A highly invasive malaria parasite has expanded its range to non-migratory birds in North America

Abstract

Parasite range expansions are a direct consequence of globalization and are an increasing threat to biodiversity. Here, we report a recent range expansion of the SGS1 strain of a highly invasive parasite, Plasmodium relictum , to two non-migratory passerines in North America . Plasmodium relictum is considered one of the world's most invasive parasites and causes the disease avian malaria: this is the first reported case of SGS1 in wild non-migratory birds on the continent. Using a long-term database where researchers report avian malaria parasite infections, we summarized our current understanding of the geographical range of SGS1 and its known hosts. We also identified the most likely geographical region of this introduction event using the MSP1 allele. We hypothesize that this introduction resulted from movements of captive birds and subsequent spillover to native bird populations, via the presence of competent vectors and ecological fitting. Further work should be conducted to determine the extent to which SGS1 has spread following its introduction in North America.

Risk of Infection, Local Prevalence and Seasonal Changes in an Avian Malaria Community Associated with Game Bird Releases

“…We found a quite high prevalence of avian malaria parasites in redlegged partridges in central Spain. The results presented here revealed malaria prevalences that are among the highest found in bird populations, particularly for Plasmodium [4,[65][66][67][68], including studies on species from comparable habitats in Spain [69]. We also found notable differences in the spatial and temporal distribution of parasites at a local scale.…”

“…Our results show that parasite species can differ in their distribution and temporal abundance with regard to game management type (sites with red-legged partridge releases and sites without releases). This distribution of parasites may potentially be caused by the effect of large-scale and widespread human activity (releases into the wild of farm-reared birds), as recently reported for the highly invasive lineage SGS1 in passerine birds of the USA [4].…”

“…On the other hand, the parasite assemblage included the presence of two previously described lineages of Plasmodium (SGS1 and GRW11), which emphasizes the general idiosyncrasy of these parasite lineages, both geographically and taxonomically (i.e., regarding the broad range of hosts infected [4,54,56,[81][82][83]). Of the eight parasite lineages isolated in partridges, six Plasmodium spp.…”

“…Two of the parasite lineages found in red-legged partridges (SGS1 and GRW11; Figure 2) are considered cosmopolitan in distribution, highly invasive, and have been recorded in more than 140 bird species-principally passerines-in over 43 countries [4,56]. The remaining six lineages corresponded to new parasite lineages, showing divergences between 0.2% and 7.8% with respect to any other Plasmodium morphospecies recorded to date in avian hosts.…”

“…There is now a large body of literature showing remarkable large-scale responses in some animal populations affected by human disturbance [1][2][3]. Among these perturbations, common practices used today such as the relocation and introduction of animals have played a significant role on the emergence and spread of several diseases [4][5][6][7][8][9][10], with significant consequences for wildlife, domestic animals, and humans [11,12]. The human-based spread of infectious agents over new areas jeopardizes wild animal populations by exposure to exotic pathogens [13][14][15][16], some of which may be parasites harboured by introduced animals [17][18][19][20][21].…”