RESUMO
In Paraguay, whose main economic activity is cattle raising, bovine brucellosis is an endemic disease. Between May 2019 and October 2020, a national prevalence survey was implemented by the Paraguayan Veterinary Services. In the frame of that survey, a cross-sectional study was conducted in the eastern region of Paraguay to identify the risk factors that could be associated with brucellosis-positive farms and to estimate the bovine brucellosis seroprevalence and farmers' awareness about the disease. A questionnaire was administered to farmers to collect data on potential risk factors for bovine brucellosis as well as awareness on the disease. A logistic regression model was used to identify the risk factors associated with a farm brucellosis positive status. Blood samples were collected from 2551 cattle on 133 farms. The overall apparent seroprevalence was 27.8 % (95 % CI: 20.4-36.3 %) at the farm level, and 5.5 % (95 % CI: 4.7-6.5 %) at the animal level. Among 18 potential risk factors, four were associated with a farm brucellosis positive status. Farm size was associated with a higher risk of positive status in medium (20-80 cows) and large farms (>80 cows), compared with small farms (<20 cows). Barn disinfection had a protective effect on the risk of positive status. Conversely, presence of dogs and not incinerating/burying aborted material increased this risk. Even if 89 % of the farmers acknowledged being aware of the bovine brucellosis transmission to humans, only 46% of these farmers declared using protective gloves during calving or when handling abortions. The findings of this study emphasize the importance of implementing biosecurity measures and proper disposal of aborted material to control the disease. Therefore, to control the disease in Paraguay, vaccination campaigns should be accompanied by awareness campaigns addressing good farm management practices to minimize the risk of introduction and maintenance of brucellosis as well as the risk of human infection.
RESUMO
Beef exports represent a substantial part of Paraguay's agricultural sector. Cattle movements involve a high risk due to the possible spread of bovine diseases that can have a significant impact on the country's economy. We analyzed cattle movements from 2014 to 2018 using the networks analysis methodology at the holding and district levels at different temporal scales. We built two types of networks to identify network characteristics that may contribute to the spread of two diseases with different epidemiological characteristics: i) a network including all cattle movements to consider the transmission of a disease of rapid spread like foot and mouth disease, and ii) a network including only cow movements to account for bovine brucellosis, a disease of slow spread that occurs mainly in adult females. Network indicators did not vary substantially among the cattle and cow only networks. The holdings/districts included in the largest strongly connected components were distributed throughout the country. Percolation analysis performed at the holding level showed that a large number of holdings should be removed to make the largest strongly connected component disappear. Higher values of the centrality indicators were found for markets than for farms, indicating that they may play an important role in the spread of an infectious disease. At the holding level (but not at the district level), the networks exhibited characteristics of small-world networks. This property may facilitate the spread of foot and mouth disease in case of re-emergence, or of bovine brucellosis in the country through cattle movements. They should be taken into account when implementing surveillance or control measures for these diseases.