Rapid risk assessment: Human infections with avian influenza A viruses, China

In its new Rapid Risk Assessment, ECDC summarises the latest information about human infections with avian influenza A viruses in China. It focuses on A(H7N9) and A(H5N1) and includes other avian influenza A viruses recently identified. It assesses the risk to public health in the EU/EEA countries and to EU/EEA citizens. The severe nature of human infections and the persistence of avian influenzas A(H7N9) and A(H5N1) in poultry represents a significant long-term threat to humans, either through zoonotic transmission or potentially through developing pandemic capacity. However, the most likely current scenario for China is that these outbreaks remain zoonotic outbreaks in which the virus is transmitted sporadically to humans in close contact with the animal reservoir, similar to the influenza A(H5N1) situation.   The recent importation of A(H5N1) from China to Canada and A(H7N9) from China to Malaysia in travellers highlights the possibility of travel-related cases being detected also in Europe. This should be prepared for by the EU Member States. However, sporadic cases imported from China would not alter ECDC’s current risk assessment.   The A(H7N9) transmission pattern and the continued and increasing transmission of this novel reassortant avian influenza virus capable of causing severe disease in humans remains a cause for concern due to its pandemic potential. While likely human-to-human transmission of A(H7N9) and A(H5N1) in clusters of reported cases has been documented in a few instances, there is no indication of sustained human-to-human transmission. The detection of other new avian influenza human cases, namely A(H10N8) and A(H6N1) likely reflects enhanced surveillance activities in China and Taiwan.   At present, the most immediate threat to EU citizens is to those living in China or visiting the country. It is advised to avoid live-bird markets and contact with live poultry in China.   This new ECDC rapid risk assessment aims to:   summarise the epidemiological, virological and environmental information about human infections with avian influenza A viruses in China of subtypes H7N9, H5N1, H10N8, and H6N1;  assess the risk to public health in the EU/EEA and to EU/EEA citizens; anticipate development scenarios and provide options for prevention and control in the EU/EEA;