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In October 2018, two Atelerix algirus hedgehogs were admitted to the Wildlife Rehabilitation Hospital in Mallorca (Balearic Islands, Spain) with signs of acute neurological disease. Necropsy detected immature, fully developed nematodes in the subarachnoid space of both hedgehogs, including a gravid female worm. DNA-based molecular tools confirmed the nematode as Angiostrongylus cantonensis , an important aetiological agent of eosinophilic meningitis in humans. So far this zoonotic parasite in has not been reported in western European wildlife.

Lungworms in the genus Angiostrongylus cause disease in animals and humans. The spread of Angiostrongylus vasorum within Europe and the recent establishment of Angiostrongylus cantonensis increase the relevance of these species to veterinary and medical practitioners, and to researchers in parasitology, epidemiology, veterinary science and ecology. This review introduces the key members of the genus present in Europe and their impacts on health, and updates the current epidemiological situation. Expansion of A. vasorum from localized pockets to wide distribution across the continent has been confirmed by a rising prevalence in foxes and increasing reports of infection and disease in dogs, while the list of carnivore and mustelid definitive hosts continues to grow. The tropically distributed rat lungworm A. cantonensis, meanwhile, has been recorded on islands south of Europe, previously the Canary Islands, and now also the Balearic Islands, although so far with limited evidence of zoonotic disease. Other members of the genus, namely, A. chabaudi, A. daskalovi and A. dujardini, are native to Europe and mainly infect wildlife, with unknown consequences for populations, although spill-over can occur into domestic animals and those in zoological collections. The epidemiology of angiostrongylosis is complex, and further research is needed on parasite maintenance in sylvatic hosts, and on the roles of ecology, behaviour and genetics in disease emergence. Improved surveillance in animals and humans is also required to support risk assessments and management.

The present document has been produced and adopted by the bodies identified above as authors. In accordance with Article 36 of Regulation (EC) No 178/2002, this task has been carried out exclusively by the authors in the context of a grant agreement between the European Food Safety Authority and the authors. The present document is published complying with the transparency principle to which the Authority is subject. It cannot be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

T he rat lungworm, Angiostrongylus cantonensis, infects animals and humans. Although this nematode species is recognized as the main etiologic agent of eosinophilic meningitis (1), infection might result in other central nervous system disorders (2). Clinical manifestations are aggravated by movement and subsequent death of the worms in the central nervous system, causing physical lesions and inflammation in accidental hosts (3). In humans, severe headache, neck stiffness, paresthesia, convulsions, urinary failure, visual impairment, and other symptoms, occasionally leading to coma and death, have been reported (1,4).The life cycle of A. cantonensis worms includes rats as definitive and gastropods as intermediate hosts; crustaceans, planarians, amphibians, reptiles, and fish might act as paratenic hosts (2). More than 20 vertebrate species, including humans, have been reported as A. cantonensis lungworm accidental hosts (5). This long list of vertebrate hosts includes nonhuman primates (6), marsupials (7), bats (8), horses (9), dogs (10), birds (11), and more recently, hedgehogs (12). The role of hedgehogs in the transmission of this parasite remains to be clarified.A. cantonensis worms were detected in Canton, China, infecting the lungs of rats ( 13) and a decade later, in the cerebrospinal fluid of a person from Taiwan (14). For decades, disease-endemic areas were limited to the Pacific basin and Southeast Asia, but this parasite has spread to new territories at an alarming rate (1). The invasion of A. cantonensis lungworms has been associated with unintended importation of infected rats and gastropods on ships (2,15). Almost 3,000 cases of human neuroangiostrongyliasis have been reported (16) from 30 territories (3), although the prevalence might be higher (17).Europe was considered to be nonendemic for A. cantonensis worms until 2018 when the parasite was reported infecting the brains of 2 hedgehogs on the Mediterranean island of Mallorca (12). Although the rat lungworm had been previously reported on Tenerife, a subtropical, non-European overseas oceanic island (18), its detection in Mallorca is an indisputable indication of its presence in Europe (5). Mallorca is a major Mediterranean tourism hotspot, highly interconnected with continental Europe. After the detection, the question remained whether A. cantonensis nematodes could survive the temperate winters of Europe. The purpose of this study was to use sentinel surveillance for symptomatic fauna to confirm whether the rat lungworm has been successfully established on Mallorca.

During studies of malaria vectors in Indonesia and Thailand, several specimens identified by field staff as members of the Anopheles barbirostris group (Diptera: Culicidae) were found to belong to the Anopheles hyrcanus group, as shown by marked differences in the size of the nuclear rDNA second internal transcribed spacer (ITS2) between the barbirostris (~1500 bp) and hyrcanus (~600 bp) groups. Identification of the species concerned required a more detailed study of ITS2 sequences and subunit I of the mitochondrial DNA cytochrome oxidase gene (COI). A phylogenetic analysis, based on Bayesian methods, revealed that the hyrcanus group specimens comprised five distinct clades, two of which corresponded with known species, Anopheles peditaeniatus and Anopheles sinensis. The remaining specimens formed three additional clades, for which there are no similar sequences in GenBank and which cannot be linked to previously described species. The misidentification of hyrcanus group species has important implications for malaria vector control; more comprehensive studies employing gene sequences are required to clarify the number of species in the group, their distribution and vector status.

Backgrounds Aedes albopictus (Diptera; Culicidae) is a highly invasive mosquito species and a competent vector of several arboviral diseases that have spread rapidly throughout the world. Prevalence and patterns of dispersal of the mosquito are of central importance for an effective control of the species. We used site-occupancy models accounting for false negative detections to estimate the prevalence, the turnover, the movement pattern and the growth rate in the number of sites occupied by the mosquito in 17 localities throughout Mallorca Island.ResultsSite-occupancy probability increased from 0.35 in the 2012, year of first reported observation of the species, to 0.89 in 2015. Despite a steady increase in mosquito presence, the extinction probability was generally high indicating a high turnover in the occupied sites. We considered two site-dependent covariates, namely the distance from the point of first observation and the estimated yearly occupancy rate in the neighborhood, as predicted by diffusion models. Results suggested that mosquito distribution during the first year was consistent with what predicted by simple diffusion models, but was not consistent with the diffusion model in subsequent years when it was similar to those expected from leapfrog dispersal events.ConclusionsAssuming a single initial colonization event, the spread of Ae. albopictus in Mallorca followed two distinct phases, an early one consistent with diffusion movements and a second consistent with long distance, ‘leapfrog’, movements. The colonization of the island was fast, with ~90% of the sites estimated to be occupied 3 years after the colonization. The fast spread was likely to have occurred through vectors related to human mobility such as cars or other vehicles. Surveillance and management actions near the introduction point would only be effective during the early steps of the colonization.