tropical diseases
Neglected tropical diseases
are diseases that are either bacterial or parasitic and infect around one in six people around the world. Over half of a billion children are infected with these diseases.

These diseases are considered “neglected” because they do not receive very much attention or funding from governments or medical communities around the world.

These diseases tend to be especially widespread in areas with high levels of poverty, bad sanitation and poor access to health care. These diseases tend to especially affect women and children.

While they are grouped together, neglected tropical diseases can be very different from one another. Some kill quickly while others will infect for years or simply harm, but not kill, their victims. Some are parasitic, caused by parasites, and spread through mosquitoes, snails or flies. Others are bacterial and are spread through water or soil.

Treatments for these diseases also vary. Some have cheap treatments available (although this could potentially lead to drug resistance), others have no treatment or a very expensive or difficult treatment.

According to the World Health Organization there are 17 neglected tropical diseases. Here is a brief description of the seven most common neglected tropical diseases. These seven diseases account for 90 percent of global cases of neglected tropical diseases.

1. Ascariasis (roundworm) is the infection of the small intestine that is caused by a roundworm. The eggs of the roundworm are often ingested and the eggs then hatch in the person’s intestine. They then reach the lungs through the bloodstream. The worms can grow to be longer than 30 centimeters. Roundworm causes about 60,000 deaths each year.

2. Trichuriasis (whipworm) is spread and moves through the body like roundworm. Around the world about 700 million people are infected with whipworm.

3. Schistosomiasis (snail fever) is caused by parasitic worms. A person can become infected by coming in direct contact with contaminated fresh water. Over 200 million are infected with snail fever around the world.

4. Lymphatic filariasis (elephantiasis) is transmitted through mosquitoes and damages the lymphatic system causing painful, visible disfigurations. More than 120 million are infected around the world.

5. Trachoma is an infection of bacteria in the eye, causing the yield to turn inwards, eventually resulting in blindness. Six million people are blind due to trachoma.

6. Onchocerciasis (river blindness) is a parasitic disease caused by flies that carry larval worms that grow to cause blindness, lesions and loss of pigmentation in the skin.

7. Hookworm is spread and moves through the body like whipworm and roundworm. Around 600 million people throughout the world are infected with hookworm.

Although neglected tropical diseases affect millions, they are relatively inexpensive to treat: for around 50 cents a year, one person could be treated and protected for all of the seven most common neglected diseases.

– Lily Tyson

Sources: Reuters, Global Network, CDC, WHO
Photo: EndTheNeglect

The World's First Hookworm Vaccine
One-third of children and women living below the World Bank’s poverty line are infected with hookworm today, which often causes moderate to severe anemia. Hookworm and other Neglected Tropical Diseases, or NTDs, disproportionately affect the poorer Islamic countries such as Indonesia, Bangladesh, Mali, Nigeria and others in North Africa and the Middle East.

Children and pregnant women are by far the most drastically affected by this disease. Children with long-standing blood loss from hookworm often experience sufficient mental and motor development delays. They can actually lose IQ points as well. These detrimental effects undoubtedly follow them into adulthood, making productivity more difficult.

The blood loss caused by hookworm may affect women in labor, making their chance of death much higher. Additionally, the baby is more likely to be born prematurely or with low birth weight. This makes those babies less likely to survive, contributing to the child mortality rate.

Additionally, the link between hookworms and anemia is a large concern because of its relation to disabilities. Anemia accounted for 8.8 percent of the total disability of the world in 2010. Today, children under 5 years old and women of all ages still hold the heaviest burden.

Fortunately, the Sabin Vaccine Institute’s Product Development Partnership is developing the world’s first hookworm vaccine for human use. The Sabin Institute was established in 2000 with funding from the Bill & Melinda Gates Foundation and is the only Product Development Partnership in the world working to develop a vaccine for human hookworm infections.

The institute is receiving support from the European Commission FP7 program and uniting professionals from around the world to build research. This global consortium has been coined HOOKVAC and includes members from the Netherlands, the United States, Belgium, England, Germany and Gabon. This project aims not only to perfect the manufacturing process of the vaccine, but also to increase and share research on NTDs.

The first clinical testing of the vaccine will take place in Sub-Saharan Africa once it is ready. Gabon’s Lamberene Research Centre will lead clinical testing in adults and children in Gabon, a region plagued with hookworm.

The vaccine is being called the “anti-poverty” vaccine due to its vast potential to lower child mortality rates, save mothers in labor and improve health conditions for agricultural workers, who are the backbone of many poorer economies.

The vaccine, as of now, is intended only for use in the poorest regions of the world, where hookworm thrives. This means that the product will likely not be sold commercially by pharmaceutical companies, but will remain in the nonprofit sector with HOOKVAC.

The project will hopefully conduct trials in the coming years and bring health relief to millions, while contributing to the united fight against global poverty.

– Cambria Arvizo

Sources: Huffington Post, Sabin Vaccine Institute, American Society of Hematology
Photo: The Guardian

A new hookworm vaccine is the hope of millions of infected people in Africa. Although it is experimental and will be the first African clinical trial for this parasite, it is already scheduled for 2014 because hookworm infestations are rampant among the African poor. Over 102 trial participants, ages 18 to 45 will be given the vaccine over a four month period and be rechecked after a year. Once the adult participants remain safe and have positive immune responses, children will be given the vaccines. These trials will begin in Gabon, Africa.

Hookworms are easily transmitted to children who walk around barefoot. Most children who also suffer from malnutrition are attacked by the parasite and become extremely weak, which leads to learning problems and stunted growth. These parasites drain the blood of any individual and eventually cause anemia. Hookworms also infest adults and cause financial strains on the family as men and women gradually weaken from loss of blood. Even pregnant women are not free from danger since their fetus is also affected from the blood loss. These worms enter the body through the feet. Once they are inside the bloodstream they travel towards the lungs. From the lungs they reach the intestines where they grip the interior walls with their two sets of teeth. Here they are able to remain attached, suck any quantity of blood and grow to half an inch long.The aim of the hookworm vaccine is to create antibodies which will slowly kill the worms. As the antibodies are formed, it will work against two enzymes present in the hookworm’s gut. One enzyme processes iron in its blood diet and the other enzyme allows for digestion of blood proteins. As the antibodies fight against these enzymes, the hookworm’s energy source weakens and will eventually die.

Clinical trials are set for a minimum of five years regardless of whether there is   success with treatments. This vaccine could potentially be the answer to hookworm elimination which is the leading cause of iron deficient anemia among millions of the world’s poor.  Dr. Hotez, the director of the Sabin Vaccine Institute has been working on this vaccine for over 30 years. His effort and commitment over this lapse of time will surely be a victory to be seen.

–  Maybelline Martez

Sources: NIH, Medical News Today, New York Times