北京市一起新型冠状病毒Omicron变异株聚集性疫情特征分析

目的 分析北京市海淀区一起新型冠状病毒肺炎聚集性疫情流行病学特征及传播链。方法 采用描述性流行病学方法分析疫情流行病学特征,应用现场调查和大数据技术分析传播链。结果 2022年4月27日至5月13日, 海淀区发生一起新型冠状病毒肺炎聚集性疫情,全基因组测序系Omicron变异株（BA.2.2进化分支）;涉及感染者38例,确诊病例34例,无症状感染者4例;临床分型以轻型（88.2%）为主,无重型、危重型和死亡病例;早期临床症状以咽部不适（50.0%）、咳嗽（29.4%）为主;17 d内传播7代,涉及3起社区聚集、2起单位聚集和8个家庭内传播;暴露方式以同住（47.6%）、同时空暴露（31.6%）为主;代间距M（Q₁,Q₃）为3（1,6）d;总续发率为1.5%（37/2 482）,其中家庭续发率为36.7%（18/49）。结论 本起Omicron变异株疫情临床症状轻,家庭、社区聚集性明显,疫情传播速度较快,同时空暴露感染风险较高,需利用信息化技术全面摸排密切接触者,以快制快,有效阻断疫情传播。     

Serum Metabonomics of Articular Cartilage Destruction Induced by T-2 Toxin in Wistar Rats

正The molecular pathogenesis of T-2toxin-induced cartilage destruction has not been fully unraveled yet.The aim of this study was to detect changes in serum metabolites in a rat anomaly model with articular cartilage destruction.Thirty healthy male Wistar rats were fed a diet containing T-2 toxin(300 ng/kg chow)for 3 months.     

Chromosomal Rearrangement Features of Yersinia pestis Strains from Natural Plague Foci in China

The Yersinia pestis chromosome contains a large variety and number of insert sequences that have resulted in frequent chromosome rearrangement events. To identify the chromosomal rearrangement features of Y. pestis strains from five typical plague foci in China and study spontaneous DNA rearrangements potentially stabilized in certain lineages of Y. pestis genomes, we examined the linking mode of locally collinear blocks (LCBs) in 30 Y. pestis strains by a polymerase chain reaction-based method. Our results suggest most strains have relatively stable chromosomal arrangement patterns, and these rearrangement characteristics also have a very close relationship with the geographical origin. In addition, some LCB linking modes are only present in specific strains. We conclude Y. pestis chromosome rearrangement patterns may reflect the genetic features of specific geographical areas and can be applied to distinguish Y. pestis isolates; furthermore, most of the rearrangement events are stable in certain lineages of Y. pestis genomes.     

A systematic review of air pollution as a risk factor for cardiovascular disease in South Asia: Limited evidence from India and Pakistan

Cardiovascular diseases (CVD) are major contributors to mortality and morbidity in South Asia. Chronic exposure to air pollution is an important risk factor for cardiovascular diseases, although the majority of studies to date have been conducted in developed countries. Both indoor and outdoor air pollution are growing problems in developing countries in South Asia yet the impact on rising rates of CVD in these regions has largely been ignored. We aimed to assess the evidence available regarding air pollution effects on CVD and CVD risk factors in lower income countries in South Asia. A literature search was conducted in PubMed and Web of Science. Our inclusion criteria included peer-reviewed, original, empirical articles published in English between the years 1990 and 2012, conducted in the World Bank South Asia region (Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka). This resulted in 30 articles. Nine articles met our inclusion criteria and were assessed for this systematic review. Most of the studies were cross-sectional and examined measured particulate matter effects on CVD outcomes and indicators. We observed a bias as nearly all of the studies were from India. Hypertension and CVD deaths were positively associated with higher particulate matter levels. Biomarkers of oxidative stress such as increased levels of P-selection expressing platelets, depleted superoxide dismutase and reactive oxygen species generation as well as elevated levels of inflammatory-related C-reactive protein, interleukin-6 and interleukin-8 were also positively associated with biomass use or elevated particulate matter levels. An important outcome of this investigation was the evidence suggesting important air pollution effects regarding CVD risk in South Asia. However, too few studies have been conducted. There is as an urgent need for longer term investigations using robust measures of air pollution with different population groups that include a wider range of air pollutants and outcomes, including early indicators of CVD. These regions are facing burdens from increasing urbanization, air pollution and populations, generally weaker health infrastructure, aging populations and increased incidence of non-communicable diseases, included CVD. The extent to which the problem of air pollution and CVD will impact these countries will depend largely on the information available to inform policy and programs, which are still lacking, political will as well as social and economic development.     

