Division 3 Samples must be subjected to laboratory testing by serological methods, when taken for:

complementary surveillance for HPAI in poultry species which generally do not show significant clinical signs of HPAI referred to in Section 5 supplementing virological testing, as appropriate;

detection of clusters of LPAIV infected establishments referred to in Section 6. When for technical reasons or other duly justified reasons sampling for serology is not appropriate, virological testing must be performed.