Dracunculiasis: aggressive vector control to accelerate interruption of transmission

29 May 2017
Departmental update
Geneva
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According to the World Health Organization (WHO), the “last mile” of eradicating dracunculiasis (guinea-worm disease) can be achieved if countries where the disease is endemic maintain robust surveillance and implement prompt control measures, awareness levels and case containment strategies.

In Chad in particular, implementing more aggressive vector control alongside other eradication strategies will be key to interrupting transmission through the treatment of all water bodies with the cyclopicide temephos in order to kill water fleas (cyclops) that carry the infective guinea-worm larvae.

“In light of new operational research findings, the programme is currently gearing up to apply a more aggressive vector control strategy which will surely accelerate the interruption of transmission in Chad,” Dr Matshidiso Moeti, WHO’s Regional Director for Africa, who briefed an informal ministerial meeting on dracunculiasis eradication during the Seventieth World Health Assembly in Geneva on 24 May 2017.

Since January of this year, Chad is the only country to have reported human cases (4). The fewer than 300 infected dogs represent a 30% reduction from the number reported during the same period in 2016.

“We need to apply all the interventions that are available to us. So we know that we have to contain these human cases and these infections in animals, particularly in dogs in Chad,” said Dr Dean Sienko, Vice-President for Global Health at The Carter Center. “We need everyone to cooperate to ensure that we can bring the infections in Chad in both humans and dogs and in any other animals to zero.”

The Carter Center, WHO’s main partner in the eradication effort, has led activities since 1986, along with the United Nations Children’s Fund and the United States Centers for Disease Control and Prevention.

Guinea-worm disease has been reported in two other countries in 2016: Ethiopia and South Sudan. A third country, Mali, has reported zero human cases since November 2015.

Chad became the epicentre of an outbreak in 2010 after having reported zero cases for almost a decade. Since 2012, an unusual epidemiology has been observed in dogs, with emerging worms that are genetically undistinguishable to those emerging in humans, detected mostly in villages along the River Chari. While more than 1000 infected dogs were reported in this area during 2016, a cumulative total of 272 have been reported from January to April this year.