Neglected tropical diseases (NTDs) comprise several parasitic, bacterial and viral infections (causing diseases such as visceral leishmaniasis and lymphatic filariasis). Neglected tropical diseases are thought to cause 500,000 deaths each year, yet their greatest impact lies in the way they promote poverty, stigmatise, disable and inhibit individuals from being able to care for themselves or their families. They are the 4th most important group of communicable diseases, behind lower respiratory infections, HIV/AIDS, and diarrhoeal diseases. They affect the world's poorest, an estimated 3 billion people, who subsist on less than $2 per day. People living in remote areas without any access to an effective health care system are most vulnerable. An increasing body of evidence also indicates that co-infection with one or more of the neglected tropical diseases adversely affects the natural history and progression of malaria and HIV/AIDS.