The 1992 epizootic of Newcastle disease in double-crested cormorants in North America

In the summer of 1992, morbidity and mortality in juvenile double-crested cormorants (Phalacrocorax auritus; DCC) attributable to Newcastle disease virus (NDV) was observed for the first time in seven northern USA states and one Canadian province, and recurred in three western Canadian provinces. Based on clinical signs and laboratory diagnostic findings, DCC mortality from NDV occurred in 59 of the 63 nesting colonies and two of three non-colony sites investigated. An estimate of in excess of 20,000 DCC died, with mortality rates ranging from < 1 to 37% in Great Lakes colonies to 20 to 92% in Minnesota (USA) and North and South Dakota (USA) colonies. Sick juvenile white pelicans (Pelecanus erythrorhynchos) exhibiting signs similar to sick cormorants, and dead pelicans were observed in Minnesota and North Dakota. Mortality rates in pelican colonies were as high as in the adjacent cormorant colonies, but no cause for the mortality of an estimated 5,000 pelicans was determined. No evidence of NDV was found in other species nesting in proximity to affected cormorants. Although the source of the NDV infection is unknown in cormorants, the simultaneous onset of the epizootics in juvenile birds over a wide geographic area implies that the virus was acquired by adults prior to migration and was carried back to nest sites, exposing susceptible nestlings. The possible transmission of this virus from free-ranging wild birds to domestic poultry is a concern. Based on repeated epizootics in cormorants since 1990, NDV seems to be established in DCC.     

Parasite assemblages of Double-crested Cormorants as indicators of host populations and migration behavior

The Double-crested Cormorant (Phalacrocorax auritus) is culled in many states because of the real and presumed damages it inflicts on farmed and recreational fisheries and other ecosystem services. Resident cormorant colonies breeding in the southeastern United States are protected in some areas, so it is important to distinguish these from co-occurring but unprotected migratory cormorants. Migratory P. auritus are likely to contain helminthic parasite communities that differ from those of non-migratory, resident birds, because they will encounter a wider variety of habitats and intermediate host communities during migrations. Here, we document five distinct assemblages of helminth parasites collected from 218 P. auritus culled from 11 sites in Alabama, Minnesota, Mississippi, and Vermont. The assemblages of P. auritus parasites are distinct among many sampling locations and can be used to correctly predict where a host cormorant has been feeding. We provide evidence for mixing of cormorants at a regional scale using discriminant analysis, which suggests there is a single population of migratory cormorants. Furthermore, our models strongly differentiate between migratory and resident P. auritus in the southeastern United States. In conjunction with species-by species latitudinal and longitudinal trends, our models could serve as effective tools for managers interested in both the population control of migratory cormorants and the conservation of non-migratory, resident birds. Finally, parasite counts per host are notoriously variable with many zeros and a few large numbers, leading many researchers to use simple prevalence in their analyses. We show that an intermediate level of data resolution, using species occurrence ranks within individual hosts, behaves well statistically and provides the greatest discrimination among distinct host groupings.     

Hematology, plasma chemistry, and serology of the flightless cormorant (Phalacrocorax harrisi) in the Galapagos Islands, Ecuador

The flightless cormorant (Phalacrocorax harrisi) is an endemic species of the Galápagos Islands, Ecuador. Health studies of the species have not previously been conducted. In August 2003, baseline samples were collected from flightless cormorant colonies on the islands of Isabela and Fernandina. Seventy-six birds, from nestlings to adults, were evaluated. Genetic sexing of 70 cormorants revealed 37 females and 33 males. Hematology assessment consisted of packed cell volume (n=19), leukograms (n=69), and blood smear evaluation (n=69). Microscopic evaluation of blood smears revealed microfilaria in 33% (23/69) of the cormorants. Plasma chemistries were performed on 46 cormorants. There was no significant difference in chemistry values or complete blood counts between male and female cormorants or between age groups. Based on a serologic survey to assess exposure to avian pathogens, birds (n=69) were seronegative for West Nile virus, avian paramyxovirus type 1 (Newcastle disease virus), avian paramyxovirus types 2 and 3, avian influenza, infectious bursal disease, infectious bronchitis, Marek's disease (herpes), reovirus, avian encephalomyelitis, and avian adenovirus type 2. Antibodies to avian adenovirus type 1 and Chlamydophila psittaci were found in 31% (21/68) and 11% (7/65) of flightless cormorants respectively. Chlamydophila psittaci was detected via polymerase chain reaction in 6% (2/33) of the cormorants. The overall negative serologic findings of this research suggest that the flightless cormorant is an immunologically na?ve species, which may have a reduced capacity to cope with the introduction of novel pathogens.     

