CIDRAP

“According to the Chinese Center for Disease Control and Prevention, about 90 per cent of the patients in the Mainland reported exposure to live poultry, mostly with exposure to live poultry markets (LPMs). There was also an increase in environmental contamination with H7N9 virus as reflected by the positive rate of environmental samples collected from LPMs or other live poultry-related environments in affected provinces,” the spokesman said.”

WHO

Analysis of recent scientific information on avian influenza A(H7N9) virus

10 February 2017

Background

An increase in human infections with avian influenza A(H7N9) virus has been reported by China since October 2016¹. This document presents recent scientific findings on A(H7N9) viruses.

An early, brisk spike in H7N9 avian flu infections in China, which is in its fifth wave of activity, has now reached at least 347 cases, passing the record 319 of infections seen in the second wave during the winter of 2013-14, just months after the first human cases were detected.

Current information

Geographical distribution in animals:

A(H7N9) virus causes little or no illness in poultry and is therefore generally only detected through active virological surveillance. A number of surveillance systems routinely monitor for A(H7N9) activity in animals in China. From December 2016, the Chinese national animal influenza virus surveillance program of the Ministry of Agriculture detected influenza A(H7N9) virus in birds in Anhui, Guangdong and Zhejiang provinces². Based on live poultry market (LPM) surveillance conducted by the Chinese provincial Health and Family Planning Commissions in December 2016, 9.4% of environmental samples were positive for A(H7N9) from LPMs in Guangdong and 15.8% of samples from LPMs in Jiangsu were positive for A(H7), of which most were positive for A(H7N9)^3,4.

The low pathogenicity of the virus in birds adds to the difficulty in identifying its international spread through infected birds. To date, A(H7N9) virus has not been reported in poultry populations outside China. Some countries adjacent to China have intensified their surveillance, and several countries have imposed a temporary ban on importing live birds from China².

Human infections:

Sudden increases in the number of human A(H7N9) cases reported during December and January have been observed in previous years⁵.* Compared to earlier waves of infection, further geographic spread of the virus was observed in this fifth wave⁶. Of the cases where information on exposure history was known, as previous waves, most reported prior exposure to live poultry or potentially contaminated environments, including in LPMs⁶.

Among cases reported in the fifth wave, three clusters were reported, comparable to findings in previous waves^1,6. Limited human-to-human transmission could not be ruled out in these clusters. So far, there has been no indication of significant changes in the epidemiology of the human infections reported, no evidence of sustained human-to-human transmission and no significant changes in the clinical presentation or disease outcome⁶.

Population immunity:

In the general population, three serological surveys using specimens collected in 2011 to 2013 reported zero or very low human population immunity against A(H7) viruses^7-9. Studies of poultry workers with specimens collected in 2011 to 2013 reported between 0 and 7% seropositivity^7,8,10. In 2015-2016, 15,191 serum samples from poultry workers were collected by 31 provincial Centers for Disease Control (CDCs) in Mainland China, and were tested for A(H7N9) antibody in the WHO Collaborating Centre for Reference and Research on Influenza (WHOCC) in Beijing (also as the Chinese National Influenza Center), of which 26 were positive (0.17%).

Disease severity:

In most cases, infection with A(H7N9) virus is characterized by high fever, cough, shortness of breath and rapidly progressing severe pneumonia. Complications include acute respiratory distress syndrome (ARDS), septic shock and multi-organ failure requiring intensive care¹¹. Severe illness and fatal outcome have been more frequently observed in pregnant women¹², in older persons⁶ and those with underlying chronic conditions¹³. Asymptomatic and mild infections with A(H7N9) virus have been detected, but the underlying rate of such infections is not well understood^14,15.

Virology:

The detailed virological surveillance data from the first 4 waves have been published^16,17. For the fifth wave, since 1 October 2016, 83 full genome sequences were analysed: 2 environmental isolates from LPMs in Guangdong and 81 A(H7N9) viruses isolated from specimens collected from human cases by the WHOCC in Beijing. These human specimens were from Jiangsu (N=26), Zhejiang (N=21), Guangdong (N=13), Anhui (N=12), Fujian (N=5) and Hunan (N=4) provinces.

