Study on the spatiotemporal trend of Japanese encephalitis in Guangxi,based on geographic information system and space-time permutation scan statistic / 中华流行病学杂志

Objective To study the spatiotemporal trend of Japanese encephalitis in Guangxi Zhuang Autonomous Region between 1989 and 2006.Methods Retrospective space-time permutation scan statistic and inverse distance weighted (IDW) interpolation were employed to detect the spatiotemporal trend of Japanese encephalitis in Guangxi,from the year 1989 to 2006.Results The spatiotemporal pattern of Japanese encephalitis was divided into four phases by IDW interpolation maps,from 1989 to 2006.The first phase was spatiotemporal cluster located in southeast region,from 1989 to 1996.The second phase showed discrete distribution from 1997 to 1998.The third phase of spatiotemporal cluster located in Lingshan county,Pubei county and Bobai county,in 1999.And the last phase was spatiotemporal cluster located in northwest region from 2000 to 2006.Three statistically significant spatiotemporal clusters were detected by retrospective space-time permutation scan statistic.The primary cluster appeared in 1999 (LLR=253.25,P=0.001,RR=4.62),with 109°54′ E,22°28′ N (located in Pubei county) as its center and radiated 45.24 km.From 2000 to 2006,the secondary cluster showed in northwest (LLR=75.91,P=0.001,RR = 1.88),with center located at 105°23′ E,24°68′ N (Longlin county),and radiated 199.85 kn.From 1989 to 1996,the other secondary cluster appeared in the southeast area(LLR=46.29,P=0.001,RR= 1.16),with center located at 110°94′ E,24°03′N(Zhaoping county) and radiated 229.12 km.Conclusion Space-time permutation scan statistic and geographical information system could be applied to quantitatively detect the potentially spatiotemporal trend of the disease.The spatiotemporal cluster shifted from southeast to northwest,from 1989 to 2006.

An exploratory study on the diagnostic cutoff value of International HIV-associated Dementia Scale in minority ethnic groups with different educational levels, in Guangxi / 中华流行病学杂志

Objective Using Intelligence Scale of Mini Mental State Estimated (MMSE) as the gold standard to determine the relevance of International HIV-associated Dementia Scale (IHDS)in minority ethnic areas in Guangxi populations with different cultural values.Corresponding boundary value related to the authenticity and reliability on IHDS were also evaluated.Methods 200 patients with HIV infection were randomly selected from the minority ethnic groups in Guangxi.For each infected person,MMSE and IHDS blind scale were tested at the same period.Using the results from MMSE scale test as the gold standard,ROC curve and IHDS scale in Guangxi minority populations with different education levels which related to the diagnosis of dementia-HIV values were determined.The value of a specific sector under the IHDS sensitivity,specificity,and internal consistency coefficients was also evaluated.Results When considering the infected person did not differ on their educational level,the IHDS scale diagnostic cutoff appeared as 8.25,while 1HDS sensitivity as 0.925,specificity as 0.731 and Kappa as 0.477 (P＜0.001).When considering the extent of cultural differences did influence the prevalence of infection,the different education groups showed different IHDS diagnostic cutoff values.People with high school,secondary school or higher education levels,the IHDS diagnosis appeared to be 8.25,when sensitivity was 0.917,specificity was 0.895 and Kappa was 0.722 (P＜0.001).People with only primary education level,the IHDS appeared to be 7.25.When sensitivity was 0.875,specificity was 0.661 and Kappa was 0.372 (P＜0.001).Conclusion The IHDS diagnostic sector in Guangxi minority groups was lower than the internationally recommended level of diagnostic cutoff value (IHDS≤ 10 points).When using IHDS to perform the HIV related dementia screening program,in the minority areas of Guangxi,culture context,the degree and difference of HIV infection should be considered,especially in using IHDS diagnostic cutoff values.

Using spatial autocorrelation analysis to study spatial heterogeneity of liver cancer in Guangxi / 中华流行病学杂志

Objective To study the spatial distribution characteristics of liver cancer in Guangxi so as to provide evidence for the development of congol and prevention on liver cancer.Methods The average eight year morbidity was computed,using the rates of liver cancer in 2000-2007.The spatial statistics module of GIS was used to conduct spatial autocorrelation analysis.and the disease mapping Was drawn,using the Map Info 8.0 software.Results The average morbidity rate Was clustered in Guangxi in the past eight years.with Moran's I index as 0.34 and P value below 0.01.G index appeared to be 0.77 and the Pvalue Was below 0.01.Moran's I correlogram lifled up in four spaces,specifically,the cluster took place in both nlacro-scale(one to three spatial intervals,45 to 135 km real Scale)and micro-scale(16 to 18 spatial intervals,720 to 800 km real scale).When the spatial interval became 14 and real scale was 60 km.the spatial distribution of liver cancer showed the most intensive autocorrelation.Most of the regions with high morbidity would be clustered in the southwest and southern parts,along the Coastal areas of Guangxi while the regions with low morbidity clustered in the northern part of Guangxi.Conclusion Liver cancer was found un-randorely distributed and geographitally clustered in Guangxi in 2000-2007.