Epidemiological characterization and risk factors associated with lentiviral infection of small ruminants at animal fairs in the semiarid Sertão region of Pernambuco, Brazilian semiarid

Abstract

Animal agglomerations at commercial events such as trade fairs represent an important facilitator in infectious disease transmission. Thus, it is crucial to understand the epidemiology of infectious diseases in small ruminants. The objective of this study was to examine lentiviral presence in goats and sheep traded at the animal fair of Tabira city (Sertão region of Pernambuco) and identify possible risk factors associated with infection. We collected serum samples from 233 crossbred goats and 119 crossbred sheep, belonging to 12 breeders, at the Tabira livestock fair from November 2014 to June 2015. An epidemiological questionnaire was used to analyze the risk factors. Agar gel immunodiffusion (AGID) and western blotting (WB) were performed to diagnose small ruminant lentivirus (SRLV) infection. In the AGID test, we used maedi-visna virus (MVV) antigens for sheep and caprine arthritis/encephalitis virus (strain Cork) (CAEV-Co) antigen for goats. The WB analysis used CAEV-Co antigen for both species. Variables from the questionnaire were analyzed with univariate and multivariate statistics. One seropositive goat but no sheep was identified via AGID. According to the WB results, 15/233 goats (6.44%; CI95% = 3.94 -10.35%) and 8/119 sheep (6.72%; CI95% = 3.45 -12.71%) were seropositive, totaling 23/352 reactive animals (6.53%; CI95% = 4.39 -9.61%) from 12 herds. Annual vermifugation of the animals was a significant risk factor (odds ratio = 5.9; CI95% = 1.7-19.8; p = 0.04) for disease in goats, but no variables associated with infection risks were identified in sheep. We concluded that SRLV was present in goats and sheep at the animal fair. Western blots were more sensitive than AGID for SRLV diagnosis. Practices aiming to improve sanitary management may reduce the risk of infection in goats. All studied herds included animals identified as seropositive for SRLV. Therefore, we recommend adopting measures that increase disease diagnosis while intensifying traffic control and surveillance of animal agglomerations.

Prevalence and risk factors associated with Maedi-Visna infection in sheep in the State of Maranhão, Brazil

“…The same was observed between age group and the occurrence of MVV, similar to the findings of Moura Sobrinho et al (2008). In the study by Alves et al (2017), all the sheep male were negative and 6.72% (8/119) sheep female were seropositive. Teixeira et al (2016) observed that 0.5% (1/207) of seropositive sheep were male and 0.8% (10/1288) were female.…”

“…Animal agglomerations represent an important link in the transmission of infectious diseases (Alves et al, 2017). In the absence of effective vaccines, a comprehensive understanding of the epidemiology of this diseare is of great importance to limit their spread.…”

Seroprevalence of caseous lymphadenitis in goats sold in an animal fair in the northeastern semi-arid region of Brazil

“…This raises the possibility of CL transmission through movement and close contact between the infection sources, susceptible vectors, and interferences at the agglomeration site, as well as the traffic between region's goat and sheep breeding farms to the animal fairs. Alves et al (2017) emphasized the epidemiological importance of the Tabira -PE animal fair of the northeastern semi-arid region, since the animals traded in that place originate mainly in the states such as Bahia, Pernambuco, and Paraíba and are moved to several municipalities of these and other states of the northeast region. In this way, this event can act as a facilitator of spread of diseases such as CL, since infected animals can be bought by owners of several regions, becoming disseminators of this disease after being introduced to the healthy herds.…”

Mycoplasma agalactiae in Dairy Goat Flocks Bred in State of Ceará in Association with Caprine Arthritis Encephalitis Virus

“…Além disso, o teste de Western Blot reafirmou ainda mais essa situação, uma vez que foram detectados um maior número de amostras sororeagentes, comprovando assim a maior sensibilidade do WB em relação ao IDGA (Figura 2) [3,24]. Entretanto, o valor evidenciado nesse trabalho de amostras positivas para CAE pelo WB, foi inferior aos 30,6% relatado em outra pesquisa com rebanhos de caprinos cearenses [24], porém superior aos 6,44% registrado no sertão de Pernambuco [2].…”