Strik, R. van

influenza mortality death non-registered influenza mortality disease influenza activity influenza mortality non-registered period study cause people model population netherland activity subpopulation non-registered influenza deaths figure heart disease heart impact 60 years epidemic group month epidemiol influenza epidemics influenza deaths period 1967-1989 erasmus university rotterdam nonregistered influenza mortality 1967-1989 number age group pneumonia lung disease season age groups epidemiology influenza vaccine effect surveillance regression measure entity virological data influenza death vaccination death cause category smith j influenza mortality surveillance calendar disease entity health mullooly j p sprenger m j proportion difference analysis 1..... season-year morbidity nonregistered vaccine journal category subtype rotterdam virus death certificates 2000 people surveillance system study period wales 1..... i virological system sprenger 70 years