OBJECTIVE: To determine to what extent tuberculosis incidence is associated with altitude. METHODS: Notification rates were obtained from all 41 districts in Kenya in the period 1988-1990; the mean altitude of each district was estimated. Data on indicators of socio-economic status such as literacy rate and infant mortality rate were obtained from the 1989 census, as well as data on other potential confounders such as urbanisation and median household size. RESULTS: The notification rate of new smear-positive tuberculosis was 32/100000 overall, varying between districts from 5 to 222/100000. Notification rates steeply reduced with increasing altitude (r = -0.71; 95% confidence interval [CI] -0.51 to -0.83). At altitudes of 1000 m or more the notification rates were less than 30% of those in districts at altitudes below 500 m, also after adjustment for confounding. CONCLUSION: Tuberculosis incidence in Kenya decreases strongly with increasing altitude. If the association is not due to unknown confounding factors, a range of potential biological explanations needs to be explored.
OBJECTIVE: To determine to what extent tuberculosis incidence is associated with altitude. METHODS: Notification rates were obtained from all 41 districts in Kenya in the period 1988-1990; the mean altitude of each district was estimated. Data on indicators of socio-economic status such as literacy rate and infant mortality rate were obtained from the 1989 census, as well as data on other potential confounders such as urbanisation and median household size. RESULTS: The notification rate of new smear-positive tuberculosis was 32/100000 overall, varying between districts from 5 to 222/100000. Notification rates steeply reduced with increasing altitude (r = -0.71; 95% confidence interval [CI] -0.51 to -0.83). At altitudes of 1000 m or more the notification rates were less than 30% of those in districts at altitudes below 500 m, also after adjustment for confounding. CONCLUSION:Tuberculosis incidence in Kenya decreases strongly with increasing altitude. If the association is not due to unknown confounding factors, a range of potential biological explanations needs to be explored.
Authors: Wenyi Sun; Jianhua Gong; Jieping Zhou; Yanlin Zhao; Junxiang Tan; Abdoul Nasser Ibrahim; Yang Zhou Journal: Int J Environ Res Public Health Date: 2015-01-27 Impact factor: 3.390
Authors: Sarah Eisen; Louise Pealing; Robert W Aldridge; Mark J Siedner; Alejandro Necochea; Inna Leybell; Teresa Valencia; Beatriz Herrera; Siouxsie Wiles; Jon S Friedland; Robert H Gilman; Carlton A Evans Journal: PLoS One Date: 2013-09-13 Impact factor: 3.240
Authors: Andreas Horner; Joan B Soriano; Milo A Puhan; Michael Studnicka; Bernhard Kaiser; Lowie E G W Vanfleteren; Louisa Gnatiuc; Peter Burney; Marc Miravitlles; Francisco García-Rio; Julio Ancochea; Ana M Menezes; Rogelio Perez-Padilla; Maria Montes de Oca; Carlos A Torres-Duque; Andres Caballero; Mauricio González-García; Sonia Buist; Maria Flamm; Bernd Lamprecht Journal: Respir Res Date: 2017-08-23