The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining.
BACKGROUND:Mathematical models predict an exponential distribution of infection prevalence across communities where a disease is disappearing. Trachoma control programs offer an opportunity to test this hypothesis, as the World Health Organization has targeted trachoma for elimination as a public he...
Published in: | PLOS Neglected Tropical Diseases |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Public Library of Science (PLoS)
2015
|
Subjects: | |
Online Access: | https://doi.org/10.1371/journal.pntd.0003682 https://doaj.org/article/7df361e5ce5144cf928209391f15edf6 |
id |
ftdoajarticles:oai:doaj.org/article:7df361e5ce5144cf928209391f15edf6 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:7df361e5ce5144cf928209391f15edf6 2023-05-15T15:12:45+02:00 The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. Salman A Rahman Sheila K West Harran Mkocha Beatriz Munoz Travis C Porco Jeremy D Keenan Thomas M Lietman 2015-03-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0003682 https://doaj.org/article/7df361e5ce5144cf928209391f15edf6 EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4376383?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003682 https://doaj.org/article/7df361e5ce5144cf928209391f15edf6 PLoS Neglected Tropical Diseases, Vol 9, Iss 3, p e0003682 (2015) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2015 ftdoajarticles https://doi.org/10.1371/journal.pntd.0003682 2022-12-31T11:43:00Z BACKGROUND:Mathematical models predict an exponential distribution of infection prevalence across communities where a disease is disappearing. Trachoma control programs offer an opportunity to test this hypothesis, as the World Health Organization has targeted trachoma for elimination as a public health concern by the year 2020. Local programs may benefit if a single survey could reveal whether infection was headed towards elimination. Using data from a previously-published 2009 survey, we test the hypothesis that Chlamydia trachomatis prevalence across 75 Tanzanian communities where trachoma had been documented to be disappearing is exponentially distributed. METHODS/FINDINGS:We fit multiple continuous distributions to the Tanzanian data and found the exponential gave the best approximation. Model selection by Akaike Information Criteria (AICc) suggested the exponential distribution had the most parsimonious fit to the data. Those distributions which do not include the exponential as a special or limiting case had much lower likelihoods of fitting the observed data. 95% confidence intervals for shape parameter estimates of those distributions which do include the exponential as a special or limiting case were consistent with the exponential. Lastly, goodness-of-fit testing was unable to reject the hypothesis that the prevalence data came from an exponential distribution. CONCLUSIONS:Models correctly predict that infection prevalence across communities where a disease is disappearing is best described by an exponential distribution. In Tanzanian communities where local control efforts had reduced the clinical signs of trachoma by 80% over 10 years, an exponential distribution gave the best fit to prevalence data. An exponential distribution has a relatively heavy tail, thus occasional high-prevalence communities are to be expected even when infection is disappearing. A single cross-sectional survey may be able to reveal whether elimination efforts are on-track. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 9 3 e0003682 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Salman A Rahman Sheila K West Harran Mkocha Beatriz Munoz Travis C Porco Jeremy D Keenan Thomas M Lietman The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
BACKGROUND:Mathematical models predict an exponential distribution of infection prevalence across communities where a disease is disappearing. Trachoma control programs offer an opportunity to test this hypothesis, as the World Health Organization has targeted trachoma for elimination as a public health concern by the year 2020. Local programs may benefit if a single survey could reveal whether infection was headed towards elimination. Using data from a previously-published 2009 survey, we test the hypothesis that Chlamydia trachomatis prevalence across 75 Tanzanian communities where trachoma had been documented to be disappearing is exponentially distributed. METHODS/FINDINGS:We fit multiple continuous distributions to the Tanzanian data and found the exponential gave the best approximation. Model selection by Akaike Information Criteria (AICc) suggested the exponential distribution had the most parsimonious fit to the data. Those distributions which do not include the exponential as a special or limiting case had much lower likelihoods of fitting the observed data. 95% confidence intervals for shape parameter estimates of those distributions which do include the exponential as a special or limiting case were consistent with the exponential. Lastly, goodness-of-fit testing was unable to reject the hypothesis that the prevalence data came from an exponential distribution. CONCLUSIONS:Models correctly predict that infection prevalence across communities where a disease is disappearing is best described by an exponential distribution. In Tanzanian communities where local control efforts had reduced the clinical signs of trachoma by 80% over 10 years, an exponential distribution gave the best fit to prevalence data. An exponential distribution has a relatively heavy tail, thus occasional high-prevalence communities are to be expected even when infection is disappearing. A single cross-sectional survey may be able to reveal whether elimination efforts are on-track. |
format |
Article in Journal/Newspaper |
author |
Salman A Rahman Sheila K West Harran Mkocha Beatriz Munoz Travis C Porco Jeremy D Keenan Thomas M Lietman |
author_facet |
Salman A Rahman Sheila K West Harran Mkocha Beatriz Munoz Travis C Porco Jeremy D Keenan Thomas M Lietman |
author_sort |
Salman A Rahman |
title |
The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
title_short |
The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
title_full |
The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
title_fullStr |
The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
title_full_unstemmed |
The distribution of ocular Chlamydia prevalence across Tanzanian communities where trachoma is declining. |
title_sort |
distribution of ocular chlamydia prevalence across tanzanian communities where trachoma is declining. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2015 |
url |
https://doi.org/10.1371/journal.pntd.0003682 https://doaj.org/article/7df361e5ce5144cf928209391f15edf6 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 9, Iss 3, p e0003682 (2015) |
op_relation |
http://europepmc.org/articles/PMC4376383?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003682 https://doaj.org/article/7df361e5ce5144cf928209391f15edf6 |
op_doi |
https://doi.org/10.1371/journal.pntd.0003682 |
container_title |
PLOS Neglected Tropical Diseases |
container_volume |
9 |
container_issue |
3 |
container_start_page |
e0003682 |
_version_ |
1766343391385223168 |