Modelling the distribution in Hawaii ofAngiostrongylus cantonensis(rat lungworm) in its gastropod hosts

Abstract

Angiostrongylus cantonensis (rat lungworm), a parasitic nematode, is expanding its distribution. Human infection, known as angiostrongyliasis, may manifest as eosinophilic meningitis, an emerging infectious disease. The range and incidence of this disease are expanding throughout the tropics and subtropics. Recently, the Hawaiian Islands have experienced an increase in reported cases. This study addresses factors affecting the parasite's distribution and projects its potential future distribution, using Hawaii as a model for its global expansion. Specimens of 37 snail species from the Hawaiian Islands were screened for the parasite using PCR. It was present on five of the six largest islands. The data were used to generate habitat suitability models for A. cantonensis, based on temperature and precipitation, to predict its potential further spread within the archipelago. The best current climate model predicted suitable habitat on all islands, with greater suitability in regions with higher precipitation and temperatures. Projections under climate change (to 2100) indicated increased suitability in regions with estimated increased precipitation and temperatures, suitable habitat occurring increasingly at higher elevations. Analogously, climate change could facilitate the spread of A. cantonensis from its current tropical/subtropical range into more temperate regions of the world, as is beginning to be seen in the continental USA.

Review of Cases of Angiostrongyliasis in Hawaii, 2007–2017

“…29 This temporal association of cases with months with higher rainfall, along with the identified geographic correlation of cases with regions with higher rainfall, lower temperatures, and higher levels of vegetative cover could be representative of where human activity overlaps with the habitat of A. cantonensis . A recent article described a habitat model for the parasite, demonstrating a greater suitability to areas with increased precipitation and temperatures 31 as well as its intermediate hosts (e.g., mollusks), implying an increased risk of exposure.…”

Validation of a death assay for Angiostrongylus cantonensis larvae (L3) using propidium iodide in a rat model (Rattus norvegicus)

“…Rat lungworm is an emerging and neglected tropical disease which is spreading throughout Asia, the Caribbean, Africa, Hawaii (USA), and has been recently reported from the continental USA in Florida, Louisiana, Texas, Oklahoma and Tennessee (Teem et al ., 2013; Hammoud et al ., 2017; Howe and Jarvi, 2017; Jarvi et al ., 2017; Stockdale-Walden et al ., 2017; Kim et al ., 2018). Thorough studies of the efficacy of anthelmintics on A. cantonensis may produce better treatment and/or management strategies for neuroangiostrongyliasis.…”

Annotated catalogue of species of Angiostrongylus and the related genera Gallegostrongylus, Rodentocaulus and Stefanskostrongylus (Nematoda: Metastrongyloidea, Angiostrongylidae)

“…(2019). The range may change as the global climate changes (Lv et al ., 2011; York et al ., 2014; Kim et al ., 2019). Remarks .…”