Sep 23, 2014 The World Health Organization has released a new study warning that the situation is quickly growing worse. The new study by WHO experts and scientists at Imperial College London, published today by The New England Journal of Medicine (http://www.nejm.org/doi/full/10.1056/NEJMoa1411100), is "excellent" because it fills some important gaps, says Preben Aavitsland, a Norwegian epidemiologist.