Analysis of Factors Influencing Cystic Echinococcosis in Northwest Non-Qinghai Tibetan Plateau Regions of China.

Cystic echinococcosis (CE) is an important health problem in northwest non-Qinghai Tibetan Plateau regions of China. Understanding CE risk factors may help in formulating effective prevention and control measures. In the current study, negative binomial regression was used to analyze CE-related factors using prevalence data from 147 counties (cities, districts, and banners) in northwest non-Qinghai Tibetan Plateau regions of China gathered from a national survey conducted in 2012, county economic data, and livestock production data for 2012. The negative binomial regression models indicated Echinococcus granulosus infection rate in livestock (odds ratio [OR]: 1.0471, 95% CI: 1.0128-1.0825, P = 0.0067), the mean number of dogs per family (OR: 3.0589, 95% CI: 1.5116-6.1900, P = 0.0019), the mean number of sheep per family (OR: 1.0431, 95% CI: 1.0027-1.0852, P = 0.0365), and the source of drinking water (OR: 0.9808, 95% CI: 0.9627-0.9992, P = 0.0413) were correlated with human CE prevalence, whereas altitude, surface temperature, economy, and mean number of cattle per family had a negative association. We found that the positive rate of dog stool coproantigen of Echinococcus was associated with human CE prevalence using the univariate analysis but not after controlling for covariates including the number of dogs per family. This might be partially due to the deworming campaigns that were carried out in most of the researched areas. Therefore, the positive rate of dog stool coproantigen of Echinococcus could not reflect the dog infection rate under natural conditions. These findings indicate that dogs and livestock play the most important role in CE transmission. Further studies should be carried out at the township or village level.