A German study says 40% of people infected with COVID don't know it. And long COVID symptoms may go unidentified. DW spoke to study author, Philipp Wild.
Got to get tested!Image: Todd Korol/REUTERS
Advertisement
DW's Ben Fajzullin: As principal investigator of the Gutenberg COVID-19 study, how did you and your team determine that over 40% of Germans don't realize they have COVID-19?
Philipp Wild: We drew a population-based sample from local registry offices, and we asked study participants whether they had had an infection twice, four months apart. We asked them to provide a PCR test, which we did with them, and we measured their anti-bodies. Those anti-bodies indicate whether you have had an infection, no matter whether you are vaccinated or not.
And you've looked at over 10,000 people over a six-month period.
Yes. Among the elderly, especially, there are more unknown infections — about two-thirds (63%) of the people in our study at the ages of 75 and over. Whereas, among 25 to 30-year-olds, it is only a third [of the people we asked, who had had undetected infections].
So, is it time to get self-tests out there — not only so people can see whether they are infected but also to work out whether they have had the virus in the past?
It's certainly a good idea to start testing people better, especially now when we're pulling back on preventative measures. We've got major public events again, like the recent European Football Championship, so we need early warning systems. And vaccinated people should also get tests because they can still transmit an infection to people who aren't vaccinated.
But we've also learnt that we still have to work out which antibodies we need to measure in individuals. The majority of people only show certain antibodies [Ed.: And there are different types]. So, we need to learn which anti-bodies to look for, depending on each individual, before we can start screening for long COVID.
How many of these unknown cases could be long COVID?
That's a matter of debate. We're still investigating this in our study, and it will take a little more time, because the definition of long COVID is six months after the [original] infection.
But what we do know is that among the known cases, 10% are thought to develop long COVID, and then 10% of them, which is 1% of all known cases, develop a severe form of long COVID. And what we must learn now is how many of the asymptomatic infections can get [long COVID].
Long COVID: A new challenge
02:49
This browser does not support the video element.
Could there be a concern for younger people that they could have COVID, but they may not know it, and yet their organs may be damaged but that that may only come out years later?
Indeed, that's what we fear. We're asking: Is there a molecular signature, something you can measure in the blood, that indicates that you're on the way towards developing long COVID syndrome. But that is still a matter of research. Everything we're doing there right now is still speculative. We need to gather more data to be sure about how to tackle these [cases] and how to identify them. But, yes, we fear that it is possible, even in asymptomatic infections or mild infections, that a few people are at risk of developing long COVID.
Dr. Philipp Wild is a professor of clinical epidemiology at the University of Mainz and principal investigator for the Gutenberg COVID-19 study.
COVID: Vaccinating people in the world's most remote places
Medical teams are making long, at times difficult journeys to vaccinate people all over the world against COVID-19. Their job takes them over mountains and across water, by boat or by plane — or by foot.
Image: Tarso Sarraf/AFP
A difficult mountain climb
Medical staff who want to vaccinate the inhabitants of the mountainous regions of southeastern Turkey must be physically fit. Ensuring vaccinations in the mountain villages is particularly important, Dr. Zeynep Eralp told DW. "People often live close together, and an infection could spread quickly," she said. Also, people don't like going to hospitals, so "we have to go to them."
Image: Bulent Kilic/AFP
Through snow and ice
Many elderly people can't make the journey to a vaccination center. In the Maira Valley in the western Italian Alps, close to the border with France, doctors go from house to house to give residents older than 80 their COVID-19 shot. A blessing from the roadside Madonna is a bonus.
Image: Marco Bertorello/AFP
Flight to the remote north
Carrying a single vial containing several doses of vaccine, this nurse is en route to Eagle, a town on the Yukon River in the US state of Alaska with fewer than 100 inhabitants. Indigenous people are prioritized in many immunization programs. Depending on where they live, the nearest health clinic can be far away.
Image: Nathan Howard/REUTERS
Some need convincing
Anselmo Tunubala washes his hands before vaccinating an elderly lady. Every day, the 49-year-old is out and about in the mountains of southwestern Colombia, telling people in the local language about the importance of a vaccination. He is a member of the Misak, many of whom are skeptical about vaccination because they tend to rely on traditional medicine and the guidance of religious leaders.
Image: Luis Robayo/AFP
Hours of walking
The men and women in the above photo walked up to four hours to get their coronavirus shot in the remote village of Nueva Colonia in central Mexico. They belong to the indigenous Wixarika people, perhaps better known under the name Huichol.
Image: Ulises Ruiz/AFP/Getty Images
Holding steady
For her shot, Olga Pimentel simply pulled up her boat next to that of the vaccination team. The community of Nossa Senhora do Livramento on the Rio Negro in Brazil can only be reached by river. "Beautiful! It hardly hurt," the 72-year-old laughed and shouted, "Viva o SUS!" — "long live Brazil's public health service!"
Image: Michael Dantas/AFP
Vaccination by candlelight
For a long time, right-wing populist President Jair Bolsonaro campaigned against COVID-19 vaccinations in Brazil. But in the meantime, the campaign has taken off. Indigenous people and quilombolas, descendants of African slaves, were among the first to be vaccinated. Raimunda Nonata, 70, lives in a community without power so she got her shot by candlelight.
Image: Tarso Sarraf/AFP
Paddle over the lake
After their vaccination, an elderly woman and her daughter paddle away from the island of Bwama, the largest in Lake Bunyonyi in Uganda. The government in the central African country is trying to supply remote areas with the vaccine.
Image: Patrick Onen/AP Photo/picture alliance
Rough terrain
Another journey over the water — but his time, no boat. On the way to the village of Jari in Zimbabwe, this vaccination team had to navigate a flooded road. According to the African Union's health agency, Africa CDC, fewer than 1% of the population in Zimbabwe has been fully vaccinated to date. Medical staff came first.
Image: Tafadzwa Ufumeli/Getty Images
Welcome house call
Japan may have huge, sprawling cities, but many people also live in small, isolated villages with only a few hundred inhabitants — like here, in Kitaaiki. Residents who can't make it to the next city are happy to welcome the doctor and a vaccine at home.
Image: Kazuhiro Nogi/AFP
Valuable goods
Indonesia launched its vaccination campaign in January. From Banda Aceh, the medical team traveled via boat to remote islands. The vaccines in the cooler are so valuable that the team was accompanied by security personnel.
Image: Chaideer Mahyuddin/AFP
Superspreader event?
India has been hardest hit by the pandemic in recent weeks. In mid-March, medical personnel made their way to the village of Bahakajari on the Brahmaputra River, where a group of women registered for their COVID-19 shot. None wore face masks or kept a safe distance.
