Post on 11-Dec-2015
description
Preparing responses to human infections with
Avian Influenza A(H7N9)
Background
On 31 March 2013, the National Health and Family Planning Commission, China (NHFPC) notified WHO of three
cases of human infection with avian influenza A(H7N9) from Shanghai and Anhui. This was a new influenza
subtype, not previously known to have infected humans, and therefore prompted immediate action from Chinese
authorities and WHO. A total of 432 laboratory-confirmed cases including 146 deaths have been reported to date
(as of 9 May 2014).
Although the exact source and mode of transmission are not yet known, available evidence supports animal,
particularly poultry, or contaminated environments as the potential primary source of infection. As a result, the
national and provincial authorities in China initiated several control measures including the closure of live poultry
markets.
Purpose of the document
This document is produced as a framework for action to provide Member States with a summary of information
for assessment of their specific situation and assist to focus national efforts on preparedness and response. This
document does not intend to replace previous pandemic preparedness guidelines or procedures countries may
already have in place to respond to public health emergencies. It is also not exhaustive, rather it is meant to
highlight areas where H7N9 requires specific or supplemental action.
Framework for action
A number of key components, listed below, are required for countries and areas to prepare for a response to
human cases of H7N9. These are based on preparedness as set out in the Asia Pacific Strategy for Emerging
Diseases (APSED 2010) and in line with obligations required under the International Health Regulations (IHR
2005). They also align with the WHO Interim Guidance on Pandemic Influenza Risk Management. Relevant
technical documents and papers are also listed below (as of 6 May 2014).
Possible scenarios
Since the human infection with avian influenza virus A(H7N9) was detected in 2013, concern remains over the
potential for the H7N9 virus to adapt further and become readily transmissible between humans. It is also
possible that the recent decrease of cases observed in China could be due to seasonality and that transmission
may increase next winter/spring (December-May). The resumption of live animal trading in affected areas may
result again in sporadic cases, some with clusters. There have been several cases reported in outside of Mainland
China since 2013 thus far virus spread to new areas remains a possibility. From the perspective of a given country
conducting preparedness actions and risk assessment, an H7N9 outbreak would take the form of one of the
following scenarios:
Scenario 1: No locally acquired case(s) of human infection with avian influenza A(H7N9) in country
Scenario 2: Sporadic and/or limited human-to-human cases of avian influenza A(H7N9) infection in
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country
Scenario 3: Sustained human-to-human transmission of avian influenza A(H7N9) with or without sporadic
cases in country
The objectives in preparing for response to human infection with H7N9 include:
Early detection of human case/s of avian influenza A(H7N9) (all scenarios).
Early detection of avian influenza A(H7N9) in poultry (scenario 1 and 2).
Identification of the source and reservoir of infection by conducting appropriate epidemiological and
virological investigations in humans and animals (scenario 2).
Reduction of preventable deaths by improving clinical management and infection control practices
(scenario 2 and 3).
Reduction of the transmission of the virus by instituting appropriate public health interventions (scenario
2 and 3).
Adopt risk communication strategy that positions health authorities as a reliable and trustworthy source
of information by providing timely and transparent information and proactive dissemination of
prevention messages (all scenarios)
Minimization of social disruptions and other negative consequences, where possible (scenario 2 and 3).
A way of applying the framework for response can be found in Annex 1 through considering the three
possible scenarios for H7N9 cases in the future. Each scenario includes key trigger points, an overarching
strategy and examples of response measures to take. Scenario 2 is particularly broad as it includes
everything from one or more sporadic case/s up until the time just before sustained human-to-human
transmission. The preparation and responses within this scenario are also broadly applicable across the
spectrum.
Keeping up-to-date
Table 1 provides links to general and H7N9 specific guidance, risk assessments and recommendations available at
the time of this publication. Updates specific to H7N9 can be found at
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/en/index.html.
Surveillance, risk assessment and response
Effective surveillance through enhancement of current influenza-like-illness (ILI) and severe acute respiratory
infection (SARI) systems in addition to unusual occurrences detected through event-based surveillance (EBS) will
maximize the early detection and reporting of human cases of H7N9. Risk assessment which incorporates this
information helps guide proportionate response. It should be undertaken on a continual bases, particularly as
new critical information becomes available.
Laboratory investigations
Laboratory systems and response networks have provided protocols for detection and biosafety advice specific
for H7N9. Detection can either be through a national laboratory or WHO can assist Member States to access
testing internationally if the need arises.
Human animal interface/zoonoses
Being a zoonotic disease, the human-animal interface is a key component for preventing human disease.
Coordination with the animal sector will ensure investigations to identify the source of infection and optimize
appropriate public health interventions associated with the animal source of the virus.
