Autochthonous Angiostrongylus cantonensis, Angiostrongylus vasorum and Aelurostrongylus abstrusus infections in native terrestrial gastropods from the Macaronesian Archipelago of Spain

Abstract

The presence of zoonotic relevant Angiostrongylus cantonensis infections has recently been reported in rat final hosts and gastropod intermediate hosts in Tenerife, Spain. However, data on A. cantonensis, Angiostrongylus vasorum and Aelurostrongylus abstrusus prevalences in endemic gastropods for other islands of the Macaronesian Archipelago are still missing. In order to fill this gap, we conducted an epidemiological study on terrestrial native slug (Plutonia lamarckii) and snail (Cornu aspersum, Theba pisana, Rumina decollata) species in 27 selected locations of Tenerife, Gran Canaria, El Hierro, Lanzarote, La Palma and Fuerteventura. Overall, 131 terrestrial gastropods were collected in winter/spring season 2018/2019 and examined for the presence of metastrongyloid lungworm larvae via artificial digestion. The current data revealed a total prevalence of 4.6% for A. vasorum, 3.8% for A. abstrusus and 0.8% for A. cantonensis. In Tenerife, three lungworm species were detected, thereby re-confirming A. cantonensis endemicity for this island. Prevalences of snails (C. aspersum) originating from El Hierro were 5% for A. abstrusus and 15% for A. vasorum, respectively, with larval burdens up to 290 larvae per specimen. This epidemiological study indicates the presence of human, canine and feline lungworm species in Macaronesia, Spain. The current data-particularly those on anthropozoonotic A. cantonensis-call for a regular large-scale monitoring on intermediate hosts, paratenic hosts and definitive hosts to prevent further spread of lungworm-related diseases in humans and animals.

Keywords: Aelurostronglyus abstrusus; Angiostrongylus cantonensis; Angiostrongylus vasorum; Gastropod-borne disease; Lungworm infections; Metastrongyloid nematodes.

Fig. 1

The Macaronesian region: (1) Azores; (2) Madeira; (3) Canary Islands; (4) Cape Verde

Fig. 2

Sampling locations. Green circle means locations with lungworm negative gastropod samples. Red triangle means locations with lungworm-positive gastropod samples. (1) El Hierro: La Frontera; Isora; Mocanal; San Andrés; Sabinosa; Valverde; Ruta del Goroé. (2) La Palma: Fuencaliente; Tijarafe; Los Llanos de Aridane; Puntagorda; Santa Cruz de la Palma; Barlovento (3) La Gomera (4) Tenerife: Santa Cruz de Tenerife; Tegueste; La Esperanza; Guía de Isora; La Orotava; Icod de los Vinos; La Laguna (5) Gran Canaria: Las Palmas de Gran Canaria; Santa María de Guía; Maspalomas; Firgas (6) Fuerteventura: La Oliva; Corralejo (7) Lanzarote: Puerto del Carmen; Arrieta (8) La Graciosa

Fig. 3

Morphological characteristics of metastrongyloid larvae, found in gastropods from Macaronesia, Spain. Third-stage larvae of Angiostrongylus cantonensis (A), Aelurostrongylus abstrusus (B) and Angiostrongylus vasorum (C); panel D shows an A. vasorum second-stage larva, in the sheath of a first-stage larva; details of the posterior ends are shown in (a), (b), (c) and (d). The third-stage larva of A. cantonensis can be identified by its tail pointed tip (a), whereas the A. abstrusus L3 (b) has a terminal rounded knob and the A. vasorum L3 is characterized by a short digitiform posterior end (c). The tail of an A. vasorum L1 shows a dorsal spine (d). Scale bar (A, B, C, D) 40 μm; scale bar (a, b, c, d) 20 μm