Pathogenicity of a Hong Kong-origin H5N1 highly pathogenic avian influenza virus for emus, geese, ducks, and pigeons

The H5N1 type A influenza viruses that emerged in Hong Kong in 1997 are a unique lineage of type A influenza viruses with the capacity to transmit directly from chickens to humans and produce significant disease and mortality in both of these hosts. The objective of this study was to ascertain the susceptibility of emus (Dramaius novaehollandiae), domestic geese (Anser anser domesticus), domestic ducks (Anas platyrhynchos), and pigeons (Columba livia) to intranasal (i.n.) inoculation with the A/chicken/Hong Kong/220/97 (H5N1) highly pathogenic avian influenza virus. No mortality occurred within 10 days postinoculation (DPI) in the four species investigated, and clinical disease, evident as neurologic dysfunction, was observed exclusively in emus and geese. Grossly, pancreatic mottling and splenomegaly were identified in these two species. In addition, the geese had cerebral malacia and thymic and bursal atrophy. Histologically, both the emus and geese developed pancreatitis, meningoencephalitis, and mild myocarditis. Influenza viral antigen was demonstrated in areas with histologic lesions up to 10 DPI in the geese. Virus was reisolated from oropharyngeal and cloacal swabs and from the lung, brain, and kidney of the emus and geese. Moderate splenomegaly was observed grossly in the ducks. Viral infection of the ducks was pneumotropic, as evidenced by mild inflammatory lesions in the respiratory tract and virus reisolation from oropharyngeal swabs and from a lung. Pigeons were resistant to HK/220 infection, lacking gross and histologic lesions, viral antigen, and reisolation of virus. These results imply that emus and geese are susceptible to i.n. inoculation with the HK/220 virus, whereas ducks and pigeons are more resistant. These latter two species probably played a minimal epidemiologic role in the perpetuation of the H5N1 Hong Kong-origin influenza viruses.     

Pathogenic effects on domestic poultry of a mycoplasma gallisepticum strain isolated from a wild house finch

Mycoplasma gallisepticum (MG) has been isolated from wild house finches. The pathogenic effects of MG finch strain (K4058) and MG R-strain were compared after exposure of chickens and turkeys. Gross and histologic lesions, reisolation of the organism, serology, and clinical disease were evaluated. Milder histologic and gross lesions, in addition to lower serologic titers, occurred in birds inoculated with the finch strain. Mortality, concurrent with clinical and gross respiratory signs and lesions, was observed only in chickens challenged with R-strain. Both the MG finch strain and MG R-strain were recovered from the respective challenge groups at 14 and 28 days postexposure. The results show that MG isolated from wild house finches may infect domestic poultry species but causes only mild disease and is less virulent than MG R-strain. Commercial enzyme-linked immunosorbent assay kits best detected the serologic response of chickens and turkeys to the MG finch strain.     

Susceptibility of laughing gulls (Larus atricilla) to H5N1 and H5N3 highly pathogenic avian influenza viruses

This investigation detailed the clinical disease, gross and histologic lesions, and distribution of viral antigen in juvenile laughing gulls (Larus atricilla) intranasally inoculated with either the A/tern/South Africa/61 (H5N3) (tern/SA) influenza virus or the A/chicken/Hong Kong/220/97 (H5N1) (chicken/HK) influenza virus, which are both highly pathogenic for chickens. Neither morbidity nor mortality was observed in gulls inoculated with either virus within the 14-day investigative period. Gross lesions resultant from infection with either virus were only mild, with the tern/SA virus causing decreased lucency of the air sacs (2/6), splenomegaly (2/6), and pancreatic mottling (1/6) and the chicken/HK virus causing only decreased lucency of the air sacs (2/8) and conjunctival edema (2/8). Histologic lesions in the tern/SA-inoculated gulls included a mild to moderate heterophilic to lymphoplasmacytic airsacculitis (6/6), mild to moderate interstitial pneumonia (3/6), and moderate necrotizing pancreatitis and hepatitis at 14 days postinoculation (DPI) (2/6). Immunohistochemical demonstration of viral antigen occurred only in association with lesions in the liver and pancreas. In contrast, viral antigen was not demonstrated in any tissues from the chicken/HK-inoculated gulls, and inflammatory lesions were confined to the air sac (3/8) and lungs (3/8). Both viruses were isolated at low titers (<10(1.68) mean embryo lethal dose) from oropharyngeal and cloacal swabs up to 7 days postinoculation (DPI), from the lung and kidney of one of two tern/SA-inoculated gulls at 14 DPI, and from the lung of one of two chicken/HK-inoculated gulls at 7 DPI. Antibodies to influenza viruses as determined with the agar gel precipitin test at 14 DPI were detected only in the two tern/SA-inoculated gulls and not in the two chicken/HK-inoculated gulls.     

