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Co-endemicity of Pulmonary Tuberculosis and Intestinal Helminth Infection in the People's Republic of China.

Li XX, Ren ZP, Wang LX, Zhang H, Jiang SW, Chen JX, Wang JF, Zhou XN - PLoS Negl Trop Dis (2016)

Bottom Line: There are co-endemic, high prevalence areas of both diseases, whose delimitation is essential for devising effective control strategies.Our results indicate that gross domestic product (GDP) per capita had a negative association, while rural regions, the arid and polar zones and elevation had positive association with active PTB prevalence; for the IHI prevalence, GDP per capita and distance to water bodies had a negative association, the equatorial and warm zones and the normalized difference vegetation index had a positive association.Thus, co-endemic areas of active PTB and IHI were located in the south-western regions of China, which might be determined by socio-economic factors, such as GDP per capita.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China.

ABSTRACT
Both pulmonary tuberculosis (PTB) and intestinal helminth infection (IHI) affect millions of individuals every year in China. However, the national-scale estimation of prevalence predictors and prevalence maps for these diseases, as well as co-endemic relative risk (RR) maps of both diseases' prevalence are not well developed. There are co-endemic, high prevalence areas of both diseases, whose delimitation is essential for devising effective control strategies. Bayesian geostatistical logistic regression models including socio-economic, climatic, geographical and environmental predictors were fitted separately for active PTB and IHI based on data from the national surveys for PTB and major human parasitic diseases that were completed in 2010 and 2004, respectively. Prevalence maps and co-endemic RR maps were constructed for both diseases by means of Bayesian Kriging model and Bayesian shared component model capable of appraising the fraction of variance of spatial RRs shared by both diseases, and those specific for each one, under an assumption that there are unobserved covariates common to both diseases. Our results indicate that gross domestic product (GDP) per capita had a negative association, while rural regions, the arid and polar zones and elevation had positive association with active PTB prevalence; for the IHI prevalence, GDP per capita and distance to water bodies had a negative association, the equatorial and warm zones and the normalized difference vegetation index had a positive association. Moderate to high prevalence of active PTB and low prevalence of IHI were predicted in western regions, low to moderate prevalence of active PTB and low prevalence of IHI were predicted in north-central regions and the southeast coastal regions, and moderate to high prevalence of active PTB and high prevalence of IHI were predicted in the south-western regions. Thus, co-endemic areas of active PTB and IHI were located in the south-western regions of China, which might be determined by socio-economic factors, such as GDP per capita.

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Related in: MedlinePlus

Summarization of relationships between impact factors and spatial patterns of prevalence individually and collectively associated with active pulmonary tuberculosis and intestinal helminth infection in P. R. China.
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pntd.0004580.g008: Summarization of relationships between impact factors and spatial patterns of prevalence individually and collectively associated with active pulmonary tuberculosis and intestinal helminth infection in P. R. China.

Mentions: The shared component model makes the assumption that there are unobserved covariates that display a spatial structure common to both diseases[31]. The analysis results of the separate multivariate model for active PTB and IHI in our study showed that proxies of socio-economic and climatic factors were simultaneously associated with prevalence of both diseases. The socio-economic factors had the same effects on prevalence of both diseases, while the climatic factors showed the opposite effect including positive correlation between the arid and polar zones and active PTB and positive correlation between the equatorial and warm zones and IHI. Therefore, we inferred that socio-economic factors such as GDP per capita were the main unobserved covariates that determined the co-endemic patterns of active PTB and IHI because they were common to both diseases. Moreover, we also observed that the spatial pattern of disease-specific component for active PTB were similar to the distribution of urban extents, climate (arid and polar) zones and elevation in maps, which may indicate that they represented additional risk factors only relevant to active PTB but not to IHI. Similarly, the spatial pattern of disease-specific component for IHI were similar to the distribution of climate (equatorial and warm) zones, NDVI and distance to water bodies in maps, which may indicate that these factors were the additional risk factors only relevant to IHI but not to active PTB (see Fig 8).


