From a bad salad to the Black Death: evolution of a killer

Scimex: Scientists have pinpointed the exact genetic point at which the bug behind the Black Death which killed 75 to 200 million people in Europe in the 14th Century - Yersinia pestis - evolved from a relatively benign gastric bug into a deadly killer. The researchers found that ancient types of the bacteria, after swapping genetic material, gained a gene that made them cause pneumonic plague. Later, another genetic change made them highly infectious - resulting in bacteria that are not only deadly but have the potential for pandemic spread.

Warning signals from the volatile world of influenza viruses

WHO: The current global influenza situation is characterized by a number of trends that must be closely monitored. These include: an increase in the variety of animal influenza viruses co-circulating and exchanging genetic material, giving rise to novel strains; continuing cases of human H7N9 infections in China; and a recent spurt of human H5N1 cases in Egypt. Changes in the H3N2 seasonal influenza viruses, which have affected the protection conferred by the current vaccine, are also of particular concern.

Measles by the numbers: A race to eradication

Nature: Measles debate has reached fever pitch in the United States after an outbreak that began in December at Disneyland in southern California. Many media outlets and politicians have focused on the country’s growing anti-vaccination movement. However, the bigger problem lies elsewhere. The United States was declared free of measles in 2000, and all outbreaks since then have been sparked by imported cases, which will continue to occur until measles is eradicated worldwide.

Contagion calculation: Forecasting and tracking outbreaks of influenza

Melbourne University. Australia: Epidemiologist Assoc Prof Jodie McVernon discusses research into tracking and predicting the spread of influenza and other viral diseases like Ebola.