Protocol of the Cologne Corona Surveillance (CoCoS) Study– a prospective population-based cohort study

Abstract

Background Surveillance strategies are critical to cope with the current SARS-CoV-2 pandemic and to evaluate, as well as adjust government-imposed countermeasures. Incidence estimates are widely based on laboratory confirmed cases reported by health authorities. Prevalence and incidence data of SARS-CoV-2 is still scarce, along with demographic and behavioural factors associated with infection risk. Methods The Cologne Corona Surveillance Study will be conducted in the City of Cologne, which is the fourth-largest city in Germany with a population of approximately 1.1 million. Researchers will apply self-sampling surveillance to a rolling cohort of Cologne residents. Random samples of 6000 Cologne residents 18 years of age and older will be drawn from the registration office. Upon receiving the information and saliva sample kit, participants will be asked to fill out a questionnaire online or via phone, sign written informed consent, and send back written consent, as well as saliva sample. The saliva samples will be tested for SARS-CoV-2 by reverse PCR. The questionnaire will be administered to gather information about personal characteristics such as health status and risks. A second round of testing will take place 6 weeks after the first. Discussion Self-administered saliva sampling proved to be a legitimate and feasible alternative to nasopharyngeal swabs taken by health professionals. However, it is unclear whether the targeted response rate of 40% can be achieved and whether the results are representative of the population. Trial registration DRKS.de, German Clinical Trials Register (DRKS), Identifier: DRKS00024046, Registered on 25 February 2021.

Protocol of the Luebeck longitudinal investigation of SARS-CoV-2 infection (ELISA) study – a prospective population-based cohort study

“…The used invasive methods are generally safe [ 24 ], and the app-based questionnaires make it possible to answer them regularly and remotely. Compared to face-to-face or telephone interviews used in other studies [ 11 , 12 ], more interviews can be conducted due to the lower survey burden and lower costs. In addition, there is no risk of infection linked to in-person meetings.…”

Results of the Cologne Corona Surveillance (CoCoS) project– a cross-sectional study: survey data on risk factors of SARS-CoV-2 infection, and moderate-to-severe course in primarily immunized adults

“…The study reported here is cross-sectional. It represents a further development of earlier surveys conducted as part of CoCoS project [ 22 – 24 ]. The procedure was approved in advance by the Ethics Committee of the Medical Faculty of the University of Cologne and the Ethics Committee of the North Rhine Medical Association.…”

Die zeitlich-räumliche Verteilung von COVID-19 in Köln und beeinflussende soziale Faktoren im Zeitraum Februar 2020 bis Oktober 2021

“…Dies ist mangels einer großen Bevölkerungskohorte die beste Annäherung an die tatsächliche Fallverteilung. Eine solche Kohortenstudie wurde in Köln durchgeführt und könnte weitere Aufschlüsse zur Inzidenz generieren [ 26 ]. Zum jetzigen Zeitpunkt lässt sich eine Verzerrung bei der Erkennung und dem Ausmaß der Untererfassung von Fällen, z.…”