Co-endemicity of Pulmonary Tuberculosis and Intestinal Helminth Infection in the People's Republic of China.

Li XX, Ren ZP, Wang LX, Zhang H, Jiang SW, Chen JX, Wang JF, Zhou XN - PLoS Negl Trop Dis (2016)

Summarization of relationships between impact factors and spatial patterns of prevalence individually and collectively associated with active pulmonary tuberculosis and intestinal helminth infection in P. R. China.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835095&req=5

pntd.0004580.g008: Summarization of relationships between impact factors and spatial patterns of prevalence individually and collectively associated with active pulmonary tuberculosis and intestinal helminth infection in P. R. China.
Mentions: The shared component model makes the assumption that there are unobserved covariates that display a spatial structure common to both diseases[31]. The analysis results of the separate multivariate model for active PTB and IHI in our study showed that proxies of socio-economic and climatic factors were simultaneously associated with prevalence of both diseases. The socio-economic factors had the same effects on prevalence of both diseases, while the climatic factors showed the opposite effect including positive correlation between the arid and polar zones and active PTB and positive correlation between the equatorial and warm zones and IHI. Therefore, we inferred that socio-economic factors such as GDP per capita were the main unobserved covariates that determined the co-endemic patterns of active PTB and IHI because they were common to both diseases. Moreover, we also observed that the spatial pattern of disease-specific component for active PTB were similar to the distribution of urban extents, climate (arid and polar) zones and elevation in maps, which may indicate that they represented additional risk factors only relevant to active PTB but not to IHI. Similarly, the spatial pattern of disease-specific component for IHI were similar to the distribution of climate (equatorial and warm) zones, NDVI and distance to water bodies in maps, which may indicate that these factors were the additional risk factors only relevant to IHI but not to active PTB (see Fig 8).

Bottom Line: There are co-endemic, high prevalence areas of both diseases, whose delimitation is essential for devising effective control strategies.Our results indicate that gross domestic product (GDP) per capita had a negative association, while rural regions, the arid and polar zones and elevation had positive association with active PTB prevalence; for the IHI prevalence, GDP per capita and distance to water bodies had a negative association, the equatorial and warm zones and the normalized difference vegetation index had a positive association.Thus, co-endemic areas of active PTB and IHI were located in the south-western regions of China, which might be determined by socio-economic factors, such as GDP per capita.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China.

ABSTRACT
Both pulmonary tuberculosis (PTB) and intestinal helminth infection (IHI) affect millions of individuals every year in China. However, the national-scale estimation of prevalence predictors and prevalence maps for these diseases, as well as co-endemic relative risk (RR) maps of both diseases' prevalence are not well developed. There are co-endemic, high prevalence areas of both diseases, whose delimitation is essential for devising effective control strategies. Bayesian geostatistical logistic regression models including socio-economic, climatic, geographical and environmental predictors were fitted separately for active PTB and IHI based on data from the national surveys for PTB and major human parasitic diseases that were completed in 2010 and 2004, respectively. Prevalence maps and co-endemic RR maps were constructed for both diseases by means of Bayesian Kriging model and Bayesian shared component model capable of appraising the fraction of variance of spatial RRs shared by both diseases, and those specific for each one, under an assumption that there are unobserved covariates common to both diseases. Our results indicate that gross domestic product (GDP) per capita had a negative association, while rural regions, the arid and polar zones and elevation had positive association with active PTB prevalence; for the IHI prevalence, GDP per capita and distance to water bodies had a negative association, the equatorial and warm zones and the normalized difference vegetation index had a positive association. Moderate to high prevalence of active PTB and low prevalence of IHI were predicted in western regions, low to moderate prevalence of active PTB and low prevalence of IHI were predicted in north-central regions and the southeast coastal regions, and moderate to high prevalence of active PTB and high prevalence of IHI were predicted in the south-western regions. Thus, co-endemic areas of active PTB and IHI were located in the south-western regions of China, which might be determined by socio-economic factors, such as GDP per capita.

Show MeSH
Related in: MedlinePlus