HIV/AIDS, tuberculosis and malaria, often referred to as the "Big Three" of the world's diseases account for 5.6 million deaths each year, largely in the developing world. In recent years, more global resources have been committed to fight these diseases, but some health experts argue that greater attention to so-called "neglected" tropical diseases could be a powerful aid in the fight against the "Big Three."
In a United Nations meeting last month in Stockholm, Sweden, researchers warned that 13 tropical diseases -- when taken together -- rank a close second for deadliness behind HIV/AIDS, TB and malaria.
These relatively neglected tropical diseases kill 530,000 people each year and disable many millions more, says Dr. Peter Hotez, professor and chair of the Department of Microbiology and Tropical Diseases at George Washington University "Most of these 13 neglected tropical diseases are parasitic infections," he says. "They include worm infections -- diseases caused by parasitic worms --such as guinea worm, river blindness, elephantiasis, hookworm infections, schistosomiasis, and they include bacterial infections such as trachoma, Buruli ulcer, as well as leprosy."
Hotez says these infectious diseases retard childhood development and education and carry disfiguring stigmas. They also largely afflict the poor in the same rural communities of Sub-Saharan Africa and impoverished regions of the Americas, Southeast Asia and parts of India that are infected with HIV/AIDS, TB and malaria.
"When an individual gets AIDS or malaria in the developing world, they -- more often than not -- are simultaneously afflicted with hookworm and schistosomiasis or river blindness," he says. "This profoundly affects the natural history of malaria or HIV/AIDS."
Hotez says multiple parasitic diseases promote the severity and increased number of cases of malaria and a more rapid decline among people with HIV/AIDS. "Treating a mother with underlying parasitic worms, just by treating the worms alone seems to have a huge impact on reducing the risk that she will transmit HIV/AIDS to her baby," he says. "In some cases, treating the underlying worms could have just as big an effect as anti-malarial bed nets."
Hotez says new data support a more integrated approach to disease management and control -- especially when multiple diseases are infecting individuals in the same geographic area: "that we simultaneously treat these individuals for intestinal parasites, for schitosomes, for hookworms, for lymphatic filariasis, because doing so will allow you to be much more effective with your control tools for HIV/AIDS or malaria, and that will make a significant difference."
Hotez says a cheap and effective treatment for neglected diseases already exists. "The estimates are that for 40 cents (per) individual, we can make a very profound impact indirectly on HIV/AIDS and malaria just by treating the underlying worms," he says.
Hotez says $200 million would cover drugs that could control or eliminate seven of the tropical diseases in 500 million Africans. "This is actually an instance where it is not really the money. It is a little bit the money, but it is more the political will," he says. "It is educating the organizations that are controlling the 'Big Three' on the importance of poly parasites."
Hotez says vaccines for certain diseases like hookworm look promising and could have a huge impact on the "Big Three." "It is surprising," he says "that those aiming to control HIV/AIDS, TB and malaria have largely ignored these opportunities."