[ad_1]
Researchers see three main drivers of corona infections
| Reading time: 3 minutes
Politics requires compliance with the rules of the crown
The number of corona infections continues to rise. Prime ministers and ministers of health announce toughening and urge the population to comply with hygiene and distance regulations.
The growing number of corona infections is making calls for measures stronger. But what is driving the pandemic above all? The researchers see three “transmission engines” that would offer starting points to contain the epidemic.
northAccording to the Robert Koch Institute (RKI), a large number of people in Germany are infected with the corona virus in their private lives. Measures in this area are even more important, RKI President Lothar Wieler stressed at a press conference in Berlin on Thursday. This assessment fits in with a report by American researchers in the journal Science. They describe three main drivers of the pandemic.
In the overview article, the team led by epidemiologist Elizabeth Lee of the Johns Hopkins Bloomberg School of Public Health in Baltimore emphasizes that a large portion of Sars-CoV-2 infections likely occur in homes. The authors point to several studies, according to which between 46 and 66 percent of infections occur at home. A large study from South Korea, after analyzing more than 59,000 cases, concluded that the risk of contagion in a home is six times higher than in other close contacts.
“This is consistent with the fact that domestic contact is one of the main causes of transmission of other respiratory viruses,” the authors emphasize. Other closely coexisting institutions, such as prisons, collective housing, and care facilities, would also be at comparatively high risk.
Even if many infections occur in private homes and similar living situations, it is virus transmissions outside of them that connect different homes to each other, the American experts write. These are “essential to sustain the epidemic.”
The infections in such situations therefore depend on a complex interaction of different factors. So-called super-spread events play an important role, that is, when an infected person infects many people during an event, sometimes without showing symptoms. Examples of this have been choir rehearsals, church services, weddings, or meat processing companies in the past. A small number of people could be responsible for a large number of infections. Researchers point to studies showing that with Sars-CoV-2 about 10 percent of cases caused 80 percent of infections.
The third factor that sustains the pandemic is, therefore, the interregional and international spread of travelers. Only a few long-distance connections could ensure that the virus spreads around the world. “This is one of the reasons why the first travel bans could not stop the global spread of Sars-CoV-2, even though they may have slowed the pandemic,” the scientists write. The strict rules in China, through which it was possible to contain the virus in the country, showed that travel restrictions can work.
In summary, the authors of the summary article emphasize that the three “drive engines” would offer starting points to contain the pandemic. Attempts should be made to reduce contagion in households broadly, as well as to take specific measures against other areas of infection.
However, there are still many unanswered questions, they emphasize. “The relative risk of transmission in different community settings, such as restaurants and retail stores, is still unclear, as is the impact of measures to curb transmission in those contexts,” they conclude. “Closing this and other knowledge gaps will clarify how the drivers of transmission are working together that are fueling the pandemic and how to fight back.”
