Guinea worm disease progress

Guinea worm disease (also known as dracunculiasis) is an incapacitating parasitic illness caused by drinking water that contains water fleas infected with Guinea worm larvae.

The global Guinea worm eradication programme is increasingly close to eradicating the disease, with only 12 laboratory-confirmed cases globally at the time of scoring. As of 31 October 2017, 14 confirmed cases had been reported from Chad and one from Ethiopia. An additional 11 suspected cases (yet to be laboratory confirmed) have been reported from an outbreak in Ethiopia, bringing the provisional total cases to 26, from two countries. No human cases have been reported during the past 23 consecutive months from Mali or from South Sudan during the past 11 months, whereas 19 cases were reported during the same period in 2016. This impressive progress in Mali and South Sudan was achieved under very difficult circumstances.

The main challenge to the programme is transmission in Chad. Additional interventions to understand and control transmission in this country remain a priority. Infections in dogs are a concern, and these continued in Chad (750), Ethiopia (11) and Mali (8). Although a 20% decrease was observed during January–September 2017 from the same period in 2016, it is too early to determine whether the trend will continue. There is evidence that exposure to paratenic host due to eating improperly cooked, cured or fresh aquatic animals containing infective larvae of Dracunculus medinensis may be contributing to transmission in Chad. This led the programme to recommend cooking aquatic animals well before eating them and burying or burning fish entrails so that dogs do not eat them. The programme provided a cash reward of US$ 20 for containing infection of dogs by tethering them. These actions are believed to be responsible for the observed decrease in dog infections and emerging Guinea worms. Greater use of larviciding is being discussed.

The aim of national programmes is to interrupt transmission by 2020, but persistent armed conflict in areas under surveillance threatens interruption of transmission and the ability of countries to achieve certification.

A research programme is being conducted to identify when, where and how animal infections occur in Chad, Ethiopia and Mali and the role in ongoing human transmission. The studies include genetic characterization of Guinea worm populations, studies on dog–human behaviour and risk factors, the possibility of paratenic host transmission and trials of dog treatment.