R E 1 Scenarios on the impact of pandemic influenza: preparedness planning Marianne van Genugten, Marie-Louise Heijnen, Hans Jager

r Pandemic influenza | Genugten, Heijnen en Jager Pandemic influenza? Influenza viruses changes slightly and frequently over time (antigenic drift) In some years the virus changes dramatically (antigenic shift) Earlier pandemics

r Pandemic influenza | Genugten, Heijnen en Jager Pandemic plan Another influenza pandemic is inevitable High morbidity and mortality  Influenza pandemic plan The Dutch Ministry on Health, Welfare and sports has designed a national plan in order to minimise the effects of pandemic influenza

r Pandemic influenza | Genugten, Heijnen en Jager Question What is the expected number of of hospitalisations and deaths during an influenza pandemic? 1) What are options for intervention?  Building-up of stocks (national level) 2) Number of hospital beds needed versus available.  Contingency planning (local level)

r Pandemic influenza | Genugten, Heijnen en Jager Method Many uncertainties  Scenario-analysis model and data expert consultation –assumptions –scenario’s

r Pandemic influenza | Genugten, Heijnen en Jager Model

r Pandemic influenza | Genugten, Heijnen en Jager Data need Population by risk Age-specific attack, hospitalisation and death rates –including excess Efficacy

r Pandemic influenza | Genugten, Heijnen en Jager Main assumptions pandemic influenza  ‘usual’ epidemic influenza age-specific hospitalisation, death and attack rates as in earlier epidemics basic care (sensitivity analysis on age-specific rates)

r Pandemic influenza | Genugten, Heijnen en Jager Scenarios Non intervention No influenza vaccine available and pneumococcal vaccination of risk groups No influenza vaccine available and therapeutic use of antivirals for each person with influenza like illness Influenza vaccine available

r Pandemic influenza | Genugten, Heijnen en Jager Number of hospitalisations and deaths

r Pandemic influenza | Genugten, Heijnen en Jager Result 1: Avoided number of hospitalisations / required doses

r Pandemic influenza | Genugten, Heijnen en Jager Result 2: Hospital beds needed/available Non intervention scenario –duration 6 weeks –length of hospital stay 8-14 days  beds needed Total number of beds Beds available depends on occupancy rate and nursing staff available

r Pandemic influenza | Genugten, Heijnen en Jager Preparedness planning RIVM  policy makers Message policy makers  ‘flu’ can be serious minister of Health (national level) contingency planners (local level)

r Pandemic influenza | Genugten, Heijnen en Jager Conclusions Scenario-analysis supports decision makers and contingency planners on national and local level Insight in the number of hospitalisations and deaths comparison of intervention options the crucial model parameters