Isolation of different serovars of Salmonella enterica from wild birds in Great Britain between 1995 and 2003

Postmortem examinations were carried out on the carcases of 779 wild birds. Salmonellosis was a common cause of death in greenfinches (Carduelis chloris), house sparrows (Passer domesticus) and chaffinches (Fringilla coelebs), and was also responsible for the deaths of other birds such as goldfinches (Carduelis carduelis), feral pigeons and different species of gulls. Most cases of salmonellosis in finches occurred between January and March, whereas salmonellosis in house sparrows tended to occur between October and March. Salmonella Typhimurium DT40 and DT56 (variant) predominated in finches and sparrows, DT41 and DT195 were the most common strains isolated from gulls, and DT2 and DT99 were recovered from feral pigeons. These "wild bird" strains of Salmonella made up less than 0.5 per cent of the isolates of Salmonella recovered from cattle, sheep, pigs, chickens or turkeys in Great Britain over the same period, but they made up nearly 3 per cent of the isolates from more extensively reared avian livestock such as gamebirds, ducks and geese.     

Neurotropism of highly pathogenic avian influenza virus A/chicken/Indonesia/2003 (H5N1) in experimentally infected pigeons (Columbia livia f. domestica)

This investigation assessed the susceptibility of experimentally infected pigeons to the highly pathogenic avian influenza virus (HPAIV) H5N1 that caused recent outbreaks of avian influenza in birds and humans in several countries of Asia. For this purpose 14 pigeons were infected ocularly and nasally with 10(8) EID50 and clinical signs were recorded and compared with five chickens infected simultaneously as positive controls. The chickens demonstrated anorexia, depression, and 100% mortality within 2 days postinoculation. Three of the pigeons died after a history of depression and severe neurological signs consisting of paresis to paralysis, mild enteric hemorrhage, resulting in a mortality of 21%. Gross lesions in these pigeons were mild and inconsistent. Occasionally subcutaneous hyperemia and hemorrhage and cerebral malacia were observed. Microscopic lesions and detection of viral antigen were confined to the central nervous system of these pigeons. In the cerebrum and to a minor extent in the brain stem a lymphohistiocytic meningoencephalitis with disseminated neuronal and glial cell necrosis, perivascular cuffing, glial nodules, and in one bird focally extensive liquefactive necrosis could be observed. The remaining nine pigeons showed neither clinical signs nor gross or histological lesions associated with avian influenza, although seroconversion against H5 indicated that they had been infected. These results confirm that pigeons are susceptible to HPAIV A/chicken/Indonesia/2003 (H5N1) and that the disease is associated with the neurotropism of this virus. Although sentinel chickens and most pigeons did not develop disease, further experiments have to elucidate whether or not Columbiformes are involved in transmission and spread of highly pathogenic avian influenza.     

An epornitic of avian pox in a research aviary

An outbreak of avian pox in a bird research colony was reported. Although 10 species of passerine birds were housed within the facility, clinical signs and mortality were restricted to canaries and house sparrows. Post-mortem lesions initially occurred in the upper and lower respiratory tracts and were characterized by proliferative rhinitis, proliferative bronchopneumonia, and proliferative airsacculitis, and diphtheritic lesions occurring in the esophagus were characterized by proliferative granulomatous esophagitis. Cutaneous lesions occurred subsequently in some birds, and a diagnosis was made by histopathology, electron microscopy, and virus isolation. The occurrence of diphtheritic lesions in pox infections of wild birds has been rare, and a sparrow showed an unusual combination of both diphtheritic and acute systemic lesions previously undescribed.     

Outbreak of herpesviral conjunctivitis and respiratory disease in gouldian finches

An outbreak of tracheitis, sinusitis, and conjunctivitis, originating in recently imported birds, caused high morbidity and mortality in a flock of finches in Central Illinois. Although several species were present, Gouldian finches (Erythrura [Chloebia] gouldiae) were most commonly and severely affected. Birds submitted for necropsy displayed microscopic lesions characteristic of herpesviral infection, including epithelial cytomegaly and karyomegaly with basophilic, intranuclear inclusion bodies in the nasopharynx, sinuses, trachea, parabronchi, conjunctiva, and occasionally the lacrimal gland or proximal proventricular glands. Viral particles consistent with herpesvirus were visualized within affected epithelial cells with electron microscopy. Based on a partial sequence of the viral DNA polymerase gene, this virus was found to be identical to a herpesvirus previously implicated in a similar outbreak in Canada and is most likely an alphaherpesvirus.     

