Vergleich der Viren-genetik mit der Windrichtung
H7N7, 2003 Holland,Belgien,NRW , ~25Millionen tote Hühner

http://www.ncbi.nlm.nih.gov/pubmed/23230058

Here we provide statistical evidence that the direction of spread of
avian influenza A(H7N7) is correlated with the direction of wind at
date of infection. We find the direction of spread by reconstructing
the transmission tree for a large outbreak in the Netherlands in 2003,
using detailed genetic and epidemiological data. We conservatively
estimate the contribution of a possible wind-mediated mechanism
to the total amount of spread during this outbreak to be around 18%.