Phylogenetic analysis results show that all the internal genes continue to cluster with previously reported A(H7N9) and A(H9N2) viruses. And the haemagglutinin (HA) and neuraminidase (NA) genes are clustered and evolving in two lineages on the phylogenetic trees; the Yangtze River Delta lineage and the Pearl River Delta lineage (Annex 1 and Annex 2). In general, all of the viruses causing human infections remain similar to viruses analysed since 2013.

Key molecular makers associated with mammalian adaptation and pathogenicity are summarized below and detailed in Annex 3:

• All viruses contained the 177V and 217L/I (H3 numbering 186V and 226L/I) in HA1, similar with the A(H7N9) viruses since 2013.
• All viruses contained the 69-73 deletion in NA, same with the A(H7N9) viruses since 2013.
• Of the 83 viruses, 59 carried 627K in PB2 and 10 carried 701N, and 78 viruses carried I368V in PB1, similar with the A(H7N9) viruses since 2013.

Analyses of these recently isolated viruses from Mainland China as well as Hong Kong Special Administrative Region (SAR) do not show evidence of any changes in known genetic markers of virulence or mammalian adaptation. In comparison to candidate vaccine viruses, amino acid substitutions in the HA of some viruses were identified in antigenic sites. Analysis is underway to determine if existing candidate vaccine viruses remain antigenically correspondent to fifth wave viruses.

Antiviral susceptibility:

Genetic analysis of 83 recent A(H7N9) viruses showed that one virus contained 243T (N2 numbering 246T) and two contained 289K (N2 numbering 292K) mutations in the NA gene, indicating reduced sensitivity to NA inhibitors. All of the other 80 viruses did not contain any of the amino acid substitutions that are known to confer reduced inhibition by the NA inhibitor class of antivirals. Testing of some viruses is underway to assess in vitro susceptibility to the NA inhibitor class of antivirals. As observed for A(H7N9) viruses from previous waves of human infection, all 83 viruses carried the S31N mutation on the M2 protein indicating resistance to amantadine and rimantadine.

Transmission in animal models:

Transmission studies of A(H7N9) viruses from 2013 using ferret models indicate that the virus can transmit efficiently through direct contact but inefficiently through respiratory droplets^18-25. The virus can replicate in swine respiratory tract tissue²⁶, highlighting the need to screen for further mammalian adaptation. Further studies with more recent A(H7N9) viruses are needed to monitor for any changes in transmissibility.

Conclusions

Based on information reported, there is no evidence of sustained human-to-human transmission, and there are no significant changes in A(H7N9) virus properties or the epidemiology of human infections. As long as humans are exposed to infected animals and their environments, further human cases can be expected.

WHO, through its Global Influenza Surveillance and Response System (GISRS), in collaboration with the OIE FAO Network of Experts on Animal Influenza (OFFLU) and national authorities, will continue monitoring the A(H7N9) virus situation.

As traditionally the consumption of poultry among the general population increases during the Chinese New Year celebrations, the movement, trade and slaughter of poultry during this period may subsequently increase human exposure to the A(H7N9) virus⁶. Countries are encouraged to continue strengthening influenza surveillance, including surveillance for severe acute respiratory infections (SARI) and influenza-like illness (ILI), carefully review any unusual epidemiological patterns, immediately alert WHO Global Influenza Programme (GIP) and WHOCCs of GISRS of unsubtypable influenza viruses, ensure reporting under the International Health Regulations (IHR, 2005), and continue national influenza pandemic preparedness actions.

• Annex 1: Phylogenetic tree for haemagglutinin gene
  pdf, 364kb

• Annex 2: Phylogenetic tree for neuraminidase gene
  pdf, 360kb

• Annex 3: Table of molecular markers for mammalian adaptation and pathogenicity of avian influenza A(H7N9) viruses
  pdf, 236kb

*These increases in cases have been referred to as waves. WHO defines these waves as beginning on 1 October until 30 September of the following year. Thus, currently, the increase in human cases is referred to as the fifth wave (1 October 2016 through 30 September 2017).

