Tag: Neglected Tropical Diseases

Four years ago I wrote an article about Guinea-worm disease, one of the top ten neglected tropical diseases. Thirty years ago the former President Jimmy Carter’s foundation embarked on a program to eliminate the agonizing and debilitating parasitic disease that has plagued Africa for centuries. They are now close to eliminating it and it is Pres. Carter’s wish to see it gone before he is.

When former President Jimmy Carter announced Thursday that his cancer had spread to his brain, he also revealed he had some unfinished business he wants to see through.

“I would like to see Guinea worm completely eradicated before I die,” the philanthropist said. “I’d like for the last Guinea worm to die before I do.”

Carter went on to explain that there are currently only 11 cases of dracunculiasis, or guinea worm disease, in the world. That’s a precipitous drop from 3.5 million cases across 21 countries in 1986, when he first set out to conquer the disease through his nonprofit organization the Carter Center. [..]

When Guinea worm has been eradicated, it will be only the second time in human history that a disease has been totally wiped out. The first, smallpox, was eradicated in 1977, according to the World Health Organization. Experts from the Centers for Disease Control and Prevention estimate that Guinea worm will meet the same fate – a final piece in Carter’s legacy.

Below is the article I wrote in 2011 about the Guinea-worm disease which is no longer neglected and may soon no longer exist. Thank you and bless you, Pres. Carter. May he live to see this disease gone and longer.

Cross posted from The Stars Hollow Gazette

This is a series of diaries focused on the World Health Organization Neglected Tropical Diseases Program. I initially wrote a diary about Dengue Fever that had hospitalized Salon columnist and constitutional lawyer, Glenn Greenwald. The second diary briefly introduced the other diseases on the WHO list.

This diary will focus in Human African trypanosomiasis HAT, or sleeping sickness, parasitic disease transmitted by the bite of the ‘Glossina’ insect, commonly known as the tsetse fly infected with a protozoa of the species Trypanosoma brucei. The flagellate protozoan Trypanosoma brucei exists in 2 morphologically identical subspecies: Trypanosoma brucei rhodesiense (East African or Rhodesian African trypanosomiasis) and Trypanosoma brucei gambiense (West African or Gambian African trypanosomiasis).

Tsetse flies are found in 36 countries in sub-Saharan Africa, putting 60 million people at risk. The disease affects mostly poor populations living in remote rural areas of Africa. Untreated, it is usually fatal. Travelers also risk becoming infected if they venture through regions where the insect is common. Generally, the disease is not found in urban areas.

Sleeping Sickness is the deadliest disease in the world. Without treatment, the parasites kill.

Cross posted from Stars Hollow Gazette

This is a series of diaries focused on the World Health Organization Neglected Tropical Diseases Program. I initially wrote a diary about Dengue Fever that had hospitalized Salon columnist and constitutional lawyer, Glenn Greenwald. The second diary briefly introduced the other diseases on the WHO list.

This week will focus on Guinea-worm disease (GWD), or Dracunculiasis, which is a debilitating and painful parasitic infection caused by a large nematode (roundworm), Dracunculus medinensis. The guinea worm is one of the best historically documented human parasites, with tales of its behaviour reaching as far back as the 2nd century BC in accounts penned by Greek chroniclers. It is also mentioned in the Egyptian scrolls, dating from 1550 BC. An Old Testament description of “fiery serpents” may have been referring to Guinea Worm: “And the Lord sent fiery serpents among the people, and they bit the people; and much people of Israel died.” (Numbers 21:4-9). The name dracunculiasis is derived from the Latin “affliction with little dragons” while the common name “guinea worm” appeared after Europeans saw the disease on the Guinea coast of West Africa in the 17th century.

It a water born disease and is contracted by drinking stagnant water that has been contaminated with the worm and copepods infested by the larvae. Copepods are tiny crustaceans found in sea and nearly every freshwater habitat. The disease manifests itself about a year after infection, usually as a large blister on the leg, that burns and itches and the mature worm, 1m long, tries to emerge. The infected person tries to relieve the pain by immersing the infected part in water, usually open water sources such as ponds and shallow wells. This stimulates the worm to emerge and release thousands of larvae into the water, thus perpetuating the cycle.