Causes of morbidity and mortality and their effect on reproductive success in double-crested cormorants from Saskatchewan

The objectives of this study were to describe causes of morbidity and mortality in a breeding colony of double-crested cormorants (Phalacrocorax auritus) on Doré Lake (Saskatchewan, Canada), and to determine cause-specific mortality rates of juvenile birds. Morbidity and mortality were monitored every third day during the breeding season from 1994 to 1996 from inside a tunnel-and-blind system. Affected eggs and birds were collected for examination and diagnosis. The cause of mortality was determined for 105 eggs, 178 nestlings (< or = 4-wk-old), 1393 post-nestling chicks (> 4-wk-old), and 10 adults. The main causes of mortality were infertility or embryonal death, avian predation, displacement of eggs and chicks from the nest, starvation from sibling competition, Newcastle disease, coyote predation, human-induced suffocation, and entrapment. In 49% of the cases, avian predation and displacement from the nest of eggs or nestlings was associated with human disturbance. Thirty-six nestlings, 40 post-nestling chicks, and three adults were examined for the presence of parasites. Contracaecum spiculigerum was found in the proventriculus; Amphimerus elongatus in the liver. Piagetiella incomposita in the gular pouch; Eidmanniella pellucida, Pectinopygus farallonii, and Ceratophyllus lari in the plumage; and Theromyzon sp. in the nasal and oral cavity. Contracaecum spiculigerum was associated with ulcerative gastritis, A. elongatus with multifocal hepatitis and bile duct hyperplasia, and P. incomposita with ulcerative stomatitis, but these lesions were not considered fatal. Other diseases included beak deformity, abnormal rotation of the carpal joint, hypopigmentation, and eye loss. Overall mortality of cormorant chicks between hatching and the end of the breeding season varied from 25 to 48%. The most important causes of mortality were Newcastle disease, which killed 21% of hatched chicks in 1995, sibling competition (maximum 12% in 1994), and coyote predation (2% in 1994).     

Using species distribution models to define nesting habitat of the eastern metapopulation of double‐crested cormorants

When organisms with similar phenotypes have conflicting management and conservation initiatives, approaches are needed to differentiate among subpopulations or discrete groups. For example, the eastern metapopulation of the double‐crested cormorant (Phalacrocorax auritus) has a migratory phenotype that is culled because they are viewed as a threat to commercial and natural resources, whereas resident birds are targeted for conservation. Understanding the distinct breeding habitats of resident versus migratory cormorants would aid in identification and management decisions. Here, we use species distribution models (SDM: Maxent) of cormorant nesting habitat to examine the eastern P. auritus metapopulation and the predicted breeding sites of its phenotypes. We then estimate the phenotypic identity of breeding colonies of cormorants where management plans are being developed. We transferred SDMs trained on data from resident bird colonies in Florida and migratory bird colonies in Minnesota to South Carolina in an effort to identify the phenotype of breeding cormorants there based on the local landscape characteristics. Nesting habitat characteristics of cormorant colonies in South Carolina more closely resembled those of the Florida phenotype than those of birds of the Minnesota phenotype. The presence of the resident phenotype in summer suggests that migratory and resident cormorants will co‐occur in South Carolina in winter. Thus, there is an opportunity for separate management strategies for the two phenotypes in that state. We found differences in nesting habitat characteristics that could be used to refine management strategies and reduce human conflicts with abundant winter migrants and, at the same time, conserve less common colonies of resident cormorants. The models we use here show potential for advancing the study of geographically overlapping phenotypes with differing conservation and management priorities.     

