Bison and elk in the greater Yellowstone area are the last-known reservoir of Brucella abortus in the United States. Diagnosis of brucellosis is challenging as there is no perfect reference test. The objectives of this study were to estimate the accuracy of the fluorescence polarization assay (FPA) ...

Diagnostic test evaluations (DTEs) for chronic infections are challenging because a protracted incubation period has to be considered in the design of the DTE, and the adverse effects of infection may be widespread and progressive over an animal's entire life. Frequently, the specific purpose o...

We developed a stochastic simulation model to compare the herd sensitivity (HSe) of five testing strategies for detection of Mycobacterium avium subsp. paratuberculosis (Map) in Midwestern US dairies. Testing strategies were ELISA serologic testing by two commercial assays (EA and EB), ELISA testing...

OBJECTIVE: To develop a solid-phase enzyme immunoassay (ELISA) for genus-specific immunoglobulin G (IgG) determination with leptospirosis and to evaluate the ELISA in different stages of the disease. METHODS: A total of 1 077 serum samples from 812 patients with suspected leptospirosis were analyzed...

Inactivation of Toxoplasma gondii oocysts occurred with exposure to pulsed and continuous UV radiation, as evidenced by mouse bioassay. Even at doses of ⩾500 mJ/cm2, some oocysts retained their viability.

Toxoplasma gondii is associated with morbidity and mortality in a variety of marine mammals, including fatal meningoencephalitis in the southern sea otter (Enhydra lutris nereis). The source(s) of T. gondii infection and routes of transmission in the marine environment are unknown. We hypothesise th...

The prevalence of equine adenovirus 1 (EAdV1) in the nasopharyngeal sections of healthy neonatal foals and horses was compared with that of hospitalized foals using an EAdV1-specific PCR assay. Nasopharyngeal swabs (NS) were obtained from 15 hospitalized foals, 12 apparently normal foals and their d...

Environmental samples collected from each of 3 locations on 23 large California dairies were cultured to evaluate the utility of this approach for identifying herds infected with Mycobacterium avium ssp. paratuberculosis. Results were compared with concurrent ELISA testing of ≥60 animals in each h...

We reviewed Bayesian approaches for animal-level and herd-level prevalence estimation based on cross-sectional sampling designs and demonstrated fitting of these models using the WinBUGS software. We considered estimation of infection prevalence based on use of a single diagnostic test applied to a ...

We developed a Bayesian approach to sample size calculations for studies designed to estimate disease prevalence that uses a hierarchical model for estimating the proportion of infected clusters (cluster-level prevalence) within a country or region. The clusters may, for instance, be villages within...

In a survey of gynaecological lesions in female zoo felids conducted to determine if the widely used progestin contraceptive melengestrol acetate (MGA) had adverse effects, numerous leiomyomas and leiomyosarcomas were detected. This current study aimed to characterize the morphologic features of the...

Correct classification of the true status of herds is an important component of epidemiologic studies and animal disease-control programs. We review theoretical aspects of herd-level testing through consideration of test performance (herd-level sensitivity, specificity and predictive values), the fa...

Horses admitted to the UC Davis Veterinary Medical Teaching Hospital between 1 July 1992 and 30 June 1994 were studied to determine associations between horse demographics, horse-management factors, and equine C. pseudotuberculosis infection in California. 134 case horses were evaluated, and 800 con...

A 6-page questionnaire was designed to collect information from owners of 134 horses diagnosed with C. pseudotuberculosis infection at the UC Davis Veterinary Medical Teaching Hospital (VMTH) between 1 July 1992 and 30 June 1994 and a further 800 control horses, to evaluate risk factors. The questio...

The effects of different control selection (sampling) techniques on odds ratio (OR) estimates for disease risk factors were analysed in a retrospective case-control study using patient records kept at the School of Veterinary Medicine, University of California, USA. 134 horses with Corynebacterium p...

In order to test if disease is present in a large herd, an investigator will often subject only a small sample of animals to a fallible diagnostic test. The herd is declared positive for disease if the number of test-positive animals is greater than or equal to a previously chosen cut-off value. Suc...

To reduce rehabilitation time and improve survival, a practical, objective test is needed to determine if marine birds are contaminated with oil before they enter captivity. The RaPID Assays and EnviroGard immunoassays for detection of polycyclic aromatic hydrocarbons (PAHs) in soil were evaluated f...

Data bias in microbial risk assessment, specifically in prevalence estimates, attributable to the use of imperfect tests is discussed. Also, the techniques available to risk analysts for the adjustment of test-based estimates to true prevalence estimates are described. Methods for the evaluation of ...

Runt white sturgeon (Acipenser transmontanus) develop during grow-out and are characterized by atrophied muscles and decreased growth. Our first objective was to compare the growth (and body condition) of previously-runt white sturgeon after they recovered from the runt state and sturgeon that had n...

We investigated the effect of raising runt white sturgeon (Acipenser transmontanus) separately from dominant fish during the initial stages of grow-out in a commercial farm. Runt fish are poor-growers, have underdeveloped muscle mass, swim slowly and are more-frequently found at the top of the water...

Important applications of diagnostic tests in non-clinical areas of veterinary medicine include surveillance, monitoring or screening for disease, prevalence estimation, and risk-factor studies. In this review, we address the processing and analysis of diagnostic data with special emphasis on serolo...

In this review, we critically discuss the objectives, methods and limitations of different approaches for the validation of diagnostic tests. We show (based on published data and our own experiences) that estimates for the diagnostic sensitivity and specificity may vary among populations and/or subp...

Reasons for performing study: West Nile virus (WNV) infection is endemic in southern Africa. With the recent emergence of WNV infection of horses in Europe and the USA the present study was performed to estimate the risk of seroconversion to WNV in a cohort of 488 young Thoroughbred (TB) horses. Obj...

We developed log-linear and logistic-modeling approaches to investigate dependence among diagnostic tests. To illustrate the approaches, we used published data for swine toxoplasmosis, bovine paratuberculosis, and swine brucellosis. These diseases were selected because each animal's true diseas...