Clinical management and Infection prevention and control
Infection prevention and control measures already practiced for influenza are appropriate for H7N9. Specific
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guidance based on evidence of H7N9 cases treated can be found in the link below.
Public health intervention and emergency preparedness
In addition to areas listed, preparedness for human cases of infection with H7N9 can be achieved through
reviewing of the pandemic plan, including practical steps to operationalize it through an event management
system. WHO does not recommend travel or trade restrictions.
Risk Communication
Developing of a strategy and communicating information in an accurate and timely manner serves to harness
public trust and enhance appropriate behaviour during public health emergencies. Reporting of cases in a timely
manner to WHO assists with international communication and is in line with country obligations under IHR (2005).
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General H7N9 specific
Keep up-to-date
WHO web page with links for technical guidelines and current status
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/en/
Background and summary, as of 31 January 2014
http://www.who.int/influenza/human_animal_interface/latest_update_h7n9/en/
Overview of the emergence and characteristics of the avian influenza A(H7N9)
virus, 31 May 2013
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/WHO_H7
N9_review_31May13.pdf?ua=1
Surveillance A guide to establishing event-based surveillance http://www.wpro.who.int/emerging_diseases/documents/docs/eventbasedsurv.pdf
WHO interim global epidemiological standards for influenza surveillance
http://www.who.int/influenza/resources/documents/INFSURVMANUAL.pdf
H5N1 investigation guidelines
http://www.who.int/influenza/resources/documents/WHO_CDS_EPR_GIP
_2006_4r1.pdf
Interim revised surveillance recommendations – H7N9, 10 May 2013
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/InterimSu
rveillanceRecH7N9_10May13.pdf?ua=1
H7N9 situation update as of 21 April 2014
http://www.wpro.who.int/outbreaks_emergencies/H7N9/en/
Risk assessment and response
Rapid risk assessment of acute public health events, WHO http://whqlibdoc.who.int/hq/2012/WHO_HSE_GAR_ARO_2012.1_eng.pdf
WPRO Internal - Practical guide: Rapid Risk Assessment for event based
surveillance World Health Organization, Western Pacific Regional Office,
December 2012
WHO risk assessment updated 28 Feb 2014 http://www.who.int/influenza/human_animal_interface/influenza_h7n9/140225_H7N9RA_for_web_20140306FM.pdf?ua=1
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Laboratory Laboratory PCR testing for H7N9, updated on 15 April 2013 http://www.who.int/influenza/gisrs_laboratory/cnic_realtime_rt_pcr_protocol_a_h
7n9.pdf?ua=1
Bio-risk management interim recommendations, H7N9 as of 10 May 2013
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/InterimRe
cLaboratoryBioriskManagementH7N9_10May13.pdf
Laboratory serology testing for H7N9 as of 20 December 2013
http://www.who.int/influenza/gisrs_laboratory/cnic_serological_diagnosis_hai_a_
h7n9_20131220.pdf?ua=1;
http://www.who.int/influenza/gisrs_laboratory/cnic_serological_diagnosis_micron
eutralization_a_h7n9.pdf; and
http://www.who.int/influenza/gisrs_laboratory/cnic_serological_diagnosis_hai_a_
h7n9.pdf
Clinical management and Infection prevention and control
Infection prevention and control guidance for influenza
http://www.who.int/csr/resources/publications/swineflu/WHO_CDS_EPR_
2007_6/en/index.html and
http://www.doh.state.fl.us/rw_Bulletins/WHO_AvianFlu_control_practice
s.pdf
Clinical management of human infection with avian influenza A (H5N1)
virus, 15 August 2007
http://www.who.int/influenza/resources/documents/ClinicalManagement
07.pdf
Post-exposure antivial chemoprophylaxis of close contacts of H7N9 patient. 17
January 2014
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/13_Janua
ry_2013_PEP_recs.pdf?ua=1
Public health intervention and emergency preparedness
Asia Pacific Strategy for Emerging Disease (2010)
http://www.wpro.who.int/emerging_diseases/documents/docs/ASPED_20
10.pdf
Pandemic influenza risk management interim guidance http://www.who.int/influenza/preparedness/pandemic/GIP_PandemicInfluenzaRiskManagementInterimGuidance_2013.pdf
International Health Regulations (2005) http://whqlibdoc.who.int/publications/2008/9789241580410_eng.pdf
Reducing transmission of pandemic (H1N1) 2009 in school settings
Vaccine preparation
WHO recommendation on influenza A(H7N9) vaccine virus. 26 September 2013
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/20130
9_h7n9_recommendation.pdf?ua=1
WHO provisional recommendation on influenza A(H7N9) vaccine virus as of 31
May 2013
Candidate vaccine viruses for avian influenza A(H7N9). 13 February 2014
http://www.who.int/influenza/vaccines/virus/candidates_reagents/summary_a
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http://www.who.int/csr/resources/publications/reducing_transmission_h1n1_2009.pdf
Interim planning considerations for mass gatherings in the context of pandemic (H1N1) 2009 influenza http://www.who.int/csr/resources/publications/swineflu/cp002_2009-0511_planning_considerations_for_mass_gatherings.pdf