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• Food and Agriculture Organization. H7N9 situation update 24 January 2017. Available from: www.fao.org/ag/againfo/programmes/en/empres/H7N9/situation_update.html
• Health and Family Planning Commission of Guangdong Province. Available from: www.gdwst.gov.cn/a/zwxw/2017011717051.html
• Jiangsu Provincial Commission of Health and Family Planning. Available from: www.jswst.gov.cn/wsxx/nrglIndex.action?catalogID=4028816b2ba99317012ba99950740003&type=2&messageID=ff80808159433fad015981a71c580427
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• Yang Y, Guo F, Zhao W, Gu Q, Huang M, Cao Q, et al. Novel avian-origin influenza A (H7N9) in critically ill patients in China. Crit Care Med. 2015;43(2):339-45. Available from: DOI: 10.1097/CCM.0000000000000695
• Liu S, Sha J, Yu Z, Hu Y, Chan TC, Wang X, et al. Avian influenza virus in pregnancy. Rev Med Virol. 2016;26(4):268-84. Available from: DOI: 10.1002/rmv.1884
• Liu B, Havers F, Chen E, Yuan Z, Yuan H, Ou J, et al. Risk factors for influenza A(H7N9) disease–China, 2013. Clin Infect Dis. 2014;59(6):787-94. Available from: dx.doi.org/10.1093/cid/ciu423
• Yu H, Wu JT, Cowling BJ, Liao Q, Fang VJ, Zhou S, et al. Effect of closure of live poultry markets on poultry-to-person transmission of avian influenza A H7N9 virus: an ecological study. Lancet. 2014;383(9916):541-8. Available from: dx.doi.org/10.1016/S0140-6736(13)61904-2
• Lin YP, Yang ZF, Liang Y, Li ZT, Bond HS, Chua H, et al. Population seroprevalence of antibody to influenza A(H7N9) virus, Guangzhou, China. BMC Infect Dis. 2016;16(1):632. Available from: dx.doi.org/10.1186/s12879-016-1983-3
• Wang, D., L. Yang, W. Zhu, Y. Zhang, S. Zou, H. Bo, et al. Two Outbreak Sources of Influenza A (H7N9) Viruses Have Been Established in China. J Virol. 2016;90(12): 5561-5573. Available from: dx.doi.org/10.1128/JVI.03173-15
• Xiang N, Li X, Ren R, et al. Assessing Change in Avian Influenza A(H7N9) Virus Infections During the Fourth Epidemic — China, September 2015–August 2016. MMWR Morb Mortal Wkly Rep 2016;65:1390–1394. Available from: dx.doi.org/10.15585/mmwr.mm6549a2
• Belser JA, Gustin KM, Pearce MB, Maines TR, Zeng H, Pappas C, et al. Pathogenesis and transmission of avian influenza A (H7N9) virus in ferrets and mice. Nature. 2013;501(7468):556-9. Available from: dx.doi.org/10.1038/nature12391
• Zhu H, Wang D, Kelvin DJ, Li L, Zheng Z, Yoon SW, et al. Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs. Science. 2013;341(6142):183-6. Available from: dx.doi.org/10.1126/science.1239844
• Zhang Q, Shi J, Deng G, Guo J, Zeng X, He X, et al. H7N9 influenza viruses are transmissible in ferrets by respiratory droplet. Science. 2013;341(6144):410-4. Available from: dx.doi.org/10.1126/science.1240532
• Watanabe T, Kiso M, Fukuyama S, Nakajima N, Imai M, Yamada S, et al. Characterization of H7N9 influenza A viruses isolated from humans. Nature. 2013;501(7468):551-5. Available from: dx.doi.org/10.1038/nature12392
• Luk GS, Leung CY, Sia SF, Choy KT, Zhou J, Ho CC, et al. Transmission of H7N9 Influenza Viruses with a Polymorphism at PB2 Residue 627 in Chickens and Ferrets. J Virol. 2015;89(19):9939-51. Available from: dx.doi.org/10.1128/JVI.01444-15
• Belser JA, Creager HM, Sun X, Gustin KM, Jones T, Shieh WJ, et al. Mammalian Pathogenesis and Transmission of H7N9 Influenza Viruses from Three Waves, 2013-2015. J Virol. 2016;90(9):4647-57. Available from: dx.doi.org/10.1128/JVI.00134-16
• Richard M, Schrauwen EJ, de Graaf M, Bestebroer TM, Spronken MI, van Boheemen S, et al. Limited airborne transmission of H7N9 influenza A virus between ferrets. Nature. 2013;501(7468):560-3. Available from: dx.doi.org/10.1038/nature12476
• Xu L, Bao L, Deng W, Dong L, Zhu H, Chen T, et al. Novel avian-origin human influenza A(H7N9) can be transmitted between ferrets via respiratory droplets. J Infect Dis. 2014;209(4):551-6. Available from: doi.org/10.1093/infdis/jit474
• Jones, JC, Baranovich T, Zaraket H, Guan Y, Shu Y, Webby RJ, and Webster RG. Human H7N9 influenza A viruses replicate in swine respiratory tissue explants. J.Virol. 2013; 87:12496-12498. Available from: dx.doi.org/10.1128%2FJVI.02499-13

