The survey of H5N1 flu virus in wild birds in 14 Provinces of China from 2004 to 2007.

• Published in: PLoS ONE
• Main Authors: Zheng Kou, Yongdong Li, Zuohua Yin, Shan Guo, Mingli Wang, Xuebin Gao, Peng Li, Lijun Tang, Ping Jiang, Ze Luo, Zhi Xin, Changqing Ding, Yubang He, Zuyi Ren, Peng Cui, Hongfeng Zhao, Zhong Zhang, Shuang Tang, Baoping Yan, Fumin Lei, Tianxian Li
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2009
• Subjects: Medicine; R; Science; Q; Anas acuta
• Online Access: https://doi.org/10.1371/journal.pone.0006926; https://doaj.org/article/9dd79d74975b4fcaa0dbb67924d1281a

BACKGROUND: The highly pathogenic H5N1 avian influenza emerged in the year 1996 in Asia, and has spread to Europe and Africa recently. At present, effective monitoring and data analysis of H5N1 are not sufficient in Chinese mainland. METHODOLOGY/PRINCIPAL FINDINGS: During the period from April of 2004 to August of 2007, we collected 14,472 wild bird samples covering 56 species of 10 orders in 14 provinces of China and monitored the prevalence of flu virus based on RT-PCR specific for H5N1 subtype. The 149 positive samples involved six orders. Anseriformes had the highest prevalence while Passeriformes had the lowest prevalence (2.70% versus 0.36%). Among the 24 positive species, mallard (Anas platyrhynchos) had the highest prevalence (4.37%). A difference of prevalence was found among 14 provinces. Qinghai had a higher prevalence than the other 13 provinces combined (3.88% versus 0.43%). The prevalence in three species in Qinghai province (Pintail (Anas acuta), Mallard (Anas platyrhynchos) and Tufted Duck (Aythya fuligula)) were obviously higher than those in other 13 provinces. The results of sequence analysis indicated that the 17 strains isolated from wild birds were distributed in five clades (2.3.1, 2.2, 2.5, 6, and 7), which suggested that genetic diversity existed among H5N1 viruses isolated from wild birds. The five isolates from Qinghai came from one clade (2.2) and had a short evolutionary distance with the isolates obtained from Qinghai in the year 2005. CONCLUSIONS/SIGNIFICANCE: We have measured the prevalence of H5N1 virus in 56 species of wild birds in 14 provinces of China. Continuous monitoring in the field should be carried out to know whether H5N1 virus can be maintained by wild birds.