Long-term study of Chlamydophilosis in Slovenia

Immune reactivity for Chlamydophila (C.) psittaci in Slovenia was monitored in parrots, canaries, finches and nine species of recently captured free-living birds (house sparrows, Eurasian goldfinches, tree sparrows, chaffinches, European greenfinches, European serines, Eurasian siskins, Eurasian linnets and Eurasian bullfinches) in the period from 1991 to 2001. In subsequent years, specific IgG antibodies were found using immunofluorescence in parrots (0.7-53.6%), canaries (0.0-3.5%), finches (0.0-5.7%) and in captured free-living birds (33.3% of Eurasian goldfinches in 1994). An experimental infection with C psittaci was performed in order to study clinical signs and pathological changes in canaries and finches. The C. psittaci strain used for experimental infection was isolated from a cockatiel (Nymphicus hollandicus). Chlamydial DNA was extracted from clinical material followed by RFLP-PCR analysis. Infection of canaries and finches was confirmed in organ smears by direct immunofluorescence and a modified Gimenez staining method. In addition, serological tests of indirect immunofluorescence and complement fixation were applied. However, in spite of positive immunological reaction there were no clinical signs three weeks after infection. The present study includes results of a serological survey of persons belonging to the most important risk groups (breeders, pet shopkeepers and veterinarians). The results of microimmunofluorescence to identify the presence of specific antibodies and correlation between appearance of infection in birds and important risk groups are presented. Out of 143 persons belonging to the high-risk group we found 10 (7%) persons who were immunologically positive. Testing of two successive samples was used to demonstrate an increase in IgG and IgA titres in human sera. However, IgM, which is indicative of acute infection, could not be detected.     

Infectivity and persistence of an outbreak strain of Salmonella enterica serotype Typhimurium DT160 for house sparrows (Passer domesticus) in New Zealand

AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand. METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 10(1), 10(2), 10(3), 10(5), 2 x 10(8) colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were euthanised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates. RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with 10(5) cfu and all six birds inoculated with 2 x 10(8) cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 10(2) cfu and four birds inoculated with 10(3) cfu, on most days in five birds inoculated with 10(5) cfu, and continuously in six birds inoculated with 2 x 10(8) cfu. DT160 was isolated from the livers of three birds which received 10(3) cfu, five birds dosed with 10(5) cfu, and all six birds given 2 x 10(8) cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 10(3) cfu, and all birds dosed with > or =10(5) cfu. CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.     

Study on the species-specificity of Isospora michaelbakeri by experimental infection

Isospora michaelbakeri is one of the Isospora species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected I. michaelbakeri (Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (Passer rutilans), spotted munia (Lonchura punctulata), canary (Serinus canaria), Java sparrows (Padda oryzivora), chicken (Gallus domesticus), ducks (Anas platyrhynchos) and BALB/c mice. The results indicated that I. michaelbakeri infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with I. michaelbakeri in the present study.     

Mycoplasma gallisepticum in house finches (Carpodacus mexicanus) and other wild birds associated with poultry production facilities.

Since 1994, an epidemic of conjunctivitis caused by Mycoplasma gallisepticum (MG) has spread throughout the eastern population of house finches (Carpodacus mexicanus). The adaptation of MG to a free-flying avian species presents potential problems for the control of mycoplasmosis in commercial poultry. To evaluate risks associated with this emerging problem, a field survey was conducted to assess prevalence of MG infection in house finches and other passerine birds associated with poultry farms. Between November 1997 and March 1999, 1058 birds were captured by mist net or trap at 17 farms and at 10 feeder stations in northeast Georgia. Birds were bled and screened by serum plate agglutination (SPA) for antibodies to MG. Birds with negative or weak positive SPA results were released at capture sites, and those with strong positive SPA reactions were kept for further evaluation. Necropsies were performed on selected house finches and individuals of 11 other passerine species, and samples were collected for MG testing by culture, polymerase chain reaction (PCR), hemagglutination inhibition, and histopathology. Testing revealed 19.1% of 671 birds caught at farms and 11.6% of 387 birds caught at feeder sites were SPA positive for MG. Three house finches captured on farms were positive for MG by culture and PCR, whereas three from feeder sites were positive only by PCR. No MG isolates were made from tufted titmice (Baeolophus bicolor), but 40% were positive by PCR. Individuals from 10 additional species were SPA positive only. Results suggest that MG persists at low levels in house finches in northeast Georgia and that tufted titmice may be nonclinical carriers of MG or a related mycoplasma. Positive SPA reactions in other species may be caused by nonspecific reactions or contact exposure. Current biosecurity recommendations should be sufficient to minimize risks of transmission between wild and domestic birds.     