Studies of viruses in penguins in the Vestfold Hills

Blood and cloacal swabs were collected from 1073 Adelie penguins (Pygoscelis adeliae) in 13 separate colonies near Davis in the Vestfold Hills, Antarctica. Three paramyxoviruses, distinct from Newcastle disease virus, were isolated from cloacal swabs obtained from penguins at three widely separated colonies. These isolates, together with others obtained from penguins in other areas of Antarctica, suggest that such viruses are widespread in antarctic penguins. Their significance in the ecology of antarctic penguins has not been determined. No evidence of infection with Newcastle disease virus or avian influenza virus was obtained during the survey.     

Phenology, distribution, and host specificity of Solenopsis invicta virus-1

Studies were conducted to examine the phenology, geographic distribution, and host specificity of the Solenopsis invicta virus-1 (SINV-1). Two genotypes examined, SINV-1 and -1A, exhibited similar seasonal prevalence patterns. Infection rates among colonies of S. invicta in Gainesville, Florida, were lowest from early winter (December) to early spring (April) increasing rapidly in late spring (May) and remaining high through August before declining again in the fall (September/October). Correlation analysis revealed a significant relationship between mean monthly temperature and SINV-1 (p<0.0005, r=0.82) and SINV-1A (p<0.0001, r=0.86) infection rates in S. invicta colonies. SINV-1 was widely distributed among S. invicta populations. The virus was detected in S. invicta from Argentina and from all U.S. states examined, with the exception of New Mexico. SINV-1 and -1A were also detected in other Solenopsis species. SINV-1 was detected in Solenopsis richteri and the S. invicta/richteri hybrid collected from northern Alabama and Solenopsis geminata from Florida. SINV-1A was detected in S. geminata and Solenopsis carolinensis in Florida and the S. invicta/richteri hybrid in Alabama. Of the 1989 arthropods collected from 6 pitfall trap experiments from Gainesville and Williston, Florida, none except S. invicta tested positive for SINV-1 or SINV-1A. SINV-1 did not appear to infect or replicate within Sf9 or Dm-2 cells in vitro. The number of SINV-1 genome copies did not significantly increase over the course of the experiment, nor were any cytopathic effects observed. Phylogenetic analyses of SINV-1/-1A nucleotide sequences indicated significant divergence between viruses collected from Argentina and the U.S.     

H9N2亚型AIV排毒及形成气溶胶的研究

为研究H9N2亚型AIV排毒及形成气溶胶规律,将SPF鸡饲养于正负压隔离器中,采用AGI-30收集器(All Glass Impinger AGI-30)和气管泄殖腔棉拭子在攻毒后不同时间收集空气、气管和泄殖腔样品,并利用HI、Dot-ELISA和RT-PCR检测样品.结果发现攻毒后第4天开始形成气溶胶,并持续到第43天,实验证明H9N2亚型AIV不仅可以在呼吸道和泄殖腔复制,而且可以形成气溶胶.气管泄殖腔棉拭子在接种后第3天开始排毒,至第7天攻毒鸡全部分离到病毒.排毒时间可持续到第45天.但泄殖腔的排毒量明显低于气管的排毒量,这也说明H9N2型禽流感主要通过呼吸道排毒.     

