March 2014 - From more than 650 000 cases in 1988 to zero today, Nigeria has successfully stopped transmission of guinea-worm disease, also known as dracunculiasis. Thousands of volunteer polio vaccinators helped to check every household nationwide to ensure that there were no remaining cases before the country could be certified free of guinea-worm disease in December 2013.

“When my elder brother Moses had guinea worm, I was not surprised because he used to pilfer fish from our mother’s pot and small yams from our father’s barn,” says Samuel Alo, today a community leader of Ejine Amagu, Ikwo Community in Ebonyi State, in south-east Nigeria. As a child in primary school, Samuel was told that guinea worm was a punishment for naughty children.

“Little did I know that the source of the worm was the pond from which we fetched water for drinking and cooking," says Alo.

A crippling, parasitic disease

Guinea-worm disease (dracunculiasis) is almost exclusively found in poor, rural communities in low-income countries. It is a crippling, parasitic disease caused by a thread-like worm that grows up to 100cm long and migrates inside the body. Transmission occurs when people drink water contaminated with parasite-infected water fleas. Around one year after infection, one or more worms emerge from the skin through a painful blister, often on the leg. To soothe the excruciating pain, people often immerse the infected area in water. The worms then re-infect the water with thousands of larvae that are ingested by water fleas and the life cycle starts again.

There is no vaccine or treatment for this disease. The primary way to prevent guinea-worm infection is to provide a safe water supply, treat contaminated water and educate people to change their behaviour.

In 1988, when Nigeria reported more than 650 000 cases of guinea-worm disease, the Government launched an eradication programme following a World Health Assembly Resolution that called for the disease's global eradication. The country could only be certified guinea-worm free when no cases were detected for 3 years.

Polio vaccinators help search house-to-house

One of the cardinal strategies for guinea-worm eradication in Nigeria has been active case search – a surveillance programme that used thousands of village volunteers to conduct house-to-house search for disease. Polio vaccinators helped to support surveillance during this final stage of eradication. In every house they entered during each polio vaccination round, the volunteers were trained to ask about guinea-worm disease, using a pictorial to demonstrate signs of the disease.

The last person known to have had guinea-worm disease in Nigeria was Grace Otubo, a 58-year-old migrant farmer from the remote rural village of Ezza Nwukbor in eastern Nigeria.

“Twenty five years ago, Mrs Otubo would have been just one of more than 650 000 victims of guinea-worm disease," says Dr Rui Gama Vaz, WHO Representative in Nigeria. “The fact that she can be specifically identified as the final victim of the disease in her country is due to this successful system of surveillance.”

Combined effort and continued vigilance

Eradication efforts from WHO and partners, including the Yakubo Gowon Centre, The Carter Center, the Government of Japan and UNICEF, have included improving safe water supply, education and disease awareness, supporting behaviour change and training health workers to recognize and report suspected cases of guinea-worm disease. A cash reward provided an incentive for members of the public to report cases too.

In December 2013, on the recommendation of the WHO certification commission, Director-General, Dr Margaret Chan declared Nigeria free of guinea-worm disease. Dr Chan highlights the successful integration of guinea-worm surveillance into the disease surveillance and polio immunization campaigns: “This is the kind of joined-up effort that makes the most effective use of our human and financial resources, and has a dramatic and measurable impact.”

Since neighbouring countries (Chad, Ethiopia, Mali and South Sudan) still have on-going transmission of guinea-worm disease, Nigeria continues to remain vigilant for cases that might cross the border. Eradicating the disease, which incapacitates infected people for 3 weeks on average, has made an enormous contribution to Nigeria’s social and economic advancement.