Certifying Guinea worm eradication: current challenges

The Guinea Worm Eradication Programme (GWEP) is, along with polio, one of two active eradication programmes endorsed by the World Health Assembly. Currently, smallpox is the only human infection to have been eradicated. 1 Guinea worm disease, or dracunculiasis, is caused by infection with Dracunculus medinensis that is acquired by the ingestion of infected copepods (of the genera Cyclops and Mesocyclops) or by consuming viable infective larvae in fish or other paratenic hosts. 2 , 3 Polio and Guinea worm programmes have made great progress; however, both programmes face major challenges as they progress towards eradication because certifying the global absence of transmission of the pathogen requires meeting stringent criteria. The incidence of Guinea worm has declined from an estimated 3·6 million cases per year in the late 1980s to 53 human cases reported in 2019. 4 , 5 The overall epidemiological situation in 2019 has been summarised by WHO. 5 This Viewpoint describes the challenges facing the GWEP regarding the certification of zero global incidence following the findings of animal infections, particularly in dogs in Chad.