Despite much progress that has been made to battle the disease, it remains a significant global healthcare challenge. By the 1970s, through public health measures such as the use of insecticides and anti-malarial drugs, the disease was virtually eliminated from the more affluent regions of the globe, but sadly it remains endemic in most of the tropical and subtropical regions of the world today, disproportionately affecting poor and vulnerable populations. It is found in more than 100 countries mainly in tropical regions of the world, including: large areas of Africa and Asia, Central and South America, Haiti and the Dominican Republic, parts of the Middle East and some Pacific islands. In regions where transmission remains high, it is often the leading cause of illness and death.