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Volume 13, Number 7—July 2007
Research

Effects of Internal Border Control on Spread of Pandemic Influenza

James G. Wood*†Comments to Author , Nasim Zamani†, C. Raina MacIntyre*†, and Niels G. Becker‡
Author affiliations: *National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, Sydney, New South Wales, Australia; †The University of Sydney, Sydney, New South Wales, Australia; ‡Australian National University, Canberra, Australian Capital Territory, Australia;

Main Article

Table 1

Summary of parameter values, assumptions, and sources used in models of the effect of travel restrictions on pandemic influenza in Australia*

Variable/concept Value (range)/assumption Source/interpretation
Reproduction no. (R0) 1.5–3.5 Mills (14)
Infectivity function (ρ) Flat or peaked† Longini, Ferguson (7,8)
Latent period 1 (1–2 in sensitivity analysis) d(s) Ferguson (6)
Infectious period 5 d Literature suggests 4–7 d in adults (6,7)
Mixing Homogenous (within city) Modeling literature (15)
Propensity to travel Everyone equal Assumption
Populations Sydney (4.2 million), Melbourne 
(3.6 million), Darwin (110,000) ABS figures (16)
Travel rate‡ Sydney ↔ Melbourne (weighted by stay length) (4.7 × 103, 8.9 × 103) BTRE figures (17,18), NSW, and 
Victoria Tourism reports (19,20)
Travel rate‡ Sydney ↔ Darwin 
(weighted by stay length) (9.2 × 104, 4.4 × 103) BTRE figures (17,18), NSW, and 
NT Tourism reports (19,21)
Travel restrictions 20%,10%, or 1% of current levels Assumption
Time between 20 current cases 
in city 1 and city 2 (T20) Random variable (T20), different for 
each simulation. Median value over 
all simulations is given by m20. Output variables used to measure 
effect of travel restrictions

*ABS, Australian Bureau of Statistics; BTRE, Bureau of Transport and Regional Economics; NSW, New South Wales; NT, Northern Territory.
†See Figure 1, panel C, for shapes used.
‡This assumes a constant travel rate over the year with no seasonal variation in travel volumes.

