Fhe risk of human papillomavirus infection for male ertility abnormality： a meta-analysis

Human papillomavirus （HPV） is the most common sexually transmitted virus in males and females worldwide; yet its impact upon male fertility remains unclear. The objective of this study was to evaluate the potential impact of HPV infection in semen on male fertility abnormality. A systematic literature search was performed in PubMed, Medline, Embase, Web of Science, and the Cochrane Library database for relevant publications up to May 6,2017. The odds ratio （OR）, and its corresponding 95% confidence interval （CI）, was selected to represent the effect size. Statistical analysis was conducted using STATA 12.0. In total, eight articles, providing data on 1955 participants, were included in this meta-analysis. Collectively, the data suggested that HPV infection of semen was a risk factor for male fertility abnormality with an OR of 3.02 （95% Ch 2.11-4.32; I2= 6.9%）. Sensitivity analysis revealed that the results of this study were robust. In conclusion, HPV infection of semen represents a risk factor for male fertility abnormality.

Quantifying the impacts of human mobility restriction on the spread of coronavirus disease 2019:an empirical analysis from 344 cities of China

Background:Since the outbreak of coronavirus disease 2019(COVID-19),human mobility restriction measures have raised controversies,partly because of the inconsistent findings.An empirical study is promptly needed to reliably assess the causal effects of the mobility restriction.The purpose of this study was to quantify the causal effects of human mobility restriction on the spread of COVID-19.Methods:Our study applied the difference-in-difference(DID)model to assess the declines of population mobility at the city level,and used the log-log regression model to examine the effects of population mobility declines on the disease spread measured by cumulative or new cases of COVID-19 over time after adjusting for confounders.Results:The DID model showed that a continual expansion of the relative declines over time in 2020.After 4 weeks,population mobility declined by-54.81%(interquartile range,-65.50%to-43.56%).The accrued population mobility declines were associated with the significant reduction of cumulative COVID-19 cases throughout 6 weeks(ie,1%decline of population mobility was associated with 0.72%[95%CI:0.50%-0.93%]reduction of cumulative cases for 1 week,1.42%2 weeks,1.69%3 weeks,1.72%4 weeks,1.64%5 weeks,and 1.52%6 weeks).The impact on the weekly new cases seemed greater in the first 4 weeks but faded thereafter.The effects on cumulative cases differed by cities of different population sizes,with greater effects seen in larger cities.Conclusions:Persistent population mobility restrictions are well deserved.Implementation of mobility restrictions in major cities with large population sizes may be even more important.