http://www.who.int/csr/don/20-february-2017-ah7n9-china/en/
WHO uutinen 20.2. 2017
Emergencies preparedness, response
Human infection with avian influenza A(H7N9) virus – China
Disease outbreak news
20 February 2017
Between 19 January and 14 February 2017, a total of 304
additional laboratory-confirmed cases of human infection have been
reported to WHO from mainland China though the China National IHR focal
point.
On 19 January 2017, the National Health and Family Planning
Commission of China (NHFPC) notified WHO of 111 additional
laboratory-confirmed cases of human infection with avian influenza
A(H7N9) virus.
On 24 January 2017, the NHFPC notified WHO of 31
additional laboratory-confirmed cases of human infection with avian
influenza A(H7N9) virus.
On 30 January 2017, the NHFPC notified WHO of
41 additional laboratory-confirmed cases of human infection with avian
influenza A(H7N9) virus.
On 7 February 2017, the NHFPC notified WHO of
52 additional laboratory-confirmed cases of human infection with avian
influenza A(H7N9) virus.
On 14 February 2017, the NHFPC notified WHO of
69 additional laboratory-confirmed cases of human infection with avian
influenza A(H7N9) virus.
Details of the cases
Between 19 January and 14 February 2017, the NHFPC reported a
total of 304 human cases of infection with avian influenza A(H7N9).
Onset dates range from 13 December 2016 to 9 February 2017.
Of these 304
cases, 86 are female (28%). Cases range in age from 3 to 85 years, with
a median age of 58 years. The cases are reported from Jiangsu (67),
Zhejiang (53), Guangdong (32), Anhui (31), Jiangxi (27), Hunan (26),
Fujian (20), Hubei (20), Sichuan (6), Guizhou (4), Henan (4), Shandong
(4), Shanghai (3), Liaoning (2), Yunnan (2), Beijing (1), Hebei (1), and
Guangxi (1).
At the time of notification, there wer
e 36 deaths,
two cases
had mild symptoms and 82 cases were diagnosed as either pneumonia (34)
or severe pneumonia (48).
The clinical presentations of the other 184
cases are not available at this time.
144 cases reported exposure to
poultry or live poultry market, 11 cases have no clear exposure to
poultry or poultry-related environments. 149 cases are under
investigation.
Two clusters of two-person were reported:
- A 22-year-old female (mother of 3-year-old girl case who had
symptom onset on 29 January 2017, died on 7 February 2017) reported from
Yunnan province. She had developed symptom on 4 February 2017. She took
care of her daughter during her daughter was sick. Both are reported to
expose to poultry in Jiangxi province.
- A 45-year-old female (previously reported on 9 January) from
Sihui city, Guangdong province. She had symptom onset on 17 December
2016, and died on 24 December 2016. She was exposed to poultry.
- Another
case was a 43-year-old female from Guangzhou city, Guangdong province.
She had symptom onset on 30 December 2016 and was admitted to hospital
on the same day.
- She is the sister of the 45-year old female described
above. She took care of her hospitalized sister but also had exposure to
poultry. At the time of reporting, she was suffering from pneumonia.
While
common exposure to poultry is likely,
human to human transmission cannot be ruled out.
To date, a total of 1222 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 in the number of human infections
with avian influenza A(H7N9) since December 2016, the Chinese government
has enhanced measures such as:
- Strengthened early diagnosis and early treatment, treatment of severe cases to reduce occurrence of severe cases and deaths.
- Convened meetings to further deploy prevention and control measures.
- Conducted public risk communication and sharing information with the public.
- The NHFPC strengthened epidemic surveillance, conducted timely
risk assessment and analysed the information for any changes in
epidemiology.
- The NHFPC requested local NHFPCs to implement effective control
measures on the source of outbreaks and to minimize the number of
affected people.
- The NHFPC, joined by other departments such as agriculture,
industry and commerce, Food and Drug Administration, re-visited Jiangsu,
Zhejiang, Anhui and Guangdong provinces where more cases occurred for
joint supervision. The affected provinces have also strengthened
multisectoral supervision, inspection and guidance on local
surveillance, medical treatment, prevention and control and promoted
control measures with a focus on live poultry market management control.
- 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.
WHO risk assessment
While similar sudden increases in the number of human avian
influenza A(H7N9) cases identified have been reported in previous years
the number of cases reported during this season is exceeding previous
seasons. The number of human cases with onset from 1 October 2016
accounts for nearly one-third of all the human cases of avian influenza
A(H7N9) virus infection reported since 2013.
However, human infections with the avian influenza A(H7N9)
virus remain unusual. Close observation of the epidemiological situation
and further characterization of the most recent human viruses are
critical to assess associated risk and to adjust risk management
measures timely.
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, and live poultry vending continues,
further human cases can be expected. Additional sporadic human cases may
be also expected in previously unaffected provinces as it is likely
that this virus circulates in poultry of other areas of China without
being detected.
Although
small clusters of human cases with avian influenza
A(H7N9) virus have been reported including t
hose involving healthcare
workers, current epidemiological and virological evidence suggests that
this virus has not acquired the ability of sustained transmission among
humans. Therefore the likelihood of further community level spread is
considered low.
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.
