title: Dynamic epidemic model for influenza with clinical complications.
abstract: OBJECTIVE
  To incorporate clinical complications in the susceptible-infectious-recovered model to estimate parameters needed in dynamic changes of infectious diseases and to further evaluate the impact of disease-controlling methods.
  
  
  METHODS
  We developed a new extended epidemic model that incorporates of disease-related complications. This model was applied to empirical data on influenza during the epidemic season of 2001-2002 in Taipei County, Taiwan, to estimate the transmission parameters that were converted to the basic reproductive rate (R(0)). The proposed model, in conjunction with estimated parameters, was applied in quantifying the efficacy of different preventive strategies.
  
  
  RESULTS
  During the study period there were 5 outbreaks of influenza. The estimated transmission probability for outbreak 1 was 0.135, with corresponding estimate of R(0), 2.7; for outbreak 2, 0.165, with estimated R(0), 3.3; for outbreak 3, 0.15, with R(0), 4.5; for outbreak 4, 0.165, with R(0), 5; and for outbreak 5, 0.165, with R(0), 5. The efficacy of antiviral prophylaxis to reduce the total episodes was 18% (95% CI, 15%-21%) under the coverage rate of 30%, 31% (95% CI, 26%-36%) under the coverage rate of 50%, and 73% (95% CI, 59%-90%) under the coverage rate of 80%. The corresponding figures for the efficacy of vaccination were 17% (95% CI, 15%-20%), 41% (95% CI, 35%-48%), and 76% (95% CI, 61%-95%). Combination of both methods would yield efficacy of 32% (95% CI, 28%-38%), 59% (95% CI, 49%-71%), and 88% (95% CI, 66%-118%), respectively.
  
  
  CONCLUSIONS
  We demonstrate how to apply a novel extended model to empirical surveillance data of an influenza study for estimating parameters pertaining to dynamic changes in the infection process. These parameters were further used to evaluate the impact of antiviral prophylaxis alone, vaccination alone, or the use of both methods.
authors.affiliation: Department of Family Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Sen-Te
authors.initials: ST
authors.lastname: Wang
authors.forename: Li-Sheng
authors.initials: LS
authors.lastname: Chen
authors.forename: Long-Teng
authors.initials: LT
authors.lastname: Lee
authors.forename: Hsiu-Hsi
authors.initials: HH
authors.lastname: Chen
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D008954:Models, Biological; D011159:Population Surveillance; D013624:Taiwan
chemical_list: D000998:Antiviral Agents; D007252:Influenza Vaccines