Assessment of HCV genotypes in Yunnan Province of Southwest China

Recently, we reported that the frequency of hepatitis C virus (HCV) genotypes and subtypes has rapidly changed among intravenous drug users (IDUs) in Yunnan Province over the last 5 years; this is especially true for subtype 6a which has increased in frequency from 5 to 15%. Here, we assessed 120 HCV-positive plasma samples from the general population (GP). HCV NS5B fragments were amplified and sequenced by PCR. We identified four HCV genotypes (1, 2, 3 and 6) and seven HCV subtypes (1b, 2a, 3a, 3b, 6a, 6n, and 6k) in this population. Genotype 3 was predominant, with a distribution frequency of 0.484, followed by genotype 1 (0.283), genotype 6 (0.133) and genotype 2 (0.100). HCV subtypes 3b (frequency 0.292) and 1b (frequency 0.283) were the most common subtypes. A comparison of the current data with previous results reported for IDUs showed that the distribution frequencies of genotypes 1, 2 and 6 were significantly different between patients in the GP and IDUs (P < 0.05). Among the HCV subtypes, the distribution frequencies of 1b, 2a, 6a, and 6n were significantly different between patients in the GP and IDU groups (P < 0.05). Moreover, Phylogenetic analyses showed that HCV subtype 6a strains isolated from IDUs and the GP were intermixed and not separately clustered. HCV subtype 6a was predominant not only among IDUs but also among those in the GP in the Guangdong Province and Vietnam. However, HCV subtype 6a was predominant only among IDUs and not among those in the GP in the Yunnan and Guangxi Provinces. Our results indicate that the HCV subtype 6a could rapidly spread across China.     

Bacterial associates of Hyalesthes obsoletus (Hemiptera: Cixiidae), the insect vector of bois noir disease,with a focus on cultivable bacteria

The planthopper Hyalesthes obsoletus (Hemiptera: Cixiidae) is an important vector of phytoplasma diseases in grapevine. In the current study, the bacterial community compositions of symbionts of this insect were examined. Two dominant bacterial lineages were identified by mass sequencing: the obligate symbiont Candidatus Sulcia, and a facultative symbiont that is closely related to Pectobacterium sp. and to BEV, a cultivable symbiont of another phytoplasma vector, the leafhopper Euscelidius variegatus. In addition, one bacterium was successfully isolated in this study – a member of the family Xanthomonadaceae that is most closely related to the genus Dyella. This Dyella-like bacterium (DLB) was detected by FISH analysis in H. obsoletus guts but not ovaries, and its prevalence in H. obsoletus increased during the fall, suggesting that it was acquired by the host through feeding. We found that DLB inhibits Spiroplasma melliferum, a cultivable relative of phytoplasma, suggesting that it is a potential candidate for biological control against phytoplasma in grapevines.     

Logistic 微分方程模型在结核病疫情预警中的应用

目的 利用 Logistic 微分方程模型进行结核病传播预测,为结核病早期防控特别提供新方法。 方法 对 Logistic 微分方程模型的原理、疫情加速关键点计算、优缺点等进行分析,以厦门市报告数据为例开展模拟研究。 结果 厦门市自 2005-2018 年来结核病高发,存在明显的冬春季节流行高峰。 通过 Logistic 微分方程拟合结果较好,疫 情加速期为每年第 1 或第 2 个月。 结论 Logistic 微分方程模型能较好地反映结核病“疫情加速时间”和“建议预警 时间”,以及疫情变化的时间点,对于基层开展结核病预警防控工作,具有较好的参考意义。     

日本血吸虫病常用诊断方法现场查病效果的评估

目的 评估几种常用血吸虫病诊断方法现场查病的效果。 方法 2005年11月，选取江西省鄱阳湖沿岸3个血吸虫病流行村的6~65岁居民为调查对象，用改良加藤厚涂片法（Kato-Katz法， 3张涂片）和尼龙绢集卵孵化法进行病原学检测的同时，分别用胶体染料试纸条法（DDIA）、快速酶联免疫吸附试验（F-ELISA）及2种间接红细胞凝集试验（IHA-A和IHA-B）进行血清学检测，以评价该几种检测方法的效果。 结果 3村共检测居民1 864人，平均粪检阳性率为9.7%。改良加藤法在血吸虫病中度、重度流行区的漏检率相对稳定，为20.0%~27.8%；尼龙绢集卵孵化法的漏检率在每克粪便虫卵数（EPG）＞100时相对稳定（约25％）。DDIA、F?鄄ELISA、IHA?鄄A和IHA?鄄B的平均阳性率分别为47.8%、50.0%、66.3%和40.1%。以病原学检测结果为金标准，DDIA、F?鄄ELISA、IHA-A和IHA-B的敏感性分别为75.3％、65.8％、85.6％和76.0%；特异性为55.1％、51.7％、35.7%和63.6％。与其他几种免疫血清学诊断方法相比，IHA?鄄B试剂的特异性、Youden指数、阳性似然比及粪检符合率最高。DDIA法与IHA-B法的符合率最高（77.3％），而F-ELISA和IHA-A的符合率最低（61.5％）。 结论 在血吸虫病中、重度流行区，改良加藤法虫卵检出率和稳定性均优于尼龙绢集卵孵化法；IHA-A的敏感性最高，IHA-B的4个指标最高，具有较高的现场使用价值，但需进一步提高其敏感性。     

Risks associated with cryopreserved semen in a human sperm bank during and after the COVID-19 pandemic

