Lessons from emergence of A/goose/Guangdong/1996-like H5N1 highly pathogenic avian influenza viruses and recent influenza surveillance efforts in southern China

Abstract

Southern China is proposed as an influenza epicentre. At least two of the three pandemics in the last century, including 1957 and 1968 influenza pandemics, originated from this area. In 1996, A/goose/Guangdong/1/1996 (H5N1), the precursor of currently circulating highly pathogenic H5N1 avian influenza viruses (HPAIVs) was identified in farmed geese in southern China. These H5N1 HPAIVs have been spread across Asia, Europe and Africa and poses a continuous threat to both animal and human health. However, how and where this H5N1 HPAIV emerged are not fully understood. In the past decade, many influenza surveillance efforts have been carried out in southern China, and our understanding of the genetic diversity of non-human influenza A viruses in this area has been much better than ever. Here, the historical and first-hand experimental data on A/goose/Guangdong/1/1996(H5N1)-like HPAIVs are reviewed within the context of the findings from recent surveillance efforts on H5N1 HPAIVs and other non-human influenza A viruses. Such a retrospective recapitulation suggests that long-term and systematic surveillance programmes should continue to be implemented in southern China that the wet markets on the animal-human interface shall be the priority area and that the surveillance on the animal species bridging the interface between wildlife and domestic animal populations and the interface between the aquatics and territories shall be the strengthened.

Fig. 1

Geographic map of southern China. Southern China and northern China are narrowly defined by the boundary of the Dayuling-Qitian-ling-Dupangling-Mengzhuling-Yuechengling Mountains line. Southern China includes Guangdong, Guangxi, Hainan, Hong Kong and Macau SAR, Taiwan, and southern parts of Fujian, Jiangxi and Hunan Provinces. The locations of recently emerging influenza A viruses are marked.

Fig. 2

A model for the influenza ecosystem. The major bird species in poultry farms, backyards and wet markets in southern China include chickens, ducks, geese and quails; the major animal species in farms and wet markets in southern China is swine.