Prevalence of Diphyllobothrium latum infestation in fishes from Lakes Geneva, Le Bourget and Annecy in France, and estimation of human case incidence based on data provided by medical laboratories of the region (2001-2013) Several surveys were conducted on Lakes Geneva, Annecy and Bourget from 2011 to 2013 to estimate the prevalence of Diphyllobothrium latum larvae in fish of commercial interest. Examination of 960 perch fillets from Lake Geneva showed an overall prevalence of 0.93% [0.3%-1.5%]. Plerocercoid larvae were found in the muscle or body cavity of 62 fish from Lake Geneva (6 out of the 6 pikes, 7 out of 24 perches and 2 out of 7 burbots). No larvae were found in the other species examined, char and whitefish in particular. The highest densities of larvae were observed in pike (up to 18 larvae in a single fish). No plerocercoid larvae were found either in the 25 fish (and 76 perch fillets) from Lake Annecy or in the 51 fish from Lake Bourget. A survey of medical laboratories in Savoie and Haute-Savoie identified six human cases exclusively located in Haute-Savoie from 2011 to 2013. When compared to other surveys carried out a few years ago, the prevalence of this parasitic disease in fish and the incidence of its human form seem to be declining.