Social network analysis (SNA) and graph theory have been used widely in sociology, psychology, anthropology, biology and medicine. Social network analysis and graph theory provide a conceptual framework to study contact patterns and to identify units of analysis that are frequently or intensely connected within the network. Social network analysis has been used in human epidemiology as a tool to explore the potential transmission of infectious agents such as HIV, tuberculosis, hepatitis B and syphilis. In preventive veterinary medicine, SNA is an approach that offers benefits for exploring the nature and extent of the contacts between animals or farms, which ultimately leads to a better understanding of the potential risk for disease spread in a susceptible population. Social network analysis, however, has been applied only recently in preventive veterinary medicine, therefore the characteristics of the technique and the potential benefits of its use remain unknown for an important section of the international veterinary medicine community. The objectives of this paper were to review the concepts and theoretical aspects underlying the use of SNA and graph theory, with particular emphasis on their application to the study of infectious diseases of animals. The paper includes a review of recent applications of SNA in preventive veterinary medicine and a discussion of the potential uses and limitations of this methodology for the study of animal diseases.

Emerging infectious diseases (EIDs), especially those with zoonotic potential, are a growing threat to global health, economy, and safety. The influence of global warming and geoclimatic variations on zoonotic disease epidemiology is evident by alterations in the host, vector, and pathogen dynamics and their interactions. The objective of this article is to review the current literature on the observed impacts of climate change on zoonoses and discuss future trends. We evaluated several climate models to assess the projections of various zoonoses driven by the predicted climate variations. Many climate projections revealed potential geographical expansion and the severity of vector-borne, waterborne, foodborne, rodent-borne, and airborne zoonoses. However, there are still some knowledge gaps, and further research needs to be conducted to fully understand the magnitude and consequences of some of these changes. Certainly, by understanding the impact of climate change on zoonosis emergence and distribution, we could better plan for climate mitigation and climate adaptation strategies.

Tuberculosis (TB) caused by Mycobacterium bovis and closely related members of the Mycobacterium tuberculosis complex continues to affect humans and animals worldwide and its control requires vaccination of wildlife reservoir species such as Eurasian wild boar (Sus scrofa). Vaccination efforts for TB control in wildlife have been based primarily on oral live BCG formulations. However, this is the first report of the use of oral inactivated vaccines for controlling TB in wildlife. In this study, four groups of 5 wild boar each were vaccinated with inactivated M. bovis by the oral and intramuscular routes, vaccinated with oral BCG or left unvaccinated as controls. All groups were later challenged with a field strain of M. bovis. The results of the IFN-gamma response, serum antibody levels, M. bovis culture, TB lesion scores, and the expression of C3 and MUT genes were compared between these four groups. The results suggested that vaccination with heat-inactivated M. bovis or BCG protect wild boar from TB. These results also encouraged testing combinations of BCG and inactivated M. bovis to vaccinate wild boar against TB. Vaccine formulations using heat-inactivated M. bovis for TB control in wildlife would have the advantage of being environmentally safe and more stable under field conditions when compared to live BCG vaccines. The antibody response and MUT expression levels can help differentiating between vaccinated and infected wild boar and as correlates of protective response in vaccinated animals. These results suggest that vaccine studies in free-living wild boar are now possible to reveal the full potential of protecting against TB using oral M. bovis inactivated and BCG vaccines.

This is an open-access article.-- et al.This research was funded by EU FP7 grant ANTIGONE (#278976).Peer Reviewe