Experts from around the world are trying to attract attention to deadly but little-known illnesses, such as Chagas disease, visceral leishmaniasis and sleeping sickness, that have been neglected by the pharmaceutical industry. So-called neglected tropical diseases, which also include malaria, dengue fever and schistosomiasis, in conjunction with tuberculosis are responsible for 11.4 percent of the global burden of illness, but only 1.3 percent of the 1,556 new drugs registered between 1975 and 2004 were specifically developed for these diseases.