Digital COVID-19 surveillance tool for a mass gathering event - a prospective cohort study

Abstract Introduction Mass gatherings have been associated with a high risk of SARS-CoV-2 transmission. On-site research can foster knowledge of risk factors for infections and improve risk assessments and precautionary measures at future events. We tested a web-based participatory disease surveillance tool to detect COVID-19 infections at and after an outdoor mass gathering by collecting self-reported COVID-19 symptoms and tests. Methods We conducted a digital prospective observational cohort study among fully immunized attendees of a sports event that took place from September 2 to 5, 2021 in Thuringia, Germany. Participants used our study app to report demographic data, COVID-19 tests, symptoms, and their contact behavior. This self-reported data was used to define probable and confirmed COVID-19 cases during the full “study period” (08/12/2021 - 10/31/2021) and within the 14-day “surveillance period” during and after the event, in which the highest likelihood of an event related COVID-19 outbreak could be expected (09/04/2021 - 09/17/2021). Results A total of 2,808 of 9,242 (30.4%) event attendees participated in the study. During the study period, 776 symptoms and 5,255 COVID-19 tests were reported in the study app. During the surveillance period, seven PCR positive COVID-19 cases were found to be associated with the event. This translated to an estimated seven-day incidence of ∼125/100,000 cases (95% CI [67.7/100,000, 223/100,000]), which was comparable to the average age-matched incidence in Germany during this time (118.3/100,000). Conclusions COVID-19 cases attributable to the mass gathering were comparable to the German-wide age-matched incidence, implicating that our active participatory surveillance tool was able to detect mass gathering related infections. Further studies are needed to evaluate and apply our participatory disease surveillance tool in other mass gathering settings. Key messages • Our digital COVID-19 surveillance tool for mass gathering events was easy to implement within the organizational structure of the event and well accepted amongst event attendees. • Our active participatory surveillance tool was able to detect mass gathering related infections comparable to the Germany-wide incidence.


Introduction:
During the COVID pandemic, COVID-related data collected in family medicine were scarce. We aimed to monitor cantonal trends of COVID-related activity in family medicine and paediatric practices during the year 2021. Methods: Family physicians and paediatricians established in the canton of Vaud were invited to join an ad hoc sentinel surveillance system. Online data collection was based on daily activity reports and monthly questionnaires. In particular, participants categorized daily counts of consultations and phone calls into predefined COVID-related categories. Results: Thirty-seven practices contributed regularly to the system between March 20th and December 31st 2021. Out of 81'407 medical consultations, 4'950 (6.1%) were related to new COVID suspicions as defined by the Federal Office of Public Health, and 5'252 (6.4%) otherwise related to COVID. Depending on the week and the practice, between 5.6% and 26.5% of face-to-face consultations were COVID-related. In paediatrics, COVID-related activity corresponded mostly to new COVID suspicions (11.2% of on-site consultations), whereas among family physicians other COVID topics predominated (9.8% of face-to-face consultations), mainly questions about vaccination. Consultations for persisting COVID-related symptoms were stable at a low level throughout the year, and constituted less than 1% of all consultations. Most practices swabbed patients for SARS-CoV-2 tests, and an increasing proportion performed rapid antigenic tests over the year. In paediatrics, COVID-suspicions were not systematically tested.

Conclusions:
Throughout 2021, COVID-related consultations constituted an important part of family medicine and paediatric practices' activity in the canton of Vaud. Monitoring COVID-related activity in primary care during a pandemic documents how physicians translate recommendations into practice and provides health authorities with valuable information to guide public health action.

Key messages:
Throughout 2021, COVID-related consultations constituted an important part of family medicine and paediatric practices' activity in the canton of Vaud.
Monitoring COVID-related activity in primary care during a pandemic documents how physicians translate recommendations into daily practice.
Abstract citation ID: ckac131.561 Digital COVID-19 surveillance tool for a mass gathering event -a prospective cohort study 19 infections at and after an outdoor mass gathering by collecting self-reported COVID-19 symptoms and tests.

Methods:
We conducted a digital prospective observational cohort study among fully immunized attendees of a sports event that took place from September 2 to 5, 2021 in Thuringia, Germany. Participants used our study app to report demographic data, COVID-19 tests, symptoms, and their contact behavior. This self-reported data was used to define probable and confirmed COVID-19 cases during the full ''study period'' (08/12/2021 -10/31/2021) and within the 14-day ''surveillance period'' during and after the event, in which the highest likelihood of an event related COVID-19 outbreak could be expected (

Background:
Innovative solutions are used to monitor the spread of COVID-19, to research and develop vaccines, and to ensure online privacy and security. The aim of the study is to investigate which innovative methods, including algorithms and digital tools (e.g., social media, artificial intelligence, contact tracing applications) are used to monitor health issues related to COVID-19 in Europe, and who is using them.

Methods:
A questionnaire was developed and administered online to European countries' representatives and stakeholders of the project Population Health Information Research Infrastructure (PHIRI). The survey investigated the use of innovative solutions and digital tools in Europe to monitor COVID-19 and vaccination programs, to research and develop diagnostics and teleconsultations, and to fight online disinformation. Legislative and ethical aspects were also considered. A descriptive data analysis was performed.

Results:
19 responses were collected from 14 countries. Digital tools are used to monitor COVID-19 (13/14 countries), vaccination programs (12/14), for telemedicine (7/14), and to fight disinformation (10/14). Specific algorithms to detect the patterns of the pandemic spread are available in five countries. The main target groups of the tools are the general population, healthcare providers, patients and epidemiologists. The uptake rate of the tools ranged 5-100% across countries. Measures to evaluate the impact of digital tools (e.g., user surveys, reviews, evaluation teams) have been adopted in seven countries. Information on legislative and ethical aspects related to the use of digital solutions are available in 10 countries.

Conclusions:
The development and use of innovative methods for population health monitoring and research purposes have been the key to mitigate the COVID-19 pandemic. Improving the uptake rate, impact assessment of digital tools and fight against disinformation could enhance countries' preparedness for future pandemics.
Key messages: Given that digital solutions are deployed in population health monitoring, research, and for online privacy and security, they have a key role in mitigating the COVID-19 pandemic. Enhancement of the uptake rate and assessment of digital tools, and fight against disinformation could strengthen countries' preparedness for future pandemics.