The Story of Neglected Tropical Diseases

Warning: There are images within this article that may be disturbing to some.

Like many Americans, when I think of the problems associated with living in poverty, the first thing to come to mind are issues of material wealth. Not having access to things like cell phones, the internet, and a car, but being impoverished has many challenges that stem deeper than that. One of the biggest difficulties facing the underprivileged globally that often is overlooked, is poor health. Those living in poverty tend to be more prone to illness, due to things like lack of information, money, or access to quality healthcare. The poor are more likely to suffer from certain diseases than those of a higher social order. Infectious diseases and Neglected Tropical Diseases (NTDs) disproportionately affect  “The Bottom Billion,” a term coined by Paul Collier, an economist at the University of Oxford, referring to the billion poorest people in the world who are stuck in a cycle of poverty.

Who are the Bottom Billion?

Collier’s book attempts to analyse why the most destitute can’t seem to break free from this cycle of poverty. He states that while the majority of the world’s population is growing richer, the world’s poorest people have been stuck in poverty. He suggests that the poor fall into traps that prevent them from developing economically with the rest of the world. Among these traps are war, an abundance of natural resources, being in an area surrounded by other poor people, and poorly run governments. The bottom billion are found mostly in Africa, Asia, and a few smatterings in the Americas which just happens to be where you find people affected by the NTDs. People living in poverty are commonly housed in areas with poor shelters, inadequate sanitation, in close contact with domestic animals and livestock, thus they are more likely to be affected by infectious diseases and NTDs.

So what are the Neglected Tropical Diseases?

The NTDs are a collection of 20 (this list was expanded in 2017) communicable tropical diseases that are caused by a variety of pathogens including viruses, bacteria, worms, and parasites which impact around 1 in 6 people world wide. Some of these diseases are well known like leprosy, rabies, dengue fever, and african sleeping sickness. Some are diseases that most people have never heard of like Chagas disease, Dracunculiasis, and Onchocerciasis. These diseases affect a vast amount of people across the world and cause high levels of morbidity and sometimes mortality as well.

Chagas disease is a caused by the infection of a protozoan parasite that most commonly enters the host by transmission from a kissing bug (It is called this because it typically bites people near their lips). Chagas can cause heart disease and intestinal problems in those infected. It is endemic in the Americas where it affects approximately 8 million people.

Dracunculiasis, a.k.a. Guinea-worm disease, is caused by the largest tissue parasite affecting humans (up to 800 mm in length and 2 mm in diameter). Parasites migrate through tissues causing severe pain until they eventually emerge out of the skin. The patient is usually unable to work for several months due to pain and infections in ulcers that result from the worm surfacing. It is contracted through drinking contaminated water. While there are no available drugs for treatment, it is largely preventable by access to clean drinking water. Picture of Guinea-worm can be found here, but be warned they are particularly gnarly.

River blindness, or Onchocerciasis, as indicated by its name causes blindness. It also causes lesions in the skin which is sometimes referred to as “lizard skin.” It is transmitted by the bite of a black fly. In the 1970s in some west african villages 50% of the men were blinded by Onchocerciasis. People eventually fled the fertile river land to escape the disease. It caused the West African savannah an annual estimated economic loss of 30 million of USD.  

The effects of these of diseases in developing countries is debilitating to many people and billions of dollars every year, but could be controlled easily with public-health interventions like access to clean drinking water.

Info on all the Neglected Tropical Diseases can be found here.

Why are they neglected?

If these neglected diseases cost so much money and affect so many people then why do they still go on untreated and under-researched?

It may be an issue of privilege. Some activists claim 10 percent of research is done on diseases that cause 90 percent of the global health burden and virtually no money is going to research and design in neglected disease. These claims are controversial. Regardless of the validity of the 10-90 gap as a true estimate of research inequality, there does exist a significant gap in funding. Only 1% of the pharmaceuticals produced from 1975-1999 were purposed for treating tropical diseases even though 1 in 6 of the world population is affected. This discrepancy hurts people in poorer areas, because diseases that don’t affect the rich and poor equally are unlikely to receive adequate funding, despite the fact that a significant number of people are affected by these diseases every year.

Many of these diseases have major effects on life expectancy and health but they can also make it impossible for those who are ill to work and provide for their families. Specifically, River blindness and severe schistosomiasis seem to have the largest effect on people’s ability to work. They not only decrease individual productivity but that of the nation as a whole as well. The money that goes into treatment and labor lost due to disease can have substantial effects on the Gross Domestic Product of affected countries, which makes it that much more difficult for these already poor countries to put money towards the health issues created by NTDs.

Another potential reason for the lack of funding of NTD research is because these diseases tend not to be known. It is a lot harder to get people with deep pockets to care about a disease if it isn’t getting attention, even if it does have significant effects (e.g. blindness or debilitating pain) on those afflicted. Disease burden does not tend to line up with funding.

What can be done?

The World Health Organization (WHO) has made strides to eradicate NTDs by 2020. They have produced a roadmap for implementation of changes that includes recommendations, cost, benefits, and providing financial support. The WHO recommends preventive drugs, innovative disease treatment, vector control, better sanitation and education as possible solutions for combating NTDs. The roadmap relies on funding from governments, including the U.S and the European Union, and pharmaceutical companies in an agreement called the London Declaration.

Individuals can also have a profound effect on control and treatment of NTDs. It has been estimated that the cost of protection from 7 of the NTDs could be as low as only 50 cents a year per person affected. Everyone can help with the eradication of NTDs by raising awareness and donating money to organizations like Global Network from the Sabin Institute. We all can help to end some of the burden of these diseases.

About the author:

kruckow Katherine Kruckow is a graduate of the University of Georgia with a Bachelor’s degree in Microbiology. She is looking for a PhD program to further her passion of studying microbes. When not in the lab she loves hiking, cooking, going to all the concerts she can afford, and reading a good book in her hammock. She also plans on visiting every national park at some point in time during her life. Contact her at kkruckow@uga.edu. More from Katherine Kruckow.