Presentation on theme: "What is an influenza pandemic? A global epidemic of influenza resulting from a combination of –the emergence of an influenza A virus with a sub-type different."— Presentation transcript:
What is an influenza pandemic? A global epidemic of influenza resulting from a combination of –the emergence of an influenza A virus with a sub-type different from strains circulating among humans in recent years –a high proportion of susceptible people in the community –high person-to-person transmissibility of the new virus, with accompanying human disease
Re-assortment and Direct Transmission Human virus virus Reassortantvirus Non-humanvirus
Global situation as of 18:00 GMT, 13 th May countries have officially reported 6,302 cases of influenza A (H1N1) infection. Mexico has reported 2,282 laboratory confirmed human cases of infection, including 58 deaths. The United States has reported 3,352 laboratory confirmed human cases, including three deaths. Canada has reported 353 laboratory cases, one death. Costa Rica has reported 8 laboratory cases, one death. The following countries have reported laboratory confirmed cases with no deaths: Argentina (1)Australia (1) Austria (1) Brazil (8) China mainland and Hong Kong SAR (4) Colombia (7) Cuba (1) Denmark (1)El Salvador (4) Finland (2)France (14) Germany (12)Guatemala (3) Ireland (1) Israel (7) Italy (9)Japan (4) Netherlands (3)New Zealand (7) Norway (2)Panama (29) Poland (1)Portugal (1) Republic of Korea (3) Spain (100) Sweden (2)Switzerland (1) Thailand (2)UK (71)
How has the situation evolved? From present day… 13 May, Africa is the only unaffected continent. Cases exceed 6000, with the highest number being in US (3352), Mexico (2282), Canada (353) Spain (100) and UK (71). 11 May, a new death is reported in Costa Rica, where there are 8 confirmed cases 9 May, by now, 29 countries have reported case with deaths occuring in Mexico, USA and Canada. 5 May, continued increase in cases reported by country, although WHO does not believe it is seeing community transmission elsewhere outside the PAHO region. 3 May, WHO will release its stockpile of oseltamivir to 72 developing countries and Mexico. 30 April, confirmed figures continue to change rapidly. USA also reports a death, hospitalized patients. WHO moves to phase April, Mexico government announced closure of schools across the country. Spain and the United Kingdom confirmed first cases. WHO moves to phase 4.
How has the situation evolved? 26 April, Mexican government closed schools, some public places in Mexico city. Canada confirmed first cases. By 25 April, Mexico government reported 1149 persons (71 deaths, CFR 6.2%) occurring from April under investigation for severe respiratory disease. Mexican government issued health advisory, closed some public places (schools, libraries, museums, theatres), distributed surgical masks. WHO declares a public health emergency of international concern (PHEIC). Evening of 24 April, it was reported that 18 out of 51 specimens from Mexico sent for laboratory confirmation in Canada tested positive for H1N1 and 12 were identical to the strain confirmed in US Early morning of 24 April, US confirmed 7 cases (5 California, 2 Texas). 23 April, Mexico alerted WHO in the middle of the night of a sudden high number of cases and deaths from a severe respiratory disease. WHO activated their SHOC room. End March – April 09: Unusual 'end of season' influenza activity was observed in Mexico. …to genesis
Phase 1No animal influenza virus circulating among animals has been reported to cause infection in humans. Phase 2An animal influenza virus circulating in domesticated or wild animals is known to have caused infection in humans and is therefore considered a specific potential pandemic threat. Phase 3An animal or human-animal influenza reassortant virus has caused sporadic cases or small clusters of disease in people, but has not resulted in human-to-human transmission sufficient to sustain community-level outbreaks. Phase 4Human-to-human transmission (H2H) of an animal or human-animal influenza reassortant virus able to sustain community-level outbreaks has been verified. Phase 5The same identified virus has caused sustained community level outbreaks in two or more countries in one WHO region. Phase 6In addition to the criteria defined in Phase 5, the same virus has caused sustained community level outbreaks in at least one other country in another WHO region. Post-peak period Levels of pandemic influenza in most countries with adequate surveillance have dropped below peak levels. Possible new wave Level of pandemic influenza activity in most countries with adequate surveillance rising again. Post- pandemic period Levels of influenza activity have returned to the levels seen for seasonal influenza in most countries with adequate surveillance. WHO PANDEMIC PREPAREDNESS AND RESPONSE GUIDANCE 2009: PHASES
Phase 5 changes Phase 5 is characterized by human-to- human spread of the virus into at least two countries in one WHO region. The declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short. All countries should immediately activate pandemic preparedness plans.
