High-pathogenicity avian influenza (HPAI) virus, low-pathogenicity avian influenza (LPAI) virus, virulent Newcastle disease virus (vNDV) and low-virulent Newcastle disease virus (lNDV) can be present on the eggshell surface, and HPAI viruses and vNDV can be present in the internal contents of chicken eggs laid by infected hens. With the increase in global trade, egg products could present potential biosecurity problems and affect international trade in liquid and dried egg products. Therefore, the generation of survival curves to determine decimal reduction times (DT -values) and change in heat resistance of the viruses (zD-value) within fat-free egg product could provide valuable information for development of risk reduction strategies. Thermal inactivation studies using A/chicken/Pennsylvania/1370/83 (H5N2) HPAI virus resulted in D55-, D56-, D56.7-, D57-, D58-, and D59-values of 18.6, 8.5, 3.6, 2.5, 0.4, and 0.4 min, respectively. The zD-value was 4.4°C. LPAI virus A/chicken/New York/13142/94 (H7N2) had D55-, D56.7-, D57-, D58-, D59-, and D60-values of 2.9, 1.4, 0.8, 0.7, 0.7, and 0.5 min, respectively, and a z-value of 0.4°C. vNDV avian paramyxoviruses of serotype 1 (AMPV-1)/chicken/California/212676/2002 had D55-, D56-, D56.7-, D57-, D58-, and D59-values of 12.4, 9.3, 6.2, 5, 3.7, and 1.7 min, respectively. The zD-value was 4.7°C. lNDV AMPV-1/chicken/United States/B1/1948 had D55-, D57-, D58-, D59-, D61-, and D63-values of 5.3, 2.2, 1.1, 0.55, 0.19, and 0.17 min, respectively, and a zD-value of 1.0°C. Use of these data in developing egg pasteurization standards for AI and NDV-infected countries should allow safer trade in liquid egg products.
Sero-surveillance and risk factors for avian influenza and Newcastle disease virus in backyard poultry in Oman
