Pathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the United States, as well as potential economic losses for resource-poor farmers. Free-roaming backyard chickens are commonly kept in shade-grown coffee plantations, habitats that attract large numbers of wild birds. The husbandry and pathogen prevalence of backyard chicken flocks in San Luis, Costa Rica, were investigated. Based on serologic evidence, Newcastle disease virus, infectious laryngotracheitis virus, infectious bronchitis virus, chicken anemia virus, and infectious bursal disease virus, as well as both Mycoplasma gallisepticum and Mycoplasma synoviae, appear to be significant diseases of this population, and thus, we consider these backyard chickens potential reservoirs for these diseases. There was no evidence of avian influenza. Interviews, clinical examinations, and microscopic examination of tissues led us to believe that poxvirus is also a significant cause of morbidity and mortality in these chickens. We found that Escherichia coli isolates were resistant against tilmicosin, tetracycline, ampicillin, amoxicillin with clavulanic acid, ticarcillin, and cephalothin, and contained genes considered responsible for conferring tetracycline resistance. Additionally, although production was not measured, we suspect that husbandry and lack of preventative medicine are directly related to the diseases reported, all of which negatively affect production.
Abbreviations: AE = avian encephalomyelitis virus; AI = avian influenza; AMRP = antimicrobial resistance profile; APV = avian pneumovirus; CAV = chicken anemia virus; ELISA = enzyme-linked immunosorbent assay; IBD = infectious bursal disease; IBV = avian infectious bronchitis; ILT = infectious laryngotracheitis; MAG = Costa Rican Ministry of Agriculture; MIC = minimum inhibitory concentrations; MG = Mycoplasma gallisepticum; MS = Mycoplasma synoviae; NDV = Newcastle disease virus; PDRC = Population Diagnostic Research Center; PPMV = pigeon paramyxovirus; RT-PCR = real-time polymerase chain reaction; S/N ratio = signal-to-noise ratio; USDA = U.S. Department of Agriculture
Las parvadas de aves de traspatio representan un riesgo de enfermedad para las aves tropicales en Costa Rica.
Los patógenos de las aves de traspatio generan un riesgo de enfermedad para las aves silvestres, algunas de las cuales migran a los Estados Unidos, generando a su vez potenciales pérdidas económicas para granjeros de escasos recursos. Las aves de traspatio criadas a la intemperie son comúnmente mantenidas en plantaciones de café con abundante sombra, un habitat que atrae un gran número de aves silvestres. En San Luis, Costa Rica, se investigó el manejo y la prevalencia de patógenos en aves de traspatio. Basado en evidencia serológica, los virus de la enfermedad de Newcastle, laringotraqueitis infecciosa, bronquitis infecciosa, anemia infecciosa aviar y enfermedad infecciosa de la bolsa, así como el Mycoplasma gallisepticum y el Mycoplasma synoviae, son agentes causantes de enfermedades en esta población y en consecuencia se consideran a estas aves de traspatio como reservorios potenciales de estas enfermedades. No se encontró evidencia de influenza aviar. Entrevistas, exámenes clínicos y evaluaciones microscópicas de tejidos nos llevan a creer que el virus de la viruela aviar es también una causa significativa de morbilidad y mortalidad en estas aves. Se demostró que los aislamientos de Escherichia coli eran resistentes a la tilmicosina, tetraciclina, ampicilina, amoxiciclina y ácido clavulánico, ticarciclina, cefalocina y contenían genes consi
