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ARCHIVE H7N9 situation update

27 June 2018, 17:00 hours; Rome

The next update will be issued on 25 July 2018

Disclaimer

Information provided herein is current as of the date of issue. Information added or changed since the last H7N9 situation update appears in red. Human cases are depicted in the geographic location of their report. For some cases, exposure may have occurred in one geographic location but reported in another. For cases with unknown onset date, reporting date was used instead. FAO compiles information drawn from multiple national (Ministries of Agriculture or Livestock, Ministries of Health, Provincial Government websites; Centers for Disease Prevention and Control [CDC]) and international sources (World Health Organization [WHO], World Organisation for Animal Health [OIE]) as well as peer-reviewed scientific articles. FAO makes every effort to ensure, but does not guarantee, accuracy, completeness or authenticity of the information. The designation employed and the presentation of material on the map do not imply the expression of any opinion whatsoever on the part of FAO concerning the legal or constitutional status of any country, territory or sea area, or concerning the delimitation of frontiers.

 

 Overview

Hazard: Influenza A(H7N9) virus with pandemic potential.
Country: China; imported cases in Malaysia (1) and Canada (2).
Number of human cases: 1,625 confirmed; 623 deaths (since February 2013).
New findings in birds / environment since last update (23 May 2018): 1

New human cases since last update (23 May 2018): 0

Map 1. Human cases and positive findings in birds or the environment

Human cases and positive findings in birds or the environment
Click to enlarge - Note: Human cases are depicted in the geographic location where they were reported; for some cases, exposure may have occurred in a different geographic location. Precise location of 20 human cases in Guangdong (1), Guangxi (1), Hebei (3), Hunan (1), Hubei (1), Jiangsu (1), Jiangxi (5), Zhejiang (2) and unknown (5) Provinces are currently not known, these cases are therefore not shown on the map.

 

Provinces/municipalities affected: Beijing, Chongqing, Shanghai and Tianjin Municipalities; Anhui, Fujian, Gansu, Guangdong, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Qinghai, Shaanxi, Shanxi, Shandong, Sichuan, Taiwan, Yunnan and Zhejiang Provinces; Hong Kong SAR, Macao SAR; Guangxi, Inner Mongolia, Ningxia Hui, Tibet and Xinjiang Uyghur Autonomous Regions (China); Sabah (Malaysia); British Columbia (Canada).

Highly pathogenic virus findings: Since 10 January 2017, highly pathogenic avian influenza (HPAI) type H7N9 virus was detected in a total of 58 poultry or environmental samples (46 chickens, 2 duck and 10 environmental samples); H7N9 virus isolates from 32 human cases were found to be HPAI virus.

 

Table. Number of locations testing positive for H7N9 HPAI virus (n=43) in birds and/or the environment, by province and sampling site as of 27 June 2018.

Province

LBM*

Farm

Backyard

Airport

Total

Anhui

0

1

0

0

1

Fujian

1

0

0

0

1

Guangdong

22

0

0

0

22

Guangxi

0

1

0

0

1

Hebei

0

1

0

0

1

Heilongjiang

0

1

0

0

1

Henan

0

1

0

0

1

Hunan

3

1

1

0

5

Liaoning

0

1

0

0

1

Inner Mongolia

0

2

0

0

2

Ningxia Hui

0

2

0

0

2

Shaanxi

0

2

0

0

2

Shanxi

0

1

0

0

1

Tianjin

0

1

0

0

1

Unknown

0

0

0

1

1

TOTAL

26

15

1

1

43

*LBM: live bird market

 

 Situation update

Animals

  • 31 May 2018, Liaoning Province: The outbreak that occurred on 22 May in a layer chicken farm with 17000 birds in Liaozhong District, Shenyang City has been confirmed to be due to H7N9. During the outbreak, 11,000 birds showed clinical signs of which 9,000 died. [reference 1, reference2].

Animal/environmental findings: Since 4 April 2013 around 2500 virological samples from the environment, chickens, pigeons, ducks, turkeys, a tree sparrow and a magpie robin tested positive; positives mainly from live bird markets, vendors and some commercial or breeding farms.

Figure 1. Number of positive virological samples from birds or the environment, by province and origin as of 27 June 2018. Data include both high and low pathogenic H7N9 viruses.

Number of positive virological samples from birds or the environment, by province* and origin
Click to enlarge

Figure 2. Distributions of low* and highly pathogenic H7N9 virologically positive samples (nLPAI=245; nHPAI=43) collected from birds or the environment, by sampling location, between October 2016 and 27 June 2018. Samples from the same location and time are grouped.

