Mortality and Egg Production Patterns in the United States Prior to HP/LPAI H7N9 Detection.

In March 2017, two commercial broiler breeder operations were confirmed with H7N9 highly pathogenic avian influenza (HPAI), and an additional six commercial broiler breeder operations were found positive with an H7N9 low pathogenicity avian influenza virus (LPAIV) or an H7 LPAIV (N type not identified). To better understand conditions leading up to testing positive for AI, egg production and mortality data for the 6 mo before the outbreak were obtained from five case farms (two HPAIV-infected farms and three LPAIV-infected farms) and two control farms. Both HPAI farms experienced a sudden spike in mortality immediately before testing positive.

Factors Associated with Salmonella Prevalence in U.S. Swine Grower-Finisher Operations, 2012.

Nontyphoidal Salmonella is an important foodborne pathogen with diverse serotypes occurring in animal and human populations. The prevalence of the organism on swine farms has been associated with numerous risk factors, and although there are strong veterinary public health controls for preventing Salmonella from entering food, there remains interest in eradicating or controlling the organism in the preharvest environment. In this study, using data collected via the U.

Factors Associated with Highly Pathogenic Avian Influenza H5N2 Infection on Table-Egg Layer Farms in the Midwestern United States, 2015.

A case-control study was conducted among commercial table-egg layer and pullet operations in Iowa and Nebraska, United States, to investigate potential risk factors for infection with highly pathogenic avian influenza (HPAI) H5N2. A questionnaire was developed and administered to 28 case farms and 31 control farms. Data were collected at the farm and barn levels, enabling two separate analyses to be performed-the first a farm-level comparison of case farms vs.

Factors affecting use of veterinarians by small-scale food animal operations.

Objective: To identify factors associated with use of a veterinarian by small-scale food animal operations.

Design: Cross-sectional descriptive survey.

Sample: 16,000 small-scale farm or ranch operations in all 50 states.

Description of live poultry markets in the United States and factors associated with repeated presence of H5/H7 low-pathogenicity avian influenza virus.

In 2005 the National Animal Health Monitoring System conducted a survey in 183 live poultry markets throughout the United States. The objectives of this study were to describe characteristics of live poultry markets in the United States and to identify potential risk factors for markets to be repeatedly positive for low-pathogenicity avian influenza virus (LPAIV) H5/H7. A questionnaire was administered to market operators that included questions regarding types of birds and other animals in the market, biosecurity, and cleaning and disinfecting practices.

Evaluation of risk factors for the spread of low pathogenicity H7N2 avian influenza virus among commercial poultry farms.

Objective: To identify risk factors associated with the spread of low pathogenicity H7N2 avian influenza (AI) virus among commercial poultry farms in western Virginia during an outbreak in 2002.

Design: Case-control study.

Procedure: Questionnaires were used to collect information about farm characteristics, biosecurity measures, and husbandry practices on 151 infected premises (128 turkey and 23 chicken farms) and 199 noninfected premises (167 turkey and 32 chicken farms).

Salmonella enterica serotype enteritidis in table egg layer house environments and in mice in U.S. layer houses and associated risk factors.

Prevalence was estimated for Salmonella enterica serotype eneritidis (SE) in layer house environments (n = 200 layer houses) and house mice (n = 129 layer houses) in 15 states throughout the United States. Environmental swabs were collected from manure, egg belts, elevators, and walkways. Live-catch rodent traps were placed for 4-7 days.

Case-control study of factors associated with excessive proportions of early fetal losses associated with mare reproductive loss syndrome in central Kentucky during 2001.

Objective: To identify factors associated with excessive proportions of early fetal losses associated with mare reproductive loss syndrome in central Kentucky during 2001.

Design: Case-control study.

Procedure: Questionnaires were used to collect information on farm-, pasture-, and individual animal-level factors purportedly associated with mare reproductive loss syndrome.

Development of a real-time reverse transcriptase PCR assay for type A influenza virus and the avian H5 and H7 hemagglutinin subtypes.

A real-time reverse transcriptase PCR (RRT-PCR) assay based on the avian influenza virus matrix gene was developed for the rapid detection of type A influenza virus. Additionally, H5 and H7 hemagglutinin subtype-specific probe sets were developed based on North American avian influenza virus sequences. The RRT-PCR assay utilizes a one-step RT-PCR protocol and fluorogenic hydrolysis type probes.

Factors Associated with the Presence of Escherichia coli O157 in Feces of Feedlot Cattle.

Fecal samples were collected from pens of cattle in a total of 100 feedlots in 13 states. Fecal samples were cultured for Escherichia coli O157. E.