Long-term Study of Chlamydophilosis in Slovenia

Immune reactivity for Chlamydophila (C.) psittaci in Slovenia was monitored in parrots, canaries, finches and nine species of recently captured free-living birds (house sparrows, Eurasian goldfinches, tree sparrows, chaffinches, European greenfinches, European serines, Eurasian siskins, Eurasian linnets and Eurasian bullfinches) in the period from 1991 to 2001. In subsequent years, specific IgG antibodies were found using immunofluorescence in parrots (0.7– 53.6%), canaries (0.0–3.5%), finches (0.0–5.7%) and in captured free-living birds (33.3% of Eurasian goldfinches in 1994). An experimental infection with C. psittaci was performed in order to study clinical signs and pathological changes in canaries and finches. The C. psittaci strain used for experimental infection was isolated from a cockatiel (Nymphicus hollandicus). Chlamydial DNA was extracted from clinical material followed by RFLP-PCR analysis. Infection of canaries and finches was confirmed in organ smears by direct immunofluorescence and a modified Gimenez staining method. In addition, serological tests of indirect immunofluorescence and complement fixation were applied. However, in spite of positive immunological reaction there were no clinical signs three weeks after infection. The present study includes results of a serological survey of persons belonging to the most important risk groups (breeders, pet shopkeepers and veterinarians). The results of microimmunofluorescence to identify the presence of specific antibodies and correlation between appearance of infection in birds and important risk groups are presented. Out of 143 persons belonging to the high-risk group we found 10 (7%) persons who were immunologically positive. Testing of two successive samples was used to demonstrate an increase in IgG and IgA titres in human sera. However, IgM, which is indicative of acute infection, could not be detected.     

An epidemic of salmonellosis caused by Salmonella Typhimurium DT160 in wild birds and humans in New Zealand

AIM: This study reports an outbreak of salmonellosis due to S. Typhimurium DT160 which caused extensive mortality in wild birds and enteric disease in humans in New Zealand during the winter and spring months of the year 2000. METHODS: Necropsies were performed and microbiological examinations undertaken on wild birds from populations in which mass mortality was reported, and on captive indigenous birds which died suddenly during the winter and spring of 2000. Affected tissues were examined histologically and isolates of S. Typhimurium were phage typed and examined using pulsedfield gel electrophoresis (PFGE). Isolates of S. Typhimurium obtained from cases of human enteric disease which occurred during these months were phage typed, examined using PFGE and compared with the bird isolates. RESULTS: Central and northern areas of the South Island and the southern North Island were worst affected with die-offs of several hundreds of sparrows and other birds reported in rural areas. Mortalities reached a peak in winter (July-August) 2000 and decreased to small numbers during the spring and early summer. The birds usually died of an acute septicaemia with multifocal necrotising lesions in the liver and spleen. Human cases throughout the country increased gradually over the same period. Isolates from birds, livestock and humans examined using PFGE were indistinguishable from one another. CONCLUSION: This strain of Salmonellahas emerged as a major cause of septicaemia in wild birds in New Zealand. Because of the close association between house sparrows (Passer domesticus) and humans, the organism also poses a serious zoonotic risk. The possibility that the infection may spread to involve indigenous species needs investigation.     

Pathobiology of A/chicken/Hong Kong/220/97 (H5N1) avian influenza virus in seven gallinaceous species