Phase 5 changes Effective and essential measures include heightened surveillance, early detection and treatment of cases, and infection control in all health facilities. The criteria to move to phase 6 (pandemic) would be triggered by sustained community in a second WHO region, where there is clear evidence of community-level transmission outside the Americas An influenza pandemic is a global event that calls for global solidarity.
What is important to monitor Spread of epidemic, Severity of illness (case fatality rate) Community outbreaks further international spread of the virus, and further spread in countries that are already reporting cases. Historically, influenza pandemics have encircled the globe in two, sometimes three, waves. The present situation can change because influenza viruses are constantly changing in unpredictable ways.
Why not rapid containment? WHO has a containment protocol Containment = efforts to stop the pandemic Mitigation = efforts to minimize illness/death (and slow down transmission to buy time for better preparedness and vaccine development/production) Protocol includes criteria for decision-making This situation does not meet criteria for attempting containment (based on available evidence) –too widespread already –Unfeasible to operationalize
So, what to do? Countries should focus efforts more on mitigation rather than containment Actions to ensure safety of people Ensure clear messages and transparent communications Social and personal protection (social distancing, hand hygiene, cough etiquette) Refrain from introducing measures that are economically and socially disruptive, yet have no scientific justification and bring no clear public health benefit - all the more important at a time of economic downturn.
Main Actions for Phase 5 Phase 5: The virus has caused sustained community level outbreaks in two or more countries in one WHO Region. Increase surveillance Implement individual & community precaution measures Consider switching to pandemic vaccine Continue communication & updates Activate contingency plan for Health care Activate multi- sector coordination
Travel related measures issued by WHO as temporary recommendations under IHR: Not to close borders and not to restrict international travel and The relevant provisions in the IHR with respect to such measures and the need to inform WHO and provide the public health rationale and relevant scientific information for measures that significantly interfere with international traffic –At this point FOCUS should be on safety of people –Closing borders or restricting travel WILL NOT slow virus spread much –Previous experiences (SARS) have shown that closure of points of entry is very effective in disrupting the economy but not virus transmission!
However… It is prudent for people who are ill to delay international travel Returning travelers who have become ill to seek medical attention in line with guidance from national authorities These steps are prudent for all diseases not just influenza
Is it safe to eat pork? Yes Influenza viruses are not known to be transmissible to people through eating processed pork or other food products derived from pigs. Heat treatments commonly used in cooking meat (e.g. 70°C/160°F core temperature) will readily inactivate any viruses potentially present in raw meat products.
Treatment of cases Standard treatment as for previous guidelines Virus have shown sensitivity to: Oseltamivir Zanamivir
Vaccine production No vaccine currently available for this novel strain A multi-step process with many groups involved to develop a vaccine 4-6 months to develop a new vaccine and have the first batch of vaccine available; several months for mass production. WHO is working closely with its partners to make vaccine virus prototypes – the first steps Global manufacturing capacity, though greatly increased, is insufficient to produce enough antiviral medication and pandemic vaccines to protect the entire world population in time. Acquiring data to guide wise and targeted use of interventions, conserve supplies, and, in the case of antiviral medicines, reduce the risk of drug resistance. Influenza viruses tend to change constantly thus virus sharing critical to have as many strains as possible available to increase the likelihood of a protective vaccine.
What WHO is doing Constant monitoring and risk assessment Providing support to Mexico through GOARN (Global Outbreak Alert and Response Network) Working with its network of laboratories to development laboratory reagents to test for this novel virus and the vaccine Working with WHO Member States to enhance surveillance Working with WHO Collaborating Centers for vaccine preparation
What WHO is doing Providing written guidance to support Member States: –Hospitals/Infection control –Surveillance –Laboratory Activating preparedness plans Communicating real time information/advice to the public, Member States, partners, etc. Ensuring 2-way communication
What can the public do? Prepare for social distancing (home supplies) Practice good hand hygiene Practice good cough etiquette Listen for public health advisories (WHO,MOH) as the situation is very fluid The risk is not hyping the pandemic threat, but undeplaying it. We know a tsunami is coming. No one can say whether it will be just a large wave, or a monsterous one, but it is time to start thinking about at least being ready to move to higher ground. Nature, vol 459, issue no May 2009