Objective—To evaluate the epidemiologic efficacy
and economic efficiency of current and potential
future control programs for paratuberculosis (Johne's
disease) on midsize dairy herds in the United States.
Sample Population—Data on prices and other input
variables collected from various sources were used to
represent a population of midsize US dairy herds
infected with paratuberculosis.
Procedure—The simulation model was modified to
reflect management and production characteristics of
midsize dairy herds in the United States. The model
was validated by use of field data and expert opinion.
Various control strategies then were simulated and
compared on an epidemiologic basis and on the basis
of economic efficiency.
Results—Test-and-cull strategies and vaccination
against paratuberculosis were not able to decrease the
mean prevalence of disease in the United States.
Typically, only vaccination was economically attractive.
Improved management strategies decreased the
prevalence of paratuberculosis considerably and had
high economic benefits.
Conclusions and Clinical Relevance—Analysis of
results of this study suggests that test-and-cull strategies
alone do not reduce the prevalence of paratuberculosis
in cattle and are costly for producers to pursue.
Vaccination did not reduce the prevalence but was
economically attractive. Finally, improved calf-hygiene
strategies were found to be critically important in
every paratuberculosis control program and most
were economically attractive programs for midsize US
dairy farms with the disease. (J Am Vet Med Assoc