Following the first occurrence of highly pathogenic avian influenza (HPAI) in the human population in 1997, the migratory pathways of wild birds have become a topic of growing interest. By using nuclear technologies — specifically, stable isotope analyses — it is possible to trace the origin of individual birds and to identify their migration patterns during a specific period. Nuclear technologies can also be used for early and rapid diagnosis of avian influenza, to trace the origin of the virus or the avian carrier, and to identify traits related to resistance to the virus. The IAEA is providing support in these areas through regional technical cooperation project RER/5/015, Supporting Early Warning and Surveillance of Avian Influenza Infection in Wild and Domestic Birds and Assessing Genetic Markers for Bird Resistance. On the trail of avian influenza: Using nuclear technologies to support early warning and surveillance counterpart laboratories were matrix gene detection, and H5 and H7 subtype differentiation (as the last two are notifible for the World Organisation for Animal Health – OIE). Additionally, the counterparts were trained to differentiate high pathogenic from low pathogenic subtypes of the AI viruses using translation of the haemaglutinine (HA) genome sequences to amino acid sequences. Resistance trials were conducted in which Mx gene sequences in domestic poultry from different countries were analysed to determine if there are differences between them. The secrets of the Mx gene may contribute to the development of chicken lines resistant to AI. With stable isotope analyses, it is possible to trace the origin of individual birds by measuring the ratio of one or more stable isotopes in the feathers or beaks of migratory birds. This is because diverse geographical regions have different, but relatively constant, stable isotope patterns. The isotopes build up in a bird depending on its food and water intake, and can be measured to give important information on the bird's origin and path of migration. Moreover, as the feathers and beak are constantly growing, sequential measurement can provide information on where the particular bird has been during a certain period. The stable isotopes most frequently used as tracers are 2 13 15 hydrogen ( H), carbon ( C), nitrogen ( N), oxygen 18 34 87 208 ( O), sulphur ( S), strontium ( Sr) and lead ( Pb, 207 206 Pb and Pb). The main goal of the project was to harmonize the diagnostic procedures for both detection and characterization of AI viruses. The methods of detection to implement/reinforce in the counterpart The project aims to: (i) improve the early and rapid diagnosis of avian influenza (AI); (ii) assess genetic markers to identify advantageous traits related to bird resistance using nuclear related, molecular technologies; and (iii) use stable isotope analysis for tracing the migratory movements of waterfowl that might be involved in the spread of AI. Tracking migratory movements Diagnosing avian influenza Identifying virus resistance traits Fellowships and trainings To ensure sustainable improvement in the early and rapid diagnosis of AI, it was essential that each laboratory participating in this technical cooperation project have staff that are adequately trained in the relevant technologies. The project therefore focused on providing individual fellowship training and group training courses. A first coordination and planning meeting took place 26–30 January 2009 in Vienna, during which counterparts defined a detailed work plan for the project. Eighteen participants from 15 countries in Europe and Asia (Albania, Armenia, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Hungary, Kazakhstan, Montenegro, Republic of Moldova, Republic of Serbia, Romania, Russian Federation and The Former Yugoslav Republic of Macedonia) took part. Practical classes during the training courses in the IAEA Laboratory in Seibersdorf.