This focus article has been prepared by Scott Reid of the APHA's virology department with Sharon Brookes, Rowena Hansen, David Welchman, Richard Irvine and Ian Brown of the APHA.
Psittacines (e.g. parrots, macaws and cockatoos) are common companion animals that are also kept in zoos and private breeding collections. Despite this popularity, long-term, comprehensive studies of ...diagnostic data from captive psittacines are rare. This study was conducted to assess trends in disease prevalence and to describe causes of morbidity and mortality in psittacines submitted for post-mortem examination to the veterinary hospital and diagnostic laboratory at the University of Guelph, Ontario, Canada. Post-mortem reports of 1,850 psittacines from 1998 to 2017 were assessed and included 110 species from 45 genera. Birds were often diagnosed with infectious disease processes (n = 823; 44.5%), including viral (n = 428; 23.1%), bacterial (n = 284; 15.4%) and fungal (n = 161; 8.7%). Non-infectious disease processes (n = 1,076; 58.2%) were most commonly degenerative (n = 465; 25.1%), metabolic (n = 392; 21.2%) or haemodynamic (n = 270; 14.6%). Exploratory statistical analyses, used to guide further research, revealed significant correlations and associations among disease processes and genera, age categories and sex. This 19-year retrospective study is the first to be conducted in Canada for psittacine birds and provides a broad overview of disease prevalence that can be used as a baseline to inform other studies addressing common and uncommon diseases affecting these birds in the future.
The most common primary disease processes resulting in mortality that were diagnosed in a cohort of psittacine birds submitted for post-mortem examination to the Ontario Veterinary College and Animal Health Laboratory from 1998 to 2017 (n = 1,850). Display omitted
► The epidemiological role of birds in N. caninum epidemiology is yet to be determined. ► We have screened 17 different species for serological and parasitological positivity. ► Specific antibodies ...were not detected in the analyzed samples. ► However, Neospora-like tissues cysts were positively stained in two Psittacine birds. ► Birds should be considered as potential reservoirs of N. caninum in wildlife.
Neospora caninum is a protozoan parasite that presents worldwide distribution and is mainly implicated as responsible for bovine abortion. Although the presence of birds in cattle-raising properties is positively correlated to higher infection rates, very little has been described about the role of these animals in the parasite's life cycle. In that sense, this work aimed to investigate the serological and histological positivity of different avian species sampled in its natural habitat or in captivity. No serological positivity was observed in the 294 tested serum samples. On the other hand, Apicomplexa-like cysts found in muscular tissues of two Psittaciformes were immunostained with N. caninum antisera. These findings indicate that N. caninum may infect a wider range of hosts than described to date, and that further studies should be performed in order to determine the presence of the infection in different avian species.
Numerous studies addressed the diversity of bird Plasmodium and Haemoproteus parasites. However, a few have been carried out in continental avian hotspot regions such as Brazil, a country with ...markedly different biomes, including Amazon, Brazilian Savanna, Atlantic Forest, Caatinga, Pantanal, and Pampas. We present the first study on hemosporidian (Haemosporida) parasites in free-living birds from an Atlantic Forest fragment where more than 80 avian species have been reported. Within this area, the São Paulo Zoo locates, and it is the fourth largest zoo in the world and the largest in Latin America. A total of 133 free-living bird samples representing 12 species were collected in the zoo, with the overall hemosporidian prevalence of 18 % by PCR-based diagnostics. Twenty-four positive PCR signals were reported from four different bird species, including migratory ones. Columba livia, an urban species, considered nowadays a pest in big cities, showed 100 % prevalence of Haemoproteus spp., mainly Haemoproteus columbae. We discuss the epidemiological importance of new parasites introduced by migratory birds in the São Paulo Zoo area and the risk it poses to the captive species, which are natives or exotics. We also warn about the influence these parasites can have on the biodiversity and the structure of host populations by altering the competitive interaction between the free-living and the captive birds.
Crested screamers, a unique, mainly terrestrial avian species native to South America, are known to have a markedly high chick mortality rate in captivity, ranging from 61% to 94%; however, there is ...very limited information on this species' natural history within the literature, and even less about common diseases that affect them. Four captive-born crested screamer chicks (
) at a U.S. zoological institution died acutely from different causes over the course of 2.5 months. Although a hands-off approach was initially taken, each chick became acutely weak on exhibit and medical intervention was deemed necessary, but proved unsuccessful in all cases. Necropsy results of the chicks revealed various causes of death, including acute
colitis, aspiration pneumonia complicated by concurrent gastrointestinal Candidiasis, severe dehydration and emaciation, and acute amoebic gastroenteritis. No direct associations were found between these deaths and diet or husbandry; however, the limited literature on this topic suspects inadequate husbandry and immunosuppression to be the greatest cause of chick mortality in this species. The cases presented here are consistent with this hypothesis, but further exemplify the limited knowledge of this species and the need to optimize their survivability and proliferation in captivity.