Research questionWhat are the risks associated with cryopreserved semen collected during and after the coronavirus disease 2019 (COVID-19) pandemic wave in Wuhan, China?DesignRetrospective cohort study involving young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank (China) during the pandemic wave (1 January 2020 to 30 January 2020) and after the wave and return to work (7 April 2020 to 30 May 30 2020). One hundred paired semen and blood specimens from 100 donors were included. One-step single-tube nested quantitative real-time polymerase chain reaction (OSN-qRT-PCR) was used to detect SARS-CoV-2. Moreover, to control the unacceptable risk of false-negative results, a second round of screening was performed with pooled RNA from negative semen samples using crystal digital PCR (cd-PCR).ResultsFor individual blood and semen samples, the target genes, namely the nucleocapsid protein (N) and open reading frame (ORF-1ab) genes, tested negative in all of the 100 paired samples. Further, as per cd-PCR results, there were >20,000 droplets per well in the RNA for each combined sample and no positive droplets were present for either of the aforementioned target genes. A total of 100 paired semen and blood samples from these two groups tested negative for SARS-CoV-2.ConclusionsCryopreserved semen at the Hunan Province Human Sperm Bank during and after the COVID-19 pandemic wave was free of SARS-CoV-2 and was judged safe for external use in the future.     

日本福岛核事故期间由日本入境人员体表放射性污染分析

目的 分析了福岛第一核电站事故期间由日本入境人员体表放射性污染情况.方法 根据《人员体表放射性污染处理技术方案(试行)》,组织国内重点监测省市放射技术机构,检测并报送由日本可能受辐射污染地区入境人员体表放射性污染检测数据.结果 根据各省市报送数据,截至2011年12月8日,全国共检测432人,其中429人检测结果接近本底水平,仅有3人高于本底水平.结论 通过福岛核事故期间由日本入境人员体表放射性污染检测,对他们的心理健康疏导以及避免当地民众的恐慌情绪起到了重要的作用.     

我国开展耐多药肺结核诊疗管理的可行性分析

针对我国耐多药肺结核(MDR -TB)的严峻形势和控制现状,结合国内外MDR -TB诊疗管理经验和成本效益研究结果,对全国范围内开展MDR -TB诊疗管理的可行性进行探讨.     

男男性行为者安全套使用及影响因素分析

目的 了解男男性行为者(men who have sex with men,MSM)安全套使用状况,并分析影响因素.方法 通过MSM同伴招募调查对象,在MSM活动场所进行安全套使用等相关因素的匿名现场问卷调查.结果 共调查400人,最近1次、近6个月不同性伴肛交/阴道交安全套使用率差异均有统计学意义(分别有x2=21.82,P＜0.001和x2=28.26,P＜0.001),男性、男男卖性使用率较高(73.8％、66.7％,45.5％、46.2％),男男买性、女性使用率较低(47.1％、47.9％,29.4％、30.1％).单因素分析显示,不同年龄、近6个月男男肛交数,近1年是否做过HIV检测并知道结果、接受润滑剂免费发放、接受过同伴教育,艾滋病知识是否来源于咨询服务、宣传材料发放,是否知道性伴从不用安全套、是否知道性伴健康状况,不同场所寻找性伴这10个方面近6个月男男肛交安全套坚持使用率差异有统计学意义(x2=4.043、9.850、6.663、7.525、5.213、4.208、10.042、4.121、12.319、8.456,均有P＜0.05).多因素非条件Logistic回归分析中,最终进入回归模型的有年龄、做过HIV检测并知道结果、艾滋病知识来源于宣传材料发放、不知道性伴健康状况、寻找性伴的场所,近1年做过HIV检测并知道结果(OR=0.074)、艾滋病知识来源于宣传材料发放( OR=0.409)、以酒吧/歌舞厅/会所(OR=10.495)、浴室/公园/公厕(OR =36.601)、互联网(OR=10.807)为主要性伴寻找场所者近6个月男男肛交安全套坚持使用率较高,年龄≥35岁(OR=0.330)、不知道性伴健康状况(OR =0.892)安全套坚持使用率较低.结论 MSM人群安全套使用较低,受年龄、预防性服务、健康意识等多种因素影响,应针对性加大行为干预力度.     

柳州市1996-2010年“查无此人”HIV/AIDS病例特征分析

目的 对柳州市1996-2010年病例报告数据库中“查无此人”病例的基本情况进行分析.方法 分析资料来源于“全国艾滋病综合防治信息系统”柳州市1996-2010年度疫情信息库中的病例随访管理“查无此人”数据资料,采用SPSS 13.0进行统计分析.结果 柳州市1996-2010年报告的病例中有2 405例随访状态为“查无此人”,其中艾滋病病毒(human immunodeficiency virus,HIV)感染者2 217例,艾滋病(acquired immunodeficiency syndrome,AIDS)病例188例.报告的“查无此人”病例以21～40岁青壮年为主(80.6％),男性1 731例(72.0％);病例主要分布在2003 -2007年(66.4％);1996-2009年主要来源是广西其他地市(53.45％)和柳州市(41.83％);感染途径主要为注射毒品(38.03％)和异性性传播(19.10％),传播途径不详占40.33％;“查无此人”病例的工作单位、身份证号、联系方式、民族、文化程度等信息缺失较多;自2010年柳州市全面开展实名制检测后,“查无此人”病例数明显下降,且各类常见缺失变量的缺失率均低于实名制检测实施前(均有P＜0.001).结论 “查无此人”病例与个人信息缺失、艾滋病网络监测系统、人群特征等多种因素有关,应针对这些因素采取措施,减少“查无此人”病例的再次出现.