For persons living in remote areas with no access to medical care, healing of the ulcers can take several weeks. People in endemic villages are incapacitated during peak agricultural activities. This can seriously affect their agricultural production and the availability of food in the household, and consequently the nutritional status of their family members, particularly young children. Outbreaks can cause serious disruption to local food supplies and school attendance.

The good news is that the end of GWD is currently in sight. Thanks to President Jimmy Carter and the his Center’s initiative to eradicate this disease there are currently only four countries in the world where GWD is endemic, Sudan, Ghana, Mali and Ethiopia. The major focus is on Sudan where 84% of the 3,190 infections reported in 2009 occurred. WHO predicted it will be “a few years yet” before eradication is achieved, on the basis that it took 6-12 years for the countries that have so far eliminated Guinea worm transmission. Endemic countries must report to the International Commission for the Certification of Dracunculiasis Eradication and document the absence of indigenous cases of GWD for at least three consecutive years to be certified as Guinea worm-free. Guinea worm disease will be only the second human disease, after smallpox, to be eradicated globally.

Prevention

Guinea worm disease can only be transmitted by drinking contaminated water, and can be completely prevented through relatively simple measures that could result in the disease being eradicated:

   * Drinking solely water drawn from underground sources free from contamination, such as a borehole or hand-dug wells.

   * Filtering drinking water, using a fine-mesh cloth filter like nylon, to remove the guinea worm-containing crustaceans.

   * Preventing people with emerging guinea worms from entering ponds and wells used for drinking water.

   * Developing new sources of drinking water that lack the parasites, or repairing dysfunctional ones.

Water sources can also be treated with larvicides to kill worm-carrying crustaceans.

Further discussion is below the fold, since the brief description of treatment and video are graphic and not for the squeamish.

Recently I wrote a diary about Dengue Fever, a tropical disease that is caused by a mosquito transmitted virus, I mentioned that it was classed as a “neglected disease” by the World Health Organization. I’d like to talk about some of the other neglected diseases, what causes them, how they are spread and, most importantly, who they affect and how they impact on the rest of the world. In up coming diaries, I will focus on each one as I did with Dengue.

First, why are these diseases neglected? It is mostly because they are diseases of of poverty. Until these diseases impact on the wealthy in some way, treatment and prevention will remain a struggle for the countries and people where they are endemic. The lives of over one billion people are impacted in developing regions of Africa, Asia, and the Americas. Some of these diseases have known preventive measures or acute medical treatments which are available in the developed world but which are not universally available in poorer areas. In some cases, the treatments are relatively inexpensive. For example, the treatment for schistosomiasis is $0.20 per child per year. In the last few years, the Bill and Melinda Gates Foundation and The Carter Center have brought attention to the diseases caused by flavivirus, trypanosomiasis (sleeping sickness) and parasitic worms.

These are the diseases classified as neglected by WHO:

   * Buruli Ulcer

   * Chagas disease(American trypanosomiasis)

   * Cysticercosis

   * Dengue/dengue haemorrhagic fever

   * Dracunculiasis (guinea-worm disease)

   * Echinococcosis

   * Fascioliasis

   * Human African trypanosomiasis

   * Leishmaniasis

   * Leprosy

   * Lymphatic filariasis

   * Onchocerciasis

   * Rabies

   * Schistosomiasis

   * Soil transmitted helminthiasis

   * Trachoma

   * Yaws

I’m fairly certain most of you have never heard of most of them and might be a bit surprised by one that is on that list, Rabies, which is a virus spread by wild and domestic animal bites. It is endemic on every continent except Antarctica and is easily treatable and can be controlled and prevented. Yet, here it is on a list of neglected diseases.

I look forward to your comments and questions which I will try to answer as best I can.

The next diary will focus on Dracunculiasis (guinea-worm disease) and its eradication.