Free-living Wild Birds Research Articles

High Rates of Detection of Clade 2.3.4.4 Highly Pathogenic Avian Influenza H5 Viruses in Wild Birds in the Pacific Northwest During the Winter of 2014–15

In 2014, clade 2.3.4.4 H5N8 highly pathogenic avian influenza (HPAI) viruses spread across the Republic of Korea and ultimately were reported in China, Japan, Russia, and Europe. Mortality associated with a reassortant HPAI H5N2 virus was detected in poultry farms in western Canada at the end of November. The same strain (with identical genetic structure) was then detected in free-living wild birds that had died prior to December 8, 2014, of unrelated causes in Whatcom County, Washington, U. S. A., in an area contiguous with the index Canadian location. A gyrfalcon (Falco rusticolus) that had hunted and fed on an American wigeon (Anas americana) on December 6, 2014, in the same area, and died 2 days later, tested positive for the Eurasian-origin HPAI H5N8. Subsequently, an active surveillance program using hunter-harvested waterfowl in Washington and Oregon detected 10 HPAI H5 viruses, of three different subtypes (four H5N2, three H5N8, and three H5N1) with four segments in common (HA, PB2, NP, and MA). In addition, a mortality-based passive surveillance program detected 18 HPAI (14 H5N2 and four H5N8) cases from Idaho, Kansas, Oregon, Minnesota, Montana, Washington, and Wisconsin. Comparatively, mortality-based passive surveillance appears to have detected these HPAI infections at a higher rate than active surveillance during the period following initial introduction into the United States.

Pathogenicity and tissue tropism of currently circulating highly pathogenic avian influenza A virus (H5N1; clade 2.3.2) in tufted ducks (Aythya fuligula)

Reports describing the isolation of highly pathogenic avian influenza (HPAI) virus (H5N1) clade 2.3.2 in feces from apparently healthy wild birds and the seemingly lower pathogenicity of this clade compared to clade 2.2 in several experimentally infected species, caused concern that the new clade might be maintained in the wild bird population. To investigate whether the pathogenicity of a clade 2.3.2 virus was lower than that of clades previously occurring in free-living wild birds in Europe, four tufted ducks were inoculated with influenza A/duck/HongKong/1091/2011 (H5N1) clade 2.3.2 virus. The ducks were monitored and sampled for virus excretion daily during 4 days, followed by pathologic, immunohistochemical, and virological investigations. The virus produced severe disease as evidenced by clinical signs, presence of marked lesions and abundant viral antigen in several tissues, especially the central nervous system. The study shows that HPAI-H5N1 virus clade 2.3.2 is highly pathogenic for tufted ducks and thus, they are unlikely to maintain this clade in the free-living population or serve as long-distance vectors.

English

Birds are increasingly close to men, and many times are raised as pets. However, many times, these animals may carry and spread enterobacteria that are deleterious to human health. Salmonella sp. is considered one of the most common zoonoses in the world, causing important losses to public health. Although, Escherichia coli is an important commensal in the gastrointestinal tract of most animals, it may cause disease both in men and animals, depending on the strain and its pathogenicity. Therefore, the objective of this study was to assess the occurrence of Salmonella sp. and Escherichia coli in free-living and captive wild birds in the city of Guarapuava, PR, Brazil. Animals were divided according to the taxonomic order, as follows: Columbiformes (228), Psittaciformes (128), Passeriformes (63), Piciformes (26), Falconiformes (19), Stringiformes (6), and Accipitriformes (01), in a total of 471 birds. Bacterial isolation was carried out by means of cloacal swabs, with 69.38% birds positive for E. coli and 22.32% for Salmonella sp. From the total of birds, 143 showed co-infection with Salmonella sp. and E. coli. Columbiformes showed the greatest occurrence of E. coli (82.33%). Falconiformes showed the greatest number of negative birds (57.9%). These results demonstrate that birds that were analyzed may carry and spread these enterobacteria, and preventive measures for human exposure should be determined, as these microorganisms are public health concerns. Key words: Escherichia coli, Salmonella sp., zoonosis.

Wild bird surveillance around outbreaks of highly pathogenic avian influenza A(H5N8) virus in the Netherlands, 2014, within the context of global flyways.

