Ehrlichioses and anaplasmoses: (re)emerging tickborne zoonoses in humans and in animals.

One cannot but point out that the variety of topics related to zoonoses, and in particular zoonoses transmitted by ticks, is fascinating and ranges from environmental to clinical sciences, also in emergency situations, from veterinary sciences to human epidemiology, in a finely woven network of interactive ecological, social and health factors. Anthropic and cultural factors are correlated to the presence and distribution of zoonoses and, in most cases, become risk factors themselves. The epidemiology of zoonoses is, in fact, closely tied to the socio-economic conditions and the characteristics of the different rural areas, where complex interrelations and close living conditions exist between men and animals and are often unavoidable. In recent years the situation has become even worse, making zoonoses one of the most serious problems of Public Health. The list of zoonoses is extensive and the agents responsible for infection include bacteria, fungi, chlamydiae, rickettsiae, viruses and protozoa, transmitted by faeces, food, animal bites or inoculations by arthropods. The role of arthropods is significant and is in constant expansion. Human activities modify the ecological balance and facilitate an increase in arthropods and, consequently, the spread of pathogens they transmit with their relative pathologies [1-3]. Because of the vast range of hosts among pets and wild animals, it is very difficult to control arthropods and their respective pathologies. The same tick may have different specificities of hosts, the same host may be parasitized by various species of ticks. Mammals, birds, and reptiles can be hosts for ticks, which transmit more pathogens than any other vector and can guarantee the transmission and continuance in nature even by transtadial or transovarial means. In recent years, moreover, the epidemiology of arthropods has changed: new forms of transmission have been described and new pathogens have been isolated [4-8].