Public health preparedness H1N1 review document (mass gathering_travel_risk comms) http://whqlibdoc.who.int/hq/2011/WHO_HSE_GIP_ITP_2011.3_eng.pdf Advice on the use of masks in the community setting in Influenza A (H1N1) http://www.who.int/influenza/preparedness/measures/Adviceusemaskscommunityrevised.pdf
_h7n9_cvv_20140213.pdf?ua=1
Update of WHO biosafety risk assessment and guidelines for the production and quality control of human influenza vaccines against avian influenza A(H7N9) virus
Development and distribution of candidate vaccine viruses for avian influenza A(H7N9)
Risk communication
WHO media handbook
http://www.who.int/csr/resources/publications/WHO%20MEDIA%20HAND
BOOK.pdf
WHO media field guide
http://www.who.int/csr/resources/publications/WHO%20MEDIA%20FIELD
%20GUIDE.pdf
WHO outbreak communication planning guide http://www.who.int/ihr/elibrary/WHOOutbreakCommsPlanngGuide.pdf
Frequently asked questions H7N9 infections http://www.who.int/influenza/human_animal_interface/faq_H7N9/en/
Standardization of the influenza A (H7N9) virus terminology http://www.who.int/influenza/human_animal_interface/influenza_h7n9/H7N9VirusNaming_16Apr13.pdf?ua=1
China-WHO joint mission on human infection with avian influenza A(H7N9) virus, 18-24 April 2013, mission report http://www.who.int/influenza/human_animal_interface/influenza_h7n9/ChinaH7N9JointMissionReport2013u.pdf?ua=1
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Annex 1: Possible scenarios and framework for response Scenario 1: No locally acquired human case of avian influenza A(H7N9) in country Key trigger points for the scenario:
No evidence of locally acquired human infection with H7N9
Detection of H7N9 infection with a recent history of travel to the affected area
No evidence of H7N9 in animals Overarching strategy for the response:
Ensure systems are in place to detect, report, manage and prevent infections from animal or environmental sources.
Ensure systems are in place to undertake epidemiological and virology investigations.
Ensure systems are in place to recognize and manage clinical cases and implement infection prevention and control in healthcare facilities.
Ensure systems are in place for the timely and full reporting to WHO in line with IHR (2005).
Regularly reassess and communicate the public health risk of human cases of H7N9 in country.
Review preparedness and readiness for a change in risk. Key technical areas Preparedness and Response measures for country
Surveillance, risk
assessment and
response
Monitor and strengthen existing ILI and SARI surveillance including awareness raising with healthcare workers and at points of entry
Monitor and strengthen event-based surveillance and reporting mechanisms
Ensure risk assessment mechanism is in place to assess incoming information and ensure a proportionate response
Review rapid response team field investigation mechanism/guideline
Laboratory Ensure mechanisms in place for laboratory diagnostics, shipping of specimens and reporting for surveillance
Human-animal
interface/zoonoses Establish a multi-sector joint working mechanism
Establish close cooperation with agriculture/animal authorities to share details of each other’s investigations, particularly about the potential of human exposure from animals
Clinical management
and infection prevention
and control
Alert hospitals and community medical practitioners to symptoms, diagnosis, clinical management and Infection, prevention and control procedures
Public health
interventions and
emergency
preparedness
Review pandemic plan, including how to operationalize it e.g. activating an event management system
Review all response systems including readiness of event operations center (EoC), logistics, equipment and standard operating procedures
Review the status of oseltamivir and PPE stockpile and examine mechanisms for distribution
Investigate the status of vaccine preparedness and policies for vaccine distribution
Risk communication Ensure that a risk communication strategy is set up for H7N9 with a system for developing messages and clearance procedures established, coordination arrangements agreed and spokespersons appointed and trained.
Agree on mechanism for timely development, release and updating of information on H7N9 to the public and appropriate distribution arrangements are in place (talking points, FAQs, web pages press releases, etc.)
Ensure roles and responsibilities are agreed for international cooperation and communication including timely reporting in line with IHR (2005)
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Scenario 2: Sporadic &/or limited human-to-human case/s of avian influenza A(H7N9) in country Key trigger points for the scenario:
This scenario has a wide spectrum o From one or more sporadic case/s of H7N9 reported in country, without history of travel to a
country with known H7N9 in the previous 14 days. o Including limited human-to-human transmission. o To just prior to sustained human-to-human.
Detection of H7N9 infection in animals. Overarching strategy for the response:
Ensure systems are in place to detect, report, manage, and prevent further infections from animal or environmental sources.