Avian Influenza Virus Surveillance in Wild Birds in Georgia: 2009–2011

The Caucasus, at the border of Europe and Asia, is important for migration and over-wintering of wild waterbirds. Three flyways, the Central Asian, East Africa-West Asia, and Mediterranean/Black Sea flyways, converge in the Caucasus region. Thus, the Caucasus region might act as a migratory bridge for influenza virus transmission when birds aggregate in high concentrations in the post-breeding, migrating and overwintering periods. Since August 2009, we have established a surveillance network for influenza viruses in wild birds, using five sample areas geographically spread throughout suitable habitats in both eastern and western Georgia. We took paired tracheal and cloacal swabs and fresh feces samples. We collected 8343 swabs from 76 species belonging to 17 families in 11 orders of birds, of which 84 were real-time RT-PCR positive for avian influenza virus (AIV). No highly pathogenic AIV (HPAIV) H5 or H7 viruses were detected. The overall AIV prevalence was 1.6%. We observed peak prevalence in large gulls during the autumn migration (5.3–9.8%), but peak prevalence in Black-headed Gulls in spring (4.2–13%). In ducks, we observed increased AIV prevalence during the autumn post-moult aggregations and migration stop-over period (6.3%) but at lower levels to those observed in other more northerly post-moult areas in Eurasia. We observed another prevalence peak in the overwintering period (0.14–5.9%). Serological and virological monitoring of a breeding colony of Armenian Gulls showed that adult birds were seropositive on arrival at the breeding colony, but juveniles remained serologically and virologically negative for AIV throughout their time on the breeding grounds, in contrast to gull AIV data from other geographic regions. We show that close phylogenetic relatives of viruses isolated in Georgia are sourced from a wide geographic area throughout Western and Central Eurasia, and from areas that are represented by multiple different flyways, likely linking different host sub-populations.     

Prevalence of West Nile virus neutralizing antibodies in wild birds from the Camargue area, southern France

The Camargue area of southern France experienced the re-emergence of West Nile Virus (WNV) in the late summer of 2000 and 2004. Immediately preceding the 2004 outbreak, samples were collected from 432 birds of 32 different species captured in mist nets and from 201 Cattle Egret (Bubulcus ibis) nestlings sampled in their nests between 1 April and 12 June 2004. West Nile virus neutralizing titers of >/=40 were detected in 4.8% (95% confidence limit, 2.9-7.5%) of the adult birds and in 1.6% (0.3-4.6%) of the egret nestlings. Migratory passerines had a higher prevalence of WNV neutralizing antibodies (7.0%) than did resident and short-distance migratory passerines (0.8%), suggesting exposure to WNV or a related flavivirus during overwintering in Africa.     

Detection of low pathogenic avian influenza viruses in wild ducks from Canada: comparison of two sampling methods

Surveillance for avian influenza viruses in wild birds was initiated in Canada in 2005. In 2006, in order to maximize detection of highly pathogenic avian influenza viruses, the sampling protocol used in Canada's Inter-agency Wild Bird Influenza Survey was changed. Instead of collecting a single cloacal swab, as previously done in 2005, cloacal and oropharyngeal swabs were combined in a single vial at collection. In order to compare the two sampling methods, duplicate samples were collected from 798 wild dabbling ducks (tribe Anatini) in Canada between 24 July and 7 September 2006. Low pathogenic avian influenza viruses were detected significantly more often (P<0.0001) in combined oropharyngeal and cloacal samples (261/798, 33%) than in cloacal swabs alone (205/798, 26%). Compared to traditional single cloacal samples, combined samples improved virus detection at minimal additional cost.     

Prevalence of <Emphasis Type="Italic">Arcobacter</Emphasis> species in market-weight commercial turkeys

The prevalence of Arcobacter in live market weight turkeys was determined for six Midwestern commercial flocks at three intervals. Samples (n = 987) were collected from cloaca, feathers, ceca, crop, drinkers and environmental samples on farms and from carcasses at slaughter. Initially, EMJH-P80 and CVA isolated Arcobacter from 7.1% (40 of 564) of samples, while Arcobacter enrichment broth and selective agar recovered the microbe in 4.7% of samples (23 of 489 samples). Although EMJH-P80 coupled with CVA yielded Arcobacter more frequently, the selectivity of the modified Arcobacter agar enhanced the recognition of Arcobacter colonies. A multiplex PCR was used to identify all Arcobacter species and to differentiate Arcobacter butzleri. The low prevalence of Arcobacter detected in cloacal swab (2.0%, 6 of 298 samples) and cecal contents (2.1%, 3 of 145 samples) suggests that Arcobacter infrequently colonizes the intestinal tract. Despite its low prevalence in live turkeys, Arcobacter spp. were identified in 93% of carcass swabs (139 of 150 samples). The overall prevalence of Arcobacter in drinker water decreased from 67% (31 of 46 samples) in the summer of 2003 to 24.7% (18 of 73 samples) during resampling in the spring of 2004 and was inversely related to the chlorination level.     