Hong Kong

H7N9 Outbreak Characterization

CDC

What is the current situation?

As of January 16, 2017, Chinese health authorities have confirmed 120 new human cases of avian influenza A (H7N9) to the World Health Organization since September 2016. Most of these patients reported exposure to live poultry or poultry markets. A few cases of H7N9 have been reported outside of mainland China but most of these infections have occurred among people who had traveled to mainland China before becoming ill. CDC advises people traveling to China to avoid contact with poultry (including poultry markets and farms), birds, and their droppings and to avoid eating undercooked poultry. Infected birds that appear healthy may still be able to transmit this virus to humans. There are no recommendations against travel to China.

What is avian influenza A (H7N9)?

Avian influenza A (H7N9) is a virus found in birds that does not normally infect humans. However, in the spring of 2013, the first human cases of H7N9 virus infection were reported in China. Since then, 924 laboratory-confirmed cases of human infection with H7N9 virus have been reported, with about one-third of cases resulting in death. Most of these infections have been associated with exposure to infected poultry or contaminated environments (such as poultry markets) in China. In rare cases, limited, non-sustained  person-to-person spread of H7N9 virus likely occurred, but there is no evidence of sustained human-to-human infection. Early symptoms are similar to those of other respiratory viruses, including seasonal flu and may include fever, cough, sore throat, muscle aches and fatigue, loss of appetite, and runny or stuffy nose. However, infection with this virus often causes severe respiratory illness and, in some cases, death (see http://www.cdc.gov/flu/avianflu/h7n9-virus.htm). Risk factors for severe and fatal outcomes include older age and having certain chronic medical conditions.

What can travelers do to protect themselves?

There is no vaccine available to prevent H7N9 virus infection. To protect yourself when visiting China, take the following steps:

• Do not touch birds.
  • Don’t touch birds, whether they are alive or dead.
  • Avoid live bird or poultry markets, including where birds are slaughtered (wet markets).
  • Avoid  places that might be contaminated with bird feces. .
• Eat food that is fully cooked.
  • Eat meat and poultry that is fully cooked (not pink) and served hot.
  • Eat hard-cooked eggs (not runny).
  • As a general precaution, don’t eat or drink dishes that include blood from any animal.
  • As a general precaution, don’t eat food from street vendors.
• Practice hygiene and cleanliness.
  • Wash your hands often.
  • If soap and water aren’t available, clean your hands with hand sanitizer containing at least 60% alcohol.
  • Don’t touch your eyes, nose, or mouth. If you need to touch your face, make sure your hands are clean.
  • Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing.
  • Try to avoid close contact, such as kissing, hugging, or sharing eating utensils or cups with people who are sick.
• If you feel sick after visiting China:
  • Talk to your doctor or nurse if you feel seriously ill, especially if you have a fever, cough, or shortness of breath.
  • Tell your health care provider about your travel to China.
  • For more information about medical care abroad, see Getting Health Care Abroad (https://wwwnc.cdc.gov/travel/page/getting-health-care-abroad)
  • Avoid contact with other people while you are sick.