Ensure systems are in place to undertake epidemiological and virology investigations.
Ensure systems are in place to recognize and manage clinical cases and implement infection, prevention and control measures in healthcare facilities.
Ensure timely and full reporting to WHO in line with IHR (2005).
Regularly reassess and communicate the public health risk of further human cases of H7N9 in country.
Consider public health interventions to help limit spread through sustained human-to human transmission (e.g. preliminary consideration of rapid containment)
Key technical
areas
Preparedness and Response measures for country
Surveillance, risk
assessment and
response
Implement time-limited enhanced ILI and SARI surveillance in geographic location of each sporadic case
Enhance event-based surveillance, particularly for cluster reports
Apply risk assessment mechanism for proportionate response (including determination of potential sustained human-to-human cases and rapid containment)
Ensure timely field investigation including contact tracing, detailed history of travel and animal contact and rapid reporting in place for each suspected/probable and confirmed case
Laboratory Ensure timely laboratory diagnostics, shipping of specimens and reporting for surveillance occurring
Human-animal
interface/zoonoses Ensure Ministry of Health and Ministry of Agriculture are in communication regarding
surveillance for H7N9 in animals, particularly in locations surrounding with human cases
Based on the results of surveillance in animals and epidemiological investigations of human cases, decide about control strategies in consultation with the agriculture/animal authorities
Clinical
management and
infection
prevention and
control
Alert hospitals and community medical practitioners to symptoms, diagnosis, clinical management and IPC procedures
Ensure hospitals where cases have been detected have appropriate facilities and expertise in place
If case numbers indicate, consider policy and practice of triage at healthcare facilities
Public health
interventions and
emergency
preparedness
Consider activating event management system and event operations centre
Determine the status of oseltamivir and PPE stockpile and examine mechanisms for distribution, including pre-positioning once case numbers indicate the need
Investigate the status of vaccine preparedness and policies for vaccine distribution
Review preparedness and readiness for immediate response surge if level of risk were to change (EOC capability; response logistics capacity, business continuity plan).
Risk
communication Proactively provide accessible information on H7N9 to stakeholders and the public, e.g.
health prevention advice, talking points, FAQs, press releases of cases
Listen to the public and gather feedback through a systematic media monitoring and analysis of issues. Ensure a system for dealing with rumors and misinformation.
Report cases in a timely manner to WHO in alignment with IHR (2005).
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Scenario 3: Sustained human-to-human transmission of avian influenza A(H7N9) with or without
sporadic cases in country Key trigger points for the scenario:
Rapid risk assessment suggests or concludes that sustained human-to-human transmission of H7N9 is occurring in country.
Overarching strategy for the response:
Assess the feasibility of rapid containment and implement if feasible.
Reduce clinical attack rate
Reduce burden on health care facilities
Support and maintain business continuity.
Ensure timely and full reporting to WHO in line with IHR (2005).
Regularly reassess and communicate the public health risk of further human case H7N9
Regularly review preparedness and for a change in risk. Key technical areas Preparedness and Response measures for country
Surveillance, risk
assessment and
response
Adjust surveillance system appropriate to case number and time following reporting of sustained human-to human transmission including:
o Undertake time-limited enhanced ILI and SARI surveillance in country o Review case definition and testing strategy for understanding overall
number of cases o Normalize H7N9 surveillance into seasonal system already in place
Laboratory Review laboratory testing recommendations as more cases are reported (consider only testing a subset of suspected cases)
Ensure surge capacity in place to backup testing strategy
Human-animal
interface/zoonoses Continue sharing information between Ministry of Health and Ministry of
Agriculture regarding surveillance in animals and H7N9 cases in humans
Clinical management
and infection prevention
and control
Alert hospitals and community medical practitioners to symptoms, diagnosis, clinical management and IPC procedures
Ensure hospitals where cases have been detected have appropriate facilities and expertise in place (including surge capacity at peak times)
Put in place triage practice in healthcare facilities
Public health
interventions and
emergency
preparedness
Activate MOH EOC, institute event management system, prepare stockpile for deployment and/or deploy needed items, ensure sure capacity in place
Review and activate measures, including: provision of prophylaxis to targeted groups; school closure; mass gatherings; border control measures (entry and exit screening); quarantine and isolation measures; vaccine availability and distribution; and Business continuity guidelines.
Risk communication Proactively provide accessible information on H7N9 to stakeholders and the public, e.g. health prevention advice, talking points, FAQs, press releases of cases.
Listen to the public and gather feedback through a systematic media monitoring and analysis of issues. Ensure a system for dealing with rumours and misinformation.
Develop and disseminate evidence-based health messages for behavior change and community-level prevention.
Report cases in a timely manner to WHO in alignment with IHR (2005).