At the rate the coronavirus is being reported in various countries especially with the release of passengers, including those infected from the cruise ship in Japan, and reports of cases in Italy, the production concern leg by leg will have to be exposure going through air, ship, and train terminals. One report I read today in a news feed was that the virus can live on undisinfected surfaces for up to nine days. And the incubation period has not been determined. So avoiding east Asia may not be enough. IIRC, cases have been reported in Iran.
If we haven’t accounted for all teams yet for US departure cities then we may want to look at other cities that fly direct to London, eg Miami, Dallas, Atlanta. IIRC there were more than three airports involved in teams flying to Mexico City at the beginning of TAR 28.