Avian haematozoan parasites and their associations with mosquitoes across Southwest Pacific Islands

Abstract

The degree to which haematozoan parasites can exploit a range of vectors and hosts has both ecological and evolutionary implications for their transmission and biogeography. Here we explore the extent to which closely related mosquito species share the same or closely related haematozoan parasites, and examine the overlap in parasite lineages with those isolated from avian hosts, Zosterops species, sampled across the same study sites. Mosquito samples were collected and analysed (14 species, n = 804) from four islands in Vanuatu and the main island of New Caledonia. Using polymerase chain reaction, 15.5% (14/90) of pooled mosquito (thoracic) samples showed positive amplifications. Subsequent phylogenetic analysis of the cytochrome b gene identified four genetically distinct Plasmodium and two Haemoproteus lineages from these samples, five of which were identical to parasite lineages (n = 21) retrieved from the avian hosts. We found that three Plasmodium lineages differing by a maximum of 0.9% sequence divergence were recovered from different species and genera of mosquitoes and two Haemoproteus lineages differing by 4.6% sequence divergence were carried by 10 distantly related (11-21% divergent) mosquito species. These data suggest a lack of both cospeciation and invertebrate host conservatism. Without experimental demonstration of the transmission cycle, it is not possible to establish whether these mosquitoes are the biological vectors of isolated parasite lineages, reflecting a limitation of a purely polymerase chain reaction-based approach. Nonetheless, our results raise the possibility of a new transmission pathway and highlight extensive invertebrate host shifts in an insular mosquito-parasite system.

Host compatibility rather than vector–host-encounter rate determines the host range of avian Plasmodium parasites

“…We assume that the proportion of infected mosquitoes is correlated with the proportion of infectious mosquitoes across different Plasmodium lineages. This assumption is supported by Ishtiaq et al [33], who demonstrated that Plasmodium prevalence from mosquito thorax isolations was statistically indistinguishable from abdominal isolations in wild mosquitoes collected across southwest Pacific Islands.…”

Detection and molecular characterization of a Haemoproteus lineage in a Tawny Owl (Strix aluco) in Turkey

“…However, in recent years, Inci et al (12) report that two Haemoproteus lineages were sequenced from abdomen pools of two mosquito species which are Aedes vexans and Culex pipiens. Ishtiaq et al (13) and Njabo et al (16) report similar findings in which Haemoproteus spp. were isolated from the head and thoracic parts of culicine and anopheline mosquito species.…”

MOLECULAR ASSESSMENT OFHEPATOZOON(APICOMPLEXA: ADELEORINA) INFECTIONS IN WILD CANIDS AND RODENTS FROM NORTH AFRICA, WITH IMPLICATIONS FOR TRANSMISSION DYNAMICS ACROSS TAXONOMIC GROUPS

“…are transmitted by invertebrate hosts such as ticks, mites, lice, fleas, reduviid bugs, sand flies, tsetse flies, mosquitoes, and leeches (Smith 1996), and transmission typically occurs after an infected invertebrate host (i.e., definitive host) has a blood meal or is ingested by a vertebrate host (i.e., intermediate host) (Telford 2009). In addition, transmission in vector-borne diseases may be facilitated by 1) host habitat sharing and distribution of suitable vectors (Eisen and Wright 2001;Ishtiaq et al 2008), 2) host grooming that results in ingestion of infected oocysts in the vector (Ewing et al 2002;East et al 2008), and 3) trophic transmission by ingestion of infective cystozoites in prey (Sloboda et al 2008;Johnson et al 2009) or ingestion of infected vectors attached to prey (Ewing and Panciera 2003;Johnson et al 2009). Recent molecular studies have supported this trophic mode of transmission by detecting a few distinct Hepatozoon haplotypes in canids that were not related to Hepatozoon canis (Vojta et al 2009) or Hepatozoon americanum (Almeida et al 2013), but were rather more related to Hepatozoon species infecting typical prey of canids such as rodents and reptiles.…”