Direct bird-to-human transmission, with the production of severe respiratory disease and human mortality, is unique to the Hong Kong-origin H5N1 highly pathogenic avian influenza (HPAI) virus, which was originally isolated from a disease outbreak in chickens. The pathobiology of the A/chicken/Hong Kong/220/97 (H5N1) (HK/220) HPAI virus was investigated in chickens, turkeys, Japanese and Bobwhite quail, guinea fowl, pheasants, and partridges, where it produced 75-100% mortality within 10 days. Depression, mucoid diarrhea, and neurologic dysfunction were common clinical manifestations of disease. Grossly, the most severe and consistent lesions included splenomegaly, pulmonary edema and congestion, and hemorrhages in enteric lymphoid areas, on serosal surfaces, and in skeletal muscle. Histologic lesions were observed in multiple organs and were characterized by exudation, hemorrhage, necrosis, inflammation, or a combination of these features. The lung, heart, brain, spleen, and adrenal glands were the most consistently affected, and viral antigen was most often detected by immunohistochemistry in the parenchyma of these organs. The pathogenesis of infection with the HK/220 HPAI virus in these species was twofold. Early mortality occurring at 1-2 days postinoculation (DPI) corresponded to severe pulmonary edema and congestion and virus localization within the vascular endothelium. Mortality occurring after 2 DPI was related to systemic biochemical imbalance, multiorgan failure, or a combination of these factors. The pathobiologic features were analogous to those experimentally induced with other HPAI viruses in domestic poultry.     

Determination of the incidence of Salmonella spp., Campylobacter jejuni, and Clostridium perfringens in wild birds near broiler chicken houses by sampling intestinal droppings

Several methods were evaluated for collecting fecal and intestinal samples from wild birds found near broiler chicken houses. A few intestinal samples and cloacal swabs were obtained from European starlings and house sparrows. Most of the samples collected consisted of wild bird droppings found on or near the houses. Samples were collected from each of four farms of a broiler integrator during a grow-out cycle: a cycle in the summer for farm A, fall for farm B, and spring, summer, fall, and winter for farms C and D. Of the 25 wild bird intestinal and fecal samples collected from a broiler house on farm A during a grow-out cycle in July-August 1997, 24% were positive for Salmonella spp., 4% for Campylobacter jejuni, and 28% for Clostridium perfringens. Of the nine fecal samples collected from broiler house B in a grow-out cycle in September-November 1997, 33% were positive for Salmonella spp., 11% for C. jejuni, and 22% for C. perfringens. For farms C and D, of the 23 samples collected in March-April 1998, 0 were positive for Salmonella spp., 11% for C. jejuni, and 52% for C. perfringens; of 27 samples collected in June-July 1998, 4% were positive for Salmonella spp., 0 for C. jejuni, and 13% for C. perfringens; of 24 samples collected in August-October 1998, 14% were positive for Salmonella spp., 5% for C. jejuni, and 4% for C. perfringens; of 14 samples collected December 1998-January 1999, 0 were positive for Salmonella, 50% for C. jejuni, and 14% for C. perfringens. The incidence of these bacterial enteropathogens in wild birds near the broiler chicken houses suggests that wild birds that gain entry to poultry grow-out houses have the potential to transmit these pathogens to poultry.     

Effects of Mycoplasma gallisepticum on reproductive success in house finches

Long known as a pathogen of poultry, Mycoplasma gallisepticum (MG) was first detected in house finches in 1994. The disease rapidly spread throughout the eastern United States and Canada and was associated with debilitating disease and high mortality in house finches. However, in the late 1990s, the proportion of infected finches dying as a result of infection with MG decreased, and asymptomatic infection was more common among wild birds than in the past. We documented MG infections in breeding house finches and concluded that adults of both sexes transmit the infection to dependent young, probably after hatch. MG infections of breeding adults occurred late in the breeding season and were found in birds completing significantly more nests than birds that never tested positive for MG, implying that higher rates of reproduction carry a cost in the form of increased risk of infection. We found evidence of an MG-induced delay in dispersal of nestlings from their natal area and demonstrated a significant impact of infection on nestling growth.     

Epidemic of infectious laryngotracheitis in Italy: characterization of virus isolates by PCR-restriction fragment length polymorphism and sequence analysis

Between May 2007 and October 2008, 34 outbreaks of mild to moderate forms of infectious laryngotracheitis (ILT) occurred in commercial broiler flocks in Italy. Affected birds showed watery eyes, conjunctivitis, nasal discharge, reduction of feed and water consumption, and gasping with expectoration of blood-stained mucus. The mortality rate was < 10%. Gross lesions consisted of conjunctivitis, excess of mucus, blood, or presence of diphtheritic membranes in trachea. A real-time PCR assay was performed to confirm the presence of ILT virus (ILTV) DNA in tracheal tissue homogenates. Twenty-three ILTV isolates were propagated on the chorion-allantoic membrane of embryonated chicken eggs showing typical plaques. PCR combined with restriction fragment length polymorphism and gene sequencing of isolates showed a high genetic correlation between field strains and chicken embryo origin vaccines.     

