Understanding Neglected Tropical Diseases

As a public health issue, neglected tropical diseases affect a billion people globally. Preventing neglected tropical diseases is a significant task that starts with high-quality, thorough clinical research.

Whether you need a principal investigator for your clinical research or a CRO to manage your clinical trial site, Infiuss Health can help with every aspect of neglected tropical disease research in Africa.

Understanding Neglected Tropical Diseases - Infiuss Health
Decentralized Trials

Neglected Tropical Diseases Meaning

Neglected tropical diseases (NTDs) are infectious diseases endemic to tropical regions such as Southeast Asia, Africa, Latin America, and India.

Statistically, NTDs thrive in underdeveloped regions with weak or nonexistent sanitation, healthcare, and infrastructure. In addition to being often underdeveloped economically, these regions have tropical climates perfectly suited for the spread of parasites, viruses, and bacteria that cause NTDs.

Why Are Neglected Tropical Diseases Neglected?

The main reason neglected tropical diseases are neglected is because they mainly afflict poor communities.

Unfortunately, medical advancements can be expensive, and underdeveloped communities don’t have the necessary resources to perform medical research themselves. Therefore, their well-being lies in the hands of the wealthy few who are willing to invest in the research of these endemic diseases.

Philanthropic efforts, such as the ones made by the Bill and Melinda Gates Foundation, have started to address neglected tropical diseases in recent years. These efforts aim to eliminate illnesses such as trachoma, Chagas disease, and dengue fever not just for the wealthy, but for everyone. Luckily, with the rise of technology, decentralized trials have made it easier than ever to study diseases endemic to countries and continents thousands of miles away.


Neglected Tropical Diseases Examples

Each neglected tropical disease has a different set of symptoms, treatment plans, and transmission methods. Here’s a brief description of the 18 most common NTDs:

1. Buruli Ulcer

Buruli ulcer is a neglected tropical disease caused by a bacteria, Mycobacterium ulcerans.

This disease is prevalent in West Africa and Australia. The main symptom of Buruli ulcer are ulcers that can destroy the skin and the soft tissue, primarily on arms and legs.

2. Chagas Disease

Chagas disease is caused by a parasite called Trypanosoma cruzi.

If left untreated, this parasite can cause digestive issues and heart issues (if the parasite spreads to the heart through the bloodstream). Chagas disease is most common in rural areas of Latin America.

3. Cysticercosis

A parasitic disease caused by larval cysts of a tapeworm (Taenia solium).

These cysts spread through the bloodstream and can infect the brain, muscles, the heart, and other tissues. Cysticercosis is the main cause of adult-onset seizures in low-income areas due to the devastating effects it can have on the brain if left untreated.

4. Dracunculiasis

Dracunculiasis (Guinea Worm Disease) is caused by a parasite called Dracunculus medinensis.

This parasite is spread through contaminated water and is most prevalent in remote, poor African communities that lack access to clean water. Symptoms of the Guinea worm disease include nausea, vomiting, fever, diarrhea, dizziness, and an itchy rash.

5. Dengue Fever

Dengue fever is a mosquito-borne tropical disease.

Symptoms of this illness include a persistent, high fever, as well as muscle pain, joint pain, headaches, nausea, swollen glands, and a rash. Dengue fever is common in all tropical and subtropical climates, with Southeast Asia, Africa, and Latin America being particularly high-risk.

6. Echinococcosis

A parasitic tropical illness caused by tapeworms of the Echinococcosis genus.

The two most common forms of this disease are cystic echinococcosis and alveolar echinococcosis. This parasite is found all over tropical and subtropical parts of Africa, Asia, the Middle East, and South America.

7. Fascioliasis

A parasitic tropical infection caused by Fasciola hepatica.

It’s known as ‘the sheep liver fluke’ as it mostly attacks livestock, such as sheep, but it can also infect people. Symptoms of fascioliasis include nausea, vomiting, fever, diarrhea, liver function issues, swollen liver, abdominal pain, and sometimes skin rashes.

8. Human African Trypanosomiasis

One of the most common foodborne trematode infections.

Also known as African Sleeping Sickness. Just like all foodborne trematodiases, this illness is transmitted via contaminated food. Symptoms of the African sleeping sickness include extreme fatigue (hence the name), irritability, headaches, confusion, swollen lymph nodes, and muscle and joint pain.

9. Leishmaniasis

An NTD caused by a parasite that spreads via female phlebotomine sand fly bites

This illness can be found in tropic and subtropic climates, as well as in southern Europe.

Visceral leishmaniasis, the most deadly form of leishmaniasis, is fatal in over 95% of untreated cases and is characterized by symptoms such as weight loss, bouts of fever, anemia, and spleen and liver enlargement.

10. Leprosy (Hansen’s Disease)

A tropical infection caused by bacteria called the Mycobacterium leprae.

