Objective—To estimate the potential spread of foot-and-mouth disease (FMD) if infected livestock had been exhibited at the 2005 California State Fair.
Animals—Dairy cattle, dairy goats, and pygmy goats exhibited between August 24 and August 28 by 195 exhibitors.
Procedures—2 stochastic models were used to simulate epidemics of FMD that might originate from 1, 3, 5, 7, or 10 index cases at the state fair. Data obtained from state fair exhibitors were used to determine the spatial distribution and types of herds to which livestock visiting the state fair returned.
Results—Mean estimated numbers of latently infected animals on day 5 were 12.3 and 75.9, respectively, when it was assumed that there were 1 and 10 index cases. Regardless of the number of index cases, mean estimated numbers of subclinically infected and clinically infected animals were low throughout the 5-day study period. Mean estimated duration of the resulting epidemic ranged from 111 to 155 days, mean number of infected premises ranged from 33 to 244, and mean probability that at least 1 animal that became infected with FMD would subsequently leave the state ranged from 28% to 96% as the number of index cases increased from 1 to 10, respectively.
Conclusions and Clinical Relevance—Results suggested that following introduction of FMD at the California State Fair, infection would likely go undetected until after animals left the fair and that the subsequent outbreak would spread rapidly.
Objective—To compare seroprevalence of antibodies
against equine arteritis virus (EAV) in horses residing
in the United States with that of imported horses.
Sample Population—Serum samples from 364 horses
on 44 equine operations in California and 226 horses
imported from various countries.
Procedure—Serum samples were collected from
each imported horse and from up to 20 horses on
each operation. For resident horses, the number of
sampled horses on each operation was determined
on the basis of the number of horses on the operation.
Samples were tested for antibodies against EAV
by use of a serum neutralization test.
Results—1.9% of resident horses and 18.6% of
imported horses were seropositive to EAV, including
16.1% of imported stallions.
Conclusions and Clinical Relevance—Results indicate
that the EAV seroprevalence of horses residing
in California is considerably lower than that of imported
horses, including imported stallions. (J Am Vet
Med Assoc 2001;219:946–949)