RESUMO
BackgroundThe beginning of the COVID-19 pandemic was shaped by superspreading events including large-scale outbreaks. In Germany the first SARS-CoV-2 outbreak was a superspreading event in a rural area during indoor carnival festivities in February 2020. Methods51 days after the event all known participants were asked to give blood samples, pharyngeal swabs and answer a self-administered questionnaire. Metric room coordinates for all tables, seats, and ventilation-points were assessed. FindingsWe analyzed infection rates among all 411 participants, and the risk of infection in relation to various factors including age, alcohol consumption, and ventilation system. Overall, 46% (n=186/404) of the participants had been infected. We demonstrate that the spatial distribution of infected participants was associated with proximity to the ventilation system (represented as inverse distance, with Odds Ratio OR 1.39, 95% KI [0.86; 2.25]). Interestingly, the risk of infection was highly associated with age, whereby children (OR: 0.33 [0.267; 0.414]) and young adults (age 18-25) had a lower risk of infection than older participants resulting in an average infection risk increase of 28% per 10 years age difference. Behavioral differences also impacted the risk of infection including time spent outside (OR: 0.55 [0.33; 0.91]) or smoking (OR: 0.32 [0.124; 0.81]). InterpretationOur findings underline the importance of proper indoor ventilation for events in the future. The lower susceptibility for children and young adults indicates their limited involvement in superspreading events. FundingThe government of North Rhine-Westphalia (Germany) supported the study with 65,000 Euro. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe scientific literature was searched for the term "superspreading event AND Covid-19 OR Sars Cov 2" and identified published papers from China, South Korea, Europe, and North America. Most researchers analyzed superspreading events within a health care setting e.g. in hospitals or nursing homes, or described the general impact of superspreading events on the global pandemic. Only a few metanalyses of transmission clusters analyzed party occasions (e.g. a nightclub in Berlin, Germany) as superspreading events. These reports describe less than 100 infections and are very limited due to missing data or reporting biases. Therefore, the ability to draw scientific conclusions is also limited. Additionally, to our knowledge, there are no studies, which investigated individual behavior, the location, and role of children during a superspreading event. The research for the study started April 2020 and was concluded in June 2021. Added value of this studyOur report analyzes the first COVID-19 superspreading event in Germany in detail, which was not only a unique setting but also included children and adults in the same room. We demonstrate that nearly half of the participants were infected with SARS-CoV-2 and that the proximity of the seating to the ventilation system was an important risk factor for infection. The data showed that low physical distance including singing and duration of attendance at this event increased the risk of infection, while regular smoking and spending the break of the event outside lowered the risk of infection. This underlines the benefit of airing to lower the amount of both droplets and aerosols. Furthermore, we found lower infection in children than adults despite being in the same room suggesting differences in infectability in children. Indeed, we observed that an additional 10 years of age is on average associated with 28% increased risk of infection. Implications of all the available evidenceTaken together, the results demonstrate the importance of the ventilation system during superspreading events. In particular children and young adults had a lower risk of infection during the event indicating that they have a limited role during this pandemic. Overall, our data demonstrate in detail age-dependent infectability as well as highlights to understand transmission dynamics in order to improve comprehensive public health preparedness measures.
RESUMO
BackgroundSeasonality is a characteristic of some respiratory viruses. The aim of our study was to evaluate the seasonality and the potential effects of different meteorological factors on the detection rate of the non-SARS Corona Virus detection by PCR. MethodsWe performed a retrospective analysis of 12763 respiratory tract sample results (288 positive and 12475 negative) for non-SARS, non-MERS Corona viruses (NL63, 229E, OC43, HKU1). The effect of seven single weather factors on the Corona virus detection rate was fitted in a logistic regression model with and without adjusting for other weather factors. ResultsCorona virus infections followed a seasonal pattern peaking from December to March and plunging from July to September. The seasonal effect was less pronounced in immunosuppressed patients compared to immunocompetent. Different automatic variable selection processes agreed to select the predictors temperature, relative humidity, cloud cover and precipitation as remaining predictors in the multivariable logistic regression model including all weather factors, with low ambient temperature, low relative humidity, high cloud cover and high precipitation being linked to increased Corona virus detection rates. ConclusionsCorona virus infections followed a seasonal pattern, which was more pronounced in immunocompetent patients compared to immunosuppressed. Several meteorological factors were associated with the Corona virus detection rate. However, when mutually adjusting for all weather factors, only temperature, relative humidity, precipitation and cloud cover contributed independently to predicting the Corona virus detection rate.
