Health workers celebrated the remarkable step towards eradication the flesh-burrowing guinea worm, once by far the worst-affected country recorded a drastic drop in infections.
"South Sudan is on the verge of eliminating guinea worm disease," South Sudan Minister of Health Riek Gai Kok said in a statement, after workers recorded just five cases last year, a more than 90 percent drop from 2014, when 70 cases were recorded -- the highest number globally.
‘Guinea-worm disease is caused by the parasitic worm Dracunculus medinensis. The parasite migrates through the victim's subcutaneous tissues and eventually emerges out of the body.
Guinea worm is a debilitating parasite that digs out the body -- including even eyes and sexual organs -- but is close to being stamped out for good following a two-decade campaign by The Carter Center, a not-for-profit organisation founded by former US president Jimmy Carter.
Last year there were 22 cases in just four nations across Africa, compared to 3.5 million in 20 countries in 1986 when The Carter Centre began its massive push began to stop the water-borne parasite.
If the campaign succeeds, guinea worm will become the first parasitic disease to be eradicated and only the second human disease to wiped out worldwide after smallpox in 1979.
"Eradication of this painful and debilitating disease is within our reach," Kok said of the progress which occurred despite a civil war which has gripped South Sudan for the past two years.
Aside from South Sudan, guinea worms exist only in Chad, Ethiopia and Mali. In 2015, Chad recorded nine cases, Mali had five and Ethiopia just three, the Center said.
"As we get closer to zero, each case takes on increasing importance," said Jimmy Carter. "Full surveillance must continue in the few remaining endemic nations and neighboring countries until no cases remain."
Also known as dracunculiasis, from the Latin for "little dragons", the long white worms dig through the body towards the skin, releasing chemicals to burn the flesh and then spewing thousands of larvae as they exit.
The breeding cycle can be broken by making sure people do not wash in sources of drinking water while the worm is emerging from the skin.
They must be teased out by wrapping the wriggling worm around a stick -- the reported origin for the medical symbol of a snake coiled around a staff.