Concepts in Understanding Infectious Disease Dynamics in Populations.

Veterinarians are better prepared to assist producers in disease prevention, control, and eradication when they understand the relationships among the agent, the host, and the environment. Although vaccination may reduce disease prevalence in a herd, test and selective removal remain the most common method of disease control.

Biosecurity Practices for Mycobacterium aviun subspecies paratuberculosis Infection, Salmonellosis, and Bovine Leukemia Virus on Cattle Operations.

Mycobacterium avium subspecies paratuberculosis infection, salmonellosis, and bovine leukosis virus are important dairy and beef cattle diseases from a health perspective. For herds without infection, keeping the disease out through testing of source herds should be prioritized. For herds with infection, control programs should be instituted and followed to reduce the prevalence and ultimately eliminate the disease.

Outdoor access practices in the Canadian dairy industry.

Dairy cows are highly motivated to access pasture and have a partial preference for alternative forms of outdoor access (e.g., deep-bedded outdoor sand or wood-chip packs).

The devil you know and the devil you don't: current status and challenges of bovine tuberculosis eradication in the United States.

Having entered into its second century, the eradication program for bovine tuberculosis (bTB, caused by Mycobacterium bovis) in the United States of America occupies a position both enviable and daunting. Excepting four counties in Michigan comprising only 6109 km (0.06% of US land area) classified as Modified Accredited, as of April 2022 the entire country was considered Accredited Free of bTB by the US Department of Agriculture for cattle and bison.

Improving farm-level antimicrobial stewardship benchmarks by reporting antimicrobial use within the context of both the magnitude of disease pressure and the outcome of therapy.

This manuscript explores a method of benchmarking antimicrobial use within the context of farm level therapeutic incidence (a proxy for disease incidence), and the outcome of that therapy. This is reported both within the same farm over time (2016-2019), as well as evaluated across participating farms. Reporting antimicrobial use in this format addresses multiple primary questions necessary for evaluating on farm antimicrobial stewardship: How much disease is recorded? How much antimicrobial use is recorded? How often are antimicrobials included in therapy for each disease? What is the outcome of therapy? The three primary metrics reported are: therapeutic events per 100 cow years (TE/100CY), antimicrobial regimens per 100 cow years (REG/100CY), and the percent therapeutic success (% Success).

Sympatric Recombination in Zoonotic Cryptosporidium Leads to Emergence of Populations with Modified Host Preference.

Genetic recombination plays a critical role in the emergence of pathogens with phenotypes such as drug resistance, virulence, and host adaptation. Here, we tested the hypothesis that recombination between sympatric ancestral populations leads to the emergence of divergent variants of the zoonotic parasite Cryptosporidium parvum with modified host ranges. Comparative genomic analyses of 101 isolates have identified seven subpopulations isolated by distance.

Manure management strategies are interconnected with complexity across U.S. dairy farms.

Among one of the key challenges in dairy production is the management of manure in a way that is beneficial for agricultural production, with minimal environmental and public health impacts. Manure management systems (MMS)-the entire system of handling, storage, and application of manure-are diverse in countries with developed dairy industries such as the United States, enabled by a number of different technologies. The ways in which dairy farmers manage manure is driven by varying tradeoffs, including economic, social, and environmental; however, existing research has not examined the relationships between components of MMS.

Enhanced detection of Giardia duodenalis mixed assemblage infections in pre-weaned dairy calves using next generation sequencing.

Giardia duodenalis is one of the most common parasitic causes of gastrointestinal illness in humans worldwide with widespread infections in mammalian hosts. It frequently infects cattle, producing a high number of cysts. Cattle can harbor both host-adapted assemblage E and human pathogenic assemblages A and B.

Outbreak of Multidrug-Resistant Heidelberg Infections Linked to Dairy Calf Exposure, United States, 2015-2018.

In August 2016, the Wisconsin Department of Health Services notified the U.S. Centers for Disease Control and Prevention of multidrug-resistant (MDR) serovar Heidelberg infections in people who reported contact with dairy calves.

The National Animal Health Monitoring System's perspective on respiratory disease in dairy cattle.

In 1991, USDA's National Animal Health Monitoring System (NAHMS) conducted its first dairy study, a baseline assessment that focused on the health and management of heifer calves. During the study, producers ranked respiratory disease among the top two most common health problems affecting dairy calves. Over the last 25 years, U.

Colostrum Management for Dairy Calves.

Colostrum management is the single most important management factor in determining calf health and survival. Additional benefits of good colostrum management include improved rate of gain and future productivity. Successful colostrum management requires producers to provide calves with a sufficient volume of clean, high-quality colostrum within the first few hours of life.

Zoonotic and genetically diverse subtypes of Blastocystis in US pre-weaned dairy heifer calves.

Blastocystis is an emerging zoonotic pathogen with global distribution. However, limited data exist on the prevalence and genetic diversity of Blastocystis in the USA and in food animals. We conducted the first large-scale molecular investigation of Blastocystis in the USA by testing 2539 fecal samples from dairy heifer calves from 13 states.