Clinician information

Clinicians should consider the possibility of avian influenza A (H7N9) virus infection in people presenting with respiratory illness within 10 days of travel to China, particularly if the patient reports exposure to birds or poultry markets. Although most H7N9 cases have resulted in severe respiratory illness, infection may cause mild illness in some people, including both adults and children. Guidance for clinicians who suspect avian influenza A (H7N9) virus infection in a returned traveler from China is available. Clinicians should initiate infection control precautions (airborne, droplet, and contact), obtain appropriate specimens, and notify their local or state health department promptly. State health departments should notify CDC of suspected cases within 24 hours. Empiric treatment with influenza antiviral medications may be warranted while testing is pending.

Note that influenza diagnostic testing in patients with respiratory illness of unknown etiology may identify human cases of avian influenza A virus infection. Patients with H7N9 virus infection are expected to have a positive test result for influenza A virus via reverse-transcription polymerase chain reaction (RT-PCR testing), although most assays will not be able to determine the influenza virus subtype. Use of rapid influenza diagnostic tests are not recommended if H7N9 virus infection is suspected.

Additional information

• Avian Influenza A (H7N9) Virus (CDC)
• Avian Influenza: Information for Health Professionals and Laboratorians

CDC

What is the current situation?

Chinese health authorities have confirmed 120 new human cases of avian influenza A (H7N9) since September 2016, with 37 deaths. Most of these patients reported exposure to live poultry or poultry markets. Infections have been reported in the provinces of Jiangsu, Fujian, and Guangdong, as well as the Macau and Hong Kong Special Administrative Regions.

CDC advises people traveling to China to avoid contact with poultry (including poultry markets and farms), birds, and their droppings and to avoid eating undercooked poultry. There are no recommendations against travel to China.

What is avian influenza A (H7N9)?

Avian influenza A (H7N9) is an influenza (flu) virus found in birds that does not normally infect humans. However, in spring of 2013, China began reporting infections with the virus in people. Most of these infections have been associated with contact with infected poultry or contaminated environments (such as poultry markets) in China. In rare cases, it can be spread from person to person. Early symptoms are similar to those of seasonal flu and may include fever, cough, sore throat, muscle aches and fatigue, loss of appetite, and runny or stuffy nose. However, infection with this virus often causes severe respiratory illness and, in some cases, death (see http://www.cdc.gov/flu/avianflu/h7n9-virus.htm).

What can travelers do to protect themselves?

There is no vaccine to prevent H7N9 flu. To protect yourself when visiting China, take the following steps:

• Do not touch birds, pigs, or other animals.
  • Don’t touch animals, whether they are alive or dead.
  • Avoid live bird or poultry markets.
  • Avoid other markets or farms with animals (wet markets).
• Eat food that is fully cooked.
  • Eat meat and poultry that is fully cooked (not pink) and served hot.
  • Eat hard-cooked eggs (not runny).
  • Don’t eat or drink dishes that include blood from any animal.
  • Don’t eat food from street vendors.
• Practice hygiene and cleanliness.
  • Wash your hands often.
  • If soap and water aren’t available, clean your hands with hand sanitizer containing at least 60% alcohol.
  • Don’t touch your eyes, nose, or mouth. If you need to touch your face, make sure your hands are clean.
  • Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing.
  • Try to avoid close contact, such as kissing, hugging, or sharing eating utensils or cups with people who are sick.
• If you feel sick after visiting China:
  • Talk to your doctor or nurse if you feel seriously ill, especially if you have a fever, cough, or shortness of breath.
  • Tell your health care provider about your travel to China.
  • For more information about medical care abroad, see Getting Health Care Abroad(https://wwwnc.cdc.gov/travel/page/getting-health-care-abroad)
  • Avoid contact with other people while you are sick.

