Update on Avian influenza A (H7N9) situation in China (FAO)

Human cases

As of 10th January 2014, 163 human cases of influenza A(H7N9) virus infection were reported to WHO. Of these cases, 50 died.  Fifteen cases have been reported since the first of the year by China and its close neighbours.

Most human A(H7N9) cases have reported contact with poultry or live bird markets. Knowledge about the main virus reservoirs, and the extent and distribution of the virus in animals remains limited.

Because this virus causes only subclinical infections in poultry, it is possible that the virus continues to circulate in China and perhaps in neighbouring countries without being detected. As such, reports of additional human cases and infections in animals would not be unexpected, especially with onset of winter in the Northern Hemisphere and as poultry production and movement increase in the region in anticipation of the Chinese New Year Holidays.

Although five small family clusters have been reported, evidence does not currently support sustained human-to-human transmission of this virus.

Overall public health risk assessment for avian influenza A(H7N9) virus: Sporadic human cases and small clusters would not be unexpected in previously affected areas of China, and possibly neighbouring countries. The current likelihood of community-level spread of this virus is considered to be low.

Continued vigilance is needed within China and neighbouring areas to detect infections in animals and humans. WHO advises countries to continue surveillance and other preparedness actions, including ensuring appropriate laboratory capacity.

Current technical information related to avian influenza A(H7N9) can be found at: http://www.who.int/influenza/human_animal_interface/influenza_h7n9/en/index.html 

Animal health

The early detection of influenza A(H7N9) is challenged by the absence of clinical signs in poultry infected and very low detection rates (according to official results in China). To date, there is no evidence of wild bird infection with H7N9, although no specific surveillance results have been communicated.

Therefore, the need for country collaboration and communication in animal and human health sectors is critical not only to detect this new virus in time, but also to improve our understanding of H7N9 epidemiology in order to plan for appropriate interventions to stop virus spread.

The Food and Agriculture Organization of the United Nations (FAO) and the United States Agency for International Development (USAID) have joined forces to enhance surveillance and improve preparedness and response capacities in key countries in Asia and beyond. These initiatives were designed to enable at-risk nations to detect incursion of this virus early and reduce the threat posed by H7N9 to human health.

Continuous presence of H7N9 in China and its strong trading links within Asia raises the possibility of the virus being introduced to a number of surrounding countries, most of which are members of either the Association of the Southeast Asian Nations (ASEAN) or the South Asian Association for Regional Cooperation (SAARC).

In response, FAO recently launched two projects to step up H7N9 surveillance programmes in these regions and improve capacities to detect, control and respond to the virus in poultry and animal populations should it spread. FAO is supporting all ASEAN and SAARC nations with preparedness guidance, while targeting specific assistance to priority countries sharing borders or trade routes with China: Bangladesh, Bhutan, Lao People’s Democratic Republic, Myanmar, Nepal and Viet Nam.

FAO and USAID are also working to help countries prepare for H7N9 in other parts of the world. FAO will soon begin a related project to increase preparedness for and response to H7N9 in Cameroon, Côte d’Ivoire, Democratic Republic of Congo, Egypt, Ethiopia, Ghana, Kenya, Nigeria, Senegal, the United Republic of Tanzania and Zambia. FAO selected the beneficiary countries based on their trade linkages with China, their history of past incursions of H5N1 and their relative poultry density. The project will focus on raising awareness and providing training to improve preparedness in the face of this new virus as well animal disease threats in general. Specifically, FAO will provide immediate resources to help assess the risks of H7N9 incursion, enhance biosecurity, strengthen laboratory and risk communication capacities and update avian influenza contingency plans.

For more information check FAO website: http://www.fao.org/ag/againfo/programmes/en/empres/H7N9/index.html