But bird flu is far from the only disease-causing pathogen lurking in raw milk: Unpasteurized milk can contain bacteria such as E. coli and Listeria, for instance. Rift Valley fever is an acute viral illness spread to people through mosquitoes or the bodily fluids of infected animals. While Rift Valley fever virus mostly impacts sub-Saharan Africa, these findings have important implications for understanding human disease risk from drinking raw milk, said Brian Dawes, MD, PhD. People reading this may think of bird flu (H5N1) and recent news of its presence in raw milk samples. How do your findings add to our understanding of how viruses might spread from animals to humans via raw milk?