Friday, March 17, 2017

FAO: Reinforcing Control Efforts Against H7N9 In China

FAO March 15th H7N9 Update


In a winter where we've seen unprecedented outbreaks of H5N8 across much of Europe, H5N8's first incursions into the Middle East and Central Africa, the emergence of at least two new HPAI subtypes (H5N5 and H5N6) in Europe, the jump of HPAI H5N6 from China to South Korea, Japan, and Taiwan, and the emergence of a new (non-Asian lineage) HPAI H7N9 in the Southern United States - you'd think all that would be pretty hard to top.

But as worrying as these developments are, they pale when compared to the 500+ human H7N9 cases reported by Mainland China since October, and the recent evolutionary changes in the virus which creates not only a new antigenically distinct (Yangtze River Delta) Lineage - which likely makes existing vaccines ineffective - but a highly pathogenic (HPAI) strain as well. 

Adding to these concerns are the delayed and fragmented reporting of cases from Mainland China, along with reports (see WHO Virtual Press Conference On H7N9) that China has not allowed the physical export of any H7N9 virus isolates to outside labs since 2013.
Sequences have been deposited at GISAID, but the actual viruses have not been shared.  Something which is considered vital under the WHO's Pandemic Influenza Preparedness (PIP) Framework, which was adopted and approved by all member nations in 2011.
This Fog Of Bird Flu is far from limited to just China, but right now H7N9 is viewed by the CDC (and others) as having the greatest pandemic potential (see CDC Updated Risk Assessment On China's H7N9 Virus) of all the novel flu viruses currently on our radar.

This morning's announcement of six new cases in Guangxi Province - which borders Vietnam - reinforces concerns, as Vietnam is viewed as at high risk of seeing the virus enter via chickens smuggled across their porous border with China (see Vietnam Girds Against H7N9).

All of which serves as preface to a long article published today by the FAO, one which emphasizes the need for better control efforts on, and a better understanding of, the H7N9 virus in China. 

Due to its length I've only included some excepts.  Follow the link to read it in its entirety. You'll find the FAO's latest update on H7N9 at this link.

Reinforcing control efforts amid outbreak of avian influenza in China
Surveillance, laboratory testing, clean markets are all part of effort to contain changing H7N9 virus

17 March 2017, Rome/Paris--A resurgent outbreak of a new strain of avian influenza that can be lethal for humans underscores the need for robust and rapid detection and response systems at animal source. This would reduce the risk associated with virus spread and impacts on public health, according to Food and Agriculture Organization and the World Organisation for Animal Health.

Human cases of the H7N9 virus, first detected in China four years ago, have suddenly increased since December 2016. It is estimated, that as of early March 2017, there have been more reported human cases of influenza A (H7N9) than those caused by other types of avian influenza viruses (H5N1, H5N6, etc.) combined.
As during previous waves, most of the patients infected reported a history of visiting live bird markets or coming into contact with infected birds. Since 2013, China has invested heavily in surveillance of live bird markets and poultry farms. However the surveillance of this virus has proven particularly challenging as until recently it has shown no or few signs of disease in chickens.

"Considering the potential for mutation of avian influenza virus, constant surveillance by national Veterinary Services of the different strains circulating in animals in their country is essential to protect both animal and human health", explains Matthew Stone, Deputy Director General of the OIE.
"To protect human health and people's livelihoods, it is essential to tackle the disease at its source in poultry: efforts need to target eliminating H7N9 from affected farms and markets," said Vincent Martin, FAO's Representative in China.
"Targeted surveillance to detect the disease and clean infected farms and live bird markets, intervening at critical points along the poultry value chain - from farm to table - is required. There should be incentives for everybody involved in poultry production and marketing to enforce disease control."

Emergence of a high-pathogenicity strain

Until recently, H7N9 has demonstrated low pathogenicity, meaning it may cause mild or no illnesses in poultry.

New evidence from China's Guangdong Province now indicates that H7N9, while retaining its capacity to also cause severe disease in humans, has shifted to high pathogenicity in poultry, a genetic change that can lead to high mortality for birds within 48 hours of infection. That may potentially make it easier to see when chickens are infected, facilitate introduction of control measures also at the farm level, but also raises the risk of severe animal and economic losses for those engaged in poultry production and sales.

"China has been quick to notify international organizations about the virus' recent change from low to high pathogenicity in poultry. Given the continuous risk of virus change, inherent to all influenza viruses, timely sharing of surveillance results and sequence information with the international community is crucial for pandemic preparedness," said Stone.

The need for ongoing targeted and widespread monitoring and effective response to detections remains urgent to keep the virus from spreading beyond China's Eastern and Southeastern regions, where it is now considered endemic. This strain of H7N9 virus has so far not been notified in poultry populations outside of China despite intensified surveillance in neighbouring countries and those at risk.
Neighbouring countries remain at high risk, and all those that have poultry trade connections - either formal or informal - to China. A further concern is the possibility that changes seen in the H7N9 virus may affect wild bird population, posing risks to their health or turn them into migratory carriers of the virus, expanding the risk of the virus spreading further as has been seen with other avian influenza strains in faraway Europe, Africa or the Americas.
FAO and OIE emphasize the importance of making all information from ongoing and intensified surveillance activities in China available in a timely way. Such data are essential to the coordinated global effort to understand avian influenza in all its types, as well as to gauge H7N9's potential to spread along different poultry value chains or through wild bird movement. The two international organisations urge countries in the region to be vigilant for a potential incursion of the virus, in its low or highly pathogenic form, and are calling for urgent investment in surveillance and laboratory detection to safeguard trade, including across borders.
          (Continue. . . )

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