Background: Manganese (Mn) is an essential element in humans but its effect on semen quality is unclear. This study therefore aimed to assess the effects of Mn on semen quality in healthy men with no occupational exposure to Mn. Methods: Semen samples were obtained from healthy Chinese men 20–59 years old who were recruited from six provinces in China. Individuals with urogenital tract diseases, tuberculosis, or occupational exposure to heavy metals were excluded. A questionnaire survey was conducted, and the external genitalia, semen quality, and serum Mn levels were examined. Results: A total of 1,179 volunteers were enrolled in this study. The median serum Mn concentration was 8.2 μg/L (25th percentile (P₂₅)=3.7 μg/L, P₇₅=16.2μg/L). After adjusted area (six provinces), abstinence interval, season, registered residence, age of subjects, education level, income, smoking, and drinking, the risk of teratospermia was increased at serum Mn concentrations >19.40 μg/L (P₈₀) group, with an adjusted odds ratio of 2.27 (95% confidence interval: 1.18–4.37). Conclusion: High serum Mn levels appeared to have harmful effects on sperm morphology and motility among healthy men with no occupational exposure to Mn.

This study examined the prevalence and the determinants of risky sexual behavior (defined as having multiple sex partners and paying for sex) among male rural-to-urban migrants in China. An anonymous questionnaire was used to collect information on socio-demographics, knowledge, attitudes, and behavior associated with increased risk of risky sexual behavior from 4,069 subjects. In total 1,132 (27.8%) participants reported two or more sex partners and 802 (19.7%) participants paid for sex. A considerable proportion (29.6%–41.5%) did not use a condom during risky sexual behavior. Logistic regression analysis revealed that unmarried status (OR: 0.62, CI: 0.42–0.85 for married), earlier age at first sexual experience (OR: 0.67, 95% CI: 0.31–0.91 for ≥22 years old), poor perception of risk of acquiring HIV/AIDS (OR: 1.51, 95% CI: 1.33–1.96 for unlikely; OR: 2.38, 95% CI: 1.61–3.70 for impossible), frequent exposure to pornography (OR: 0.67, 95% CI: 0.60–0.81 for sometimes; OR: 0.31, 95% CI: 0.11–0.43 for never), attitudes toward legalization of commercial sex (OR: 0.39, 95% CI: 0.21–0.59 for no), peer influence (OR: 0.51, 95% CI: 0.27–0.88 for no), and not knowing someone who had/had died from HIV/AIDS (OR: 0.35, 95% CI: 0.20–0.53 for yes) were all significantly associated with having multiple sex partners. Those who paid for sex showed similar findings.

Background: Corona Virus Disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and rapidly spread throughout China since late December 2019. Crude case fatality ratio (CFR) with dividing the number of known deaths by the number of confirmed cases does not represent the true CFR and might be off by orders of magnitude. We aim to provide a precise estimate of the CFR of COVID-19 using statistical models at the early stage of the epidemic. Methods: We extracted data from the daily released epidemic report published by the National Health Commission P. R. China from 20 Jan 2020, to 1 March 2020. Competing risk model was used to obtain the cumulative hazards for death, cure, and cure-death hazard ratio. Then the CFR was estimated based on the slope of the last piece in joinpoint regression model, which reflected the most recent trend of the epidemic. Results: As of 1 March 2020, totally 80,369 cases were diagnosed as COVID-19 in China. The CFR of COVID-19 were estimated to be 70.9% (95% CI: 66.8%-75.6%) during Jan 20-Feb 2, 20.2% (18.6%-22.1%) during Feb 3-14, 6.9% (6.4%-7.4%) during Feb 15-23, 1.5% (1.4%-1.6%) during Feb 24-March 1 in Hubei province, and 20.3% (17.0%-25.3%) during Jan 20-28, 1.9% (1.8%-2.1%) during Jan 29-Feb 12, 0.9% (0.8%-1.1%) during Feb 13-18, 0.4% (0.4%-0.5%) during Feb 19-March 1 in other areas of China, respectively. Conclusions: Based on analyses of public data, we found that the CFR in Hubei was much higher than that of other regions in China, over 3 times in all estimation. The CFR would follow a downwards trend based on our estimation from recently released data. Nevertheless, at early stage of outbreak, CFR estimates should be viewed cautiously because of limited data source on true onset and recovery time.