Highly pathogenic avian influenza (HPAI) A(H5N8) viruses that emerged in poultry in east Asia since 2010 spread to Europe and North America by late 2014. Despite detections in migrating birds, the role of free-living wild birds in the global dispersal of H5N8 virus is unclear. Here, wild bird sampling activities in response to the H5N8 virus outbreaks in poultry in the Netherlands are summarised along with a review on ring recoveries. HPAI H5N8 virus was detected exclusively in two samples from ducks of the Eurasian wigeon species, among 4,018 birds sampled within a three months period from mid-November 2014. The H5N8 viruses isolated from wild birds in the Netherlands were genetically closely related to and had the same gene constellation as H5N8 viruses detected elsewhere in Europe, in Asia and in North America, suggesting a common origin. Ring recoveries of migratory duck species from which H5N8 viruses have been isolated overall provide evidence for indirect migratory connections between East Asia and Western Europe and between East Asia and North America. This study is useful for better understanding the role of wild birds in the global epidemiology of H5N8 viruses. The need for sampling large numbers of wild birds for the detection of H5N8 virus and H5N8-virus-specific antibodies in a variety of species globally is highlighted, with specific emphasis in north-eastern Europe, Russia and northern China.

Fatal epicarditis in a hen harrier (Circus cyaneus) a red-listed bird of high conservation concern in Britain associated with Cyathostoma species and Escherichia coli infection

Three species of the syngamid nematode Cyathostoma have been reported in raptors ( Cyathostoma ( Hovorkonema ) variegatum , Cyathostoma americanum , Cyathostoma lari ). These nematodes typically parasitise the...

Molecular Epidemiology of Newcastle Disease in Mexico and the Potential Spillover of Viruses from Poultry into Wild Bird Species

Newcastle disease, one of the most important health problems that affects the poultry industry around the world, is caused by virulent strains of Newcastle disease virus. Newcastle disease virus is considered to be endemic in several countries in the Americas, including Mexico. In order to control Newcastle disease outbreaks and spread, intensive vaccination programs, which include vaccines formulated with strains isolated at least 60 years ago, have been established. These vaccines are dissimilar in genotype to the virulent Newcastle disease viruses that had been circulating in Mexico until 2008. Here, 28 isolates obtained between 2008 and 2011 from different regions of Mexico from free-living wild birds, captive wild birds, and poultry were phylogenetically and biologically characterized in order to study the recent epidemiology of Newcastle disease viruses in Mexico. Here we demonstrate that, until recently, virulent viruses from genotype V continued to circulate and evolve in the country. All of the Newcastle disease viruses of low virulence, mostly isolated from nonvaccinated free-living wild birds and captive wild birds, were highly similar to LaSota (genotype II) and PHY-LMV42 (genotype I) vaccine strains. These findings, together with the discovery of two virulent viruses at the Mexican zoo, suggest that Newcastle disease viruses may be escaping from poultry into the environment.

Unusual increase of psittacosis in southern Sweden linked to wild bird exposure, January to April 2013

Free-living wild birds worldwide act as reservoir for Chlamydia psittaci, but the risk of transmission to humans through contact with wild birds has not been widely documented. From 12 January to April 9 2013, a total of 25 cases of psittacosis were detected in southern Sweden, about a threefold increase compared with the mean of the previous 10 years. A matched case-control study investigating both domestic and wild bird exposure showed that cases were more likely than controls to have cleaned wild bird feeders or been exposed to wild bird droppings in other ways (OR: 10.1; 95% CI: 2.1-47.9). We recommend precautionary measures such as wetting bird feeders before cleaning them, to reduce the risk of transmission of C. psittaci when in contact with bird droppings. Furthermore, C. psittaci should be considered for inclusion in laboratory diagnostic routines when analysing samples from patients with atypical pneumonia, since our findings suggest that psittacosis is underdiagnosed.

