiti country director at the nongovernmental organization Solidarites Internationales and helped design Covisan. "We used to send mobile teams to isolate whole blocks of houses in Haiti — that was necessary to prevent individual households from getting stigmatized," he told DW, adding that the method made it possible to isolate more than 80 percent of all infected people and eventually defeat the illness.

The French government would like to replicate that success and has been creating so-called COVID brigades across the country. These include mobile teams such as the one in Aubervilliers as well as call centers operated by the National Sickness Insurance Fund (CNAM). The mobile brigades will handle specific cases and clusters and are still being set up. The call centers have been in operation since May 13, two days after the first lifting of restrictions. Some 6,500 people, a tenth of CNAM's workforce, have reached 9,000 infected people and 25,000 contact persons within the first 10 days.

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'Targeted isolation is now possible'

On that same Tuesday in the suburb of Evry, about 40 kilometers (25 miles) south of Aubervilliers, Sophie Merk was picking up a phone in one of the CNAM's call centers. She was calling a 59-year-old man who had recently tested positive. Only four instead of the usual 12 employees were working in the room. The desks were separated by plexiglass. A screen on the wall read "Good morning, brigade!" 

"Hello, I'm calling from the CNAM to talk through how you can self-isolate at home," said Merk into the phone. The bus driver at the other end of the line told her he had been self-isolating with his wife and two kids at home since mid-March. Merk said he would receive free face masks. Then, she talked to his wife and one of the sons to try to convince them to get tested. But they refused. "They are afraid the test could be really unpleasant. But this is not dramatic — the family is hardly leaving the house and their chances of contaminating others are very low anyway," she told DW, once she had hung up.

"We aim to interrupt the infection chain and want to convince people to get tested as soon as there's the slightest suspicion of COVID-19," she added. Merk said she had immediately volunteered when her boss had told her about the brigades. "I feel useful here — I am helping defeat the epidemic."

CNAM Director-General Nicolas Revel said the brigades are necessary to prevent a renewed lockdown.

"The stay-at-home order helped us bring down the infection rate, so that targeted isolation is now possible," he told DW, adding that France's strategy seemed to be working with the number of new infections continuing to go down, even if the country shouldn't let its guard down for at least a few more weeks.

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Data collection cause for concern

But France's new system is also being met with resistance — due to the kind of data it collects. The call center agents retrieve the infected persons' contact details from two new databases. There is now a duty to report positive COVID-19 test results and GPs enter these in the so-called Contact COVID database with test laboratories registering them in what's called Sidep.

In addition, France is one of Europe's first countries to have voted through a new smartphone tracking app, called StopCovid, which goes live this week. On a voluntary basis, people can download the app and enter positive test results with a barcode or a number they receive after the test. The app then alerts people who the infected person has been in touch with and recommends they get tested, too.

StopCovid has had doctors' associations, NGOs and even lawmakers from France's ruling party up in arms. They fear, among other things, that the app could be hacked. Privacy groups also don't trust the government to delete the app after the COVID-19 crisis.

"After the 2015 terror attacks, the government extended the state of emergency six times and eventually enshrined it in common law. How can we seriously believe this app won't be used for other means after this crisis?" Neha Oudin from the privacy group Quadrature du Net told DW. He said he doubts the app will be of much use, anyway. "The most vulnerable people are the elderly and many of them don't own a smartphone," he said.

Read more: Coronavirus contact-tracing apps put users at risk, EU lawmaker says

Anonymous data?

Oudin is also concerned about the new databases. The collected data is supposed to be erased after three months, but positive test results will be saved anonymously on the government's Health Data Hub for statistical purposes.

"This relatively new server is being operated by Microsoft, which means the American company has its decryption codes," he claimed.

"It'll be easy for the US government to force Microsoft to hand over the data and then pass it on to the CIA or other organizations — that's a real threat to our personal rights," he added.

What's more, Oudin said he doesn't believe this kind of data can be made anonymous: "Each entry includes the patient's medical history and that makes it easy to identify him or her."

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