Anita Suri Kåss explains how Dr Anders Seim had the initiative to put a simple prevention measure into large scale production to help eradicate a painful and debilitating parasitic disease.

The guinea worm or Dracunculus (Latin for little dragon) is thought to have existed since ancient times. To this day, treatment involves wrapping the worm around a stick. This ancient parasitic infection is nearing extinction, with only Sudan standing as a major obstacle to the disease's disappearance in the coming years.

Humans acquire the infestation by drinking water infected with guinea worm larvas. The larvas penetrate the upper gastrointestinal tract and remain in the peritoneal space for up to three months. The female worm bores holes through the body and makes its way to the surface; holes may be anywhere on the body but they are usually on the legs and feet. At this stage millions of eggs, embryos, and first stage larvas occupy most of the worm's body cavity. A blister forms on the skin of the host at the anterior end of the worm and erupts. The female worm then protrudes its anterior end from the ulcer and releases first stage larvas into the water. Upon emergence the Dracunculus medinensis parasite can be up to a metre long.

Immersing the affected skin into water provides some relief from the pain the infestation causes. The temperature change causes the blister to erupt, exposing the worm. People, having no choice, drink the newly infested water, ingest the worm, and the entire cycle begins again; it is possible to have more than one worm at a time.

Using the pipe filter to drink

The worm has to be physically extruded, usually by winding it round a matchstick a few turns a day. Where available, local anaesthetic is injected and a 5-10 mm incision made adjacent to a coil of the worm, near its midpoint if possible. A blunt probe is used to separate the worm from connective tissues and to lift out a section of worm sufficiently long to grasp with the fingers, this is an excruciatingly painful procedure. Gentle traction and firm massage along the limb towards the incision facilitates removal. When the entire worm cannot be removed at once, it is ligated, rolled on to a piece of gauze, and taped down and the wound dressed until the next session. It usually takes several weeks for the worm to completely exit the body.

Inevitably some of the instruments that the Sudanese use to extract the worm can introduce infection, and people can die from the infection caused rather than the guinea worm itself.

Gangrene is common in severe untreated cases and tetanus has been associated with dracunculiasis in many areas. Very infrequently, larvas lodge in sensitive ectopic sites, mostly in joints, the orbit, or the central and peripheral nervous systems, leading to severe arthritic changes, blindness, and septic subdural abscesses.

Preventing guinea worm disease

Previously, standard household filters were the only way of filtering contaminated water. But these filters are often impractical due to the war and problems alien to those in the developed world. Many people don't have a home or even clothing, so expecting them to carry water jugs and filters around was unrealistic. People in Mauritania had a simple solution--they carry around the neck a small pipe with a filter and use it as a straw when drinking water. Dr Anders Seim thought this would be particularly applicable for Sudan. Sudan remains a pocket of infestation: in 2000, 73% of cases in the world were in Sudan.¹ Seim heard about the problems in the late 1980s at a lecture in Manchester. On returning to his rural medical practice in Norway, he thought how he might help. It may sound like a simple solution, but putting it into practice took a tremendous amount of team effort, and took years to persuade some of the team to get involved. The project is a collaboration of many different companies working together for a worthwhile cause under the initiative of a man with unrelenting motivation.

Filtering unsafe water has been an intervention right from the start, before Seim became involved at all. His part was encouraging the use of the Mauritanian pipe-filter idea as a good solution for Sudan. They have been popular in Mauritania since their initial introduction, and have been distributed there annually for several years. Thus, the Hydro project was not new in concept. What was new was to provide a filter for every person in the entire population at the same time, distributed from both sides of the war zone. The idea was that if everyone in the population had (and used) a filter at the same time, during the same peak transmission season, we could achieve a strong reduction in cases even in spite of the ongoing war.

Providing safe drinking water is of course the best solution, but unrealistic for all of Africa's populations to receive within the time frame of this project. So where there is no safe water, people can filter their water through precision woven fabric with a sufficiently tight mesh.

Problems

The civil unrest badly affected the project. Almost half of the villages known to be endemic for the disease are neither accessible to the programme from the north (Khartoum), nor from the south. But the filter pipes are so light and easily transported that the idea has been for the local population to spread them around even without healthcare staff participating.

The future

This project distributed a filter to every person old enough to drink on their own in 2001. An exciting boost for Seim's project has been the additional support from the medical students of Norway. The Norwegian medical students voted for the Sudan guinea worm pipe filter project as their humanitarian action campaign in 2003.

Having provided the whole population with a filter, the next idea is to provide every village volunteer throughout Sudan with a medical kit for treating guinea worms. Each kit has material such as antiseptics and devices for extracting worms for about 50 people. In addition, the aim is to buy replacement pipe filters with any extra money raised but not spent on the medical kits. The aim of this follow up project by the medical students, is that everyone should be treated as well as being able to filter their water with the pipe filters or replacement filters. Treatment only makes sense when most or all in the population can simultaneously protect themselves from further infection. At present, the medical students are planning a campaign to make their project as successful as possible.

1. The World Health Organization, Division of Control of Tropical Diseases. http://www.who.int/ctd/dracun/index.html

The author thanks Dr Anders Seim, Health and Development International and John Øivind Selmer of Hydro Polymers. This article appears with Dr Seim's permission.

Further information on these projects and facts and figures about dracunculiasis

• Centers for Disease Control and Prevention--www.cdc.gov/ncidod/dpd/parasites/guineaworm/default.htm
• Health and Development International--www.hdi.no
• The Norwegian medical students--www.legeforeningen.no