Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza
This paper focuses on a fundamental input parameter for most existing mathematical models of pandemic influenza, the ‘basic reproductive number R[subscript 0],’ defined to be the mean number of new influenza infections created by a newly infected person in a population of all susceptible people. We...
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| Format: | Working Paper |
| Language: | en_US |
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Massachusetts Institute of Technology. Engineering Systems Division
2016
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| Online Access: | http://hdl.handle.net/1721.1/102864 |
| _version_ | 1826195158863970304 |
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| author | Larson, Richard Charles |
| author_facet | Larson, Richard Charles |
| author_sort | Larson, Richard Charles |
| collection | MIT |
| description | This paper focuses on a fundamental input parameter for most existing mathematical models of pandemic influenza, the ‘basic reproductive number R[subscript 0],’ defined to be the mean number of new influenza infections created by a newly infected person in a population of all susceptible people. We argue that R[subscript 0] is limited in policy and scientific value as is any single parameter attempting to characterize a complex probabilistic process. In particular, we demonstrate by simple logic that R[subscript 0] does not exist as a separate ‘constant of a particular influenza,’ but rather its value is determined by social context and behavioral patterns as well as by the “physics’’ of the influenza virus. To the extent that R[subscript 0] is useful, it is best viewed as an output of a modeling analysis, not an input. But with R[subscript 0] being the mean of a random variable, much more information is contained in the entire probability distribution. With this view, we show – again by simple arguments – that R[subscript 0] can be greater than 1.0 and still, contrary to popular belief, the probability of an exponentially growing pandemic may be arbitrarily small. Finally, we show that attempts to estimate R[subscript 0] from data of previous pandemics is fraught with methodological complexities, due primarily to heterogeneities in the population that cause super-spreaders and socially active people to be the first propagators of the disease. Unless one is careful, statistical estimates of R[subscript 0] based on early exponential growth of reported cases may be significantly upwardly biased. |
| first_indexed | 2024-09-23T10:08:06Z |
| format | Working Paper |
| id | mit-1721.1/102864 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:08:06Z |
| publishDate | 2016 |
| publisher | Massachusetts Institute of Technology. Engineering Systems Division |
| record_format | dspace |
| spelling | mit-1721.1/1028642019-04-11T05:37:55Z Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza Larson, Richard Charles This paper focuses on a fundamental input parameter for most existing mathematical models of pandemic influenza, the ‘basic reproductive number R[subscript 0],’ defined to be the mean number of new influenza infections created by a newly infected person in a population of all susceptible people. We argue that R[subscript 0] is limited in policy and scientific value as is any single parameter attempting to characterize a complex probabilistic process. In particular, we demonstrate by simple logic that R[subscript 0] does not exist as a separate ‘constant of a particular influenza,’ but rather its value is determined by social context and behavioral patterns as well as by the “physics’’ of the influenza virus. To the extent that R[subscript 0] is useful, it is best viewed as an output of a modeling analysis, not an input. But with R[subscript 0] being the mean of a random variable, much more information is contained in the entire probability distribution. With this view, we show – again by simple arguments – that R[subscript 0] can be greater than 1.0 and still, contrary to popular belief, the probability of an exponentially growing pandemic may be arbitrarily small. Finally, we show that attempts to estimate R[subscript 0] from data of previous pandemics is fraught with methodological complexities, due primarily to heterogeneities in the population that cause super-spreaders and socially active people to be the first propagators of the disease. Unless one is careful, statistical estimates of R[subscript 0] based on early exponential growth of reported cases may be significantly upwardly biased. 2016-06-02T20:10:53Z 2016-06-02T20:10:53Z 2008-02 Working Paper http://hdl.handle.net/1721.1/102864 en_US esd;ESD-WP-2008-10 application/pdf Massachusetts Institute of Technology. Engineering Systems Division |
| spellingShingle | Larson, Richard Charles Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title | Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title_full | Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title_fullStr | Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title_full_unstemmed | Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title_short | Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza |
| title_sort | revisiting r subscript 0 the basic reproductive number for pandemic influenza |
| url | http://hdl.handle.net/1721.1/102864 |
| work_keys_str_mv | AT larsonrichardcharles revisitingrsubscript0thebasicreproductivenumberforpandemicinfluenza |