[Correlation between hepatitis B virus infection and adverse pregnancy outcomes-a systematic review and meta-analysis].

Objective: To systematically evaluate the effect of hepatitis B virus (HBV) infection on the risk of adverse pregnancy outcomes. Methods: We searched PubMed, Embase, Web of Science, and Cochrane databases. Two researchers independently screened the literature, extracted data, and evaluated the quality. Meta-analysis and cumulative meta-analysis were performed using R4.4.1 software. Fixed/random effects models were used to analyze heterogeneous and non-heterogeneous results. Heterogeneous modifiers were identified by subgroup analysis. Funnel plots and Peters' test were used to analyze potential publication bias. Results: A total of 48 studies involving 92 836 HBsAg-positive pregnant women and 7 123 292 HBsAg-negative pregnant women were included. In terms of adverse pregnancy outcomes, HBV infection was significantly correlated with the occurrence of gestational diabetes mellitus [odds ratio (OR)=1.34, 95% confidence interval (CI): 1.17-1.53] and intrahepatic cholestasis (OR=2.48, 95%CI: 1.88-3.29), with statistically significant differences. In terms of adverse neonatal outcomes, HBV infection was significantly correlated with the occurrence of neonatal asphyxia (OR=1.49, 95%CI: 1.20-1.86) and preterm birth (OR=1.22, 95%CI: 1.12-1.33), with statistically significant differences. In addition, the cumulative meta-analysis demonstrated that the risk of gestational diabetes mellitus and preterm birth both tended to be stable in pregnant women with HBV infection following 2009 and 2010, respectively. The supplementary questions answered for repeated studies had limited significance. Conclusion: Intrahepatic cholestasis, gestational diabetes mellitus, neonatal asphyxia, and preterm birth occurrence risk can be raised with HBV infection in pregnant women.

Infestation and distribution of chigger mites on Brown rat (Rattus norvegicus) in Yunnan Province, Southwest China.

Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some "data mining" strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H'=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (Css) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston's lognormal model with s(R)=15e-[0.31(R-1)]2 (α=0.31, R2=0.95). On the basis of fitting the theoretical curve by Preston's model, the total mite species on R. norvegicus was estimated to be 86 species, and 25 rare mite species were missed in the sampling field investigation. The curve tendency of the species-plot relationship indicates that R. norvegicus have a great potential to harbor many species of chigger mites, and more species of the mites would be collected if more rats are sampled.

Infestation and distribution of chigger mites on Brown rat (Rattus norvegicus) in Yunnan Province, Southwest China

@#Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some “data mining” strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H’=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (Css) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston’s lognormal model with S