Comparison of Chicken Immune Responses to Immunization with Vaccine La Sota or ZG1999HDS Strain of Newcastle Disease Virus

Newcastle disease (ND) is a highly contagious avian disease. Global control of ND is mainly based on vaccination of poultry; however, reported outbreaks of ND in vaccinated flocks indicate a constant need to re-evaluate the existing vaccines and a development of the new ones. In this study, 4-week-old male chickens of the layer commercial hybrid were immunized oculonasally with a commercial NDV live La Sota vaccine (LS group), a suspension of lyophilized NDV strain ZG1999HDS (ZG group), or saline (Control (K) group). Antibody response was determined by haemagglutination inhibition (HI) assay. Cell-mediated immunity (CMI) was characterized by immunophenotyping of leukocyte’s and T-lymphocyte’s subpopulations (flow cytometry). Applied NDV strains did not cause any adverse reaction in treated chickens. Both strains induced the significantly higher HI antibody response in comparison to the control group, and overall antibody titer was higher in ZG group than in LS group. CMI, manifested as a higher proliferation of B- and T-helper cells, yielded better results in the ZG groups than in the LS group. Based on the obtained results, we conclude that the strain ZG1999HDS is immunogenic and is a suitable candidate for further research and development of poultry vaccines.

Land Use Change and Avian Disease Dynamics

Birds live on a human-dominated planet. Over half of Earth’s ice-free land area has been modified by anthropogenic disturbance including deforestation, agriculture, and urbanization, impacting ecosystems around the world. Disturbances associated with these land use types, such as habitat loss, fragmentation, and pollution, influence the dynamics between birds, their pathogens, and the environment they share. Such shifts in disease dynamics can arise through the impacts of land use change on aspects of hosts, vectors, and/or pathogens, including vector and host abundance, behavior, and physiology, and through pathogen persistence in the environment. To address this complexity, the major causes of land use change that can impact birds across diverse ecosystems are described. The chapter then discusses key changes associated with land use change such as habitat loss, pollution, and anthropogenic resources that are relevant to avian disease ecology. These key changes are followed by a synthesis of documented changes in avian health with urbanization, the fastest growing type of land use change on Earth. The chapter closes with relevant implications for One Health systems and future directions for advancing avian disease ecology in rapidly changing landscapes.

A Flight Path Forward for Avian Infectious Disease Ecology

The field of avian infectious disease ecology is at a key precipice, poised for exciting new ‘flight paths’ in the coming decades. Given the enormous human interest in birds, the unique biology of birds, and the scientific tractability of many avian species, birds represent ideal study systems for generating important insights for the field of infectious disease ecology more broadly. A flight path forward for avian infectious disease ecology must leverage these unique characteristics of birds to bridge and integrate across disciplines and scales, from the levels of biological organization (individual to community) to the spatial and temporal units of analysis. The broader field of One Health provides a key framework for transdisciplinary work that recognizes and studies avian infectious disease as intimately interconnected to that of human and ecosystem health. The flight path forward for avian infectious disease ecology should also continue to leverage the highly engaged community scientists in several parts of the world who collect data relevant to avian disease across unprecedented spatial scales. Finally, the flight path forward for avian infectious disease should leverage technological innovations to improve our ability to track avian movements, from those occurring within forest patches or cities up to those that cross hemispheres. With effective community engagement, transdisciplinary collaboration, and technological innovation, the flight path forward for avian infectious disease ecology can, just like birds themselves, know no boundaries.

A Bird’s Eye View of Avian Disease Ecology

Wild birds are a source of joy and fascination to people worldwide and unmatched in their capacity to connect people to nature. Yet, the fate of wild birds is being threatened by human activities that alter and destroy habitat, increase pollution, and contribute to global climate change. Pathogens and parasites pose another threat to birds—a threat that we are just beginning to uncover. The chapter explores avian disease ecology and the ways in which the avian host–parasite interaction is both influenced by and has consequences for every level of ecological hierarchy, from the physiology, behavior, and evolution of individual hosts to the complex biotic and abiotic interactions occurring within biological communities and ecosystems. In addition, these diverse parasite–bird interactions are increasingly occurring in rapidly changing global environments—their ecology is changing—and this shapes the complex ways by which parasites influence the interconnected health of birds, humans, and shared ecosystems.

