Leucocytozoon lineages

Inumaru, Mizue, Murata, Koichi & Sato, Yukita, 2017, Prevalence of avian haemosporidia among injured wild birds in Tokyo and environs, Japan, International Journal for Parasitology: Parasites and Wildlife 6 (3), pp. 299-309 : 307-308

4.5. Analysis of Leucocytozoon lineages

8 lineages of Leucocytozoon were detected from only wintering visitors ( Table 5). Of these, 5 lineages were detected solely from Anseriformes , which are all wintering visitors in the Kanto area and have a widespread breeding zone from Europe to Russian Far East ( Brazil, 2009; Ornithological Society of Japan, 2012). Transmission of the parasite can take place at both the breeding and wintering sites of the avian host as long as the vector is active (Waldenstrom¨ et al., 2002; Valkiunas ¯, 2005). There have been no studies regarding the ecology and prevalence of haemosporidia in blackflies of Japan. Although the seasonal dynamics of blackflies, which are thought to be the vectors of Leucocytozoon , in this area are poorly studied, bloodsucking activities are known to decline when temperatures decrease lower than 10 ǫC ( Crosskey, 1990). The average temperature of the Kanto region from December to February in the years 1981 — 2010 was 7.6 ǫC, with the highest being 11.9 ǫC ( Japan Meteorological Agency; http://www.data.jma.go.jp) suggesting that blackflies cannot be active during the winter. However, other studies reveal the possibility of bloodsucking activities in the winter ( Saito et al., 1986; Rubtsov,1989). Saito et al. (1986) collected over 1000 blackflies in Tokyo prefecture in five samplings days from November to February, although bloodsucking activities were not checked. Rubtsov (1989) stated that although low temperature inhibits adult blackfly emergence and bloodsucking activities in northern areas, some blackflies in lower latitudes can be active for bloodsucking in late autumn to winter. It is therefore difficult to distinguish whether bloodsucking activities take place during the winter in the Kanto region. However, lineage TUSW04 has also been found in Mongolia from Bar-headed goose ( Anser indicus ) and continental subspecies of Great cormorant ( Phalacrocorax carbo ), which breed in continental East Asia and are accidental visitors in Japan ( Brazil, 2009). Hence, it is more likely that these lineages were infected at their breeding grounds in Northern Japan or continental Asia. ANACU04 has been previously found from Northern pintail ( Anas acuta ) of North America, which are known to change their wintering grounds between Japan and North America depending on year (Yamashina Institute for Ornithology, 2002; Nicolai et al., 2005). This supports the fact that the same lineage was found from Anatidae in Japan and North America, suggesting that Anatidae have an important role in the transmission of parasites between continents ( Ramey et al., 2015). It is essential to note again the fact that some of the birds were rescued a year or more before sampling, giving the possibility that they were infected in the facilities, rather than in their breeding grounds.

1 lineage, CIAE02, was detected from a wintering visitor and migratory breeder. This lineage has been previously seen in other countries. It is difficult to distinguish the area and distribution of transmission, as there is no vector information. However, because there have been many reports from various countries and various hosts, it is possible that this species is transmitted across a wide range. Meanwhile, COCOR10 shows a similar pattern to the Plasmodium lineage CXPIP12, being previously found in Hawfinch. Although the distribution range for this lineage is unknown, it is safe to say that this lineage is transmitted in Japan, as it has been found in resident breeders.

For the remaining 16 lineages from resident and migratory breeders, there is little information, as they were all detected for the first time. For the 11 lineages from resident breeders, there is a high possibility that they are transmitted within Japan. However, for the 5 of the lineages were found from migratory breeders, it is difficult to identify the location of transmission. Further studies on the possible vector species are needed in order to justify this. Although Leucocytozoon is known to have strong host specificity, apparent lineages with high host specificity were not found due to the fact that the majority of the lineages were described for the first time or have few reports of previous hosts. However, TUSW04 seems to have high host specificity in Anseriformes .

In this study, we were able to determine the prevalence of haemosporidia of rescued wild birds in the Kanto area. Although rescued wild birds are not truly in their natural state, they are important samples to survey the prevalence of avian haemosporidia in wild birds of the Kanto region. Migratory birds have a chance of coming in contact with various different haemosporidia that are distributed in areas they migrate, hence making them important carriers for the distribution and dispersal of haemosporidia. Meanwhile, the appropriate vector differs among species of haemosporidia and the presence of the appropriate vector is a key factor for transmission. Influence on the changes in distribution due to climate changes are reported in both the avian hosts and arthropod vectors, therefore emphasizing the need to monitor their ecology in order to prevent infectious diseases.