title: Determination of incidence rates for chronic mastitis using heifer prevalence data.
abstract: Two methods for calculating the incidence rate for staphylococcal mastitis were investigated, using prevalence data among heifers. A method utilizing bacteriologic culture results from prevalence surveys, clinical cases, and fresh heifers was more sensitive in determining incidence rates than was a method utilizing results from serial prevalence surveys only.
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000382:microbiology; D008433:Mathematics; D008892:Milk / Q000382:microbiology; D013210:Staphylococcus / Q000302:isolation & purification