[Test Concept of the City of Cologne for Critical Infrastructure (KRITIS) during the First Wave of the COVID-19 Pandemic].

Background: At the beginning of the COVID-19 pandemic, the Public Health Department of the City of Cologne established preferential testing for critical infrastructure (KRITIS) personnel. The aim of this study was to retrospectively analyze this concept.

Methods: Test results as well as demographic and job-related data from March to April 2020 were collected and descriptively analyzed using a specially developed software. KRITIS personnel who tested positive were systematically interviewed over the phone.

Results: 1521 individuals were tested, of whom 896 (59%) were from the healthcare sector, particularly from the nursing professions (35%). Testing and consultation services were also utilized by employees of non-profit organizations (8%), administration (7%), fire department (11%), and police (4%). KRITIS personnel who tested positive suspected increased risk from contacts at the workplace (58%), mostly without adequate protection (85%). Of those surveyed, 83% rated the KRITIS concept as 'good' or 'very good'. Processes at the testing center were rated as 'good' or 'very good' by 89%, while 47% rated phone support as 'good' or 'very good', and 30% as 'sufficient' or poor. Free comments showed that frequent phone contact from the Public Health Department was perceived as positive and even more often as negative interindividually. Communication and advice were positively highlighted, while lack of competence and coordination were criticized. The respondents criticized the comparatively lower provision of testing services for family members, for example, due to limited resources.

Conclusion: With the KRITIS concept, the Public Health Department of Cologne developed and implemented an offer for system-relevant professional groups that was intensively used and mostly assessed as positive. This concept can be used as a blueprint for other pandemics.