Coughs and sneezes spread diseases

There are some very interesting archaeological conclusions from the examination of the skeletons of victims of the Black Death found near Charterhouse in London, where mass burials are known to have taken place during the epidemic. The evidence suggests they died of pneumonic rather than bubonic plague, and that the infection was not therefore spread by rat fleas, but by human interaction. Many of the victims were the undernourished of the city's population. There is a newspaper report on the investigation which can be read here.