Clinician information

Clinicians should consider the possibility of avian influenza A (H7N9) virus infection in people presenting with respiratory illness within 10 days of travel to China, particularly if the patient reports exposure to birds or poultry markets. Although most H7N9 cases in adults have resulted in severe respiratory illness, infection may cause mild illness in some. Illness also has been reported in children. Influenza diagnostic testing in patients with respiratory illness of unknown etiology may identify human cases of avian influenza A or new cases of variant influenza (such as human infections caused by influenza viruses from pigs) in the United States. Patients with H7N9 infection are expected to have a positive test result for influenza A virus via reverse-transcription polymerase chain reaction (RT-PCR testing) that will be unsubtypeable by most assays. Nonmolecular rapid test results may be variable. Clinicians who suspect avian influenza A (H7N9) should initiate infection control precautions (airborne, droplet, and contact), obtain appropriate specimens and notify their local or state health department promptly. State health departments should notify CDC of suspected cases within 24 hours.

Additional information

• Avian Influenza A (H7N9) Virus (CDC)
• Frequently Asked Questions on human infection with influenza A (H7N9) virus, China (WHO).

Hong Kong

“…Avian influenza A(H7N9)

     The activity of avian influenza A(H7N9) has been increasing markedly since the end of 2016. The Mainland health authorities reported six and 106 human H7N9 cases in November and December 2016 respectively. In the first half of January 2017, 111 cases were detected. The situation this winter has been progressing much faster than the situation last winter.

In the neighbouring Guangdong, 11 human H7N9 cases, with two deaths, were recorded in the first half of this month. The H7-positive percentage of environmental samples from live poultry markets was substantial at 9.42 per cent in the first week of this month. In Hong Kong and Macau, four cases (imported) and two cases were recorded respectively.

“As there is a likely risk that environments with live poultry in the Mainland are contaminated with avian influenza viruses, the public, especially poultry traders and travellers, should be on full alert,” the spokesman said.

“Travellers to the Mainland or other affected areas must avoid visiting wet markets, poultry markets or farms. Stay alert to possible backyard poultry when visiting relatives and friends. Avoid buying live or freshly slaughtered poultry and avoid touching poultry/birds or their droppings,” the spokesman added.

More information and the risk assessment have been reported in the CHP’s latest bi-weekly Communicable Diseases Watch….”

WHO

Human infection with avian influenza A(H7N9) virus – China

On 5 January 2017, the Department of Health, Hong Kong Special Administrative Region (SAR) notified WHO of a case of laboratory-confirmed human infection with avian influenza A(H7N9) virus and on 9 January 2017, the National Health and Family Planning Commission of China (NHFPC) notified WHO of 106 additional laboratory-confirmed cases of human infection with avian influenza A(H7N9) virus.

Details of the cases

On 5 January 2017, a human case of infection with avian influenza A(H7N9) was reported from the Department of Health, Hong Kong Special Administrative Region (SAR). The case is a 62-year-old man with underlying illnesses, who travelled to Zengcheng, Guangzhou on 15 December 2016. He developed influenza-like symptoms on 1 January 2017 while he was in Guangzhou. He was admitted to a hospital in Dongguan on 2 January 2017 and returned to Hong Kong SAR on 3 January 2017, where he was admitted to hospital on 4 January 2017 for further treatment. His condition deteriorated and he was transferred to an intensive care unit for further management. He passed away on 6 January 2017. His samples tested positive for A(H7N9) by RT-PCR on 5 January 2017. The patient reported no recent exposure to poultry or live poultry markets. Contact tracing is underway.

On 9 January 2017, 106 human cases of infection with avian influenza A(H7N9) were reported from the NHFPC. The onset dates ranged from 22 November 2016 to 29 December 2016. Of these 106 cases, 36 are female. The median age is 54 years (age range among the cases is 23 to 91 years old). The cases are reported from Jiangsu (52), Zhejiang (21), Anhui (14), Guangdong (14), Shanghai (2), Fujian (2) and Hunan (1). At the time of notification, there were 35 deaths and 57 severe cases. Eighty of the cases are reported to have had exposure to poultry or a live poultry market.

Two clusters were reported.