Experimental infection of house sparrows (Passer domesticus) with West Nile virus isolates of Euro-Mediterranean and North American origins

West Nile virus (WNV) is a zoonotic arboviral pathogen transmitted by mosquitoes in a cycle involving wild birds as reservoir hosts. The virus has recently emerged in North America and re-emerged in Europe. North American WNV outbreaks are often accompanied by high mortality in wild birds, a feature that is uncommon in Europe. The reason for this difference is unknown, but the intrinsic virulence of the viruses circulating in each continent and/or the susceptibility to the disease of Palearctic as opposed to Nearctic wild bird species could play a role. To assess this question, experimental inoculations with four lineage 1 WNV strains, three from southern Europe (Italy/2008, Italy/2009 and Spain/2007) and one from North America (NY99) were performed on house sparrows (Passer domesticus), a wild passerine common in both continents. Non-significant differences which ranged from 0% to 25% were observed in mortality for the different WNV strains. Viremias lasted from 1 to 5–6 days post-inoculation (dpi) in all cases; individuals inoculated with NY99 had significantly higher titres than those inoculated with any of the Euro-Mediterranean strains. Remarkably, host competence was found to be higher for NY99 than for the other strains. Consequently, albeit being pathogenic for house sparrows, some Euro-Mediterranean strains had reduced capacity for replication in -and transmission from- this host, as compared to the NY99 strain. If applicable also to other wild bird host species, this relatively reduced transmission capacity of the Euro-Mediterranean strains could explain the lower incidence of this disease in wild birds in the Euro-Mediterranean area.     

The occurrence of Cryptococcus neoformans in fecal samples from birds kept in human living areas]

With help of Guizotia creatinine agar (syn. bird seed agar) Cryptococcus (Cr.) neoformans var. neoformans was isolated from 71 (7.7%) of 925 investigated droppings of birds kept within human living area. Cr. neoformans was detected in droppings of 1.2% from 164 psittacines, in droppings of 1.7% from 118 budgerigars and in droppings of 18.4% from (carrier) pigeons. This yeast was not isolated from droppings of 13 small parrots, 10 eclectus parrots, 13 rosellas, 21 cockatiels, 6 Polytelidus sp., 32 Cacatua sp., 13 Carduelis sp., 5 waxbills, 5 starlings, 120 chicken, 9 turkeys, 2 geese, 2 Turdus sp., 1 duck and 1 gull.     

Venous blood gas and lactate values of mourning doves (Zenaida macroura), boat-tailed grackles (Quiscalus major), and house sparrows (Passer domesticus) after capture by mist net, banding, and venipuncture

Blood gas partial pressures, pH, and bicarbonate and lactate concentrations were measured from the basilic vein of mourning doves (Zenaida macroura) and the jugular vein of boat-tailed grackles (Quiscalus major) and house sparrows (Passer domesticus) to assess immediate impacts of mist net capture and handling for banding and venipuncture. Mourning doves and house sparrows exhibited mild acidemia (median [minimum-maximum] venous blood pH(41 degrees C) = 7.394 [7.230-7.496] and 7.395 [7.248-7.458], respectively), relative to boat-tailed grackles (Quiscalus major; 7.452 [7.364-7.512]), but for different reasons. Mourning doves exhibited relative metabolic acidosis (lower venous blood pH, higher lactate concentrations, lower bicarbonate, and no significant differences in partial pressure of CO2 (pCO2) or partial pressure of O2 (pO2) compared with boat-tailed grackles). House sparrows exhibited relative respiratory acidosis (lower venous blood pH, higher pCO2, lower pO2, and no significant differences in bicarbonate and lactate concentrations compared with boat-tailed grackles). All birds captured by mist net and handled for banding and venipuncture experienced some degree of lactic acidemia; and values were greater in mourning doves (lactate, 7.72 [3.94-14.14] mmol/L) than in boat-tailed grackles (5.74 [3.09-8.75] mmol/L) and house sparrows (4.77 [2.66-12.03] mmol/L), despite mourning doves resisting least and being easiest to disentangle from the mist net. House sparrows were more susceptible to respiratory acidosis, warranting particular care in handling birds <30 g to minimize interference with ventilation. The different sample collection site for mourning doves may have affected results in comparison with the other two species, due to activity of the wing muscles. However, despite the higher lactate concentrations, pCO2 was relatively low in doves. The metabolic, respiratory, and acid-base alterations observed in this study were minor in most cases, indicative of the general safety of these important field ornithology techniques. The effect of other adverse conditions, however, could be additive.