云南省德宏州2007年和2010年蚊虫及蚊媒病毒调查

目的 调查云南省德宏州蚊虫和蚊媒病毒分布特点。方法 2007年和2010年的7月在德宏州5个县市利用诱蚊灯采集蚊虫标本,采用C6/36和BHK-21细胞分离病毒,RT-PCR和序列分析方法鉴定病毒分离物。结果 共采集到6属29种43 634只蚊虫,其中三带喙库蚊构成比高达78.69%,中华按蚊构成比为14.77%,其他蚊种数量较少。从蚊虫中分离到6株病毒,经RT-PCR和进化分析表明,其中3株为基因Ⅰ型流行性乙型脑炎病毒 （JEV）,均分离自三带喙库蚊;1株盖塔病毒 （GETV） 分离自三带喙库蚊; 2株淡色库蚊浓核病毒 （CppDNV） 分别分离自三带喙库蚊和迷糊按蚊。结论 三带喙库蚊是德宏州优势蚊种和蚊媒病毒主要传播媒介,当地存在基因Ⅰ型JEV、 GETV和CppDNV的流行,并与以往云南省及我国其他地区的分离株有较近亲缘关系。     

Identification and phylogenetic relationship of Iranian strains of various Leishmania species isolated from cutaneous and visceral cases of leishmaniasis based on N-acetylglucosamine-1-phosphate transferase gene

The identity of Iranian Leishmania species has been resolved to some extent by some genetic markers. In this study, based on N-acetylglucosamine-1-phosphate transferase (nagt) gene, we further elucidated the identity and phylogeny of the prevalent species in this country. DNAs of 121 isolates belonging to cutaneous leishmaniasis (CL) patients, canine visceral leishmaniasis (CVL) cases, and Rhombomys opimus rodents were amplified by targeting a partial sequence of nagt gene. All the amplicons were analyzed with restriction fragment length polymorphism (RFLP) using Acc1 enzyme, and 49 amplicons representing different reservoir hosts were sequenced and aligned with similar sequences from GenBank database. The RFLP analysis revealed that 41 CL patients were infected Leishmania tropica and 36 with Leishmania major. Among 10 CVL isolates, 6 were identified as Leishmania infantum and 4 as L. tropica. Amongst 34 rodents’ isolates, 11 and 23 isolates exhibited patterns similar to those of L. major, and L. tropica/Leishmania turanica, respectively. The sequencing results from all CL patients, CVL cases, and 4 reservoir rodents were in agreement with RFLP analysis and showed 99–100% homologies with the registered species of L. major, L. tropica, and L. infantum from Turkey, Tunisia, Iraq and Israel. Of the 7 rodent isolates exhibiting RFLP patterns similar to L. tropica/L. turanica, 3 exhibited the highest homologies (99–100%) with L. turanica and 4 with Leishmania gerbilli. The 49 nagt DNA sequences were grouped into five clusters representing L. major, L. tropica, L. infantum, L. turanica and L. gerbilli species, encompassing 19 haplotypes. No correlation was observed between intraspecies divergence and geographic distribution of haplotypes. The L. tropica haplotypes exhibited more homologies with those of L. infantum than L. major (97.2% vs. 96.9%), a probable indication to the potential ability of L. tropica to visceralize. Characterization of Iranian Leishmania isolates using nagt gene allowed unambiguous identification of five prevalent species with a high-resolution phylogeny.     