Haemosporida is a large group of vector‐borne intracellular parasites that infect amphibians, reptiles, birds, and mammals. This group includes the different malaria parasites (Plasmodium spp.) that ...infect humans around the world. Our knowledge on the full life cycle of these parasites is most complete for those parasites that infect humans and, to some extent, birds. However, our current knowledge on haemosporidian life cycles is characterized by a paucity of information concerning the vector species responsible for their transmission among vertebrates. Moreover, our taxonomic and systematic knowledge of haemosporidians is far from complete, in particular because of insufficient sampling in wild vertebrates and in tropical regions. Detailed experimental studies to identify avian haemosporidian vectors are uncommon, with only a few published during the last 25 years. As such, little knowledge has accumulated on haemosporidian life cycles during the last three decades, hindering progress in ecology, evolution, and systematic studies of these avian parasites. Nonetheless, recently developed molecular tools have facilitated advances in haemosporidian research. DNA can now be extracted from vectors' blood meals and the vertebrate host identified; if the blood meal is infected by haemosporidians, the parasite's genetic lineage can also be identified. While this molecular tool should help to identify putative vector species, detailed experimental studies on vector competence are still needed. Furthermore, molecular tools have helped to refine our knowledge on Haemosporida taxonomy and systematics. Herein we review studies conducted on Diptera vectors transmitting avian haemosporidians from the late 1800s to the present. We also review work on Haemosporida taxonomy and systematics since the first application of molecular techniques and provide recommendations and suggest future research directions. Because human encroachment on natural environments brings human populations into contact with novel parasite sources, we stress that the best way to avoid emergent and reemergent diseases is through a program encompassing ecological restoration, environmental education, and enhanced understanding of the value of ecosystem services.
The Ile du Grand Connétable nature reserve is a rocky island off the Northern Atlantic coast of South America that hosts a unique population of Magnificent Frigatebirds (Fregata magnificens, ...Pelecaniformes). A high chick mortality, associated with nodular proliferative lesions, involving featherless areas, such as legs, neck, eyelids, and beak, was recorded during a consecutive 2 yr and affected almost half of the generation. Investigations were, therefore, conducted to determine the cause of these epidemics. Although histopathologic investigations suggested that malnutrition, because of fewer resources in the Frigates’ fishing area, could be the cause of the epidemic, a novel alphaherpesvirus, tentatively called Fregata magnificens herpesvirus, was detected in cutaneous crusts on the diseased birds. Although in this study, we do not prove the causal link of this new virus to the symptoms observed, it can nevertheless be suggested that in debilitated hosts, a productive herpesvirus infection might accelerate, and/or be accelerated by, population declines. These results emphasize the need to take into consideration the possible role of herpesviruses in weakened populations of wild birds in conservation management plans.
Raillietina saudiae is a well‐studied avian gastrointestinal parasite belonging to the family Davaineidae and is the most prevalent cyclophyllid tapeworm infecting pigeon in Saudi Arabia. The present ...study considered as a complementary analysis of Al‐Quraishy et al. (2019; Parasitol Int 71, 59–72) with molecular studies for two ribosomal DNA genes employed for precise recognition of this Raillietina species. The annotated partial 18S and 28S rDNA gene regions were found to be 888 and 900 bp long that utilized further to elucidate their genetic relationships at species level using maximum likelihood method. The query sequence of R. saudiae is well aligned and placed within the Davaineidae family, with the same clade of all species of Raillietina that well separated from other cyclophyllidean cestodes especially taeniid and hymenolepid species. Sequence data recorded the monophyly of Raillietina species. The current phylogeny supports the usage of the partial 18S and 28S rDNA genes as reliable markers for phylogenetic reconstructions.
Significance and impact of the study: The nuclear ribosomal DNA genes (18S and 28S rDNA) are regarded as useful genetic markers in taxonomic anaylsis of Raillietina saudiae and distinguish it from the other related species.
Aspergillosis is a major cause of severe respiratory disease in birds. The prevalence of cryptic section Fumigati and other non-Aspergillus fumigatus species as causative agents is unknown. Species ...identity was determined in 30 isolates from affected birds from zoos, pet birds and poultry by PCR of the ITS1-5.8S-ITS2 and partial β-tubulin genes. The most prevalent isolate was A. fumigatus sens. str. in 87% (26) cases. Other Aspergillus species were identified in 13% (4) cases, including A. restrictus (1), A. flavus sens. str. (2), and A. nidulans-clade (1). This is the first report of A. restrictus causing avian disease.
Understanding host-symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: ...Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird–feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used.
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