The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality
Mathematical models predict that the community-level incidence of a controlled infectious disease across a region approaches a geometric distribution. This could hold over larger regions, if new cases remain proportional to existing cases. Leprosy has been disappearing for centuries, making an excel...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2018-09-01
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| Series: | Epidemics |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1755436516300652 |
| _version_ | 1818864268184911872 |
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| author | Thomas M. Lietman Lee Worden Fengchen Liu Travis C. Porco |
| author_facet | Thomas M. Lietman Lee Worden Fengchen Liu Travis C. Porco |
| author_sort | Thomas M. Lietman |
| collection | DOAJ |
| description | Mathematical models predict that the community-level incidence of a controlled infectious disease across a region approaches a geometric distribution. This could hold over larger regions, if new cases remain proportional to existing cases. Leprosy has been disappearing for centuries, making an excellent candidate for testing this hypothesis. Here, we show the annual new case detection rate of leprosy in Indian districts to be consistent with a geometric distribution. For 2008–2013, goodness-of-fit testing was unable to exclude the geometric, and the shape parameter of the best fit negative binomial distribution was close to unity (0.95, 95% CI 0.87–1.03). Ramifications include that a district-level cross-sectional survey may reveal whether an infectious disease is headed towards elimination, that apparent outliers are expected and not necessarily representative of program failure, and that proportion 1/e of a small geographical unit may not meet a control threshold even when a larger area has. Keywords: Leprosy, Geometric distribution, Elimination, Mathematical model |
| first_indexed | 2024-12-19T10:28:57Z |
| format | Article |
| id | doaj.art-0654a2e5df4b4fda95bbb31263b71695 |
| institution | Directory Open Access Journal |
| issn | 1755-4365 |
| language | English |
| last_indexed | 2024-12-19T10:28:57Z |
| publishDate | 2018-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Epidemics |
| spelling | doaj.art-0654a2e5df4b4fda95bbb31263b716952022-12-21T20:25:48ZengElsevierEpidemics1755-43652018-09-01242125The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticalityThomas M. Lietman0Lee Worden1Fengchen Liu2Travis C. Porco3F.I. Proctor Foundation, USA; Department of Ophthalmology, USA; Department of Epidemiology and Biostatistics, USA; Global Health Sciences, University of California San Francisco, San Francisco, CA, USAF.I. Proctor Foundation, USAF.I. Proctor Foundation, USAF.I. Proctor Foundation, USA; Department of Ophthalmology, USA; Department of Epidemiology and Biostatistics, USA; Correspondence to: Travis C Porco, PhD MPH, University of California, San Francisco, 513 Parnassus, Medical Sciences Room S334, San Francisco, CA 94143-0944 USA.Mathematical models predict that the community-level incidence of a controlled infectious disease across a region approaches a geometric distribution. This could hold over larger regions, if new cases remain proportional to existing cases. Leprosy has been disappearing for centuries, making an excellent candidate for testing this hypothesis. Here, we show the annual new case detection rate of leprosy in Indian districts to be consistent with a geometric distribution. For 2008–2013, goodness-of-fit testing was unable to exclude the geometric, and the shape parameter of the best fit negative binomial distribution was close to unity (0.95, 95% CI 0.87–1.03). Ramifications include that a district-level cross-sectional survey may reveal whether an infectious disease is headed towards elimination, that apparent outliers are expected and not necessarily representative of program failure, and that proportion 1/e of a small geographical unit may not meet a control threshold even when a larger area has. Keywords: Leprosy, Geometric distribution, Elimination, Mathematical modelhttp://www.sciencedirect.com/science/article/pii/S1755436516300652 |
| spellingShingle | Thomas M. Lietman Lee Worden Fengchen Liu Travis C. Porco The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality Epidemics |
| title | The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality |
| title_full | The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality |
| title_fullStr | The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality |
| title_full_unstemmed | The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality |
| title_short | The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality |
| title_sort | distribution of district level leprosy incidence in india is geometric stable consistent with subcriticality |
| url | http://www.sciencedirect.com/science/article/pii/S1755436516300652 |
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