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The precision of a Porcine reproductive and respiratory syndrome virus (PRRSV) oral fluid antibody enzyme-linked immunosorbent assay (ELISA) was evaluated by calculating reliability coefficients for assay repeatability (within laboratory) and assay reproducibility (between laboratories). Randomly ordered oral fluid samples of known (n = 39) and unknown (n = 224) PRRSV antibody status were tested in 12 diagnostic laboratories. Each laboratory tested the samples twice, first using an antibody ELISA kit and reagents provided to them (phase 1) and then using an ELISA kit and reagents configured in their respective laboratory (phase 2). Repeatability (within laboratory) reliability coefficients calculated using results from samples of known PRRSV antibody status ranged from 0.724 to 0.997 in phase 1 and from 0.953 to 0.998 in phase 2. Reproducibility (between laboratories) reliability coefficients were calculated for 3 conditions: case 1--samples of unknown status (n = 224); case 2--samples of known status (n = 39), and case 3--all samples (n = 263). Among the 3 cases, reliability coefficients ranged from 0.937 to 0.964 in phase 1 and from 0.922 to 0.935 in phase 2. For case 3, it was estimated that 96.67% of the total variation in phase 1 and 93.21% in phase 2 could be attributed to the oral fluid samples themselves. Overall, the PRRSV oral fluid antibody ELISA was highly repeatable and reproducible. The current study supports the routine use of this test in laboratories providing diagnostic service to pig producers.

Japanese encephalitis was recently reported from individuals in the mountain districts of Nepal without travel history to Japanese encephalitis virus (JEV) endemic areas. We performed a cross-sectional study to estimate the seroprevalence of JEV in pigs and subsequently conducted a survey of farmers to identify risk factors associated with seropositivity. In July and August, 2010, 454 pig serum samples were collected and tested by competitive ELISA. Data from a 35-question survey of 109 pig owners were analysed using multivariate logistic regression. Seventy-six (16.7, 95% CI 13.6-20.4) pigs tested positive for anti-JEV antibodies, none of which had been vaccinated against JEV or sourced from JEV endemic areas. Risk factors associated with JEV seropositivity were 'summer abortion', 'wells as a water source', 'urban location', 'reported presence of mosquitoes' and 'lower elevation'. Our results suggest that JEV is likely circulating in the mountain districts of Nepal, and that locally acquired JEV should be considered a risk for residents and travellers in these areas., (© 2012 Blackwell Verlag GmbH.)

The objectives of this cross-sectional study were to estimate the seroprevalence of infectious bovine rhinotracheitis (IBR, BHV-1) and bovine viral diarrhea virus (BVDV) in a population of non-vaccinated, double purpose, dairy and beef herds in the Pacific Region of Central Costa Rica. Blood samples were collected from a total of 496 animals from 35 herds. Sera were tested for antibodies against BHV-1(IBR) and BVDV types 1 and 2 using serum neutralization test. The average number of animals tested in each herd for each of the viruses was 14. Overall individual seroprevalence was 48%, 27%, and 19% for IBR, BVDV type 1, and BVDV type 2, respectively. Median within-herd seroprevalence for IBR, BVDV type 1 and type 2 were 43%, 27%, and 24%, respectively.