Pretty sure he was joking.
UPDATE: Transmissibility estimates of #coronavirus #2019nCoV at 2.6
Identification & testing potential cases to be as extensive as permitted by healthcare & testing capacity
🔰https://t.co/7A77NXZ3iw@neil_ferguson @dr_anne_cori @SRileyIDD @MarcBaguelin @IlariaDorigatti pic.twitter.com/tHpDNeNBa4— MRC Centre for Global Infectious Disease Analysis (@MRC_Outbreak) January 25, 2020
Yep...black (plague) humor.