A Survey for Avian Influenza from Gulls on the Coasts of the District of Pinamar and the Lagoon Salada Grande, General Madariaga, Argentina

In the present study, fecal samples obtained from kelp gulls (Larus dominicanus), brown-hooded gulls (Larus maculipennis), and Olrog's gulls (Larus atlanticus) on the coast of the District of Pinamar, and grey-hooded gulls (Larus cirrocephalus) on the coast of the Lagoon Salada Grande and surrounding wetlands, General Madariaga, Buenos Aires Province, Argentina, were tested for evidence of avian influenza virus over a period of 3 yr. This surveillance in free-living wild birds in the Buenos Aires Province started in October 2008. Additional samples, which included cloacal swabs, tracheal swabs, or pooled organs, were obtained from sick or dead gulls that arrived at the Fundaci6n Ecol6gica Pinamar or were provided by the Direcci6n de Seguridad en Playas, Municipalidad de Pinamar. Samples were pooled according to date, species, and area. Pooled samples were inoculated in 9- to 11-day-old eggs, and after 5 days, allantoic fluids were tested for evidence of hemagglutination. None of the samples was positive for avian influenza viruses.

Genotyping of Cryptosporidium spp. from free-living wild birds from Brazil

In wild and domestic birds, cryptosporidiosis is often associated with infections by Cryptosporidium galli, Cryptosporidium baileyi and Cryptosporidium meleagridis. In addition to these species, a number of avian Cryptosporidium species yet to be fully characterized are commonly found among exotic and wild avian isolates. The present study aimed to detect and identify samples of Cryptosporidium spp. from free-living wild birds, in order to contribute to the knowledge of the variability of this parasite in the free-living population of Brazil. Stool samples were collected from 242 birds, with the following proportions of individuals: 50 Emberizidae (20.7%), 112 Psittacidae (46.3%), 44 Cardinalidae (18.2%), 12 Turdidae (5.0%), eight Ramphastidae (3.3%), seven Icteridae (2.9%), three Estrilididae (1.2%), two Contigidae (0.8%), two Thraupidae (0.8%) and two Fringilidae (0.8%). Among the 242 fecal samples from wild birds, 16 (6.6%) were positive for the presence of oocysts of Cryptosporidium. Molecular characterization of the 16 samples of Cryptosporidium, were performed with phylogenetic reconstructions employing 292 positions of 18S rDNA. None of the samples of birds was characterized as C. meleagridis. C. galli was identified in one rufous-bellied thrush (Turdus rufiventris), five green-winged saltators (Saltator similis), one slate-coloured seedeater (Sporophila schistacea), one goldfinch (Carduelis carduelis) and three saffron finches (Sicalis flaveola). One goldfinch isolate, one buffy-fronted seedeater (Sporophila frontalis), one red-cowled cardinal (Paroaria dominicana) and one other saffron finch (S. flaveola) were identified as C. baileyi. Avian genotype II was found in an isolate from a white-eyed parakeet (Aratinga leucophthalma). Clinical symptoms of cryptosporidiosis in birds have already been described and the number of wild birds which were shedding parasites was high. Therefore, further epidemiological research and disease surveillance of birds in the wild is warranted.

Very virulent infectious bursal disease virus isolated from wild birds in Korea: Epidemiological implications

To explore the epidemiological link between infectious bursal disease virus (IBDV) in wild birds and domestic chickens in Korea, we examined 107 free-living wild birds, representing 7 species, that were found dead of apparent natural causes in Korea over the past two years for the presence of IBDV. Five birds were tested positive for IBDV by RT-PCR assay: black-billed magpie ( n = 1), mallard duck ( n = 2), bean goose ( n = 1) and white-fronted goose ( n = 1). IBDV was isolated from RT-PCR-positive tissues following chicken embryo inoculation. Sequence analysis of the VP2 gene indicated that all of the isolates from the wild birds encode amino acids A222, I242, I256, I294 and S299 of VP2, which are conserved among strains of very virulent IBDV (vvIBDV). Phylogenetic analysis revealed that the wild bird IBDV isolates are closely related to strains of vvIBDV. An IBDV isolate from a magpie showed 60% mortality in SPF chickens and severe bursal atrophy. The epidemiological implications of IBDV in free-living wild birds are discussed. To our knowledge, this is the first report of vvIBDV in free-living wild birds.

Seroprevalence of infectious bursal disease virus in free-living wild birds in Japan.

