NIAID Now | January 30, 2020
Neglected tropical diseases (NTDs) include a range of conditions that can blind, disfigure, and disable people. They steal not only health, but also the ability to succeed in school or earn a living. Globally, 1.5 billion people live in areas where such NTDs as dengue, leprosy, sleeping sickness, and schistosomiasis cause many millions of cases of illness each year.
In recognition of the first World NTD Day on January 30, NIAID scientist Shaden Kamhawi, Ph.D., who studies an NTD called leishmaniasis, shared her thoughts on the challenges and achievements of NTD control in a guest post for NIAID Now.
Happily for the world’s health, the so-called neglected tropical diseases are much less neglected today than they have been in the past. In 2000, the concept of NTDs as a distinct area of concern was born under the umbrella of the United Nations Millennium Declaration, which aimed to reduce world poverty. Since then, with support from the World Health Organization (WHO), NTDs have been defined as a group of prevalent chronic or debilitating infections disproportionately affecting the poor. These diseases are associated with high morbidity, long-term disability, societal stigmatization, and a significant loss in the quality of life.
Over the past two decades, it has been recognized that NTDs not only impact health but also represent a real threat to global economies and political stability. This recognition fueled tangible action aimed at control and elimination of several of these infections. Most notable are the WHO Roadmap to overcome the global burden of NTDs and the London Declaration on NTDs. Both programs were, and remain, instrumental in mobilizing stakeholders and policy makers to unite in a global fight against NTDs. Their goal now is to eliminate NTDs as a public health problem by 2030.
I work in NIAID’s Lab of Malaria and Vector Research, where my colleagues and I study the parasitic disease leishmaniasis, which is transmitted to people through the bite of infected sand flies. Clinically, leishmaniasis infections can cause a range of illness forms, including slow-healing skin ulcers, disfiguring disease in the mucous membranes of the nose, and a form that affects internal organs, including the spleen and liver, and that is often fatal. Our group has both basic and translational research interests. One area of focus is on the early immune response to insect bites in skin, both in humans and in animal models of infection, to understand their influence on parasite establishment and disease progression.
We are also interested in vector saliva and are studying whether salivary proteins can function as vaccines against leishmaniasis. Currently, there are no vaccines available to prevent leishmaniasis (or to prevent any other parasitic disease.) Generating protective immunity through a vaccine is complex and requires a deep understanding of the parasite’s lifecycle as well as biological and environmental parameters that influence vaccine efficacy. Additionally, each kind of parasite has evolved diverse and clever ways to hide from, or overcome, the human immune system. Nevertheless, progress is being made. Over many decades, scientists have made significant advances in understanding the immune mediators of protection for many parasites. I am optimistic because we are at an exciting time in science where increasingly powerful techniques are bringing us closer to reaching our goal of developing vaccines against parasitic diseases.
In addition to my research activities, I also serve as a co-Editor-in-Chief of PLOS NTDs, the first journal exclusively dedicated to publishing on aspects of NTDs from pathology to policy. It has been humbling and rewarding to work with our community of researchers where one can see first-hand the dedication to defeating NTDs despite the many challenges this presents. We have a long but worthwhile journey towards a world free of NTDs and I am proudly committed to furthering this work so that all people may experience healthy and prosperous lives.