Thursday, May 11, 2017

CHINA: HPAI H7N9 Expands Its Range


The full significance and ultimate impact of the recently emerged HPAI (highly pathogenic) strain of H7N9 - first recorded in January of this year - remains unknown.  But any hopes that it might quickly fall by the wayside - unable to compete with more established strains -  are quickly fading as this new strain continues to spread across China.

Last week, China's MOA reported HPAI H7N9 in Hebei Province, a thousand miles north of where it was first reported four months ago.

Ministry of Agriculture to strengthen the deployment of poultry H7N9 influenza prevention and control work

Author: Date: 2017-05-05 17:49 Keywords: H7N9; Ministry of Agriculture; prevention and control

For the current H7N9 influenza prevention and control situation, the Ministry of Agriculture in the preliminary work on the basis of guidance around the animal husbandry and veterinary departments to further improve the prevention and control work. All around the requirements to do a good job monitoring and emergency treatment, the detection of pathogen positive or the outbreak of the farm households poultry, and resolutely culling and harmless treatment, the timely elimination of risks.

It is reported that on April 28, Xingtai County, Xingtai County, Hebei Province, the Department of Veterinary Medicine in the monitoring found a farm breeding chickens suspected bird flu symptoms, the incidence of 8500, 5000 deaths. April 30, Hebei Province, animal disease prevention and control center for the diagnosis of suspected avian influenza epidemic. May 5, by the National Avian Influenza reference laboratory confirmed the outbreak for the H7N9 flu epidemic. After the outbreak, the local according to the relevant plans and control technical requirements, adhere to the law prevention and control, scientific prevention and control, and effectively do the work of the epidemic, has been culling and harmless treatment of 80057 poultry. At present, the epidemic has been effectively controlled.null

Yesterday's updated FAO report on H7N9 in China lists the following outbreaks and/or detections.

Highly pathogenic virus findings: The H7N9 highly pathogenic avian influenza virus was detected in a total of 42 poultry or environmental samples (31 chickens, 1 duck and 10 environmental samples) from 23 live bird markets (LBMs) in: Fujian (Longyan City), Guangdong (Dongguan, Guangzhou, Huizhou, Lufeng, Meijiang, Meizhou, Zhongshan Cities and Haifeng County), Hunan (Chenzhou City) and Provinces; and from 3 farms in: Guangxi (Guilin City), Hebei (a chicken layer farm in Xingtai City [reference 1, reference 2]) and Hunan (backyard in Chenzhou City and a large layer farm in Yongzhou City [reference1, reference2]) Provinces.
Out of the 1486 confirmed human cases, H7N9 virus isolates from three human cases (two from Guangdong and one from Taiwan Provinces) were found to be highly pathogenic for chickens.
FAO actions: liaise with China and partners, monitor situation, monitor virus evolution, conduct market chain analysis, risk assessment, surveillance guidance and communication.

This emerging strain - plausibly being carried north by migratory birds - is a growing concern for Mongolia and Russia (see China's Nervous Neighbors), but is also generating worried headlines to the south in Vietnam.

Yesterday Vietnam's Ministry of Preventive Medicine issued a cautionary report on this HPAI strain (see Detection of low to high virulence of influenza A virus (H7N9) in China 10/05/2017), which - in part - reads:

In the face of the complexity of influenza A (H7N9) in China and the virulent pathogens of the virus, the Ministry of Health assesses the high risk of influenza A virus (H7N9) can penetrate into our country. The Prime Minister, the Ministry of Health, the Ministry of Agriculture and Rural Development has issued official dispatches to focus on preventing the smuggling of poultry and poultry products from the border into Vietnam at the same time.
Strict control, prohibit the transportation, sale and sale of poultry products of unknown origin, unqualified on the market. Surveillance of early disease outbreaks has also been intensified in high risk areas, poultry trading areas, health facilities and at border gates.
The Ministry of Health has updated the professional guidance materials and organized training courses for health workers in border provinces on surveillance, testing and treatment of the outbreak.
The joint exercises between the two sectors of health and agriculture have been implemented in localities, especially in key provinces such as Lang Son, Hanoi, Quang Ninh ... The Ministry of Health also Five working missions have been established to directly inspect the implementation of epidemic control activities in the localities.
         (Continue . . . )

The H7N9 virus - or more accurately, a growing array of H7N9 viruses - continue to evolve and spread in China.  
This year a second LPAI lineage (Yangtze River Delta) has dominated (see MMWR:Increase in Human Infections with Avian Influenza A(H7N9) In China's 5th Wave).

A recent analysis of cases (see Eurosurveillance: Preliminary Epidemiology & Analysis Of Jiangsu's 5th H7N9 Wave) suggests this new lineage may be more virulent, and possibly more `heat tolerant' , and may be able to spread more efficiently during warmer months.

The addition of an HPAI strain to the mix only serves to complicate an already complicated picture. Granted, none of this guarantees that H7N9 will spark the next pandemic, but the CDC's IRAT ( Influenza Risk Assessment Tool) ranks H7N9 as having the highest pandemic potential of 11 novel viruses currently being tracked.
And last month renown virologist Dr. Guan Yi at the University of Hong Kong, in an interview (see NPR: A Pessimistic Guan Yi On H7N9's Evolution),  was quoted as saying  "I think this virus poses the greatest threat to humanity than any other in the past 100 years."
With warmer weather on the doorstep, we may be lucky enough to see a slowdown over the next few months. In the past, June - September has been very slow for H7N9 reports.

But even so - we are only five months away from the start of next fall's  `bird flu season' - when the growing constellation of H5 & H7 avian flu viruses return, and we get to find out what they were up to on their summer vacation.