First cluster:

• A 66-year-old male from Suzhou city, Jiangsu province. He had symptom onset on 25 November 2016, was admitted to hospital on 28 November 2016 and died on 12 December 2016. He was exposed to a live poultry market.
• A 39-year-old female from Suzhou city, Jiangsu province. She had symptom onset on 8 December 2016 and was admitted to hospital on the same day. She is the daughter of the 66-year old male. At the time of report, she was suffering from severe pneumonia.

Human-to-human transmission between the 66-year-old male and the 39-year-old female cannot be ruled out.

Second cluster:

• A 66-year-old male from Hefei city, Anhui province. He had symptom onset on 16 December 2016, and was admitted to hospital on 17 December 2016 and died on 20 December 2016. He was exposed to a live poultry market.
• A 62-year-old male from Hefei city, Anhui province. He had symptom onset on 22 December 2016. He was admitted in the same ward as the 66-year old male. His current condition is severe.

Human-to-human transmission between the 66-year-old male and the 62-year-old male cannot be ruled out.

To date, a total of 916 laboratory-confirmed human infections with avian influenza A(H7N9) virus have been reported through IHR notification since early 2013.

Public health response

Considering the increase of laboratory-confirmed cases of human infection with avian influenza A(H7N9) in December 2016, the Chinese government has enhanced measures:

• NHFPC strengthened epidemic surveillance, conducted timely risk assessment and studies for any changes in epidemiology.
• NHFPC requested local NHFPCs to implement effective control measures on the source of outbreaks and to minimize the number of affected people.
• Strengthened early diagnosis and early treatment, treatment of severe cases, and reduce occurrence of severe cases and deaths.
• Further enhanced medical treatment.
• Joint investigations between NHFPC and Ministries of agriculture, industry and commerce visited Jiangsu, Zhejiang, Anhui and Guangdong provinces where more cases occurred for joint supervision, inspection and guidance on local surveillance, medical treatment, prevention and control and to promote control measures with focus on live poultry market management and cross-regional transportation.
• Relevant prefectures in Jiangsu province have closed live poultry markets in late December 2016 and Zhejiang, Guangdong and Anhui provinces have strengthened live poultry market regulations.
• Conducting public risk communication and sharing information with the public.

The Centre for Health Protection of the Department of Health in Hong Kong SAR has taken the following measures:

• Urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.
• Issued an alert to doctors, hospitals, schools and institutions of the latest situation.

WHO risk assessment

Similar sudden increases in the number of human cases of avian influenza A(H7N9) infection have been observed in previous years during this period of time (December-January). Nevertheless close monitoring of the epidemiological situation and further characterization of the most recent viruses are critical to assess associated risk and to make timely adjustments to risk management measures.

Most human cases are exposed to avian influenza A(H7N9) virus through contact with infected poultry or contaminated environments, including live poultry markets. Since the virus continues to be detected in animals and environments, further human cases can be expected. Although small clusters of human cases with avian influenza A(H7N9) virus have been reported including those involving healthcare workers, current epidemiological and virological evidence suggests that this virus has not acquired the ability of sustained transmission among humans. Based on available information we have, further community level spread is considered unlikely.

Human infections with the avian influenza A(H7N9) virus are unusual and because there is the potential for significant public health impact, it needs to be monitored closely.

WHO advice

WHO advises that travellers to countries with known outbreaks of avian influenza should avoid, if possible, poultry farms, contact with animals in live bird markets, entering areas where poultry may be slaughtered, or contact with any surfaces that appear to be contaminated with faeces from poultry or other animals. Travellers should also wash their hands often with soap and water, and follow good food safety and good food hygiene practices.

WHO does not advise special screening at points of entry with regard to this event, nor does it currently recommend any travel or trade restrictions. As always, a diagnosis of infection with an avian influenza virus should be considered in individuals who develop severe acute respiratory symptoms while travelling in or soon after returning from an area where avian influenza is a concern.

WHO encourages countries to continue strengthening influenza surveillance, including surveillance for severe acute respiratory infections (SARI) and influenza-like illness (ILI) and to carefully review any unusual patterns, ensure reporting of human infections under the IHR (2005), and continue national health preparedness actions.

