Prevalence of avian haemosporidia among injured wild birds in Tokyo and environs, Japan

Abstract

Avian haemosporidia have been reported in various birds of Japan, which is part of the East Asian-Australian flyway and is an important stopover site for migratory birds potentially carrying new pathogens from other areas. We investigated the prevalence of avian malaria in injured wild birds, rescued in Tokyo and surrounding areas. We also evaluated the effects of migration by examining the prevalence of avian malaria for each migratory status. 475 birds of 80 species were sampled from four facilities. All samples were examined for haemosporidian infection via nested polymerase chain reaction (PCR) of the cytochrome b (cytb) gene. 100 birds (21.1%) of 43 species were PCR positive for avian haemosporidia. Prevalence in wintering birds, migratory breeders, and resident birds was 46.0%, 19.3%, 17.3% respectively. There was a bias in wintering birds due to Eurasian coot (Fulica atra) and Anseriformes. In wintering birds, lineages which are likely to be transmitted by Culiseta sp. in Northern Japan and lineages from resident species of Northern Japan or continental Asia were found, suggesting that wintering birds are mainly infected at their breeding sites. Meanwhile, there were numerous lineages found from resident and migratory breeders, suggesting that they are transmitted in Japan, some possibly unique to Japan. Although there are limits in studying rescued birds, rehabilitation facilities make sampling of difficult-to-catch migratory species possible and also allow for long-term monitoring within areas.

Characterization of Plasmodium relictum, a cosmopolitan agent of avian malaria

“…The negative effects of P. relictum (pSGS1) on bird physiological parameters and behaviour are documented due to delicate experimental studies [ 54 , 55 ]. Observations of infected, naive birds in zoos and rehabilitation centres provided evidence of the severity of disease caused by these and related parasite lineages in wild birds [ 71 – 74 ]. These studies are the basis of understanding the predictions and conclusions of field observations about negative influence of P. relictum on population decline or even extinction, particularly on oceanic islands [ 63 , 75 – 78 ].…”

Malaria parasites and related haemosporidians cause mortality in cranes: a study on the parasites diversity, prevalence and distribution in Beijing Zoo

“…However, parasitological studies in zoos and other centres usually are under professional veterinary control and provide valuable information about parasites. This is particularly valuable in case of large protected bird species, which are difficult to sample in the wild [ 15 ]. Scott was the first to publish information about severe diseases caused by haemosporidian parasites in captive zoo birds in London [ 16 , 17 ], and severe haemosporidioses were reported subsequently in many zoos in Asia, Europe, South and North Americas and Africa [ 18 – 25 ].…”

The first clinical cases of <i>Haemoproteus</i> infection in a snowy owl (<i>Bubo scandiacus</i>) and a goshawk (<i>Accipiter gentilis</i>) at a zoo in the Republic of Korea

“…are vector-borne pathogens belonging to the families Plasmodiidae, Haemoproteidae and Leucocytozoidae, and are also known as avian malaria parasites [ 4 , 25 ]. Parasites are transmitted through exclusive vectors, such as mosquitoes (Culicidae) for Plasmodium , blood-sucking simuliid flies (Simuliidae) for Leucocytozoon and biting midges (Ceratopogonidae) and hippoboscid flies (Hippoboscidae) for Haemoproteus [ 7 , 24 ].…”

“…Recent studies have shown that migratory birds can act as important carriers of the parasites, transporting the parasites from one geographical region to another. Moreover, migratory birds can cause cross-species transmission to resident birds [ 7 , 8 ].…”