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Small ruminant lentiviruses include viruses with diverse genotypes that frequently cross the species barrier between sheep and goats and that display a great genetic variability. These characteristics stress the need to consider the whole host range and to perform local surveillance of the viruses to opt for optimum diagnostic tests, in order to establish control programmes. In the absence of effective vaccines, a comprehensive knowledge of the epidemiology of these infections is of major importance to limit their spread. This article intends to cover these aspects and to summarise information related to characteristics of the viruses, pathogenesis of the infection and description of the various syndromes produced, as well as the diagnostic tools available, the mechanisms involved in transmission of the pathogens and, finally, the control strategies that have been designed until now, with remarks on the drawbacks and the advantages of each one. We conclude that there are many variables influencing the expected cost and benefits of control programs that must be evaluated, in order to put into practice measures that might lead to control of these infections., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Abstract: Small Ruminant Lentivirus is transmitted vertically by ingestion of contaminated milk/colostrum and horizontally by the respiratory route through close contact with infected animals. In order to detect presence of virus in a shed environment, we sampled and tested drinking water, pen air and air exhaled from infected sheep in both commercial flocks and groups of culled sheep. Nucleic acids were extracted and analysed by retrotranscription, Pol PCR amplification and sequencing. Virus sequences were detected in 9% and 11% of samples of water and air, respectively, collected from pens, and in 35% of sheep whose expelled air was tested. Our results are in concordance with previous evidences of air and waterborne transmission of the infection and might have implications for the design of control strategies. [Copyright &y& Elsevier]

Abstract: A compulsory control program to control-eradicate Brucella infections was initiated 1985 in the Basque Country in Northern Spain. The program included both Brucella melitensis infection (ovine/caprine brucellosis), which were later included in a national plan, and Brucella ovis infection (ovine epididymitis), which was promoted by the local animal health authorities. Prevalences of these infections in small ruminant farms at that time were 10% and 60% of flocks, respectively. Since then, the flocks/herds have been tested annually and animals found to be infected by means of the tests employed were slaughtered. At the same time, a voluntary Small Ruminant Lentivirus infection control program also started in some sheep flocks of the region. Currently, prevalences of brucellosis have dropped to 0% for B. melitensis infection and <0.1% for B. ovis. This implies an overall rate reduction of 100% and 99.9%, respectively. The results for Small Ruminant Lentivirus infection have not been so good and only three of the eight flocks into the scheme have reached eradication. Good results have been obtained by local and national animal health authorities and farmers during the past 25 years for brucelosis control. Use of simple serological testing and culling has allowed reduction-eradication of the infection. Once advanced control is reached, an economic balance will be necessary, in order to optimize best use of resources, including allocating them to control other small ruminant problems. [Copyright &y& Elsevier]

Abstract: A single broadly reactive standard ELISA is commonly applied to control small ruminant lentivirus (SRLV) spread, but type specific ELISA strategies are gaining interest in areas with highly prevalent and heterogeneous SRLV infections. Short (15-residue) synthetic peptides (n =60) were designed in this study using deduced amino acid sequence profiles of SRLV circulating in sheep from North Central Spain and SRLV described previously. The corresponding ELISAs and two standard ELISAs were employed to analyze sera from sheep flocks either controlled or infected with different SRLV genotypes. Two outbreaks, showing SRLV-induced arthritis (genotype B2) and encephalitis (genotype A), were represented among the infected flocks. The ELISA results revealed that none of the assays detected all the infected animals in the global population analyzed, the assay performance varying according to the genetic type of the strain circulating in the area and the test antigen. Five of the six highly reactive (57–62%) single peptide ELISAs were further assessed, revealing that the ELISA based on peptide 98M (type A ENV-SU5, consensus from the neurological outbreak) detected positives in the majority of the type-A specific sera tested (Se: 86%; Sp: 98%) and not in the arthritic type B outbreak. ENV-TM ELISAs based on peptides 126M1 (Se: 82%; Sp: 95%) and 126M2 0,65 0.77 (Se: 68%; Sp: 88%) detected preferentially caprine arthritis encephalitis (CAEV, type B) and visna/maedi (VMV, type A) virus infections respectively, which may help to perform a preliminary CAEV vs. VMV-like typing of the flock. The use of particular peptide ELISAs and standard tests individually or combined may be useful in the different areas under study, to determine disease progression, diagnose/type infection and prevent its spread. [Copyright &y& Elsevier]