Hong Kong Health

CHP alerts public to high avian influenza A(H7N9) activity in Guangdong

     The Centre for Health Protection (CHP) of the Department of Health today (January 17) drew the public’s special attention to the high activity of avian influenza A(H7N9) in Guangdong. Travellers should be on full alert and maintain strict personal, hand, food and environmental hygiene particularly in the upcoming Lunar New Year holidays.

The Health and Family Planning Commission of Guangdong Province reported that 11 human cases of avian influenza A(H7N9), with two deaths, have been recorded so far in 2017 including three from Foshan, two from Guangzhou and one each in Zhongshan, Zhaoqing, Meizhou, Dongguan, Qingyuan and Shunde.

Of note, in the first week of January, 60 out of 637 environmental samples from 21 live poultry markets in 15 cities in Guangdong tested positive for H7 virus. The positive percentage is 9.42 per cent.

The CHP is also closely monitoring an additional human H7N9 case in Hunan. According to the Hunan Provincial Center for Disease Control and Prevention the female patient, aged 36 from Hengyang and in a critical condition, had poultry exposure.

“As human H7N9 cases continue to occur in Guangdong and the positive percentage of environmental samples is substantial, we again urge the public to pay special attention to health risks of the places of visit,” a spokesman for the CHP said.

“We strongly urge the public to avoid touching birds, poultry or their droppings and visiting poultry markets or farms during travel. If feeling unwell, such as having a fever or cough, wear a mask and seek medical advice at once. Travellers returning from affected areas should consult doctors promptly if symptoms develop, and actively inform the doctors of their travel history for prompt diagnosis and treatment,” the spokesman said.

Adults and parents should also look after children with extra care in personal, hand, food and environmental hygiene against infections during travel.

“While local surveillance, prevention and control measures are in place, we will remain vigilant and work closely with the World Health Organization and relevant health authorities to monitor the latest developments,” the spokesman said.

As the H7N9 virus continues to be detected in animals and environments in the Mainland, additional human cases are expected in affected and possibly neighbouring areas. In view of the heavy trade and travel between the Mainland and Hong Kong, further sporadic imported human cases in Hong Kong every now and then are expected, especially in the coming few months.

The CHP’s Port Health Office conducts health surveillance measures at all boundary control points. Thermal imaging systems are in place for body temperature checks on inbound travellers. Suspected cases will be immediately referred to public hospitals for follow-up.

The display of posters and broadcasting of health messages in departure and arrival halls as health education for travellers is under way. The travel industry and other stakeholders are regularly updated on the latest information.

The public should maintain strict personal, hand, food and environmental hygiene and take heed of the advice below while handling poultry:

• Avoid touching poultry, birds, animals or their droppings;
• When buying live chickens, do not touch them and their droppings. Do not blow at their bottoms. Wash eggs with detergent if soiled with faecal matter and cook and consume them immediately. Always wash hands thoroughly with soap and water after handling chickens and eggs;
• Eggs should be cooked well until the white and yolk become firm. Do not eat raw eggs or dip cooked food into any sauce with raw eggs. Poultry should be cooked thoroughly. If there is pinkish juice running from the cooked poultry or the middle part of its bone is still red, the poultry should be cooked again until fully done;
• Wash hands frequently, especially before touching the mouth, nose or eyes, before handling food or eating, and after going to the toilet, touching public installations or equipment such as escalator handrails, elevator control panels or door knobs, or when hands are dirtied by respiratory secretions after coughing or sneezing; and
• Wear a mask if fever or respiratory symptoms develop, when going to a hospital or clinic, or while taking care of patients with fever or respiratory symptoms.

The public may visit the CHP’s pages for more information: the avian influenza page, the weekly Avian Influenza Report, global statistics and affected areas of avian influenza, the Facebook Page and the YouTube Channel.

Government of Hong Kong

Hong Kong

“…..From 2013 to date, 900 human cases have been reported by the Mainland health authorities, 125 of which have been recorded from November 2016 thus far….”

CDC:  H7N9 Outbreak Characterization