Neglected diseases: Teach or treat?
Scientists are taking the debate over how to address neglected tropical diseases to the pages of PLoS Medicine, with one camp arguing in favor of more drug development, and another pushing for more funding and research on public health strategies such as sanitation and education.
In 2005, researchers coined the term "neglected tropical diseases" to refer to thirteen diseases primarily occurring in rural, poor areas that have been largely ignored by policymakers and public health officials. Thes
Scientists are taking the debate over how to address neglected tropical diseases to the pages of PLoS Medicine,
with one camp arguing in favor of more drug development, and another pushing for more funding and research on public health strategies such as sanitation and education.
In 2005, researchers coined the term "neglected tropical diseases" to refer to thirteen diseases primarily occurring in rural, poor areas that have been largely ignored by policymakers and public health officials. These diseases, including sleeping sickness, river blindness, hookworm infection and more, traditionally fall second in attention and funding to "the big three" -- HIV/AIDS, malaria, and tuberculosis.
|A mass drug administration in Mali|
Image: www.neglecteddiseases.gov, Albis Cabrelle
In the last five years, however, neglected tropical diseases are have experienced a hike in funding from private and government sources, including a linkurl:recent boost;http://www.neglecteddiseases.gov/ from the administration of U.S. President Barack Obama. But there is disagreement about how that money should be used. In a series of three opinions published together in a paper this week in PLoS Medicine,
researchers examine past and present ways of tackling neglected tropical diseases (NTDs) and come to very different conclusions about which are the most promising.
linkurl:Jerry Spiegel;http://www.ligi.ubc.ca/?p2=/modules/liu/profiles/profile.jsp&id=13 and colleagues at the University of British Columbia argue that there has been an over-reliance on biomedical approaches to NTDs, and research has largely ignored the socio-environmental roots of diseases, including sanitation, access to clean water, community education, and more. "Health is far more than a biomedical challenge," said Spiegel, director of global health at the Liu Institute for Global Issues in Vancouver, and a professor at UBC.
A second opinion, written by Burton Singer of the linkurl:Emerging Pathogens Institute;http://www.epi.ufl.edu/ at the University of Florida, agrees with this assessment, arguing that there are many examples of the "over-medicalization" of NTD control strategies, citing the primarily drugs-only efforts to treat schistosomiasis and hookworms. Such programs don't prevent the reworming of the same individuals, argues Singer, and funds and support can fade away: The loss of a 10-year World Bank Loan Project for schistosomiasis in China in 2001 resulted in re-emergence of the disease in some areas. "These programs amount to establishing a chain of dependence on drugs with no terminal horizon in sight," he writes.
But to linkurl:Marleen Boelaert,;http://www.itg.be/itgtool_v2/PersonalPages/PersonalPage.asp?CID=34&L=E an epidemiologist at the Prince Leopold Institute of Tropical Medicine in Antwerp, Belgium, who was not an author on any of the opinions, the picture is more complex. "They are right to say that social-economic context is important and that health systems are crucial for control, but I would not push it so far to say there is too much attention on drug development. It's not true," she said.
Indeed, an opposing viewpoint printed in the same paper argues that few other NTD interventions rival the success of drug distribution. "We have proof-of-concept that these mass drug administration approaches work," said linkurl:Peter Hotez,;http://www.gwumc.edu/microbiology/faculty/hotez.htm author of the opinion and president of the Sabin Vaccine Institute in Washington, D.C. as well as a professor at George Washington University. "We've seen the impact." Since the 1970s, for example, a program providing drugs for river blindness has protected over 150 million people from blindness and eliminated the disease in Mali and Senegal, the authors cite.
Hotez and colleagues suggest that drugs are the fastest, cheapest way to treat and control NTDs, and one of the greatest public health challenges over the next decade will be to accelerate the expansion of such drug programs. An integrated approach -- bundling existing mass treatments for seven NTDs causing 90 percent of the global burden and implementing them simultaneously -- would make what little money there is for NTDs go a long way, said Hotez. Individuals could be treated with an integrated chemotherapy for as low as $0.50 per year. "It's one of the best buys in public health," he said.
"That's a fact," said Boelaert. "In the short term, [administering drugs] is the cheapest option. But in the long term, it is difficult to sustain these programs. Re-infection comes back." So the final solution will most likely be multi-faceted, she added.
With that idea in mind, Spiegel and colleagues suggest an offset, like a carbon offset, should be taken from any drug funding earmarked for NTDs and used to address social, environmental, and health system factors. Since companies tend to invest in drug development because of its promise of economic return, these offsets would help channel funds to other important social aspects of the diseases.
In the end, there is no debate, argued Boelaert -- one strategy alone won't solve the problem of NTDs. "Only drugs or only spraying is not sustainable," she said. "A responsible government will provide both. If not, you will never get rid of these types of diseases."
Read the full debate at linkurl:PLoS Medicine.
J.M. Spiegel et al. "Which new approaches to tackling neglected tropical diseases show promise?," PLoS Medicine 7(5):e1000255.
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[1st July 2007]*linkurl:Taking Aim at Neglected Diseases;http://www.the-scientist.com/article/display/15523/
[6th June 2005]*linkurl: Home-Base Biotech;http://www.the-scientist.com/article/display/56260/
[1st January 2010]