Effectiveness of Passive and Active Surveillance for Early Detection of SARS-CoV-2 in Mink during the 2020 Outbreak in the Netherlands

Table 2

Number of dead mink that were submitted for SARS-CoV-2 RT-PCR testing with their results per farm and per month between June and November 2020.

Month	Number of farms that submitted dead mink	Median number of submitted mink per farm (range)	Number (%) of farms where SARS-CoV-2 was detected
June	111	3 (1–4)	3 (2.7)
July	103	4 (1–5)	3 (2.9)
August	103	4 (1–14)	20 (19.4)
September	80	15 (1–56)	13 (16.3)
October	65	10 (1–46)	7 (10.8)
November	52	3 (1–18)	2 (3.8)

Farms that did not submit dead mink for the risk-based surveillance were either no longer active or did not report any dead mink. So all eligible farms submitted dead mink.