H7N9 situation update
22 March 2017, 17:00 hours; Rome
The next update will be issued on 29 March 2017
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.
Situation: Influenza A(H7N9) virus with pandemic potential.
Country: China; three human cases originated in China and were reported in Malaysia (1) and Canada (2).
Number of human cases: 1349 confirmed; 497 deaths (since February 2013)
Provinces/municipalities: Beijing, Chongqing, Shanghai and Tianjin municipalities; Anhui, Fujian, Guangdong, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Qinghai, Shandong, Sichuan, Taiwan, Yunnan and Zhejiang Provinces of China; Hong Kong SAR; Macao SAR, Guangxi, Ningxia Hui and Xinjiang Uyghur Autonomous Regions; Sabah (Malaysia); British Columbia (Canada).
Animal/environmental findings: around 2,500 virological samplesfrom the environment, chickens, pigeons, ducks and a tree sparrow tested positive; positives mainly from live bird markets, vendors and some commercial or breeding farms.
Highly pathogenic virus findings: Out of the 1292 confirmed human cases, H7N9 virus isolates from three cases (two from Guangdong and one from Taiwan Provinces) were found to be highly pathogenic for chickens. In addition, the H7N9 highly pathogenic avian influenza virus was detected in 16 chicken and 6 environmental samples from Guangdong Province.
Note:The United States Department of Agriculture (USDA) National Veterinary Services Laboratories (NVSL) have confirmed a H7N9 highly pathogenic (Tennessee), and a H7N9 low pathogenic avian influenza virus (Tennessee, Alabama, Kentucky). Sequencing of the genome confirmed that they are of North American wild bird lineage origin. These viruses are thus not the same as the ones currently circulating in China. [reference1, reference 2, reference 3, reference 4, reference 5]
liaise with China and partners, monitor situation, monitor virus evolution, conduct market chain analysis, risk assessment, surveillance guidance and communication.
Map. 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 18 human cases in Anhui (1), Beijing (1), Guangdong (1), Hebei (2), Hunan (1), Hubei (2), Jiangsu (1), Jiangxi (5), Sichuan (2) and Zhejiang (2) Provinces are currently not known, these cases are therefore not shown on the map.
- 16 March: MoA published the results of the national animal H7N9 surveillance for the month of February [reference]:
- Out of a total of 444,950 samples (328,211 serum samples and 116,739 virology samples) collected from 19,181 locations in 27 provinces, 756 serum and 97 virology samples tested positive.
- H7 serologically positive samples were found in eight provinces namely Chongqing, Liaoning, Hubei, Henan, Shandong, Guangdong, Jiangsu, and Hunan; of which 694 positive chicken samples (more than 90%) were from farms or households.
- H7N9 virologically positive samples were found in the following provinces: Guangdong: 28 chicken and 7 environmental samples from 1 household, 21 markets/live bird trading areas; Jiangsu: 17 chicken, 2 duck and 5 environmental samples from 4 households and 8 markets/live bird trading areas; Hubei: 12 chicken and 5 environmental samples from 1 farm and 11 markets; Fujian: 8 chicken samples from 7 markets; and 1 environmental sample from a market; Henan: 1 chicken sample and 3 environmental samples from 1 live bird slaughter shop and 2 live bird trading area; Zhejiang: 1 chicken sample and 3 environmental samples from 4 markets; Liaoning: 1 chicken and 1 environmental sample from 1 market; Chongqing: 1 chicken and 1 environmental sample from 1 farm.
- No positives were found in Beijing; Tianjin; Hebei; Shanxi; Inner Mongolia; Jilin; Heilongjiang; Shanghai; Anhui; Fujian; Jiangxi; Shandong; Guangxi; Sichuan; Guizhou; Shaanxi; Qinghai; Ningxia; Xinjiang.
- 14 March: the 2017 National Animal Disease Surveillance and Epidemiological Surveys Program was released by MoA, covering priority animal diseases [reference]. Annex 1 outlines locations, sample size, tests and responsibilities for influenza surveillance in animals.
- Zhongshan City announced a regular closure plan from 1 April 2017: LBMs will be suspended for three days twice a month (from 1 to 3 and from 15 to 17) between 1 November and 30 April (high season of avian influenza) and once a month (on the 15th) the rest of the year. [reference].
- Zuzhou City: temporary closure of all the LBMs in the entire city from 20 March to 9 April [reference].
- Shantou City: LBMs of the whole city were suspended from 18 to 20 March [reference].
- According to the provincial CDC monitoring results, during the week 10, of the 847 environmental specimens from 69 LBMs in 21 cities, 32 samples tested positive for H7 subtype. The positive rate declined with 3.6% compared to 8.3% last week [reference].
- Yizhou City: due to the report of two human cases and a positive sample collected in a LBM, live bird trade of the entire city are suspended from 17 to 26 March (10 days) [reference].
- Baise City: monthly suspension days of LBMs and live bird shops was set in Napo County on 14 and 15 March [reference].
- Guizhou: in Qiannan Prefecture, LBMs in Sandu County will be temporarily suspended of from 14 to 29 March [reference].
- Hunan: in Changsha City, all LBMs will be temporarily closed from 17 March to 6 April (21 days) [reference].
- Shangrao County: for prevention purposes, the closure of all LBMs, including live bird trading area and white poultry slaughter & sales area in Xinzhou District is extended until 2 April [reference].
- Pingxiang City: for prevention purposes, all LBMs are temporarily closed in the city from 13 to 31 March [reference].
Figure 1. Number of positive virological samples from birds or the environment, by province and origin as of 22 March 2017. Information provided corresponds to both high and low pathogenic H7N9 viruses.
Click to enlarge
- Since the last update (15 March 2017), 29 new human cases have been reported in Guangxi (7), Hunan (5), Guangdong (3), Guizhou (3), Henan (3), Jiangsu (3), Hebei (2), Chongqing (1), Fujian (1), and Jiangxi (1).
Figure 2. Number of officially reported human cases since February 2013 as of 22 March 2017. Information provided corresponds to both high and low pathogenic H7N9 viruses.
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Figure 3. Incidence of officially reported human cases by month, based on onset date as of 22 March 2017. Information provided corresponds to both high and low pathogenic H7N9 viruses.
Click to enlarge - Note: For cases with unknown onset dates from wave 1 (n=7), wave 2 (n=2), wave 3 (n=146), wave 4 (n= 27) and wave 5 (n=434) reporting dates were used instead.
- In addition to the surveillance findings by MoA and MoH, 1,728 virologically positive samples have also been reported in 12 peer-reviewed articles (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12). A total of 71,920 samples have been collected in these studies since April 2013, of which 1,728 (2.4%) were positive for H7N9 (1,215 environmental samples, 501 chickens, 1 goose and 1 tree sparrow).
- An analysis of the number of human infections during the five waves of H7N9 was published: the clinical characteristics and risk factors for human infections do not appear to have changed. The reported human infections during the fifth epidemic, total of 460 as of 24 February 2017, represent a significant increase compared with the first four epidemics, which resulted in 135 (first epidemic), 320 (second), 226 (third), and 119 (fourth epidemic) human infections [reference].
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