Last year, South Sudan registered more than half of the 126 Guinea-worm (Dracunculiasis) disease cases reported worldwide.
Most of the 70 cases reported in the country, or 56 per cent of the global total, were in Eastern Equatoria State. The other cases were reported in isolated areas of Mali (40), Chad (13) and Ethiopia (3), according to the US-based Carter Centre.
These numbers, reported by ministries of health in the four endemic nations and compiled by the centre, show that cases of the debilitating disease declined by 15 per cent in 2014 compared with the 148 recorded in 2013.
When the centre led the first international campaign to eradicate the water-borne disease in 1986, there were an estimated 3.5 million Guinea-worm cases occurring annually in Africa and Asia.
“We believe eradication of Guinea-worm disease is possible in the next few years, but success will require the strong commitment and focus of the four remaining endemic countries and the many international partners in this public health initiative,” said former US president Jimmy Carter, whose Carter Centre leads the international campaign to eradicate the disease.
Guinea-worm disease is positioned to be the second human disease, after smallpox, to be eradicated. It will be the first parasitic disease to be eradicated and the first without the use of a vaccine or medicine.
In South Sudan, the overall number of Guinea-worm cases has been reduced by 99 per cent since 2006. The Carter Centre said that while this number represents great relative success, continued efforts towards improved peace and stability will be vital in maintaining the levels of surveillance and supervision necessary to reach the ultimate goal of eradication.
The Carter Centre said that in the absence of a vaccine or medical treatment, the disease is being wiped out mainly through community-based interventions to educate and change behaviour, including teaching people to filter drinking water and preventing contamination.
In Ethiopia, the Gambella region remains the country’s only Guinea-worm-endemic area. Last year, the federal ministry revamped the national Guinea Worm Eradication Programme and expanded the network of villages under active surveillance from 62 to 173. With only three reported cases last year, transmission of the Guinea worm in Ethiopia is expected to end by December 2015.
In Chad, the programme expanded health education and continued to investigate the unusual epidemiology of its Guinea-worm cases in 2014. The government is preparing additional control measures to address remaining transmission.
In Mali, insecurity that began in April 2012 continues to delay interruption of Guinea-worm disease transmission because the national programme has not been able to operate fully and consistently in all endemic regions. Last year, the programme was partially operational in three regions and only slightly operational in one region due to insecurity. However, the programme expanded the number of villages under active surveillance from 85 to 391.
The World Health Organisation (WHO) says Guinea-worm is rarely fatal but infected people become non-functional for months. It affects people in rural, deprived and isolated communities who depend mainly on open surface water sources such as ponds for drinking water.
The Guinea-worm is transmitted exclusively when people drink water contaminated with parasite-infected water-fleas.
WHO says that about one year after the infection, a painful blister forms – 90 per cent of the time on the lower leg — and one or more worms emerge accompanied by a burning sensation. To soothe the burning pain, patients often immerse the infected area in water.
The worm(s) then releases thousands of larvae (baby worms) into the water. These larvae reach the infective stage after being ingested by tiny crustaceans or copepods, also called water fleas.
People swallow the infected water fleas when drinking contaminated water. The water fleas are killed in the stomach but the infective larvae are liberated. They then penetrate the wall of the intestine and migrate through the body. The fertilised female worm (which measures from 60–100 cm long) migrates under the skin tissues until it reaches the lower limbs, forming a blister or swelling from which it eventually emerges.
The mature worm takes 10-14 months to emerge from the body after infection.
The Guinea-worm is transmitted exclusively when people drink water contaminated with parasite-infected water-fleas. According to WHO, finding and containing the last remaining cases may be the most difficult and expensive stage of the eradication process as these usually occur in remote often inaccessible rural areas.
The Carter Centre works in partnership with national programmes and other partners including WHO, Centres for Disease Control and Prevention (CDC) and Unicef.
The Carter Centre provides technical and financial assistance to national Guinea-worm eradication programmes to interrupt transmission of the disease.
Once this happens, the centre provides continued assistance in developing or strengthening surveillance in Guinea worm-free areas, and preparing nations for official certification. CDC provides technical assistance and verifies that worms from these final patients are truly Guinea-worms.
Unicef mainly assists countries by helping to provide safe sources of drinking water to priority areas identified by the national Guinea-worm eradication programmes.