Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 13, Number 3—March 2007

Effectiveness of Neuraminidase Inhibitors for Preventing Staff Absenteeism during Pandemic Influenza

Vernon J. Lee*Comments to Author  and Mark I. Chen*

Author affiliations: *Tan Tock Seng Hospital, Singapore;

Main Article

Table 1

Parameters of neuraminadase inhibitor stockpiling strategies model*

Base case‡

General populationNg4,350,000 (13)
Healthcare staffNh20,000Estimated
ILI rate, per dayι2,800 (2)
Transmission dynamics
Incubation and latent period, dα1.02.03.0 (9,10)
Infectious period, dγ1.54.17.0 (9,10)
Reproductive numberR01.52.56.0 (9,14)
Transmission probability/dβ0.370.612.0Calculated, R/γ
HCW-to-HCW transmissionω0.20.50.8See text
HCW infections caused by incident cases of clinical influenza (H/P)δ02.0See text
Detection threshold, proportion of baseline ILI rateνIntroduction of 1st case0.11See text
Disease severity and antiviral efficacy
Hospitalization rate (HCW)/100,000 infected§η12.488.6186.7 (2)
Length of stay and medical leave if hospitalized, dφ9.012.020.0(2)
Case-fatality rate (HCW)/100,000 infected§μ1.920.365.1 (2)
Proportion of infected persons without prophylaxis who have symptomsθ10.500.670.80 (9,15)
Oseltamivir efficacy for preventing infection in exposed personsε10.280.350.52 (9,16,17)
Oseltamivir efficacy for preventing disease in infected personsε20.50.60.9 (2,9)
Oseltamivir efficacy for preventing transmission of infection by infected personsε30.60.80.98 (9)
Proportion of infected persons receiving oseltamivir prophylaxis who have symptomsθ20.07-0.2Calculated, θ2 = θ1(1−ε2)
Medical leave without treatment, dσ245 (2)
Reduction in medical leave with oseltamivir treatment, dχ0.11.02.0 (2)
Reduction in hospitalization or case-fatality rate with treatmentψ0.40.60.8 (2,18)

*HCW, healthcare workers, ILI, influenzalike illness.

†Notations are used in the equations listed in the Appendix.

‡Base case values are given with the minimum and maximum values used in the model where applicable.

§Based on hospitalizations and deaths among those with clinical influenza.

Main Article

  1. World Health Organization. Avian influenza and human pandemic influenza: summary report. Meeting held in Geneva, Switzerland, 7–9 Nov 2005. [cited 2006 Jan 15]. Available from
  2. Lee VJ, Phua KH, Chen MI, Chow A, Ma S, Goh KT, Economics of neuraminidase inhibitor stockpiling for pandemic influenza, Singapore.Emerg Infect Dis. 2006;12:95102.PubMedGoogle Scholar
  3. Balicer RD, Huerta M, Davidovitch N, Grotto I. Cost-benefit of stockpiling drugs for influenza pandemic.Emerg Infect Dis. 2005;11:1280.PubMedGoogle Scholar
  4. Cinti S, Chenoweth C, Monto AS. Preparing for pandemic influenza: should hospitals stockpile oseltamivir?Infect Control Hosp Epidemiol. 2005;26:8524. DOIPubMedGoogle Scholar
  5. Nicholson KG, Aoki FY, Osterhaus AD, Trottier S, Carewicz O, Mercier CH, Efficacy and safety of oseltamivir in treatment of acute influenza: a randomized controlled trial.Lancet. 2000;355:184550. DOIPubMedGoogle Scholar
  6. Kaiser L, Wat C, Mills T, Mahoney P, Ward P, Hayden F. Impact of oseltamivir treatment on influenza-related lower respiratory tract complications and hospitalizations.Arch Intern Med. 2003;163:166772. DOIPubMedGoogle Scholar
  7. Cooper NJ, Sutton AJ, Abrams KR, Wailoo A, Turner D, Nicholson KG. Effectiveness of neuraminidase inhibitors in treatment and prevention of influenza A and B: systematic review and meta-analyses of randomised controlled trials.BMJ. 2003;326:1235. DOIPubMedGoogle Scholar
  8. Moscona A. Neuraminidase inhibitors for influenza.N Engl J Med. 2005;353:136373. DOIPubMedGoogle Scholar
  9. Longini IMJr, Halloran ME, Nizam A, Yang Y. Containing pandemic influenza with antiviral agents.Am J Epidemiol. 2004;159:62333. DOIPubMedGoogle Scholar
  10. Salgado CD, Farr BM, Hall KK, Hayden FG. Influenza in the acute hospital setting.Lancet Infect Dis. 2002;2:14555. DOIPubMedGoogle Scholar
  11. Cox NJ, Subbarao K. Influenza.Lancet. 1999;354:127782. DOIPubMedGoogle Scholar
  12. Chow A, Ma S, Ling AE, Chew SK. Influenza-associated deaths in tropical Singapore.Emerg Infect Dis. 2006;12:11421.PubMedGoogle Scholar
  13. Singapore Department of Statistics. Key statistics. [cited 2005 Dec 21]. Available from
  14. Mills CE, Robins JM, Lipsitch M. Transmissibility of 1918 pandemic influenza.Nature. 2004;432:9046. DOIPubMedGoogle Scholar
  15. Fraser C, Riley S, Anderson RM, Ferguson NM. Factors that make an infectious disease outbreak controllable.Proc Natl Acad Sci U S A. 2004;101:614651. DOIPubMedGoogle Scholar
  16. Hayden FG, Treanor JJ, Fritz RS, Lobo M, Betts RF, Miller M, Use of the oral neuraminidase inhibitor oseltamivir in experimental human influenza: randomized controlled trials for prevention and treatment.JAMA. 1999;282:12406. DOIPubMedGoogle Scholar
  17. Welliver R, Monto AS, Carewicz O, Schatteman E, Hassman M, Hedrick J, Oseltamivir Post Exposure Prophylaxis Investigator Group. Effectiveness of oseltamivir in preventing influenza in household contacts: a randomized controlled trial.JAMA. 2001;285:74854. DOIPubMedGoogle Scholar
  18. Moscona A. Neuraminidase inhibitors for influenza.N Engl J Med. 2005;353:136373. DOIPubMedGoogle Scholar
  19. Glezen WP. Emerging infections: pandemic influenza.Epidemiol Rev. 1996;18:6476.PubMedGoogle Scholar
  20. Influenza pandemic planning. Business continuity planning guide. New Zealand Ministry of Economic Development. [cited 2006 Jul 1]. Available from
  21. Gani R. Potential impact of antiviral drug use during influenza pandemic.Emerg Infect Dis. 2005;11:135562.PubMedGoogle Scholar
  22. Chik KW, Li CK, Chan PKS, Shing MMK, Lee V, Tam JSL, Oseltamivir prophylaxis during the influenza season in a paediatric cancer centre: prospective observational study.Hong Kong Med J. 2004;10:1036.PubMedGoogle Scholar

Main Article

Page created: June 29, 2010
Page updated: June 29, 2010
Page reviewed: June 29, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.