Pandemic influenza update Prepared by Dr Sean Tobin Medical - PowerPoint PPT Presentation

Pandemic influenza update Prepared by Dr Sean Tobin Medical Epidemiologist Communicable Diseases Branch Health Protection NSW May 2013

Overview  Avian influenza A(H7N9) in China  MERS Coronavirus (MERS-CoV) in the Middle East  Pandemic influenza planning update  Existing ED / Flu Clinic Guidance  Discussion on the role of ED’s in pandemic planning and response

The influenza virus [Exiting the cell] [Entering the cell] 2

Avian influenza A(H7N9)  31 March 2013, China reported 3 cases of human infection with a novel influenza A(H7N9) virus in Shanghai and Anhui.  Novel virus is a reassortant – comprising H7 HA, N9 NA and the six internal genes of H9N2 influenza A viruses.  Total132 cases / 37 deaths. Last onset 21 May.  No sustained human-to-human transmission

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WHO H7N9 Risk Assessment  Highest pandemic potential of any known avian influenza virus – causes serious disease, including deaths (CFR 28%) – does not cause disease in poultry – hard to control – has caused more human infections in a short period of time than any other avian influenza virus – some H7N9 viruses show genetic changes that suggest they are partially adapted to infect humans more easily than other avian influenza viruses.

MERS coronavirus  Middle East respiratory syndrome coronavirus  Previously known as “novel coronavirus”

MERS-CoV Background  Not closely related to SARS. Most closely related to a Bat coronavirus but animal reservoir still not determined  First case reported from Saudi Arabia in June 2012. Retrospectively identified in 2/11 cases in a hospital SARI outbreak in Jordan from April 2012.  Continuing sporadic case reports through 2012 with links to the countries in the Arabian Peninsula.  3 UK cases in February 2013 associated with travel to Saudi Arabia and Pakistan (index case) with spread to two family members.

MERS-CoV Update  Since April 2013, over 25 new cases have been reported from Saudi Arabia, including several HCWs – most recent cases linked to a single hospital outbreak with a case fatality ratio (CFR) ~50%.  Human-to-human transmission observed but not sustained  All clusters reported to date in family contacts or in a health care setting after extensive close contact  Cases mainly reported from the Arabian Peninsula – Cases exported to UK, Germany, France, Tunisia

NSW Surveillance: H7N9 and MERS-CoV  Clinician alerts sent out and on NSW Health website www.health.nsw.gov.au/infectious  Consider MERS-CoV or H7N9 infection in: – A person with an acute respiratory infection AND suspected pulmonary parenchymal disease AND a history of recent travel to: – (1) The Arabian Peninsula or neighbouring countries within 10 days before onset of illness (for MERS-CoV) (2) China within 7 days before onset of illness (for H7N9) – OR Close contact of a confirmed case AND not yet explained by any other cause

Pandemic planning update  Pandemic viruses  Existing pandemic plans  Likely changes in the national pandemic plan

Terminology  Avian influenza – wild birds are the natural host of influenza viruses. Some strains mutate and adapt to other animal hosts  Seasonal influenza – influenza viruses that have adapted to humans (usually commence as pandemic viruses)  Swine influenza – influenza viruses that have adapted to pigs  Pandemic influenza the global outbreak of influenza that occurs when a new influenza virus emerges that is adapted to humans – Novel virus: no prior immunity in the community – Able to pass efficiently from person to person – Causes illness: may vary from mild to severe 14

Origin of pandemic influenza viruses 15

Influenza pandemics H1N1 H2N2 H3N2 pH1N1 Spanish Flu Asian Flu Hong Kong Flu “Swine Flu” 20-40M deaths 1-2M deaths ~1M deaths H3? “Asiatic Flu” 1890 1918-19 1957 1968 2009 17

Pandemic occurred in 2 waves: 1. March to early May – 2000 dead (in NSW) 2. Late May to August – 4000 dead 18

Pandemic plans  International – WHO Global Preparedness Plan  National – National Action Plan Human Influenza Pandemic (Govt) – Australian Health Management Plan for Pandemic influenza (AHMPPI)  State – NSW Human Influenza Pandemic Action Plan (Govt) – NSW Health Influenza Pandemic Action Plan  Local – LHD plans; Hospital Pandemic Plans 19

WHO Pandemic phases

National pandemic plan (AHMPPI) revision  Primary audience Govt decision makers – Covers severe seasonal influenza scenarios – Less emphasis on Border measures – More flexibility in response options  A health emergency response model – (Prevention) Preparedness, Response, Recovery – Assessment phase to inform Targeted Measures  Supported by the National Medical Stockpile

Assessment phase: “First Few 100 cases”  Surveillance Plan - Assess to Act “A key feature of the plan is the short-term enhanced data collection following the introduction of the virus to Australia. Placing a limit on the enhanced data collection activities will ensure an appropriate allocation of resources by limiting the reporting burden on front-line health professionals.”

NSW ED / Flu Clinic Guidance  PD2007_048 : Hospital Response to Pandemic Influenza Part 1: Emergency Department Response

PD2007-048: ED Response  Followed extensive consultation  Proposes 3 levels of response : 1. Enhanced triage within EDs 2. Separate pandemic influenza screening stations (at the ED entrance) 3. Stand-alone influenza clinics  Not necessarily sequential

1. Enhanced triage within EDs  When small clusters of human-to-human transmission of the new influenza virus have been reported overseas  Aim to detect new cases imported into Australia  Screening questions at Triage  Supported by plans for managing single or small numbers of cases (isolate, assess, test, treat, admit/discharge).  Reporting of cases to Public Health Units  Public NOT being instructed to attend ED

2. Separate pandemic screening stations  When the likelihood of patients with pandemic influenza being encountered has increased and poses an imminent risk to NSW health facilities  Situation warrants screening of all people presenting to ED before they enter the waiting room and before Triage  All patients / accompanying persons attending ED screened at a station located at the entrance to the ED.  If the patient does not meet the case definition, the patient proceeds to triage as normal.

3. Stand-alone influenza clinics  When there is widespread circulation of the new influenza virus in the community, and it threatens essential health service delivery.  Stand-alone influenza clinics will operate as influenza triage, assessment, and management facilities for potentially large numbers of sick people.  Influenza clinic staff will determine whether the patient requires admission to a hospital or staging facility, or whether they can be discharged home with community follow-up as required.

Discussion  Is the ED response model still appropriate? Is it flexible enough?  In the Assessment Phase, how should suspect pandemic cases reported to Public Health Units be investigated?  What is the role of EDs in pandemic planning?  How should influenza clinics be established? Where should they be and staffed by whom? * Seasonal Flu