COVID-19: first long-term care facility outbreak in the Netherlands following cross-border introduction from Germany, March 2020 (preprint)

ABSTRACT

Background: The Dutch province of Limburg borders the German district of Heinsberg, which had a large cluster of COVID-19 cases linked to local carnival activities in February, before any cases were reported in the Netherlands. However, Heinsberg was not included as an area reporting local or community transmission per the national case definition at the time. In early March, two residents from a long-term care facility (LTCF) in Sittard, a Dutch town located in close vicinity to the district of Heinsberg, started experiencing respiratory symptoms and were admitted to the regional hospital at which they were tested for COVID-19. Introduction of the virus could have occurred following the carnival activities in the surrounding area by LTCF visitors or health care workers.Methods: Surveys and semi-structured oral interviews were conducted with all present residents by health care workers during regular points of care for information on new or unusual signs and symptoms of disease. Both throat and nasopharyngeal swabs were taken from residents suspect of COVID-19 for the detection of SARS-CoV-2 by Real-time Polymerase Chain Reaction and whole genome sequencing was performed using a SARS-CoV-2 specific amplicon-based Nanopore sequencing approach. Additionally, twelve random residents were sampled for possible asymptomatic infections.Results: Since the start of the outbreak, nineteen (19%) residents tested positive for COVID-19. Eleven samples were sequenced, along with three random samples from COVID-19 patients hospitalized in the regional hospital at the time of the LTCF outbreak. Conclusions: All samples were linked to COVID-19 cases from the cross-border region of Heinsberg, Germany. Symptoms were reported only in about two third of the cases, and tended to be generally mild. We therefore recommend low-level screening of HCWs and residents following a confirmed COVID-19 case, even in the absence of symptoms. Since the LTCF residents who tested positive did not meet the criteria for suspect cases of COVID-19 at the time, this highlights the importance of cooperation among cross-border partners in order to establish a coordinated implementation of infection control measures in the region on top of national guidelines to limit the spread of infectious diseases such as COVID-19.