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Evidence for waning of latency in a cohort study of tuberculosis

BACKGROUND: To investigate how the risk of active tuberculosis disease is influenced by time since original infection and to determine whether the risk of reactivation of tuberculosis increases or decreases with age. METHODS: Cohort analysis of data for the separate ten year birth cohorts of 1876-18...

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Autores principales: Wiker, Harald G, Mustafa, Tehmina, Bjune, Gunnar A, Harboe, Morten
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843612/
https://www.ncbi.nlm.nih.gov/pubmed/20178619
http://dx.doi.org/10.1186/1471-2334-10-37
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author Wiker, Harald G
Mustafa, Tehmina
Bjune, Gunnar A
Harboe, Morten
author_facet Wiker, Harald G
Mustafa, Tehmina
Bjune, Gunnar A
Harboe, Morten
author_sort Wiker, Harald G
collection PubMed
description BACKGROUND: To investigate how the risk of active tuberculosis disease is influenced by time since original infection and to determine whether the risk of reactivation of tuberculosis increases or decreases with age. METHODS: Cohort analysis of data for the separate ten year birth cohorts of 1876-1885 to 1959-1968 obtained from Statistics Norway and the National Tuberculosis Registry. These data were used to calculate the rates and the changes in the rates of bacillary (or active) tuberculosis. Data on bacillary tuberculosis for adult (20+) age groups were obtained from the National Tuberculosis Registry and Statistics Norway from 1946 to 1974. Most cases during this period arose due to reactivation of remote infection. Participants in this part of the analysis were all reported active tuberculosis cases in Norway from 1946 to 1974 as recorded in the National Tuberculosis Registry. RESULTS: Tuberculosis decreased at a relatively steady rate when following individual birth cohorts, but with a tendency of slower decline as time passed since infection. A mean estimate of this rate of decline was 57% in a 10 year period. CONCLUSIONS: The risk of reactivation of latent tuberculosis decreases with age. This decline may reflect the rate at which latent tuberculosis is eliminated from a population with minimal transmission of tubercle bacilli. A model for risk of developing active tuberculosis as a function of time since infection shows that the rate at which tuberculosis can be eliminated from a society can be quite substantial if new infections are effectively prevented. The findings clearly indicate that preventative measures against transmission of tuberculosis will be the most effective. These results also suggest that the total population harbouring live tubercle bacilli and consequently the future projection for increased incidence of tuberculosis in the world is probably overestimated.
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spelling pubmed-28436122010-03-23 Evidence for waning of latency in a cohort study of tuberculosis Wiker, Harald G Mustafa, Tehmina Bjune, Gunnar A Harboe, Morten BMC Infect Dis Research Article BACKGROUND: To investigate how the risk of active tuberculosis disease is influenced by time since original infection and to determine whether the risk of reactivation of tuberculosis increases or decreases with age. METHODS: Cohort analysis of data for the separate ten year birth cohorts of 1876-1885 to 1959-1968 obtained from Statistics Norway and the National Tuberculosis Registry. These data were used to calculate the rates and the changes in the rates of bacillary (or active) tuberculosis. Data on bacillary tuberculosis for adult (20+) age groups were obtained from the National Tuberculosis Registry and Statistics Norway from 1946 to 1974. Most cases during this period arose due to reactivation of remote infection. Participants in this part of the analysis were all reported active tuberculosis cases in Norway from 1946 to 1974 as recorded in the National Tuberculosis Registry. RESULTS: Tuberculosis decreased at a relatively steady rate when following individual birth cohorts, but with a tendency of slower decline as time passed since infection. A mean estimate of this rate of decline was 57% in a 10 year period. CONCLUSIONS: The risk of reactivation of latent tuberculosis decreases with age. This decline may reflect the rate at which latent tuberculosis is eliminated from a population with minimal transmission of tubercle bacilli. A model for risk of developing active tuberculosis as a function of time since infection shows that the rate at which tuberculosis can be eliminated from a society can be quite substantial if new infections are effectively prevented. The findings clearly indicate that preventative measures against transmission of tuberculosis will be the most effective. These results also suggest that the total population harbouring live tubercle bacilli and consequently the future projection for increased incidence of tuberculosis in the world is probably overestimated. BioMed Central 2010-02-23 /pmc/articles/PMC2843612/ /pubmed/20178619 http://dx.doi.org/10.1186/1471-2334-10-37 Text en Copyright ©2010 Wiker et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Wiker, Harald G
Mustafa, Tehmina
Bjune, Gunnar A
Harboe, Morten
Evidence for waning of latency in a cohort study of tuberculosis
title Evidence for waning of latency in a cohort study of tuberculosis
title_full Evidence for waning of latency in a cohort study of tuberculosis
title_fullStr Evidence for waning of latency in a cohort study of tuberculosis
title_full_unstemmed Evidence for waning of latency in a cohort study of tuberculosis
title_short Evidence for waning of latency in a cohort study of tuberculosis
title_sort evidence for waning of latency in a cohort study of tuberculosis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843612/
https://www.ncbi.nlm.nih.gov/pubmed/20178619
http://dx.doi.org/10.1186/1471-2334-10-37
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