title: Prevalence and differentiation of diseases in Maryland backyard flocks.
abstract: Several epidemiologic surveillance studies have implicated backyard flocks as a reservoir for poultry diseases; however, much debate still exists over the risk these small flocks pose. To evaluate this concern, the prevalence of Newcastle disease (ND), infectious laryngotracheitis (ILT), Mycoplasma gallisepticum (MG), and Salmonella was determined in 39 Maryland backyard flocks. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds throughout nine counties in Maryland. Through PCR and ELISA analysis, disease prevalence and seroprevalence were determined in flocks, respectively, for the following: ND (0%, 23%); ILT (26%, 77%); MG (3%, 13%); and Salmonella (0%, not done). Vaccine status could not be accurately confirmed. Premise positives were further differentiated and identified by partial nucleotide sequencing. Screening of the 10 ILT premise positives showed that most were live attenuated vaccines: eight matched a tissue culture origin vaccine, one matched a chicken embryo origin (CEO) vaccine, and one was CEO related. The single MG-positive flock, also positive for the CEO-related sequence, was identified as the infectious S6 strain. The prevalence rates for these economically important poultry diseases ranged from none to relatively low, with the vast majority of sampled flocks presenting no clinical signs.
authors.affiliation: Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Madsen
authors.forename: Nickolas G
authors.initials: NG
authors.lastname: Zimmermann
authors.forename: Jennifer
authors.initials: J
authors.lastname: Timmons
authors.forename: Nathaniel L
authors.initials: NL
authors.lastname: Tablante
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002988:Cloaca / Q000382:microbiology / Q000821:virology; D004372:Ducks; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D046094:Galliformes; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000662:veterinary / Q000821:virology; D001352:Herpesvirus 1, Gallid / Q000235:genetics / Q000502:physiology; D008396:Maryland / Q000453:epidemiology; D009175:Mycoplasma Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D045686:Mycoplasma gallisepticum / Q000235:genetics / Q000502:physiology; D009521:Newcastle Disease / Q000453:epidemiology / Q000821:virology; D009522:Newcastle disease virus / Q000235:genetics / Q000502:physiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011200:Poultry; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology*; D015995:Prevalence; D012475:Salmonella / Q000235:genetics / Q000502:physiology; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology; D016036:Seroepidemiologic Studies; D014132:Trachea / Q000382:microbiology / Q000821:virology
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral