Circulation of Major Respiratory Pathogens in Backyard Poultry and their Association with Clinical Disease and Biosecurity

Abstract

Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens' reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.

Seroprevalence of major respiratory diseases of chickens in central Ethiopia in different chicken production systems

“…Multiple etiology and complexity are characteristic features of respiratory disease in poultry ( Malik et al, 2004 ; Roussan et al, 2008 ; Mazengia, 2012 ). Among the major pathogens affecting the respiratory tract of chickens worldwide is Newcastle disease virus ( NDV ), infectious laryngotracheitis virus ( ILTV ), infectious bronchitis virus ( IBV ), Mycoplasma gallisepticum ( Mg ), Mycoplasma synoviae ( Ms) , avian metapneumovirus ( aMPV ), avian influenza virus, Pasteurella multocida, Aspergillus fumigatus , and Avibacterium paragallinarum ( Brown Jordan et al, 2018 ; Bhuiyan et al, 2019 ; Batista et al, 2020 ; Swayne, 2020 ).…”

Microbiological assessment at slaughter of chicken carcasses from commercial, backyard and semi-backyard production systems

“…However, the two isolates resistant to the greatest number of drugs were found in carcasses from the semi-backyard system, which does not have a legal definition of production patterns. This type of production specific to some Brazilian geographic regions means that this system does not follow the strict biosafety rules of the industrial system nor the standards defined by law for the backyard system [4,6]. Thus, this scenario may be contributing to the inappropriate use of drugs and the high resistance observed.…”

“…The major concern linked to this scenario is the lack of data on the sanitary condition of backyard chickens (e.g. occurrence of zoonotic diseases, monitoring of asymptomatic carriers of zoonotic microorganisms) and the impact they might have on food safety [6][7][8]. Chicken meat is contaminated by pathogenic and spoilage microorganisms during all stages of the production chain [9][10][11].…”

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

“…Moreover, this study reported that mycoplasmosis control in this region is performed mainly through vaccination and not through biosecurity measures. Batista et al (2020) detected a high seroprevalence for MG, MS, and IBV in backyard chickens raised near commercial farms in the state of Minas Gerais. The presence of these pathogens reinforces that vaccinations protocols should be performed with biosecurity measures to prevent the entry and spread of pathogens in the poultry farms.…”