Serum samples collected from 739 free-living wild birds of 44 species from Gifu, Mie and Hyogo Prefectures in Japan during the period 1989 to 1997 were tested for antibodies to infectious bursal disease virus (IBDV) serotypes 1 and 2 by a virus neutralization test. Serological evidence of infection with serotypes 1 and 2 was found in 15 (2%) of the sera of 6 species and 36 (4.9%) of the sera of 11 species, respectively. Antibodies to IBDV were detected from both sedentary and migratory species. These findings suggest that free-living wild birds have an important role in the natural history of IBDV. These findings raise the possibility that the IBDV prevalent in the breeding grounds of these birds in other countries could be imported by the migratory species. This is the first report of an extensive serological survey of IBDV in wild birds.

Salmonella Infection in Wild Birds

The occurrence of Salmonella typhimurium, Salmonella gallinarum and Salmonella pullorum in free-living wild birds is reviewed. Four outbreaks of S. typhimurium infection are described, and the epidemiology discussed. La fréquence de Salmonella typhimurium , de Salmonella gallinarum et de Salmonella pullorum chez les oiseaux sauvages en liberté est analysée. Quatre foyers d’infection à S. typhimurium sont décrits et l’épidemiologie en est discutée. Das Auftreten von Salmonella typhimurium, Salmonella gallinarum und Salmonella pullorum in freilebendem Geflügel wurde besprochen. Vier Fälle von S. typhimurium Infektion wurden mit Rücksicht auf die Epidemiologie beschrieben. Se analiza la incidencia de Salmonella typhimurium , Salmonella gallinarum y Salmonella pullorum. Se describen cuatro brotes de la infección a S. typhimurium y se discute la epidemiología.

Aspergillus fumigatus . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Aspergillus fumigatus . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Common as a saprophyte in soil and fermenting vegetable matter. Pathogenic to mammals (including man), birds and insects. DISEASES: The most serious diseases caused by this fungus are the acute and chronic infections of the respiratory system (aspergillosis, aspergilloma) of man (Austwick, 1965; and many other references, e.g., RMVM 3, 677; 4, 316; 4, 549, 551) and animals (Ainsworth & Austwick, 1959; Austwick, 1965). It may also infect the cardiovascular, digestive, genital, musculoskeletal, nervous, and urinary systems, such infections usually following haematogenous spread of the pathogen from a primary focus in the lungs or air sacs. It is the most common cause of mycotic abortion in cattle (Ainsworth & Austwick, 1959; Austwick, RMVM 5, 660; Dijkstra; RMVM 5, 92) and less often in horses (Hensel et al. ; RMVM 4, 1227). Aspergillus fumigatus may also infect the ear (otomycosis) and mastoid cavity, the eye and sinuses (mycoses). Aspergillosis is a major disease of birds and is a cause of considerable losses in the poultry industry, particularly of very young birds (brooder pneumonia) (Vertinskii et al. ; RMVM 5, 758; Vallejo; 5, 940). It is also common in captive wild birds, especially water birds (Ainsworth & Rewell; RMVM 1, 2090; Dathe; 4, 1948; Saez; 4, 811), but reports of infections in free-living wild birds are more rare (Beer; RMVM 4, 2177; McDiarmid; 2, 1761; Rosen, 5, 558). A. fumigatus also invades eggs. Aspergillus fumigatus spores may induce allergic reactions in man, resulting in hay fever, asthma or allergic bronchopulmonary aspergillosis. It also produces toxins (Ainsworth & Austwick, 1959; Austwick, 1965). GEOGRAPHICAL DISTRIBUTION: World-wide. TRANSMISSION: Soil and air-borne. Disease incidence appears to be related to heavy infection from house dust, mouldy hay or straw, litter, or feeding stuffs (Austwick, 1965; Austwick, RMVM 5, 3b).

OCCURRENCE OF ORNITHOSIS IN THE WOOD PIGEON.

THE free-living wild birds of Britain have not been examined extensively for members of the psittacosis lymphogranuloma venereum group. Apart from domestic pigeons living free in the cities, only herring gulls on Skomer Island have been incriminated definitely but there is also some serological evidence for infection in lesser black-backed gulls on the same Island1.