Number of positive virological samples from birds or the environment, by province* and origin
Click to enlarge - *may contain unconfirmed HPAI at the time of publishing

Figure 3. Distributions of low* and highly pathogenic H7N9 virologically positive samples (nLPAI=279; nHPAI=49) collected from birds or the environment, by sample origin between October 2016 and 27 June 2018. Samples from the same origin, location and time are grouped. Incidence of officially reported human cases by week, based on onset date
Click to enlarge - *may contain unconfirmed HPAI at the time of publishing

 

Humans

  • Since the last update (23 May 2018), no new human case was reported.
  • For detailed informationon human cases, please refer to WHO report.

Figure 4. Number of officially reported human cases since February 2013 as of 27 June 2018. Data include both high and low pathogenic H7N9 viruses

Incidence of officially reported human cases by week, based on onset date
Click to enlarge

Figure 5. Incidence of officially reported human cases by month, based on onset date from October 2013 (Beginning of wave 2) to 27 June 2018. Both high and low pathogenic H7N9 viruses are included.

Incidence of officially reported human cases by week, based on onset date
Click to enlarge - Note: For cases with unknown onset dates from wave 2 (n=2), wave 3 (n=146), wave 4 (n=27) and wave 5 (n=55), reporting dates were used instead.


For a phylogenetic tree of H7N9 viruses isolated please click here. Acknowledgements:WHO report ‘Antigenic and genetic characteristics of zoonotic influenza viruses and development of candidate vaccine viruses for pandemic preparedness’ – September 2017 [reference].

 

Publications  

  • Xiang, D., Pu, Z., Luo, T., Guo, F., Li, X., Shen, X., […], Shen Y. 2018. Evolutionary dynamics of avian influenza A H7N9 virus across five waves in mainland China, 2013-2017. Journal of Infection, 2018;pii: S0163-4453(18)30158-0. doi: 10.1016/j.jinf.2018.05.006. [reference]. In this study, all available genomes for H7N9 and H9N2 influenza A viruses were evaluated. The publication describes the phylogeographic divergence and nucleotide diversity of H7N9 isolates, throughout the five first waves. The highly pathogenic avian influenza (HPAI) H7N9 viruses in the 5th wave clustered together, and were close to the low pathogenic avian influenza (LPAI) virus isolated from the Pearl River Delta in the 3rd and 4th waves.
  • Lianbin, Z., Shenglan, M., Sujie, Q., Kaichuang, S., Wenjun, L., Yanwen, Y., Jun, L., Guohua, D. 2018. Epidemiological Surveillance on Avian Influenza in Live Poultry Wholesale Markets in Border Areas of Guangxi. China Animal Health Inspection, 2018 v.5. ISSN:1005-944X. doi:10.3969/j.issn.1005-944X.2018.05.001. [reference]. [Article in Chinese]. This study aimed at providing data on the presence of avian influenza viruses in China-Vietnam border areas (Guangxi Province) through a systematic monitoring towards AIV infection in live birds markets between December 2012 and December 2015. In the border areas, the LBMs were seriously affected by AIV, and multiple subtypes of AIV coexisted. Most live poultry markets were not equipped with disinfection and biosafety disposal facilities, and closing-market system was not implemented strictly. The live poultry were mainly from local farms of backyard or largescale breeding, other areas outside of Guangxi and other countries outside of China (by cross-border smuggling).
  • Yuhua, C., Riwen, H., Jiancui, Z., Haibing, Z., Jie, X., Fei, Y., […], & Dan, S. 2018. Risk Factor Survey on Live Poultry Infection with Influenza Virus in Live Poultry Wholesale Markets in Guangzhou City. China Animal Health Inspection, 2018 v5. doi:10.3969/j.issn.1005-944X.2018.05.002. [reference]. (Article in Chinese). The study evaluated the dynamics of avian influenza infection rate and relevant risk factors before and after the live birds entering into the live bird markets in Guangzhou City. The results showed that the average prevalence in two markets before and after the poultry entering into LBMs were 24.24% and 53.79%, respectively. The main risk factors included live chicken, the poultry from other provinces and cleaning and disinfection frequency of less than once per week.

FAO actions:

    A webinar entitled “Pros and cons of avian influenza vaccination” was presented by Leslie Sims on 14 May 2018 with technical support from FAO HQ. A recording of the webinar is available [link].
  • FAO published a risk assessment update entitled, “Chinese-origin H7N9 avian influenza: spread in poultry and human exposure” [reference]
  • FAO guidance and risk assessments are available on a dedicated website [link]
  • Liaise with China and partners, monitor situation, monitor virus evolution, conduct market chain analysis, risk assessment, surveillance guidance and communication.

FAO’s support to countries