Surveillance for Newcastle Disease Virus, Avian Influenza Virus and Mycoplasma Gallisepticum in Wild Birds Near Commercial Poultry Farms Surrounded by Atlantic Rainforest Remnants, Southeastern Brazil

Abstract

The geographic overlap between areas of Atlantic rainforest and human activities allows interactions to occur between humans and wild and domestic animals. Despite the great importance of the domestic animal-wildlife-human interface that occurs at poultry farms in terms of public health, economic production and wildlife conservation, there are few studies in Brazil examining the distribution and health of wild birds that interact with poultry farms. From January to December 2010, mist nets were used to capture 166 free-ranging birds that were within close proximity to three poultry farms in Atlantic rainforest remnants in southeastern Brazil. The species composition was examined, and molecular methods were used to test for avian influenza virus, Newcastle disease virus, and Mycoplasma gallisepticum. The avian communities near the poultry farms were dominated by three synanthropic species, which corresponded to 70% of all captured individuals: house sparrows Passer domesticus (33%), saffron finches (Sicalis flaveola) (22%), and ruddy ground-doves (Columbina talpacoti) (15%). These predominant bird species were in poor body condition (27%), were infested with feather mites (43%), or presented both conditions (23%). No evidence of infection by avian influenza virus, Newcastle disease virus or M. gallisepticum was identified in any of the studied birds. Although no evidence of the studied pathogens was, our findings demonstrate that differences in the environmental characteristics and biosecurity practices influence the wild bird community near poultry farms, which in turn may affect the health status of these synanthropic birds and strengthen their role in the transmission of pathogens.

Assessment of Potential Health and Genetic Impacts in Releasing ConfiscatedParoaria coronataandSaltator similis

“…Similarly, the higher MG prevalence in seized birds probably reflects the poor hygiene and stressful conditions to which these birds are subjected [59]. Even though MG exposure has been reported for wild birds [71,74,77], the lack of qPCR-based positive samples for MG is in agreement with another Brazilian study that sampled wild birds in poultry farms surrounded by forest remnants [78]. Even though none of the positive individuals in our sample showed any clinical evidence of infection, differential MG-susceptibility across bird species has been observed after experimental infections that resulted in both clinical and subclinical symptoms [79], which also occurred in wild birds [74,77,80].…”

Occurrence of Mycoplasma gallisepticum in wild birds: A systematic review and meta-analysis

“…Many epidemiological aspects of MG infection concerning the pathogen's carriers, contagiousness, and spread in different geographic areas and among different species of birds are not widely understood. The increase in the number of MG reservoirs could disrupt the eradication of the pathogen in poultry, especially in developing countries in which the appropriate survey and eradication programs have not been introduced and biosecurity requirements are not met [47,78]. Knowing the range of potential hosts of MG and mechanisms of infection spread among species is important from the epidemiological point of view, but systematic epidemiological reviews and meta-analyses on the occurrence of MG in wild birds have not been carried out yet.…”

Avian Influenza in Wild Birds from South America: Review, Implications and Perspectives

“…Recent studies have demonstrated that synanthropic species of Passeriformes and Columbiformes may interact directly or indirectly with chickens in poultry farms in South America. 66,67 Although no evidence of AIV infection was detected thus far in such synanthropic birds near poultry facilities, such studies stress the need for the development and implementation of biosecurity measures that effectively prevent wild birds from closely interacting with poultry in farms. 67 Although domestic birds may pose the most significant risk in terms of AIV gene flow from wild birds to humans, the possibility of direct AIV transmission from wild birds to humans should not be dismissed.…”

“…66,67 Although no evidence of AIV infection was detected thus far in such synanthropic birds near poultry facilities, such studies stress the need for the development and implementation of biosecurity measures that effectively prevent wild birds from closely interacting with poultry in farms. 67 Although domestic birds may pose the most significant risk in terms of AIV gene flow from wild birds to humans, the possibility of direct AIV transmission from wild birds to humans should not be dismissed. For instance, traditional communities from some regions of South America may engage in cultural practices that provide opportunities for the transmission of AIV.…”

“…Additionally, valuable insight may be obtained by investigating the occurrence of AIV in wild birds in areas where there might be a closer interaction among humans, domestic and wild birds, such as swine and poultry farms, hunting grounds, and communities where subsistence hunting and domestication of wild birds is common practice. 33,41,43,66,67 Lastly, it is important to underline that the failure of many publications to provide detailed information on the sampling effort has limited a comprehensive meta-analysis of the literature on AIV in wild birds in South America. Although it is understandable that scientific journals need to impose restrictions on article length, authors should bear in mind that supplementary files are a valuable alternative to provide detailed datasets that greatly extends the value and contribution of any given publication.…”