The worm turns no more…

Public Health Perspectives is pleased to welcome Charles Ebikeme to the blog this week. For more information about Charles, see the end of this post.

Bandaged children read about the guinea worm.

Bandaged children read about the guinea worm.

John Stavely, age 24 and unassuming, arrived at Cape Coast Castle on the coast of Ghana in June of 1842. He spent no more than 65 days on the gold coast, stowing and moving palm oil casks in the holds of the sailing ladies that came and went.

It was not until May of the next year that he began to suspect something was seriously wrong – a sore on his left instep. It caused him little pain at the time. After a while his sore had grown – a worm the width of a violin string was searching for its way out, migrating through his subcutaneous tissue. His leg became inflamed and many abscesses formed. It turned out that there were three of those little worms – or filaria – wriggling inside his body; one in his left leg, one in his left forearm, and the other in his right foot. All were over two feet long. The disease was Dracunculiasis, and is caused by the parasitic worm Dracunculus medinensis.

It took two weeks for his physician to finally take out the worm in his foot, extracting it, little by little, wrapping it around a small piece of rag.

John Stavely’s case of guinea worm was an early documented case of dracunculiasis, but was in no way the earliest. The Ghanaians that worked with him on the ships bound their legs with leaves to cover the marks, blisters and ulcers caused by the worms. Guinea worm has been documented in Egyptian medical texts as early as the 15th century BC. In the book of Numbers, when the Israelites spoke out against their god, the Lord sent fiery serpents among the people, biting and killing them. These “fiery serpents” referenced are thought to be guinea worm.

The case of guinea worm eradication is one of the more under-reported global health stories. A completely non-revolutionary tale made even more remarkable if you think that there is no treatment or vaccine for the disease.

The only way to eliminate the disease is to avoid its playground: sources of water that are contaminated with the tiny crustaceans that act as hosts for the worm’s larvae.

From an estimated 3.5 million cases in 1986, there has been a dramatic reduction, with only 1058 cases reported in 2011. The majority of these cases occurred in South Sudan, and a few cases in Mali, Ethiopia and Chad. It is very probable that zero cases will be achieved in the coming years.

Eradication programmes have been multi-pronged and old-fashioned, a far cry from the technological revolution that inspired much of the global health revolution with former US President Jimmy Carter leading the charge. Eradication depends almost entirely on education – teaching people how to avoid contaminating water sources and how to avoid infection. This together with filtering drinking water with straws with cloth filters and treating water sources with larvicide, form a concerted eradication effort.

In many remote villages in Mali, people get their water from rivers and ponds nearby. Water potentially contaminated with the larvae of the guinea worm. It is usually the children’s job to fetch the water. If a child who is infected is in charge of collecting the water, as is often the case, they could go on to transmit the disease and contaminate a further 300 people. In Mali, UNICEF go to great lengths to isolate those already infected – placing them in makeshift clinics for the duration of their treatment. Local health authorities financially reward anyone who informs them of the presence of infected cases and those infected are also rewarded for coming in for treatment.

The safe and effective solution comes from the provision of safe supplies of water, ensuring that villagers are able to filter the water they collect. If no filter is present then people simply pour water through large pieces of clothing or fabric (another low-tech solution).

When an eradication effort comes down to the last quarter of an inch — from a global agreement across countries, fierce political will, and from an effort that spans many decades — the last remaining piece of the puzzle is that you need to be able to get to people (and to that last individual). This often proves a huge logistical challenge, and has seen some efforts fall at the final stage (the global effort to eradicate malaria is one example). But the signs of progress are in the numbers.

In January of this year, the Carter Center announced that only 148 cases of guinea worm disease remain worldwide, with South Sudan reporting 76% of total cases in 2013.

Very early on, global disease eradication campaigners understood that Sudan would likely be a last bastion of dracunculiasis. From independence in 2011, South Sudan has continued to face deteriorating humanitarian and health conditions.

With South Sudan a pastoralist community, population movements in cattle camps and continued low safe water coverage in endemic villages posed daunting operational challenges for the country eradication programme coordinated by the WHO. The WHO South Sudan report wrote in 2012 that ”there are also uncertainty and concerns in achieving good surveillance in parts of Jonglei because of poor road network and high insecurity.” Former US President Jimmy Carter said,

“As we near the finish line in this eradication campaign, The Carter Center and its partners remain committed to ending the devastating suffering caused by Guinea worm disease, recognizing that the final cases of any eradication campaign are the most challenging and most expensive to eliminate,”

Countries only enter the WHO precertification stage of eradication after completing one full calendar year of reporting no cases. South Sudan is currently some way off from this (2 new cases were reported in April) although it is a much improved situation compared to last year when 31 cases were reported during the same period.

The one year incubation period leaves little room for mistakes, and makes declaration of elimination tricky. Currently, there are nine people walking around with the little worms wriggling inside. Perhaps the worms are in the leg, the foot, or the forearm; all probably quite large. But most certainly, this will definitely be the last of the disease.

About Charles

charles_ebikeme (1)

Charles Ebikeme is a science journalist with a PhD in parisitology who serves as a Science Officer with the International Social Science Council of UNESCO and writes frequently on global health, health policy, neglected tropical diseases and infectious diseases for The Huffington Post, The Guardian, Scientific American, and Think Africa Press. He is based in Paris. You can find him on Twitter @CEbikeme.

 

Image Credit: The Carter Center/L. Gubb

 

References

Case of Filaria Medinensis, or Guinea Worm.

Oke WS.

Prov Med J Retrosp Med Sci. 1843 Aug 26;6(152):446-7.

 

Logistics of Guinea Worm Disease Eradication in South Sudan

Alexander H. Jones et al.

Am. J. Trop. Med. Hyg., 90(3), 2014, pp. 393–401

doi:10.4269/ajtmh.13-0110

 

Dracunculiasis eradication – Finishing the job before surprises arise

Benjamin Jelle Visser

Asian Pac J Trop Med. 2012 Jul;5(7):505-10. doi: 10.1016/S1995-7645(12)60088-1.

 

Dracunculiasis eradication and the legacy of the smallpox campaign: What’s new and innovative? What’s old and principled?

Frank O Richards et al.

Vaccine. 2011 Dec 30;29 Suppl 4:D86-90. doi: 10.1016/j.vaccine.2011.07.115.

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The worm turns no more… by Public Health, unless otherwise expressly stated, is licensed under a Creative Commons Attribution 3.0 Unported License.

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