Human infection with avian influenza A(H5N6) virus – China

Between 21 and 26 April 2016, the National Health and Family Planning Commission (NHFPC) of China notified WHO of 2 additional laboratory-confirmed cases of human infection with avian influenza A(H5N6) virus.

Details of the cases

• A 35-year-old male living in Shen Nong Jia forest region, Hubei Province developed fever on 9 April and sought medical care. He was admitted to hospital for treatment on 12 April and is currently in critical condition. The patient’s clinical sample was confirmed to be A(H5N6) virus nucleic acid positive by the Chinese Center for Disease Control and Prevention (China CDC) on 21 April. He had exposure to a live poultry market before symptom onset. Close contacts of the patient remain healthy.
• An 11-year-old female living in Zhuzhou City, Hunan Province developed fever and cough on 11 April. As her symptoms worsened on 12 April, the patient was admitted to hospital for treatment. She is currently in stable condition. The patient’s clinical sample was confirmed to be A(H5N6) virus nucleic acid positive by the Chinese Center for Disease Control and Prevention (China CDC) on 24 April. She was exposed to live poultry before onset of the disease. Close contacts of the patient remain healthy.

Public health response

The Chinese Government has taken the following surveillance and control measures:

• strengthening surveillance, analysis and research;
• further enhancing the medical care of the case;
• conducting public risk communication and releasing information.

WHO risk assessment

This report does not change the overall public health risk from avian influenza A(H5N6) viruses. Although influenza A(H5N6) has caused severe infection in humans, until now human infections with the virus seem to be sporadic with no ongoing human to human transmission and close contacts of the case remain healthy. However, the characterization of this virus is ongoing and its implication to the evolution and emergence of a pandemic strain is unknown. The risk of international disease spread is considered to be low at this point in time. WHO continues to assess the epidemiological situation and conduct further risk assessment based on the latest information.

WHO advice

WHO advises that travellers to countries with known outbreaks of avian influenza should avoid 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. Travellers should follow good food safety and good food hygiene practices.

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

On 18 April 2016, the National Health and Family Planning Commission (NHFPC) of China notified WHO of 17 additional laboratory-confirmed cases of human infection with avian influenza A(H7N9) virus, including 5 deaths.
Onset dates range from 21 February to 20 March. Cases range in age from 26 to 86 years, with a median age of 60 years. Of these 17 cases, 11 (65%) are male. The majority (15 cases, 88%) reported exposure to live poultry, slaughtered poultry, or live poultry markets. The exposure history of one (1) case is unknown. One (1) case is linked to a cluster of two (2) cases reported earlier to WHO (see below).
Cases were reported from 6 provinces and municipalities: Anhui (4), Jiangsu (4), Fujian (3), Guangdong (3), Zhejiang (2) and Hubei (1).
One cluster was reported. The cluster includes an 85-year-old female from Zhejiang Province. She had onset of symptoms on 1 March and passed away on 8 March. She had been admitted to the same hospital and shared the ward with a confirmed case between 22 and 23 February. She was not exposed to live poultry or live poultry market, according to her relatives.
The confirmed case admitted at the same ward was a 29-year-old male from Zhejiang Province who developed symptoms on 15 February. He had exposure to a live poultry market and a household contact who was also a confirmed case. The contact from Fujian Province developed symptoms on 4 February and had exposure to a live poultry market.
Human to human transmission between the 29-year-old male and the 85-year-old female cannot be ruled out. Further virological information is awaited.

Public health response

The Chinese Government has taken the following surveillance and control measures:

• strengthening outbreak surveillance and situation analysis;
• reinforcing all efforts on medical treatment; and
• conducting risk communication with the public and dissemination of information.

WHO risk assessment

Most human cases are exposed to the 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 influenza A(H7N9) viruses 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. Therefore further community level spread is considered unlikely.
Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and/or its transmission behaviour to humans as it may have a serious public health impact.

WHO advice

WHO advises that travellers to countries with known outbreaks of avian influenza should avoid 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. Travellers should follow good food safety and good food hygiene practices.

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

On 19 April 2016, the Department of Health, Hong Kong Special Administrative Region notified WHO of a confirmed, imported case of human infection with avian influenza A(H7N9) virus.
The patient is an 80-year-old man with underlying illnesses, travelled to Dongguan, Guangdong province from 1 to 5 April. He developed productive cough, headache and a gout attack on 6 April. On 14 April, he developed fever, and by 17 April was experiencing disorientation. He went to hospital the same day and was subsequently admitted for management of pneumonia.
On 19 April, he tested positive for avian influenza A(H7N9) virus following laboratory testing at the Public Health Laboratory Services Branch of the Centre for Health Protection (CHP). The patient is now in stable condition and will be transferred to a different hospital for further management
Initial investigations by the CHP revealed that the patient had purchased a live chicken from a wet market close to where he stayed during his time in Mainland China. He slaughtered the chicken on 3 April.

Public health response

The Centre for Health Protection of the Department of Health is continuing investigation, as well as tracing and monitoring close contacts of the case.

WHO risk assessment

Most human cases are exposed to the 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 influenza A(H7N9) viruses 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. Therefore further community level spread is considered unlikely.
Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and/or its transmission behaviour to humans as it may have a serious public health impact.

WHO advice

WHO advises that travellers to countries with known outbreaks of avian influenza should avoid 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. Travellers should 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 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 to carefully review any unusual patterns, in order to ensure reporting of human infections under the IHR (2005), and continue national health preparedness actions.