Investigating_the_re_emergence_of__Guinea_worm_infection_in_Chad. Investigating_the_re_emergence_of__Guinea_worm_infection_in_Chad

This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/ Guinea worm (Dracunculus medinensis) is an ancient scourge of humanity, and as recently as the 1970s was widespread across West and North-East Africa, India and the Middle East, with 10s of millions of cases. Thanks to improved access to safe drinking water, the disease is now close to eradication, endemic to only 4 countries, and with 1,028 out of 1,058 cases reported in 2011 being in Southern Sudan, where the recent history of civil war has hampered the eradication effort. The hope is that Guinea worm will soon become the second human disease to be eradicated, after smallpox - the current target is 2015. However, a major challenge to the eradication program has recently emerged, as new human cases have appeared in Chad for each of the last three years, after a long gap (the previous record from the country was in 1998), and where the disease was thought to be eradicated. There is no epidemiological link with the ongoing disease focus in Sudan or elsewhere. It is possible that the disease was not eradicated, but merely not detected for over a decade, despite considerable surveillance, but another possible explanation is suggested by the fact that Dracunculus spp. have also been reported in dogs in Chad. Dracunuculs medinensis, the clinical species, is thought to be restricted to humans, but laboratory infection in dogs is possible, and worms mature and produce viable larvae. Moreover, a sister species, D. insignis, is widespread in North American canids and other carnivores. The only other species of Dracunculus from Africa are probably rather divergent species in snakes and other reptiles. There are a handful of cases of alleged D. medinensis from dogs around the world, but species identification in this genus is difficult, and molecular methods to distinguish D. medinensis from D. insignis have only recently been developed - this test cannot distinguish other species in the genus, and there are thought likely to be many undescribed species circulating in wild mammals. There are no known cases of transmission of this parasite between animals and humans. This is a project to generate genomic sequence data from Dracunculus specimens, including specimens from humans from Chad from the recent outbreak, from dogs from Chad from the recent outbreak, and recent specimens from neighbouring countries where Dracunculus transmission continues. A draft genome assembly for Dracunculus medinensis has been generated recently, which will allow population genetics analysis.