Ebola Update 2014: Tropical Diseases That Kill Thousands Each Year Forgotten Amid West Africa Outbreak

The world’s resources are currently earmarked to fight Ebola, which limits governments' capacity to respond to other dire diseases in the meantime. As a consequence, the ongoing Ebola outbreak is threatening progress made against the world’s neglected tropical diseases, according to health officials. In disease endemic countries where resources are already scarce, health services are being deployed to the Ebola front line -- and in effect, curtailing programs for neglected tropical diseases.

Neglected tropical diseases are a group of diverse parasitic and bacterial diseases that cause substantial illness and mortality worldwide. They are called “neglected” because they've been largely eradicated in more developed regions of the world and, until very recently, receive limited attention from affluent nations.

To date there's been a collective total of 13,042 Ebola cases in Guinea, Liberia and Sierra Leone, with 4,818 total deaths. Meanwhile, more than 1 billion people worldwide -- or one-sixth of the world’s population -- suffer from one or more neglected tropical diseases, and an estimated 534,000 people die as a result each year, according to the Centers for Disease Control and Prevention. But the Ebola outbreak in West Africa has captivated a larger audience.

These diseases thrive in the world’s poorest, most marginalized populations and conflict areas, where access to quality health care, clean water and proper sanitation are scant. They trap the underprivileged in a cycle of poverty and disease by causing severe disabilities and disfigurements, according to the CDC.

All low-income countries are affected by at least five neglected tropical diseases simultaneously and 149 countries and territories worldwide are affected by at least one. Most mass drug administration programs for neglected tropical diseases cost less than an estimated 50 cents per person, per year. It costs $244 to test one person for Ebola virus disease, according to the World Health Organization.

Below are just some of the world’s neglected tropical diseases. A list of all 17 is available on the World Health Organization website.

CHAGAS

Chagas disease is a potentially life-threatening illness caused by the protozoan parasite. An estimated 8 million people are infected globally, mostly in Latin America, many unknowingly. This neglected tropical disease kills more people in Latin America than any other parasitic disease and causes over 10,000 deaths worldwide each year. There are two available drugs to treat Chagas disease, which is clinically curable if treatment is initiated at an early stage. If left untreated, infection is life-long and can cause severe heart damage and intestinal problems -- the greatest cause of death and disability from the disease, according to the World Health Organization. Many people with Chagas disease remain asymptomatic and never develop symptoms. However, an estimated 20 percent to 30 percent of those infected will develop debilitating and sometimes life-threatening medical problems over the course of their lives, according to the CDC.

DENGUE

Dengue is a mosquito-borne virus that was first discovered in the 1950s in the Phillippines and Thailand. This neglected tropical disease is now fast emerging and widespread. The pandemic-prone virus flourishes in urban poor areas, suburbs and the countryside, but it also affects more affluent neighborhoods in tropic and subtropical regions. Dengue cases have increased thirtyfold over the past 50 years. Some 50 million to 100 million infections are estimated to occur annually in over 100 endemic countries, putting almost half of the planet’s population at risk. The virus is transmitted via mosquitoes and infection begins abruptly after an incubation period of 4-10 days, causing severe flu-like illness and sometimes death. It’s a leading cause of hospitalization and death among children and adults in Asia and Latin America, according to the World Health Organization. There is no specific medicine to treat dengue.

LYMPHATIC FILARIASIS

Commonly known as elephantiasis, lymphatic filariasis is an extremely painful and profoundly disfiguring disease found in mainly tropical and subtropical climates. Although the WHO in 1997 classified elephantiasis as “eradicable or potentially eradicable,” following advances in diagnosis and treatment, it continues to affect more than 120 million people in 80 countries worldwide. The disease is caused by three species of thread-like nematode worms that live in the lymphatic system and are transmitted among humans by mosquitoes. The parasite can live in the human body for years without symptoms. Elephantiasis can cause temporary and permanent disability, such as severe swelling of the extremities and genitals. Roughly 40 million infected people live with painful, incapacitating symptoms and many are ostracized or shunned by their communities due to their disfigurement.

While the vast majority of infected people don’t show symptoms, virtually all of them have subclinical damage to their lymphatic system -- an essential component of the body’s immune system -- and 40 percent have kidney damage, according to the World Health Organization. There is currently no cure or vaccine for this neglected tropical disease, but symptoms can be managed with a treatment plan, says the Global Network for Neglected Tropical Diseases. The World Health Organization is targeting to eliminate lymphatic filariasis by 2020.

TRACHOMA

Trachoma is the world’s leading infectious cause of preventable blindness, responsible for the visual impairment of 2.2 million people worldwide, more than half of whom are irreversibly blind. This crippling ocular infection is caused by the bacterium Chlamydia trachomatis and is spread through direct contact with infected eye discharge from a person’s hand, clothing or even eye-seeking flies. This neglected tropical disease strikes poor, rural communities – mainly in Africa and Asia -- where crowded living conditions and extreme poverty are common. Trachoma is particularly common in young children and the adults who care for them. In some rural communities, 60 percent to 90 percent of children are infected, according to the Global Network for Neglected Tropical Diseases. Single episodes of infection usually don’t cause permanent damage, but repeated infections scar the upper eyelid, causing it to turn inward. The scarred inner lining of the eyelid develops ingrown eyelashes that scratch the cornea and can ultimately lead to partial or complete blindness. Blindness due to trachoma is irreversible but can be prevented during its early stages. The estimated economic cost of trachoma in terms of lost productivity is $2.9 billion annually, according to the World Health Organization, which is targeting to eliminate this neglected tropical disease by 2020.