title: Longitudinal data collection of Mycobacterium avium subspecies Paratuberculosis infections in dairy herds: the value of precise field data.
abstract: Longitudinal infection data on Mycobacterium avium subspecies paratuberculosis (MAP) was collected on three dairy farms in Northeastern United States during approximately 10 years. Precise data on animal characteristics and animal location within farm were collected on these farms. Cows were followed over time with regard to MAP status during biannual fecal and serum sampling and quarterly serum sampling. Approximately 13 000 serum samples, 6500 fecal samples and 2000 tissue samples were collected during these years. Prevalence of positive samples was 1.4% for serological samples, 2.2% in fecal samples and 16.7% in tissue samples. Infection dynamics of MAP was studied and resulted in a number of potential changes in our understanding of MAP infection dynamics. First, a high prevalence of MAP infection was observed in these herds due to lifetime follow up of cows, including slaughter. Second, two distinctly different infection patterns were observed, so called non-progressors and progressors. Non-progressors were characterized by intermittent and low shedding of MAP bacteria and a virtual absence of a humoral immune response. Progressors were characterized by continuous and progressive shedding and a clearly detectable and progressive humoral immune response. Strain typing of MAP isolates on the three farms identified on two of three farms a dominant strain type, indicating that some strains are more successful in terms of transmission and infection progression. Continuous high quality longitudinal data collection turned out to be an essential tool in our understanding of pathobiology and epidemiology of MAP infections in dairy herds.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, 14853, USA. y.schukken@gdanimalhealth.com.|GD Animal Health, Deventer, the Netherlands. y.schukken@gdanimalhealth.com.
authors.forename: Ynte H
authors.initials: YH
authors.lastname: Schukken
authors.affiliation: New Bolton Center, University of Pennsylvania, Kennett Square, PA, USA. rhw@vet.upenn.edu.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Whitlock
authors.affiliation: Department of Veterinary Sciences, Pennsylvania State University, University Park, State College, PA, 16801, USA. drw12@psu.edu.
authors.forename: Dave
authors.initials: D
authors.lastname: Wolfgang
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, 14853, USA. ytg1@cornell.edu.
authors.forename: Yrjo
authors.initials: Y
authors.lastname: Grohn
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, 14853, USA. ab2368@cornell.edu.
authors.forename: Annabelle
authors.initials: A
authors.lastname: Beaver
authors.affiliation: Agricultural Research Services, USDA, Baltimore, MD, USA. joann.vankessel@ars.usda.gov.
authors.forename: JoAnn
authors.initials: J
authors.lastname: VanKessel
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, 14853, USA. mjz6@cornell.edu.
authors.forename: Mike
authors.initials: M
authors.lastname: Zurakowski
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, 14853, USA. rmm257@gmail.com.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Mitchell
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D003612:Dairying; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000382:microbiology; D005260:Female; D008137:Longitudinal Studies; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D009518:New York / Q000453:epidemiology; D010283:Paratuberculosis / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D010414:Pennsylvania / Q000453:epidemiology; D015995:Prevalence; D014707:Vermont / Q000453:epidemiology