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Foot‐and‐mouth disease (FMD) is a highly infectious transboundary disease that is endemic and affects the livelihood of smallholder farmers in Lao People's Democratic Republic (PDR). Knowledge about livestock movement patterns is important for preventing the spread of FMD between villages. This study describes the livestock movement patterns in Champasak, Savannakhet and Xiangkhouang provinces of Lao PDR. Face‐to‐face interviews were conducted with randomly selected villagers (n = 195) and traders (n = 169) in 115 villages between February and March 2019. Livestock owners commonly purchased (mainly breeding) animals from other smallholders (81%) and sold (mainly slaughter) animals to traders (76%) or other smallholders (16%), typically within the same district and province. The median inter‐village trade distance was 20–30 km, with an average frequency of 4 trades per village per month. Traders purchased animals from smallholders (71%) and middlemen (25%) located within their district. It was common for many traders (74%) to retain animals at their property before selling, typically a median of 4 beef cattle per trader. Local trades within the district were far more common (72%) than distant trades. The movements of grazing/fattening large ruminants between villages were reported in 30% of the villages in all three provinces and occurred mostly within the same district or province in short distance (6 km). Social Network Analysis has identified animal movement hubs in the three provinces which could be targeted for FMD control and surveillance. Movements of animals for further use (fattening/ reproduction), long‐distance movements and frequent local movements described in this area have important implications for FMD circulation. The findings from the study will inform FMD spread simulation models for Lao PDR. The knowledge gained from these data will also help the Lao PDR authorities understand the patterns of animal movements associated with disease spread. [ABSTRACT FROM AUTHOR]

To estimate animal-level seroprevalence of Leptospira interrogans serovar Copenhageni and L. borgpetersenii serovars Ballum and Tarassovi, in beef cattle, sheep and deer on New Zealand farms, and herd/flock-level seroprevalence of any serovar when existing same-sera data for serovars Hardjobovis and Pomona were included, and to determine associations between risk factors and animal-level seroprevalence. Banked sera from sheep (n = 82), beef (n = 54) and deer (n = 62) herds/flocks (n = 3,878 animals) from seven regions were analysed using the microscopic agglutination test. Titres of ≥48 were designated positive. Herds/flocks were considered positive if either ≥1, ≥2 or ≥3 animals were positive. Existing same-sera data for serovars Hardjobovis and Pomona were included to establish farm-level any-serovar seropositivity. Factors associated with serological status were analysed using generalised estimating equations. Animal-level seroprevalence for serovars Ballum, Copenhageni, and Tarassovi, respectively, was 13.7 (95% CI = 11.7–16.0)%, 12.6 (95% CI = 10.6–14.7)% and 18.0 (95% CI = 15.7–20.5)% for beef cattle, 10.5 (95% CI = 9.0–12.1)%, 16.7 (95% CI = 14.9–18.6)% and 14.0 (95% CI = 12.4–15.8)% for sheep and 6.6 (95% CI = 5.3–8.2)%, 15.5 (95% CI = 13.5–17.7)% and 3.6 (95% CI = 2.7–4.8)% for deer, respectively. Herd/flock-level seroprevalence for Ballum was 86.6, 52.4 and 39.0% for sheep, 85.2, 52.7 and 33.3% for beef cattle and 50.8, 27.9 and 21.3% for deer at definitions ≥1, ≥2 and ≥3 seropositive animals per species, respectively. For Copenhageni, corresponding data were 95.1, 73.2 and 56.1% for sheep, 68.5, 48.2 and 29.6% for beef cattle and 73.8, 57.4 and 41.0% for deer, and for Tarassovi, 80.5, 59.7 and 45.1% for sheep, 83.3, 68.5 and 61.1% for beef cattle, and 42.6, 16.4 and 4.9% for deer. Seropositivity to all serovars was observed from all regions, with some differences in seroprevalence observed between species and regions, but not between islands. Combining with Hardjobovis and Pomona data, herd/flock-level seropositivity for all animal species and all five Leptospira serovars was 100% at definition ≥1 animal positive, and 97.5 and 96.3% for sheep flocks, 87.8 and 97.8% for beef cattle herds, and 89.3 and 75% for deer herds at ≥2 and ≥3 animals positive, respectively. Seropositivity to serovars Ballum, Copenhageni and Tarassovi is common in sheep, beef cattle and deer New Zealand and most, or all farms have ≥1 livestock species seropositive to ≥1 serovar. Serovars Ballum, Tarassovi and Copenhageni should be considered when clinical or subclinical signs of leptospirosis are observed in sheep, beef cattle or deer. Livestock sector workers are potentially at risk of exposure. [ABSTRACT FROM AUTHOR]

Aims: To describe temporal trends in bulk milk antibody ELISA and PCR testing for bovine viral diarrhoea (BVD) in New Zealand pastoral dairy herds and to assess the use of historical accession data to predict herd-level BVD incursions. Methods: Data on all diagnostic testing of bulk milk for BVD performed by the Livestock Improvement Corporation (Hamilton, NZ) over eight lactation seasons from 1 June 2010 to 31 May 2018 were analysed. This included anonymised herd identification, geographic location, herd size, sample collection date, sample to positive (S/P) ratio for antibody ELISA results, and cycle threshold values for PCR detecting viral RNA. Multivariable logistic regression was used to explore the relationship between historical accession data and the risk of herds having at least one positive bulk milk PCR test result in the 2017 season. Results: There were 156,034 bulk milk BVD diagnostic testing accessions for 10,495 uniquely identified dairy herds over the 8-season period. The prevalence of tested herds with at least one positive bulk milk PCR test result decreased from 14.6% (407/2,786) in the 2010 season to 5.6% (355/6,309) in the 2017 season with similarly marked declines in S/P ratios. In the 2017 season, 2,961/6,309 (46.9%) herds had S/P ratios greater than the 0.75 cut-off value indicating recent or active BVD virus transmission within the herd while 1,422/6,309 (22.5%) herds were classified as having negative or low S/P ratios. Herds that cleared BVD from the milking herd experienced a mean decline in S/P ratio of 0.11 units per year (min 0.05; max 0.18). In the multivariable analysis, the overall incidence risk of herds experiencing a BVD incursion in the 2017 season was 3.8% (146/3,848) and there were three significant predictors in the final model: herd size, PCR status in the 2014 season, and change in S/P ratio between the 2014 and 2015 seasons. The area under the receiver operating curve for the final model was 0.695 indicating poor discrimination. Conclusions and clinical relevance: The prevalence of dairy herds in New Zealand with positive bulk milk PCR test results and high S/P ratios has decreased over time, suggesting fewer herds are actively infected with BVD and that herd immunity may also be declining. Although monitoring trends in bulk milk test results provides useful information on changes in individual herd status, it is difficult to accurately predict when new incursions will occur and farmers should continue to maintain good biosecurity. [ABSTRACT FROM AUTHOR]