Climate Change and Avian Disease

Rapid and intensifying impacts of climate change are having profound influences on bird populations worldwide, altering their exposure and vulnerability to diverse parasites of conservation or public health concern. This chapter highlights theory and assesses empirical evidence for how climate change will affect avian host–parasite interactions through multiscale processes that jointly determine transmission potential. Shifts in the distribution and phenology of bird populations shape the diversity of parasites they encounter, while behavioral and physiological responses influence individuals’ susceptibility to infection. Additionally, direct and often non-linear effects of abiotic conditions on parasite stages in arthropod vectors or the external environment can be crucial determinants of avian exposure risk. This chapter underscores the necessity of quantifying responses to environmental change in both birds and their parasites and highlights key knowledge gaps and priorities for future research, in order to improve predictions of when climate change will intensify or reduce avian–parasite interactions.

Bird-feeder cleaning lowers disease severity in rural but not urban birds

Animals inhabiting urban areas often experience elevated disease threats, putatively due to factors such as increased population density and horizontal transmission or decreased immunity (e.g. due to nutrition, pollution, stress). However, for animals that take advantage of human food subsidies, like feeder-visiting birds, an additional mechanism may include exposure to contaminated feeders as fomites. There are some published associations between bird feeder presence/density and avian disease, but to date no experimental study has tested the hypothesis that feeder contamination can directly impact disease status of visiting birds, especially in relation to the population of origin (i.e. urban v. rural, where feeder use/densities naturally vary dramatically). Here we used a field, feeder-cleaning experimental design to show that rural, but not urban, house finches (Haemorhous mexicanus) showed increased infection from a common coccidian endoparasite (Isospora spp.) when feeders were left uncleaned and that daily cleaning (with diluted bleach solution) over a 5-week period successfully decreased parasite burden. Moreover, this pattern in rural finches was true for males but not females. These experimental results reveal habitat- and sex-specific harmful effects of bird feeder use (i.e. when uncleaned in rural areas). Our study is the first to directly indicate to humans who maintain feeders for granivorous birds that routine cleaning can be critical for ensuring the health and viability of visiting avian species.

Peculiarities of a respiratory mycoplasmosis course of birds

The authors of the article consider an avian disease -the respiratory mycoplasmosis of birds, its etiology, pathogenesis, description of clinical and pathoanatomical and pathohistological features of the course of the disease. In our country, despite the fact that there is a developed system against respiratory mycoplasmosis of birds, based on protection of farms from the introduction of infection from the outside, compliance with veterinary and sanitary rules, zoohygienic and technological standards, as well as measures aimed at timely detection of the disease, the problem of the spread of this disease is quite acute. Currently, the topic of respiratory mycoplasmosis does not lose its relevance precisely because of the high percentage of infection in poultry farms. For example, as a result of research conducted by the ARRIAH over the past 5 years, it was revealed that 218 out of 250 poultry farms in Russia were diagnosed with respiratory mycoplasmosis.

Antibiogram of Escherichia coli Isolated from Avian Colibacillosis in Chitwan District of Nepal

A cross-sectional study was conducted at National Avian Disease Investigation Laboratory, Chitwan to determine antibiogram of Escherichia coli isolated from avian colibacillosis cases of broilers and layers in Chitwan. One hundred and sixty (95 from broilers and 65 from layers) liver samples were collected aseptically during postmortem. Samples were taken purposively from dead birds showing lesions perihepatitis, pericarditis, air-saculitis, omphalitis and egg peritonitis. Isolation and identification were made by examination of cultural characteristics of E. coli in MacConkey’s agar, Eosin methylene blue (EMB) agar, Gram’s staining and biochemical tests. Antibiogram of identified E. coli isolate was evaluated against six antibiotics of six different groups by disk diffusion method following CLSI guidelines. One hundred and three E. coliisolates (73 from broilers and 30 from layers) were isolated from one hundred and sixty samples. Highest resistance was observed against Ampicillin (100%) followed by Co-trimoxazole (86.40%), Doxycycline (46.60%), Levofloxacin (45.63%), Nitrofurantoin (26.21%) and Amikacin (10.68%). Nearly about all (96.12%) isolates from 103 isolated E. coli isolates showed multidrugs resistance to two or more than two antimicrobials. All multidrug resistance isolates showed 16 different patterns with each isolate being resistance to at least two drugs. The multiple antibiotic resistance indexing ranged from 0.2 to 0.8 and proportion of isolates with MAR index greater than 0.2 was 96.12%. Int. J. Appl. Sci. Biotechnol. Vol 8(1): 52-60