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ARCHIVE H7N9 situation update

13 February 2018, 15:30 hours; Rome

The next update will be issued on 28 February2018

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; 621 deaths (since February 2013).
New findings in birds / environment since last update (24 January 2018): 0

New human cases since last update (24 January 2018): 1

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 63 human cases in Anhui (2), Beijing (2), Guangdong (1), Guangxi (1), Hebei (3), Hunan (1), Hubei (2), Jiangsu (2), Jiangxi (6), Sichuan (2), Zhejiang (3) and unknown (38) 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 54 poultry or environmental samples (42 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=38) in birds and/or the environment, by province and sampling site as of 13 February 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

Inner Mongolia

0

2

0

0

2

Shaanxi

0

1

0

0

1

Tianjin

0

1

0

0

1

Unknown

0

0

0

1

1

TOTAL

26

10

1

1

38

 

*LBM: live bird market

 

 

 Situation update

Animals

  • 8 February 2018, Hunan Province: Since January 2018, all live bird markets (LBMs) of Loudi City have been sampled every Monday. A total of 3,685 poultry samples have been collected out of which two (2) tested positive for H7. Birds of the same flock were culled and market closure, cleaning, and disinfection were conducted in LBMs where H7-positive birds were found. By the end of March 2018, an extensive monitoring of live poultry and environment in poultry farms of all sizes is expected to be completed. [reference]
  • 4 January 2018, Hunan Province:the Municipal People's Government of Yuanjiang City decided the closure of all live poultry markets and prohibited live bird trade in downtown city areas from 8 to 29 January 2018. [reference].

Animal/environmental findings: Since 4 April 2013 around 2500 virological samples from the environment, chickens, pigeons, ducks and a tree sparrow 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 13 February 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=233; nHPAI=38) collected from birds or the environment, by sampling location, between October 2016 and 13 February 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=269; nHPAI=44) collected from birds or the environment, by sample origin between October 2016 and 13 February 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 (24 January 2018), one human case was reported in Zhongshan City, Guangdong Province.
  • For detailed informationon human cases, please refer to WHO's Disease Outbreak News

Figure 4. Number of officially reported human cases since February 2013 as of 13 February 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 13 February 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.

 

Publications  

  • Liu J., Xu J., Liu L., Wei X., Song Y., Fang B., […], and Cui J. Sudden emergence of human infections with H7N9 avian influenza A virus in Hubei province, central China. Scientific Reports. 2018 Feb 6;8(1):2486. doi: 10.1038/s41598-018-20988-9. [reference]. To understand the sudden emergence of H7N9 in Hubei Province in January 2017, samples were collected from 14 influenza A(H7N9) human cases along with environmental samples from different locations of the province. The study revealed that the newly emerged human H7N9 viruses were all from persons exposed to poultry and shared the same origin as the environmental sampled viruses in the Yangtze River lineage of H7N9. An earlier and distinct importation from Jiangsu province has been observed which may have established a local environmental reservoir.
  • Teng Y., Bi D., Guo X., Hu D., Feng D., Tong Y. Contact reductions from live poultry market closures limit the epidemic of human infections with H7N9 influenza. Journal of Infection. 2018 Feb 2. pii: S0163-4453(18)30023-9. doi: 10.1016/j.jinf.2017.12.015. [reference]. This study evaluated the effects of contact reductions from live poultry market (LPM) closures on the transmission of H7N9 virus during epidemics in Guangdong Province, China. The mathematical model constructed measured the time-dependent contact quantity of the susceptible population to LPMs. The results showed that periodic intervention strategies can greatly reduce the magnitude of outbreaks, and the earlier interventions for policy are implemented, the smaller is the outbreak.
  • Dong Z., Xia Y., Ya X., Chen L., Liu C., Wang R., Shen Q. Epidemiological and genetic characteristics of the fifth avian influenza A(H7N9) wave in Suzhou, China, from October 2016 to April 2017. Virus Genes. 2018 Feb 5. doi: 10.1007/s11262-018-1534-7. [reference]. To characterize the epidemiology and genetics of the H7N9 viruses circulating from October 2016 to April 2017 in Suzhou, China, pharyngeal swab samples were collected from all severe acute respiratory infection (SARI) cases during this period. H7N9 positive samples were subjected to virus isolation and gene sequencing. The epidemiological features of H7N9 patients have not changed and there were no significant mutations in the key sites of the hemagglutinin gene sequence, but two substitutions in the PB2 protein were identified. In the neuraminidase (NA) protein, drug-resistant mutations occurred only in a few strains. The reduction of the N-glycosylation site at position 42 of NA was observed in some strains.

FAO actions:

  • FAO published a risk assessment entitled, “Chinese-Origin H7N9 Highly Pathogenic 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