This bacteria attacks the skin, eyes, lining of the nose, and nerves. Most cases of Hansen’s disease are found in Asia and Africa.

11. Lymphatic Filariasis (Elephantiasis)

Caused by a parasite that’s transmitted to humans through mosquito bites.

This illness can be asymptomatic for a long time, so it often goes untreated until people develop chronic symptoms such as tissue swelling and skin and tissue thickening (elephantiasis). About 863 million people worldwide don’t start treatment for lymphatic filariasis in time. Once chronic symptoms begin to show, the only way to stop the illness from spreading is via preventive chemotherapy. Elephantiasis can cause body deformities, which further stigmatize people afflicted by it, leading to loss of income, mental health issues, and increased medical expenses.

12. Zika Virus Disease

Caused by Zika Virus, most often found in South America, the Caribbean, Africa, Asia, and the western Pacific Islands

Symptoms of Zika virus disease include a rash, high fever, headaches, muscle pain, and joint pain. This tropical illness is spread through mosquito bites.

13. Mycetoma

Caused by bacteria and fungi found in water and soil.

It mostly afflicts people in rural areas with little access to clean water, sanitation, and hygiene. Mycetoma starts with a painless lump that forms under the skin. Over time, this lump gets infected, which causes swelling and can lead to hands, feet, and back disfigurement.

14. Onchocerciasis

Also known as river blindness, is an NTD caused by a parasite—Onchocerca volvulus.

Parasitic infections caused by ftnt include symptoms such as severe itching, skin disfigurements, and visual impairments. If left untreated, onchocerciasis can cause permanent blindness.

15. Rabies

A viral disease spread through bites and scratches by infected animals.

This illness is present in all climates but is most prevalent in underdeveloped areas. Symptoms of this disease include encephalitis, confusion, fear of water and high fever. Unfortunately, rabies is fatal but can be prevented with a vaccine.

16. Schistosomiasis

Schistosomiasis (bilharzia) is a disease caused by parasitic intestinal worms.

Acute symptoms of this disease include fever, a cough, chills, and muscle pain. If left untreated, schistosomiasis can cause chronic symptoms such as abdominal pain, blood in the stool and urine, enlarged liver, and painful urination.

17. Soil-transmitted Helminthiases

Caused by parasitic worms known as soil-transmitted helminths (hookworm, ascaris, and whipworm).

As the name suggests, this illness is soil transmitted, which means it mainly affects areas with poor sanitation and hygiene. Symptoms of the Helminth infection include abdominal pain, diarrhea, blood in the stool, and rectal prolapse.

18. Trachoma

A bacterial infection caused by Chlamydia trachomatis.

It is a highly contagious disease that spreads through contact with the eyelids, eyes, throat, or nose of infected individuals. The main symptoms of trachoma include eye and eyelid irritation, eye discharge, swelling of the eyelids, eye pain, eye redness, light sensitivity, and vision loss.

Neglected Tropical Diseases in Africa

The continent of Africa is the most affected by neglected tropical diseases. According to research done by The Developed Nations Uniting to Combat NTDs, about 40% of microbes that cause NTDs thrive in Africa.

Different areas of Africa are afflicted with different tropical diseases. Still, some illnesses are prevalent all across Africa. For example, lymphatic filariasis, river blindness, and human African trypanosomiasis are found across the continent.

The Impact of Neglected Tropical Diseases

Segments of the global population disproportionately affected by NTDs are children under the age of 5, women, and people with disabilities. Those who are impacted by neglected tropical diseases miss work, miss school, and become reliant on others. If left untreated, many NTDs can cause long-term physical and neurological disabilities that affect the quality of life of the afflicted person. These people are more likely to face economic hardships due to their inability to work, as well as face other physical and mental health issues.

Social Stigma

Social stigma is a common disease burden for illnesses that cause visible body disfigurements. As NTDs affect women more frequently than men, this social stigma can lead to a delay in gender equality, as well as poor mental health and economic conditions for women affected by neglected tropical diseases.

Economic Effects

The economic effects of NTDs are among the biggest burdens of neglected tropical diseases. Living in a developing country restricts people’s access to medication, clean food, and clean water. People who suffer from NTDs are unable to work and often need assistance for everyday tasks, which are usually done by a member of the patient’s family. This further worsens the economic status of families facing an NTD.

Mental Health

People living with chronic symptoms of NTDs frequently face mental health issues such as depression and anxiety. When it comes to neglected tropical diseases, causing mental health issues is a result of facial and bodily changes, as well as physical and sensory impairments, which can lead to chronic pain and distress.

Coinfection Risks

One of the main risk factors of infectious, communicable diseases is coinfection. People with a neglected tropical disease are more likely to be infected with other NTDs, as well as non-NTD diseases such as HIV, tuberculosis, and other bacterial infections.