An update on the distribution of Parelaphostrongylus tenuis in the southeastern United States

An update is presented on the distribution of the meningeal worm (Parelaphostrongylus tenuis) of white-tailed deer (Odocoileus virginianus) in the southeastern United States. The parasite is widely distributed and common in all or much of Arkansas, Kentucky, Louisiana, Maryland, North Carolina, Tennessee, Virginia and West Virginia. It is also common in the northern half of Alabama and Georgia. In contrast, it is rare or absent along the Atlantic and Gulf coastal plains of Alabama, Georgia, Mississippi and South Carolina. It has been collected from a single deer in Florida.     

Prevalence and subtypes of Influenza A Viruses in Wild Waterfowl in Norway 2006-2007

The prevalence of influenza A virus infection, and the distribution of different subtypes of the virus, were studied in 1529 ducks and 1213 gulls shot during ordinary hunting from August to December in two consecutive years, 2006 and 2007, in Norway. The study was based on molecular screening of cloacal and tracheal swabs, using a pan-influenza A RT-PCR. Samples found to be positive for influenza A virus were screened for the H5 subtype, using a H5 specific RT-PCR, and, if negative, further subtyped by a RT-PCR for the 3'-part of the hemagglutinin (HA) gene, encompassing almost the entire HA2, and the full-length of the neuraminidase (NA) gene, followed by sequencing and characterization. The highest prevalence (12.8%) of infection was found in dabbling ducks (Eurasian Wigeon, Common Teal and Mallard). Diving ducks (Common Goldeneye, Common Merganser, Red-breasted Merganser, Common Scoter, Common Eider and Tufted Duck) showed a lower prevalence (4.1%). In gulls (Common Gull, Herring Gull, Black-headed Gull, Lesser Black-headed Gull, Great Black-backed Gull and Kittiwake) the prevalence of influenza A virus was 6.1%. The infection prevalence peaked during October for ducks, and October/November for gulls. From the 16 hemagglutinin subtypes known to infect wild birds, 13 were detected in this study. Low pathogenic H5 was found in 17 dabbling ducks and one gull.     

Evaluation of the ESPLINE INFLUENZA A&B-N Kit for the diagnosis of avian and swine influenza

The ESPLINE INFLUENZA A&B-N kit was evaluated for its applicability to the rapid diagnosis of influenza in chickens and pigs. The kit specifically detected viral antigens in tracheal swabs and tissue homogenates of the trachea, liver, spleen, and colon of chickens inoculated with a highly pathogenic avian influenza virus strain, A/chicken/Yamaguchi/7/04 (H5N1), at 48 hr post-inoculation (p.i.) as well as in the tracheal and cloacal swabs and tissue homogenates of dead chickens. For those infected with a low pathogenic strain, A/chicken/aq-Y-55/01 (H9N2), antigens were detected only in the samples from tracheal swabs and organs 1-4 days p.i. The kit also detected viral antigens in the nasal swabs of miniature pigs infected with swine and avian influenza viruses. The kit was found to be sensitive and specific enough for the rapid diagnosis of infections of influenza A virus in chickens and pigs.     