Main Article

References
  1. Gezairy  HA. Travel epidemiology: WHO perspective. Int J Antimicrob Agents. 2003;21:868. DOIPubMedGoogle Scholar
  2. World Tourism Organization. Tourist arrivals by means of transport (2004). Nov 2005. [cited 2006 Feb 2]. Available from http://www.world-tourism.org/facts/eng/pdf/indicators/ITA_Tranps.pdf
  3. Australian Bureau of Transport and Regional Economics. Australian domestic airline activity 2004–05. Aviation statistics 102. [cited 2005 Dec 15]. Available from http://www.btre.gov.au/statistics/aviation/docs/Domestic_airlines_2004-05.pdf
  4. U.S. Bureau of Transportation Statistics. 2005 domestic airline passenger traffic up 4.1 percent from 2004. 2006. [cited 2006 Mar 24]. Available from http://www.bts.gov/press_releases/2006/bts013_06/pdf/bts013_06.pdf
  5. The Committee to Advise on Tropical Medicine and Travel (CATMAT) and the National Advisory Committee on Immunization. (NACI). Statement on travel, influenza, and prevention. [Erratum in: Can Commun Dis Rep. 2005;31:115. PMID: 15895509]. Can Commun Dis Rep. 2005;31:18.
  6. Ferguson  NM, Cummings  DAT, Cauchemez  S, Fraser  C, Riley  S, Meeyai  A, Strategies for containing an emerging influenza pandemic in Southeast Asia. Nature. 2005;437:20914. DOIPubMedGoogle Scholar
  7. Longini  IM, Nizam  A, Xu  S, Ungchusak  K, Hanshaoworakul  W, Cummings  DAT, Containing pandemic influenza at the source. Science. 2005;309:10837. DOIPubMedGoogle Scholar
  8. Ferguson  NM, Cummings  DAT, Fraser  C, Cajka  JC, Cooley  PC, Burke  DS. Strategies for mitigating an influenza pandemic. Nature. 2006;442:44852. DOIPubMedGoogle Scholar
  9. Cooper  BS, Pitman  RJ, Edmunds  WJ, Gay  NJ. Delaying the international spread of pandemic influenza. PLoS Med. 2006;3:e212. DOIPubMedGoogle Scholar
  10. Hollingsworth  TD, Ferguson  NM, Anderson  RM. Will travel restrictions control the international spread of pandemic influenza? Nat Med. 2006;12:4979. DOIPubMedGoogle Scholar
  11. Markel  H, Stern  AM, Navarro  JA, Michalsen  JR, Monto  AS, DiGiovanni  C Jr. Nonpharmaceutical influenza mitigation strategies, US communities, 1918–1920 pandemic. Emerg Infect Dis. 2006;12:19614.PubMedGoogle Scholar
  12. NSW Legislative Assembly. Report of the Director-General of Public Health NSW for the year 1919 and the report on the influenza epidemic 1919. Gullick (Australia): Sydney William Applegate; 1920.
  13. Grais  RF, Ellis  JH, Glass  GE. Assessing the impact of airline travel on the geographic spread of pandemic influenza. [Erratum in: Eur J Epidemiol. 2004;19:395]. Eur J Epidemiol. 2003;18:106572. DOIPubMedGoogle Scholar
  14. Mills  CE, Robins  JM, Lipsitch  M. Transmissibility of 1918 pandemic influenza. Nature. 2004;432:9046. DOIPubMedGoogle Scholar
  15. Anderson  R, May  R. Infectious diseases of humans. Oxford (UK): Oxford University Press; 1991.
  16. Australian Bureau of Statistics. Population projections, Australia 2002 to 2101. [cited 2005 Jan 12]. Available from http://www.abs.gov.au
  17. Australian Bureau of Transport and Regional Economics. Australian domestic airline activity. Aviation Statistics Domestic Monthly. 2005;102. [cited 2005 Dec 15]. Available from http://www.btre.gov.au/statistics/aviation/docs/domestic_airlines_0506.pdf
  18. Australian Bureau of Transport and Regional Economics. Passenger movements between Australian cities, 1970–71 to 2030–31. [cited 2006 Dec 13]. Available from http://www.btre.gov.au/docs/infosheets/is26/is26.pdf
  19. Tourism New South Wales. Travel to Sydney: year ended June 2005. [cited 2006 Jan 12]. Available from http://corporate.tourism.nsw.gov.au/corporatelive/downloads/research/sydney%20jun%202005.pdf
  20. Tourism Victoria. Domestic visitation to regions of Victoria: year ending June 1999–2005. 2005. [cited 2005 Jan 12]. Available from http://www.tourism.victoria.com.au
  21. Northern Territory Tourism. Darwin tourism region, results for the year ending June 2005. [cited 2005 Jan 12]. Available from: http://www.nttc.com.au/nt/system/galleries/download/NTTC_Research/June_quarterly_report_0405.pdf
  22. Hayden  FG, Fritz  R, Lobo  MC, Alvord  W, Strober  W, Straus  SE. Local and systemic cytokine responses during experimental human influenza a virus infection. Relation to symptom formation and host defense. J Clin Invest. 1998;101:6439. DOIPubMedGoogle Scholar
  23. 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
  24. Gani  R, Hughes  H, Fleming  D, Griffin  T, Medlock  J, Leach  S. Potential impact of antiviral drug use during influenza pandemic. Emerg Infect Dis. 2005;11:135562.PubMedGoogle Scholar
  25. Smith  DR, Sommers  T. Assessing the economic impact of public health emergencies in international concerns: the case of SARS. Geneva: World Health Organization; 2003.

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