Background: Domestic migrant populations are highly mobilized at a sexually active age, and often fail to meet their needs for contraception. Moreover, they assume sexual and reproductive health (SRH) risks and utilize fewer family planning services. Method: A quasi-experimental trial (community intervention) was adopted. Two-stage stratified cluster sampling was applied to recruit participants in Beijing and Chongqing. A comprehensive SRH/family planning intervention was implemented from August 4 2014 to August 3 2015. Propensity score matching (PSM) and multivariate probit models were adopted. Results: In total, 2100 and 2024 eligible participants were involved, and 815 and 629 pairs were matched by PSM in Beijing and Chongqing, respectively. The knowledge and attitudes of the participants regarding SRH and contraception were significantly improved through the comprehensive intervention. Reversible contraceptive methods were the most prevalent; couples largely decided to utilize condoms and family planning services. Conclusions: The comprehensive intervention had positive effects on knowledge, attitudes, and practices (KAP) for SRH/family planning among the domestic migrant population. The results acquired can be extrapolated to some extent, and the pattern of this intervention is well geared toward other similar settings in China.

To evaluate and compare the effectiveness of the combined regimen (consisting of condoms and emergency contraception pills (ECP)) and using condoms only for the purpose of preventing pregnancy. One-thousand-five-hundred-and-sixty-two (1,562) couples as volunteers enrolled at nine centers in Shanghai. Eight-hundred-and-twelve (812) were randomized to use male condoms and ECP (i.e., Levonorgestrel) as a back-up to condoms (the intervention group) and 750 to use male condoms only(the control group), according to their working unit. Participants were visited at admission and at the end of 1, 3, 6, 9, and 12 months. The cumulative life table rates were calculated for pregnancy and other reasons for discontinuation. The gross cumulative life table rates showed that the cumulative discontinuation rates for all reasons during the year of follow-up in the condoms plus emergency contraception group and the condoms only group were 7.76 ± 0.94 and 6.61 ± 0.91, respectively, per 100 women (χ2 = 0.41, p = 0.5227). The cumulative gross pregnancy rate of the condoms plus emergency contraception group and the condoms only group were 2.17 ± 0.52 and 1.25 ± 0.41, respectively, per 100 women (χ2 = 1.93, p = 0.1645). The Pearl Index in the condoms plus emergency contraception group and the condoms only group were 2.21% and 1.26%, respectively. Male condoms remain a highly effective contraceptive method for a period of one year while consistently and correctly used. In addition, the lowest pregnancy rate followed from perfect use condom.

This study attempted to explore how informed choice on contraceptive methods influenced induced abortions among reproductive-age immigrant women in China. A total of 3230 participants were recruited in Beijing, Shanghai, and Chongqing. Information on informed choice was collected by questionnaires. The annual incidence rate (spells) of induced abortions was 0.46 (1500/3230) among the participants. The sequence from the highest score to the lowest was long-term, short-term and natural contraceptive methods (p < 0.0001). Significant differences of rates in induced abortions were found in region, occupation, length of the first immigration up to now (year), purpose for immigration, number of children, marital status, sex preference, contraceptive methods, deciders of contraceptive methods and side effects. In the zero-inflated negative binomial model, the joint impacts showed when a participant with one child employed condoms or family planning service providers as the deciders of contraceptive methods introduced intrauterine devices, the occurrence of induced abortions was more likely to be reduced. Women who underwent side effects using pills were more likely to have had induced abortions.