Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort / 中华预防医学杂志

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

The risk of human papillomavirus infection for male fertility abnormality: a meta-analysis / 亚洲男科学杂志(英文版)

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% CI: 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.

Species identification of Triculinae based on COI gene segment, Fujian Province / 中国人兽共患病学报

The aim of the study is to evaluate the utility value of species identification of Triculinae based on COI gene.Triculinae-like samples were collected from different places in Fujian Province.After classification based on morphology characters,genomic DNA was extracted from collected samples.Then the segments of COI gene were amplified and sequenced for taxonomy annotation and phylogenetic analysis.Eleven samples were annotated as Gammatricula (identities:88.96％-97.82％),the other two were annotated as Tricula wumingensis (identity:87.08％) and Neotricula apart (identity:88.55％),respectively.In most cases (12 out of 13),there was a difference between results based on different classification methods on a genus level.The alignment of COI gene segment is sufficient for preliminary identification of Triclulinae at family level.However,it is need further study in species identification of Triclulinae at genus level.