2015 is poised to be a big year for global health security and human development. Following the introduction of the Global Health Security Agenda last year, there has been renewed energy around tackling infectious diseases across the world. Only two months into 2015, though, we already have our hands full with several major infectious disease challenges:
1) The Ebola outbreak in West Africa appears to be dying down, and the global community is starting to consider long-term needs for strengthening health systems, rebuilding economies, and preparing for future outbreaks.
3) Measles made an unwelcome comeback in the US, drawing attention to the impacts of vaccine hesitancy and refusal on herd immunity.
4) A recent outbreak of carbapanem-resistant Enterobacteriaceae at UCLA underscored the threats of antimicrobial resistance and healthcare-associated infections.
5) On a more positive note, South Sudan, Mali, Chad, and Ethiopia are inching closer toward eliminating dracunculiasis, more commonly known as guinea worm disease. If they succeed, dracunculiasis will become the third disease ever to be eradicated, following smallpox and rinderpest.
2015 is also the United Nations’ specified deadline for achieving the Millennium Development Goals (MDGs), a set of directives for resolving various dimensions of extreme poverty, including health. Specifically, Goal 6 outlines targets for combating HIV/AIDS, malaria, tuberculosis and other diseases. Additionally, Goal 8 – which identifies the need for building global partnerships for development – includes a target for cooperating with pharmaceutical companies to ensure affordable access to essential drugs in developing and least developed countries.
In light of the aforementioned infectious disease threats, the 2015 deadline for achieving the MDGs, and the synergies that exist between health and development, the imperative for tackling the infectious diseases afflicting the world’s most impoverished populations has never been stronger. And the challenges posed by neglected tropical diseases (NTDs) are a good place to start.
What are NTDs?
The NTDs comprise a class of diseases that are especially prevalent among low-income populations in Asia, Africa, and the Americas. In fact, the burden posed by NTDs in sub-Saharan Africa is nearly equivalent to half of the region’s malaria burden and more than double its TB burden.[i] Examples of NTDs include Chagas disease, leishmaniasis, dengue, and chikungunya. In all, the World Health Organization has identified 17 priority NTDs.
Despite their prevalence, NTDs are often overlooked because of their relative absence in wealthier, industrialized nations, and are typically overshadowed by larger caseloads and funding streams for relief efforts around HIV/AIDS, malaria, and TB. Furthermore, many NTDs have long incubation periods, which make them harder to detect. As a result, current figures likely underestimate the true global burden of these diseases.
The burden of NTDs
Many NTDs present as co-infections with HIV, malaria, and TB, and exacerbate the severity of those diseases. NTDs are also accompanied by the “hidden burden” of social stigma, since they cause physical deformities that affect patients’ self-esteem and social relations, and are frequently responsible for poor school attendance among infected children. Some NTDs may even result in chronic, non-communicable health conditions: Chagas disease, for instance, can lead to cardiovascular disease, while diseases like schistosomiasis and toxocariasis can cause cancer and chronic pulmonary disease, respectively.
Additionally, certain NTDs affect women disproportionately, and have been shown to worsen existing gender disparities in access to medical care. NTDs also inflict enormous economic burdens. WHO reported in 2010 that trachoma and lymphatic filariasis infections alone generated $2.9 billion and $1.3 billion in productivity losses, respectively.[ii] Though many NTDs are easily preventable and in many cases, treatable and curable, the regions most affected often lack the medical capacity and access to pharmaceuticals required to reduce their NTD burden.
Why tackle NTDs?
In light of recent outbreaks of non-neglected diseases, and growing emphasis on the burdens associated with non-communicable diseases, NTDs are at risk of becoming even more overlooked. So, why ensure that NTDs remain a future global health security priority?
1. Reducing the prevalence of NTDs could translate into major economic gains for low- and middle-income populations across the world.
Targeting the health needs of those at the bottom of the pyramid is one way of accelerating economic mobility among currently impoverished populations. And it’s important to remember that these gains aren’t just for developing and least-developed countries. An alarming number of NTD cases occur among the “bottom billion,” many of whom live in pockets of poverty in wealthier economies; notably, the BRICS countries and other G20 nations in Asia and the Americas.[iii] This phenomenon, described in detail by Dr. Peter Hotez, is known as “Blue Marble Health.”
2. Changing climates and increasing globalization could mean that the pathogens and vectors responsible for NTD transmission are introduced to less-affected regions.
Changing climates and increased world travel could contribute to changes in the movement of vectors and pathogens responsible for NTD incidence. Cases of malaria, dengue fever, and chikungunya, for example, have recently emerged in the US, underscoring the potential of any communicable disease – neglected or not – to pose transnational threats.
3. Increased investment in NTD mitigation, elimination, and eradication could enhance ongoing efforts to resolve national security challenges.
NTDs and conflict are inextricably linked and frequently exacerbate each other’s consequences. Among the NTDs, lymphatic filariasis, Chagas disease, yellow fever, and leishmaniasis are frequently associated with conflict settings; leishmaniasis, in fact, has been called “a disease of guerrilla warfare.”[iv] Conflict weakens or destroys the fragile health infrastructure of NTD-prone populations, which further limits the ability of those populations to access basic health services. Economically disempowered individuals, in turn, may further fuel civil unrest.
Thus far, nations across the world have acknowledged their shared vulnerabilities to communicable diseases, and have recognized the need for – and importance of – initiatives that strengthen global health security and advance human development efforts. Given the alignment between these activities and NTD elimination, it remains up to policymakers, public health practitioners, and healthcare professionals in those nations to make NTDs a priority for 2015 and beyond.
[i] Hotez PJ and Kamath A. Neglected tropical diseases in sub-saharan Africa: review of their prevalence, distribution, and disease burden. PLOS Negl Trop Dis. August 25, 2009. http://www.ncbi.nlm.nih.gov/pubmed/19707588
[ii] World Health Organization. Working to Overcome the Global Impact of Neglected Tropical Diseases. 2010. http://whqlibdoc.who.int/publications/2010/9789241564090_eng.pdf
[iii] Hotez PJ. Blue Marble Health: A New Presidential Roadmap for Global Poverty-Related Diseases. http://bakerinstitute.org/research/blue-marble-health-new-presidential-roadmap-global-poverty-related-diseases/
[iv] Beyrer C et al. Neglected Diseases, Civil Conflicts, and the Right to Health. The Lancet. 2007. http://ac.els-cdn.com/S0140673607613014/1-s2.0-S0140673607613014-main.pdf?_tid=a2ef0740-c1c4-11e4-9b1b-00000aacb360&acdnat=1425401282_48181496d9bfd816d91e31359c33bc2b