We use a stochastic simulation model to explore the effect of reactive intervention strategies during the 2002 dengue outbreak in the small population of Easter Island, Chile. We quantified the effect of interventions on the transmission dynamics and epidemic size as a function of the simulated control intensity levels and the timing of initiation of control interventions. Because no dengue outbreaks had been reported prior to 2002 in Easter Island, the 2002 epidemic provided a unique opportunity to estimate the basic reproduction number $R_0$ during the initial epidemic phase, prior to the start of control interventions. We estimated $R_0$ at $27.2$ ($95 \%$CI: $14.8$, $49.3$). We found that the final epidemic size is highly sensitive to the timing of start of interventions. However, even when the control interventions start several weeks after the epidemic onset, reactive intervention efforts can have a significant impact on the final epidemic size. Our results indicate that the rapid implementation of control interventions can have a significant effect in reducing the epidemic size of dengue epidemics.
Citation: Gerardo Chowell, R. Fuentes, A. Olea, X. Aguilera, H. Nesse, J. M. Hyman. The basic reproduction number $R_0$ and effectiveness of reactive interventions during dengue epidemics: The 2002 dengue outbreak in Easter Island, Chile[J]. Mathematical Biosciences and Engineering, 2013, 10(5&6): 1455-1474. doi: 10.3934/mbe.2013.10.1455
We use a stochastic simulation model to explore the effect of reactive intervention strategies during the 2002 dengue outbreak in the small population of Easter Island, Chile. We quantified the effect of interventions on the transmission dynamics and epidemic size as a function of the simulated control intensity levels and the timing of initiation of control interventions. Because no dengue outbreaks had been reported prior to 2002 in Easter Island, the 2002 epidemic provided a unique opportunity to estimate the basic reproduction number $R_0$ during the initial epidemic phase, prior to the start of control interventions. We estimated $R_0$ at $27.2$ ($95 \%$CI: $14.8$, $49.3$). We found that the final epidemic size is highly sensitive to the timing of start of interventions. However, even when the control interventions start several weeks after the epidemic onset, reactive intervention efforts can have a significant impact on the final epidemic size. Our results indicate that the rapid implementation of control interventions can have a significant effect in reducing the epidemic size of dengue epidemics.
| [1] | El Vigia (Boletín de Vigilancia en Salud Püblica), 16 (2002), 37-38. |
| [2] | Oxford University Press, Oxford, UK, 1991. |
| [3] | Springer-Verlag, New York, 2000. |
| [4] | BMC Infectious Diseases, 11 (2011), 164. |
| [5] | Mathematical Biosciences, 208 (2007), 571-589. |
| [6] | Epidemiology and Infection, 8 (2008), 1-11. |
| [7] | Journal of Environmental Health, 68 (2006), 40-44. |
| [8] | Wiley Series in Mathematical and Computational Biology, John Wiley & Sons, Ltd., Chichester, 2000. |
| [9] | Available from: http://www.meteochile.cl/. |
| [10] | Tropical Medicine and International Health, 11 (2006), 332-340. |
| [11] | Phil. Trans. Roy. Soc. Lond. B, 354 (1999), 757-768. |
| [12] | American Journal of Tropical Medicine and Hygiene, 53 (1995), 489-506. |
| [13] | Clinical Microbiology Reviews, 11 (1998), 480-496. |
| [14] | Mathematical Biosciences, 209 (2007), 361-385. |
| [15] | Annu Rev Entomol., 53 (2007), 273-291. |
| [16] | Trop. Med. Int. Health., 14 (2009), 628-638. |
| [17] | American Journal of Tropical Medicine and Hygiene, 80 (2009), 66-71. |
| [18] | Mathematical Biosciences, 155 (1999), 77-109. |
| [19] | Available from: http://www.ine.cl. |
| [20] | Michigan Thompson-Shore, Inc., Michigan, 1996. |
| [21] | American Journal Tropical Medicine and Hygiene, 57 (1997), 285-297. |
| [22] | American Journal of Epidemiology, 133 (1991), 1168-1178. |
| [23] | Southeast Asian Journal of Tropical Medicine and Public Health, 16 (1985), 560-568. |
| [24] | Memórias do Instituto Oswaldo Cruz, 98 (2003), 871-878. |
| [25] | Chapter Epidemics, Oxford University Press, London, (1957), 45-62. |
| [26] | Transactions of the Royal Society of Tropical Medicine and Hygiene, 88 (1994), 58-59. |
| [27] | Transactions of the Royal Society of Tropical Medicine and Hygiene, 95 (2001), 370-374. |
| [28] | American Journal Tropical Medicine and Hygiene, 70 (2004), 346-350. |
| [29] | American Journal of Tropical Medicine and Hygiene, 58 (1998), 277-282. |
| [30] | Bulletin of Mathematical Biology, 68 (2006), 1945-1974. |
| [31] | Emerg Infect Dis., 9 (2003), 1465-1467. |
| [32] | John Murray, London, 1910. |
| [33] | Southeast Asian Journal of Tropical Medicine and Public Health, 24 (1993), 369-375. |
| [34] | PLoS Biology, 2 (2004), 1957-1964. |
| [35] | PLoS Negl. Trop. Dis., 3 (2009), e481. |
| [36] | Mathematical Biosciences, 180 (2002), 29-48. |
| [37] | Journal of Infectious Diseases, 181 (2000), 2-9. |
| [38] | PLoS Medicine, 2 (2005), e174. |
| [39] | Available from: http://www.who.int/mediacentre/factsheets/fs117/en/. |
| [40] | Available from: http://www.who.int/csr/resources/publications/dengue/012-23.pdf. |