三江自然保护区野生迁徙水禽携带禽流感病毒和新城疫病毒状况的监测

[目的]为了对途经三江保护区的野生迁徙水禽携带禽流感病毒(AIV)和新城疫病毒(NDV)的状况进行有效监测.[方法]在2005年10月、2006年4月、2006年10月3个候鸟的迁徙季节从三江保护区采集了158只野鸟的咽拭子和肛拭子样本.应用SPF鸡胚盲传、血凝和血凝抑制试验和RT-PCR等方法进行了病毒的分离和鉴定.[结果]结果共分离到20株AIV和13株NDV.20株AIV均来自2006年10月采集的样品,经常规血清学分型鉴定分为12个亚型,11个亚型来源于绿头鸭,分别为H2N2(2/20),H2N6(2/20),H3N4(1/20),H3N6(2/20),H3N7(2/20),H3N8(2/20),H6N2(2/20),H11N2(1/20),H11N3(1/20),H11N5(2/20),H11N6(1/20),另外一株来源于白眉鸭,为H5N2(1/20).13株NDV则来自3个迁徙季节的5种不同水禽采,其中包括绿头鸭(8/13),豆雁(1/13),白额雁(1/13),绿翅鸭(1/13)和鸳鸯(2/13).[结论]这一结果表明,拥有极大种群数量、在世界范围内广泛分布的绿头鸭,被认为可能是AIV和NDV最重要的自然宿主之一,并在病毒的传播上比其他野生鸟类具有更为重要的生态学意义.     

Colony structure and reproduction in the thelytokous parthenogenetic ant Platythyrea punctata (F. Smith) (Hymenoptera, Formicidae)

Summary: An important evolutionary characteristic of the formicine subfamily Ponerinae is the occurrence of various alternative reproductive tactics within single species. In Platythyrea punctata Smith, 1858, queens, gamergates and parthenogenetic workers co-occur in the same species. Morphological queens, both alate and dealate, were present in only 29 percent of the colonies collected in Florida, but absent from colonies collected in Barbados and Puerto Rico. One of the six queens which were dissected (three alate and three dealate) was found to be inseminated but not fertile. Instead, in most queenless colonies, a single uninseminated worker monopolized reproduction by means of thelytokous parthenogenesis, i.e., it produced female offspring from unfertilized eggs. A single mated, reproductive worker (gamergate) was found dominating reproduction in the presence of an inseminated alate queen in one of the Florida colonies. Thelytokous parthenogenesis was examined in artificial groups of virgin laboratory-reared workers, where one worker typically monopolized reproduction despite the presence of several individuals with elongated ovaries. In 16 colonies collected in Florida, a total of 66 individuals differed morphologically from queens and workers. Their thorax morphology varied from a worker-like to an almost queen-like structure. We refer to these individuals as "intercastes" (sensu Peeters, 1991a). The remarkable complexity of reproductive strategies renders P. punctata unique within ants.     

Prevalence of Trichomonas gallinae in northern goshawks from the Berlin area of northeastern Germany

In recent years, the northern goshawk (Accipiter gentilis) has colonized suburban and urban areas in Berlin, Germany, and elsewhere in Europe. Because of the high proportion of feral pigeons (Columba livia f. domestica) in their diet, urban goshawks are suspected to have a high infection rate with Trichomonas gallinae. Therefore, from 1998 to 2001, we examined 269 nestlings from 90 nests for infection with T. gallinae by culture of swabs taken from the oropharynx and checked their oropharynx for the presence of caseous lesions indicative of trichomonosis. In 80% of the nest sites (n=90), at least one nestling was infected. The nestling infection rate with T. gallinae was 69.7% (n=33) in 1998, 73.0% (n=89) in 1999, 55.8% (n=77) in 2000, and 62.9% (n=70) in 2001. In total, 65.1% of the northern goshawk nestlings were culture positive for T. gallinae. Prevalence increased with the age of nestlings (chi2=12.4, n=269, df=5, P=0.03) and tended to increase with brood size (chi2=9.345, n=269, df=4, P=0.053). Caseous lesions were present in 12 nestlings (4.5%), but only 10 of these were culture positive for T. gallinae. Two nestlings (0.7%) had large caseous lesions (diameter>1 cm) characteristic of late-stage trichomonosis and died shortly after examination. It is suggested that the combination of a high prevalence of T. gallinae with a low rate of pathologicic changes is the result of an evolutionary-adapted parasite-host relationship.