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Shifts in the spatiotemporal dynamics of schistosomiasis: a case study in Anhui Province, China.

Hu Y, Li R, Chen Y, Gao F, Wang Q, Zhang S, Zhang Z, Jiang Q - PLoS Negl Trop Dis (2015)

Bottom Line: Parasitological data were obtained through repeated cross-sectional surveys that were carried out during 1997-2010 in Anhui Province, East China.The POPs associated with these oscillatory components showed that the pattern near the Yangtze River varied markedly and that the disease risk appeared to evolve in a Southwest/Northeast orientation.The POP coefficients showed decreasing tendency until 2001, then increasing during 2002-2005 and decaying afterwards.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China; Laboratory for Spatial Analysis and Modeling, School of Public Health, Fudan University, Shanghai, China.

ABSTRACT

Background: The Chinese national surveillance system showed that the risk of Schistosoma japonicum infection fluctuated temporally. This dynamical change might indicate periodicity of the disease, and its understanding could significantly improve targeted interventions to reduce the burden of schistosomiasis. The goal of this study was to investigate how the schistosomiasis risk varied temporally and spatially in recent years.

Methodology/principal findings: Parasitological data were obtained through repeated cross-sectional surveys that were carried out during 1997-2010 in Anhui Province, East China. A multivariate autoregressive model, combined with principal oscillation pattern (POP) analysis, was used to evaluate the spatio-temporal variation of schistosomiasis risk. Results showed that the temporal changes of schistosomiasis risk in the study area could be decomposed into two sustained damped oscillatory modes with estimated period of approximately 2.5 years. The POPs associated with these oscillatory components showed that the pattern near the Yangtze River varied markedly and that the disease risk appeared to evolve in a Southwest/Northeast orientation. The POP coefficients showed decreasing tendency until 2001, then increasing during 2002-2005 and decaying afterwards.

Conclusion: The POP analysis characterized the variations of schistosomiasis risk over space and time and demonstrated that the disease mainly varied temporally along the Yangtze River. The schistosomiasis risk declined periodically with a temporal fluctuation. Whether it resulted from previous national control strategies on schistosomiasis needs further investigations.

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Related in: MedlinePlus

Prevalence of S. japonicum infection for counties in Anhui Province, China, from 1997 to 2010.The red vertical lines denote interquartile range, the green circles denote the mean, and the black circles denote the median.
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pntd.0003715.g003: Prevalence of S. japonicum infection for counties in Anhui Province, China, from 1997 to 2010.The red vertical lines denote interquartile range, the green circles denote the mean, and the black circles denote the median.

Mentions: Fig 3 provides the annual prevalence of schistosomiasis during the study period. The mean prevalence gradually increased from 0.11% in 1997 to 0.23% in 2005, and then decreased substantially to 0.08% in 2010. This fluctuated tendency was accompanied by a corresponding variation in prevalence across counties with the interquartile range (IQR) expanding from 0–0.02/100 in 1997 to 0.04–0.28/100 in 2005 and then shrinking to 0–0.05/100 in 2010. A similar trend was observed when median prevalence was used.


Shifts in the spatiotemporal dynamics of schistosomiasis: a case study in Anhui Province, China.

Hu Y, Li R, Chen Y, Gao F, Wang Q, Zhang S, Zhang Z, Jiang Q - PLoS Negl Trop Dis (2015)

Prevalence of S. japonicum infection for counties in Anhui Province, China, from 1997 to 2010.The red vertical lines denote interquartile range, the green circles denote the mean, and the black circles denote the median.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400088&req=5

pntd.0003715.g003: Prevalence of S. japonicum infection for counties in Anhui Province, China, from 1997 to 2010.The red vertical lines denote interquartile range, the green circles denote the mean, and the black circles denote the median.
Mentions: Fig 3 provides the annual prevalence of schistosomiasis during the study period. The mean prevalence gradually increased from 0.11% in 1997 to 0.23% in 2005, and then decreased substantially to 0.08% in 2010. This fluctuated tendency was accompanied by a corresponding variation in prevalence across counties with the interquartile range (IQR) expanding from 0–0.02/100 in 1997 to 0.04–0.28/100 in 2005 and then shrinking to 0–0.05/100 in 2010. A similar trend was observed when median prevalence was used.

Bottom Line: Parasitological data were obtained through repeated cross-sectional surveys that were carried out during 1997-2010 in Anhui Province, East China.The POPs associated with these oscillatory components showed that the pattern near the Yangtze River varied markedly and that the disease risk appeared to evolve in a Southwest/Northeast orientation.The POP coefficients showed decreasing tendency until 2001, then increasing during 2002-2005 and decaying afterwards.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China; Laboratory for Spatial Analysis and Modeling, School of Public Health, Fudan University, Shanghai, China.

ABSTRACT

Background: The Chinese national surveillance system showed that the risk of Schistosoma japonicum infection fluctuated temporally. This dynamical change might indicate periodicity of the disease, and its understanding could significantly improve targeted interventions to reduce the burden of schistosomiasis. The goal of this study was to investigate how the schistosomiasis risk varied temporally and spatially in recent years.

Methodology/principal findings: Parasitological data were obtained through repeated cross-sectional surveys that were carried out during 1997-2010 in Anhui Province, East China. A multivariate autoregressive model, combined with principal oscillation pattern (POP) analysis, was used to evaluate the spatio-temporal variation of schistosomiasis risk. Results showed that the temporal changes of schistosomiasis risk in the study area could be decomposed into two sustained damped oscillatory modes with estimated period of approximately 2.5 years. The POPs associated with these oscillatory components showed that the pattern near the Yangtze River varied markedly and that the disease risk appeared to evolve in a Southwest/Northeast orientation. The POP coefficients showed decreasing tendency until 2001, then increasing during 2002-2005 and decaying afterwards.

Conclusion: The POP analysis characterized the variations of schistosomiasis risk over space and time and demonstrated that the disease mainly varied temporally along the Yangtze River. The schistosomiasis risk declined periodically with a temporal fluctuation. Whether it resulted from previous national control strategies on schistosomiasis needs further investigations.

Show MeSH
Related in: MedlinePlus