Spatiotemporal characteristics of hepatitis B based on township scale in Baoshan City, Yunnan Province

  Objective  To understand the epidemiological characteristics of acute and chronic hepatitis B in Baoshan city, Yunnan province, and provide scientific evidence for the prevention and control of hepatitis B.

  Methods  Excel 2007 and SPSS 19.0 were used for descriptive epidemiological analysis. GeoDa 1.8.0 was used for spatial autocorrelation analysis and SaTScan 9.6 software was used for retrospective time scan statistics. ArcGIS 10.5 software was used to generate the average annual incidence and the distribution of the average annual incidence of acute and chronic hepatitis B and the incidence risk charts of each township.

  Results  A total of 18 467 HBV cases were reported with an annual average incidence of 52.30/100 000. Most cases were young and middle-aged male farmers. The incidence rate in males was higher than that in females (P<0.001). Temporally, hepatitis B cases were reported in each month without obvious seasonal incidence peak. Spatially, the highest case number and incidence rate were reported in Longyang district with a spatial autocorrelation coefficient of 0.54. A spatial cluster was founded in the northeast areas covering 12 townships with a radius of 31.46, and Yangliu Township was the center of spatial cluster with a radius of 31.46 km and a relative risk (RR) of 2.26. The coefficient of spatial autocorrelation (Moran’s I) of acute hepatitis B incidence rate was 4.0. The cluster of acute hepatitis B cases was mainly found in 19 townships in the southwest area in Baoshan, including Bizai , with a radius of 38.92 km and a RR of 1.82.

  Conclusion  The incidence rates of hepatitis B in some townships of Baoshan were high, and hot areas with high incidence rates existed at the township level. The variation in hot area spatial distribution also existed. Factors associated with the variation of spatial distribution of hepatitis B in Baoshan need to be further studied.