Brachylaima spp. (Trematoda) parasitizing Cornu aspersum (Gastropoda) in France with potential risk of human consumption.

Claudia Gérard,Nolwenn Decanter,Marie-Claire Martin,Armelle Ansart,Maxime Dahirel

doi:10.1051/parasite/2020012

Abstract

The edible land snail Cornu aspersum, native to the Mediterranean coastlines of North Africa, is widely distributed on most continents and often invasive in areas where introduction is recent. This species could contribute to the geographic spread of parasites as demonstrated for Brachylaima spp. These cosmopolitan trematodes may represent a threat to human health, like in Australia where Brachylaima cribbi infects humans. In this study, we demonstrate for the first time the occurrence of Brachylaima spp. in two French populations of C. aspersum, Thorigné-Fouillard (Ille-et-Vilaine), and Arçais (Deux-Sèvres), with an overall prevalence of 10.4% (Thorigné-Fouillard) and 73.3% (Arçais), respectively and a metacercarial intensity on average three times higher in Thorigné-Fouillard (37) than in Arçais (11). Cornu aspersum may act as a first and second intermediate host, as demonstrated in Arçais. The morphometrics of metacercariae, particularly the great body length about 2 mm, discriminate our Brachylaima species from those already described in C. aspersum (B. cribbi in Australia, and B. aspersae, B. llobregatensis and B. mascomai in Europe). Molecular analysis, based on 28S and COI, suggests the occurrence of two species in our study, one of which is probably Brachylaima mesostoma, an intestinal parasite of passeriform birds described in Central Europe. We underline the need for further research to identify species of Brachylaima in France and measure the health hazard of consuming field-collected snails.

Highlights

IntroductionSome authors [15] clearly demonstrated that imported edible C. aspersum specimens could contribute significantly to the geographic spread of Brachylaima species, in their case between Spain and Africa
The land snail Cornu aspersum aspersum Müller
Occurrence of Brachylaima spp. in Cornu aspersum from Arcais and Thorigne -Fouillard. Land snails from both sites were infected by Brachylaima spp. with a total prevalence of 73.3% (CI [67.8%–78.2%]) and 12.2% (CI [5.7%–24.2%]) in Arçais and ThorignéFouillard, respectively (Table 3, Fig. 1)

Summary

Introduction

Some authors [15] clearly demonstrated that imported edible C. aspersum specimens could contribute significantly to the geographic spread of Brachylaima species, in their case between Spain and Africa. Some species parasitizing C. aspersum at the larval stage such as Angiostrongylus cantonensis and Brachylaima cribbi can infect humans as definitive hosts with a lethal risk (>10% and 5–10% mortality rate without treatment, respectively), and represent a serious human health hazard [13, 31, 55]. Species of the genus Brachylaima may have both veterinary and medical significance since they can occur in various domestic birds and mammals, including poultry, pigeons, pigs, rabbits, and dogs, representing potential reservoirs for human infection [22, 34, 43, 57]

Methods

Results

Conclusion