Herd-level prevalence of selected endemic infectious diseases of dairy cows in Great Britain.

To implement appropriate and effective disease control programs at the national level, up-to-date and unbiased information on disease frequency is needed. The aim of this study was to estimate the prevalence of selected endemic infectious diseases in the population of dairy herds in Great Britain. Bulk milk tank (BMT) samples from 225 randomly selected dairy farms, stratified by region and herd size, were tested for antibodies against bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1, Mycobacterium avium ssp. paratuberculosis, Leptospira Hardjo, Salmonella spp., Coxiella burnetii, Fasciola hepatica, Neospora caninum, and Ostertagia ostertagi. Furthermore, the presence of BVDV, C. burnetii, and Chlamydia-like organisms was determined by PCR. The apparent herd prevalence was estimated as a weighted proportion of positive herds. The true prevalence was calculated when a test was used with known test characteristics for the cut-off value used. Among unvaccinated herds, the true prevalence of BMT antibodies against BVDV was estimated at 66% [95% confidence interval (CI): 56-77%], M. avium ssp. paratuberculosis 68% (95% CI: 59-77%), bovine herpesvirus type 1 62% (95% CI: 52-73%), Leptospira Hardjo 47% (95% CI: 34-60%), and Salmonella spp. 48% (95% CI: 39-56%). The apparent prevalence of BMT antibodies against C. burnetii was 80% (95% CI: 75-85%), F. hepatica 55% (95% CI: 48-62%), N. caninum 46% (95% CI: 38-54%), and O. ostertagi 95% (95% CI: 91-98%). The BVDV, C. burnetii, and Chlamydia-like antigens were detected in 5 (95% CI: 2-9%), 29 (95% CI: 21-36%), and 31% (95% CI: 24-38%) of herds, respectively. Our results show that dairy cows across GB are frequently exposed to the studied pathogens, which are endemic at high levels with some geographical variations. These prevalence estimates provide a much-needed basis to assess whether nationwide control programs for the studied pathogens are justified by their potential economic, environmental, and public health implications. Should surveillance and control programs be initiated, the estimates presented here are a baseline against which progress can be assessed.

"Everything in this world has been given to us from cows", a qualitative study on farmers' perceptions of keeping dairy cattle in Senegal and implications for disease control and healthcare delivery.

The dairy industry in Senegal is growing and evolving against a backdrop of rapid urbanisation and increasing consumer demand for dairy products. Consideration of appropriate cattle healthcare delivery and disease control in these evolving farming systems is of paramount importance given the risks posed by zoonotic pathogens and the economic consequences of disease for livestock keepers. Planning and implementation of disease control and healthcare delivery generally follows a top down approach. Often this does not take into account the views and perceptions of the farmers it impacts and who must behave in the expected way for successful outcomes to materialise. In this study, we asked 76 farmers to discuss their experience and opinions of farming milk producing cattle in 11 focus group discussions conducted in two peri-urban areas of Senegal. The objectives were to investigate farmers' perceptions of the current conditions in farming, to understand how these might impact the future direction of this particular system and how this might affect the feasibility and appropriate methods of cattle healthcare delivery and disease control. The data collected were subjected to thematic analysis and four themes were identified; 1. Revered cattle, 2. The changing face of livestock keeping, 3. Powerlessness, 4. Optimism for the future. Farmers in our study had a deep affinity with their cattle, they respected the traditions surrounding cattle keeping at the same time as striving for advances within the system and their animal's productivity. Within strong social groupings and hierarchical structures they recognised the inherent challenges they face but were hopeful and optimistic about growth and opportunity in the future of milk production. A holistic approach to embedding healthcare delivery and disease control within the broader context in which farmers operate may prove successful. This could involve consideration of funding channels for farmers, access to appropriate inputs and utilising the strong community spirit and social norms of farmers to initiate and facilitate change.