Treatment of Neglected Tropical Diseases

Treatment of Neglected Tropical Diseases

The treatment of neglected tropical diseases starts with improving the conditions that people affected by them are living in.

Improved quality of water and sanitation massively contributes to the reduction of mosquito-transmitted diseases such as dengue and chikungunya. That’s why sustainable development goals that focus on improving living conditions in third-world countries are integral.

Climate change is making tropical and subtropical areas even more susceptible to the spread of NTDs, as it’s making these areas even warmer. Therefore, fighting climate change and fighting NTDs go hand-in-hand.

Finally, drug development is crucial for NTD treatment. That’s why Infiuss Health partners with pharma companies worldwide to conduct clinical research in Africa. From pharmacovigilance to clinical data management to regulatory guidance, we are an end-to-end CRO for African NTD research.


Treatment of Neglected Tropical Diseases NTD Programs

Some of the NTD programs focused on the prevention and treatment of neglected tropical diseases include the following.

1. World Health Organization’s Vector Control Initiative

One of the first efforts to gain control of neglected tropical diseases was the Vector Control Initiative.

In 1955, The World Health Organization deployed this initiative using insecticides to decrease the mosquitos associated with viral transmission of neglected tropical diseases.

However, the mosquitos adapted by either maneuvering different flight patterns or becoming resistant to the insecticide altogether. Though this method of disease control was ultimately unsuccessful, it created a road map for further research into NTD prevention and treatment.

2. London Declaration on Neglected Tropical Diseases.

The London Declaration on Neglected Tropical Diseases is a collaborative disease eradication program that launched in 2012.

Since then, they have provided funding and expertise with the aim to control, eliminate, or eradicate NTDs.

3. US Agency for International Development

The NTD program by the US Agency for International Development was launched in 2006.

They focus on controlling or eliminating five neglected tropical diseases— lymphatic filariasis, onchocerciasis, blinding trachoma, schistosomiasis, and soil transmitted helminths.

4. PLOS Neglected Tropical Diseases

The PLOS Neglected Tropical Diseases is an open-access journal dedicated to neglected tropical diseases.

This journal aims to make NTD clinical trials accessible to anyone as part of a coordinated effort to eradicate this global health issue.

Research of Neglected Tropical Diseases

Neglected Tropical Disease Research

In order to control and eliminate neglected diseases, high-quality clinical research is necessary.

Pharmaceutical companies aren’t willing to invest in drug discovery for NTDs if they can’t make a profit, so funding opportunities for NTD research are scarce.

Luckily, if you want to conduct an NTDs clinical trial, Infiuss is here to make the entire process—from patient recruitment to specimen collection—easier.

Our Probe product is a proprietary platform for managing clinical trials in Africa. We’ve researched and developed drugs and vaccines for many illnesses across Africa. Infiuss will manage your trial data and ensure regulatory compliance with national and international research standards.


FAQ on Neglected Tropical Diseases

Beyond neglected tropical diseases, Infiuss is your African CRO partner for all clinical trial needs. From patient recruitment to clinical data management, pharmacovigilance to site management, we will partner with you for all types of clinical research.

What is the most common neglected tropical disease?

The five most common neglected tropical diseases are trachoma, onchocerciasis, schistosomiasis, lymphatic filariasis, and soil-transmitted helminths.

Can neglected tropical diseases be cured?

Yes, many neglected tropical diseases can be cured, especially if they are diagnosed during their acute stage. Mass drug administration is necessary to slow down the spread of NTDs and reduce symptoms for those afflicted by them. Unfortunately, regular drug administrations can be prohibitive, as the drugs necessary to treat NTDs are expensive and hard to find in the areas they are needed most.

What NTDs are endemic for Cote d’Ivoire?

NTDs endemic to Côte d’Ivoire, and West Africa in general, are lymphatic filariasis, onchocerciasis, soil-transmitted helminths, leprosy, and Buruli ulcer.

What are the major causes of neglected tropical diseases?

Neglected tropical diseases are caused by pathogens such as bacteria, parasites, viruses, toxins, and fungi. These pathogens thrive in tropical climates and economically disadvantaged living conditions, which is why they are mostly found in rural areas of Africa, Southeast Asia, and South America.

What does NTDs stand for?

NTDs is an abbreviation that stands for neglected tropical diseases.

Is ebola an NTD?

Yes, ebola is an NTD. The recent ebola outbreak of 2014 caused this disease to spread and affect people worldwide, but ebola is still most common in West Africa and neglected in the developing countries affected by it.

What are the two diseases that have been eradicated?

So far, only two recognized diseases have been eradicated: smallpox and rinderpest. The last naturally occurring case of smallpox was reported in 1977, while the last case of rinderpest was documented in Kenya in 2003.

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