39 LOHMANN TIERZUCHT › MANAGEMENT GUIDE 39 quires a network of diagnostic institutions (which should include private laboratories), preparedness of stamping out methods and safe disposal of carcasses. There is more and more the discussion about the use of vaccines. Until now inactivated vaccines have been prepared, some using the DIVA principle (Differentiate Infected from Vaccinated Animals). More and more other vaccines technologies are developed, like vector vaccines. But until now all these vaccines cannot guarantee in the field a “sterile” immunity, which avoids any multipli- cation and further spread of the virus. Looking for international trade, vaccination is currently not accepted by many trade part- ners. In order to allow further international trade in the presence of NAI cases Chapter 4.3 of the Terrestrial Animal Health Code de- scribes zoning and compartmentalization as a procedure applied by a country in accord- ance with the provisions of this chapter for the definition of subpopulations with a spe- cific health status within its territory for the purposes of disease control and / or interna- tional trade. The term “zoning” (= regionali- zation) refers to a subpopulation of animals which are defined primarily geographically (by natural, artificial or legal boundaries). The term “compartmentalization” refers to a subpopulation of animals which is primarily defined by management and animal hus- bandry practices related to biosecurity. Achieving acceptance of regionalization, but even more with compartmentalization, re- quires a intensive cooperation between the poultry industry and government authorities. GENERAL RECOMMENDATIONS