众所周知,在不同的国家和地区,以至在一个国家的不同地方,各种动物作为传染源的意义不尽相同。例如,在欧洲南部,地中海沿岸和南美洲等国家是绵、山羊引起的羊种布病流行;在欧洲北部和中部国家多由牛引起的牛种布病流行;在北美的某些国家主要流行猪种布病。在我国北部地区,目 It is well known that the significance of various animals as sources of infection varies from country to country and from place to place in a country. For example, in the southern European countries, the Mediterranean coast and South America are the countries where cotton and goats cause sheep epidemics; the prevalence of bovine brucellosis caused mostly by cattle in northern and central Europe; the prevalence in some countries in North America Pig breeding disease. In our northern region, head