The Tropical Attack

Written by IISER Pune II

What are NTDs (1)?

NTDs, or Neglected Tropical Diseases, are a topic that most people haven’t heard of, as might be obvious from the name. NTDs are a very diverse group of diseases with a range of causative agents, including bacteria, viruses, fungi, protozoa and helminthic parasites.

Some examples of these are Dengue, Chagas disease, Dracunculiasis, Echinococcosis, African Trypanosomiasis, Leishmaniasis, Filariasis, Schistosomiasis, Cysticercosis and the list goes on.

A common thread amongst most NTDs is their mode of spread. A large number of them are soil-borne, waterborne, carried by insect vectors or are a result of poor sanitation.

An often surprising fact that comes up, is that most NTDs are easily curable and are in fact very cheap to treat, with the notable exception of Dengue.

This often raises a few questions; Why do NTDs seem to affect certain regions of the world? Are certain portions of the population at a higher risk of contacting NTDs? If NTDs are so easily treated, why haven’t they been eradicated? In the case of Dengue, why hasn’t it received as much attention as other incurable diseases like HIV? Why are NTDs neglected in the first place?

Where are NTDs prevalent?

NTDs are commonly found in developing countries, often located in Asia, Africa and Latin America, the so-called ‘Global South’. Poverty is prevalent here, along with poor sanitation and hygiene, poor access to clean drinking water, lack of education about sanitary practices and proper healthcare and primary occupations like farming, fishing, foraging and hunting.

Why are NTDs prevalent in these places?

The above outlined factors and social conditions, along with the modes of transmission of NTDs make these places highly susceptible to them. For example, a lack of access to clean drinking water and poor sanitation lead to people seeking sources of water which might be contaminated by waste matter. Thus, parasites spreading by the faeco-oral route can spread amongst these populations, such as Entamoebiasis and the gruesome Dracunculiasis. Soil borne diseases like ascariasis, whipworms and hookworms spread due to lack of hygiene. Farmers working in rice fields and fisherfolks are exposed to schistosomiasis and other flatworms. In areas that lack food security, bushmeat hunting is an important source of sustenance, which carries with itself the risk of echinococcosis and taeniasis.

The puddles of water accumulating in garbage dumps act as breeding grounds for mosquitoes, which then go on to spread dengue.

Why aren’t NTDs treated?

The treatment for most NTDs (with the remarkable exception of Dengue) is quite simple and affordable, despite which NTDs continue to affect a large number of people worldwide.

A major factor is the lack of infrastructure in affected areas. Poor public healthcare, lack of trained medical staff, lack of education, poor transport, erratic electric supply and isolated locations all make transport and administration of medicines very difficult.

Even in places where medicines might be available, economic factors might prevent the poor from accessing proper treatment.

Is there a social aspect to NTDs?

The question can be thought of in three ways; how do social factors lead to susceptibility to NTDs, how they affect access to treatment and how social mores affect the lives of patients.

NTDs disproportionately affect poor people due to the aforementioned reasons. Social prejudices against minorities can significantly affect their ability to access medical care, thus putting specific racial, ethinic and gender groups at a steep disadvantage.

Many NTDs have taboos associated with them, which worsen the lives of the affected. Leprosy has historically been one such disease. The disfigurement it causes leaves its victims unfit for employment and thus forces them to dependent on others. They often end up ostracized from society. Various NTDs have long lasting effects on the people they affect. There are various superstitions surrounding these that further worsen their situation.

Why are NTDs neglected?

As might be clear by now, NTDs disproportionately affect poor and disadvantaged people in tropical, developing countries. They recieve no representation in mainstream culture and their voices aren’t represented on the global stage. Thus, most of the problems troubling them go unnoticed by policy-makers and privileged people.

Why is Dengue special?

Dengue is a viral disease transmitted by mosquito bites. Unlike other NTDs, it doesn’t have a known cure. The current measures taken to treat Dengue are basic symptom control and prevention is done by vector control.

References:

1. CDC - Global Health - Neglected Tropical Diseases. https://www.cdc.gov/globalhealth/ntd/index.html (2022).