Genetic diversity and virulence profiles of Listeria monocytogenes recovered from bulk tank milk, milk filters, and milking equipment from dairies in the United States (2002 to 2014).

Unpasteurized dairy products are known to occasionally harbor Listeria monocytogenes and have been implicated in recent listeriosis outbreaks and numerous sporadic cases of listeriosis. However, the diversity and virulence profiles of L. monocytogenes isolates recovered from these products have not been fully described.

A comparison of a novel time-based summary measure of dairy cow health against cumulative disease frequency.

Background: There is an increasing push for dairy production to be scientifically grounded and ethically responsible in the oversight of animal health and well-being. Addressing underlying challenges affecting the quality and length of productive life necessitates novel assessment and accountability metrics. Human medical epidemiologists developed the Disability-Adjusted Life Year metric as a summary measure of health addressing the complementary nature of disease and death.

Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study.

The dairy farm environment is a well-documented reservoir for zoonotic pathogens such as Salmonella enterica, Shiga-toxigenic Escherichia coli, and Listeria monocytogenes, and humans may be exposed to these pathogens via consumption of unpasteurized milk and dairy products. As part of the National Animal Health Monitoring System Dairy 2014 study, bulk tank milk (BTM, n = 234) and milk filters (n = 254) were collected from a total of 234 dairy operations in 17 major dairy states and analyzed for the presence of these pathogens. The invA gene was detected in samples from 18.

Dairy cow disability weights.

Over the past 175 years, data related to human disease and death have progressed to a summary measure of population health, the Disability-Adjusted Life Year (DALY). As dairies have intensified there has been no equivalent measure of the impact of disease on the productive life and well-being of animals. The development of a disease-adjusted metric requires a consistent set of disability weights that reflect the relative severity of important diseases.

Prevalence, antimicrobial resistance, and molecular characterization of Campylobacter spp. in bulk tank milk and milk filters from US dairies.

Campylobacter spp. are frequently isolated from dairy cows as commensal organisms. Sporadic Campylobacter infections in humans in the United States are generally attributed to poultry, but outbreaks are also commonly associated with dairy products, particularly unpasteurized or raw milk.

The National Mastitis Council: A Global Organization for Mastitis Control and Milk Quality, 50 Years and Beyond.

The National Mastitis Council was founded in 1961 based on the desire of a forward-thinking group of individuals to bring together "all forces of organized agriculture in the United States to combat, through every practical device, the mastitis threat to the Nation's health and food safety". What started as a small organization focused on mastitis of dairy cattle in the United States has grown into a global organization for mastitis and milk quality. Over the last 50-plus years the concerted efforts of the membership have led to the synthesis and dissemination of a considerable body of knowledge regarding udder health, milk quality, and food safety which has improved dairy cattle health and well-being and farm productivity.

Summary of BRD data from the 2011 NAHMS feedlot and dairy heifer studies.

The USDA:APHIS National Animal Health Monitoring System collects data on health and health management in livestock and poultry populations throughout the USA in order to provide stakeholders with population estimates to use as benchmarks for comparison, to guide policy development, and to identify research needs and prioritize education efforts. Recent studies of both the beef cattle feedlot industry and dairy heifer rearing operations provided information about BRD occurrence as well as information about prevention and treatment practices used on these operations. While a great deal of effort is dedicated to BRD prevention, there are still opportunities to improve the strategies used.

The impact of movements and animal density on continental scale cattle disease outbreaks in the United States.

Globalization has increased the potential for the introduction and spread of novel pathogens over large spatial scales necessitating continental-scale disease models to guide emergency preparedness. Livestock disease spread models, such as those for the 2001 foot-and-mouth disease (FMD) epidemic in the United Kingdom, represent some of the best case studies of large-scale disease spread. However, generalization of these models to explore disease outcomes in other systems, such as the United States's cattle industry, has been hampered by differences in system size and complexity and the absence of suitable livestock movement data.

A national-scale picture of U.S. cattle movements obtained from Interstate Certificate of Veterinary Inspection data.

We present the first comprehensive description of how shipments of cattle connect the geographic extent and production diversity of the United States cattle industry. We built a network of cattle movement from a state-stratified 10% systematic sample of calendar year 2009 Interstate Certificates of Veterinary Inspection (ICVI) data. ICVIs are required to certify the apparent health of cattle moving across state borders and allow us to examine cattle movements at the county scale.

Farm-level associations with the shedding of Salmonella and antimicrobial-resistant Salmonella in U.S. dairy cattle.

Salmonella enterica is the leading cause of foodborne-related deaths and hospitalizations within the United States. Infections caused by antimicrobial-resistant (AMR) strains are associated with higher hospital costs and case fatality. The objective for this study was to determine the association of management practices with the recovery of Salmonella and AMR Salmonella on dairy herds.

Epidemiology and economics of paratuberculosis.

Johne’s disease is the clinical manifestation of Mycobacterium avium subsp. paratuberculosis (MAP) infection and has become widespread since it was first observed in the United States in the early 1900s. MAP is primarily spread through the fecal-oral route, and herds generally become infected by unknowingly purchasing infected animals.