甲型H1N1流感密切接触者感染危险因素的病例对照研究

目的 了解甲型H1N1流感密切接触者感染甲型H1N1流感病毒的危险因素.方法 选择2009年5月16日～9月15日在北京发现的7 099名甲型H1N1流感密切接触者作为研究对象,根据流行病学调查资料,将其中感染甲型H1N1流感病毒者纳入病例组,未感染者纳入对照组,开展病例对照研究,通过单因素和多因素非条件Logistic回归分析探寻甲型H1N1流感密切接触者感染流感的危险因素.结果 多因素分析结果显示:与＞50岁的甲型H1N1流感密切接触者相比较,20～ 50岁(OR=3.57,95％ CI:1.63～7.81)和＜20岁(OR=8.29,95％ CI:3.76 ～ 18.29)的密切接触者更有可能出现甲型H1N1流感病毒感染;与原发病例关系为家庭成员的密切接触者(OR=4.87,95％ CI:3.32 ～7.13)、暴露于症状期原发病例的密切接触者(OR=1.87,95％ CI:1.25～2.82)以及与原发病例暴露时间＞12h的密切接触者(OR=1.81,95％ CI:1.24～2.63)更易出现甲型H1N1流感病毒感染.结论 密切接触者年龄低、与原发病例关系密切、暴露于症状期的原发病例、长时间暴露于原发病例是甲型H1N1流感密切接触者发生感染的危险因素.     

Brazilian spotted fever: Real-time PCR for diagnosis of fatal cases

Suspicion of Brazilian spotted fever (BSF) should occur in endemic regions upon surveillance of the acute febrile icteric hemorrhagic syndrome (AFIHS). However, limitations associated with currently available laboratory tests pose a challenge to early diagnosis, especially in fatal cases. Two real-time PCR (qPCR) protocols were evaluated to diagnose BSF in 110 fatal AFIHS cases, collected in BSF-endemic regions in 2009–2010. Of these, 24 were positive and 86 negative by indirect immunofluorescence (IFA) assay (cut-off IgG and/or IgM ≥ 128). DNA from these samples was used in the qPCR protocols: one to detect Rickettsia spp. (citrate synthase gene) and another to determine spotted fever group (SFG) Rickettsia species (OmpA gene). Of the 24 IFA-positive samples, 5 (21%) were positive for OmpA and 9 (38%) for citrate synthase. In the IFA-negative group (n = 86), OmpA and citrate synthase were positive in 23 (27%) and 27 (31%), respectively. These results showed that the 2 qPCR protocols were about twice as sensitive as the IFA test alone (93% concordance). In conclusion, qPCR is a sensitive method for the diagnosis of fatal BSF cases and should be considered for routine surveillance of AFIHS in places like Brazil, where spotted fever-related lethality is high and other endemic diseases like dengue and leptospirosis can mislead diagnosis.     

我国不同地区猫和犬饲养及猫栉首蚤感染调查

目的了解我国部分地区猫、犬的饲养及其猫栉首蚤感染情况,为猫栉首蚤及其相关传染病的预防控制提供依据。方法采用入户调查法,在北京市、青岛市和云南省部分农村及城乡结合部调查猫、犬的养殖情况;用体表蚤、游离蚤、蚤卵调查和回顾调查等方法,调查家猫、流浪猫和家犬的猫栉首蚤感染率;用蚤卵调查法研究北京地区猫栉首蚤的季节发生规律。结果 (1)北京市郊区,64.52%～83.87%的农户养犬,平均0.84～1.87只/户,其中69.2%～86.8%的犬为散养;2.94%～6.45%的农户养猫,为散养。青岛市平度农村40.43%的农户养犬,平均0.50只/户,>36.5%的犬为散养。(2)北京市郊区和青岛市农村的猫,猫栉首蚤感染率为100%;而犬的蚤感染率仅为3.85%～19.15%,为人蚤和猫栉首蚤。(3)在北京市郊区,冬季猫栉首蚤产卵量依然较大。结论在我国农村和城乡结合部,家犬的养殖量较大,家猫的饲养很少,猫主要以流浪猫形式存在。流浪猫的猫栉首蚤发生普遍,且全年发生;应加强流浪猫的管理,关注猫栉首蚤及其相关人兽共患传染病的预防控制。     

北京市新生儿接种乙型肝炎疫苗的流行病学效果评价

目的评价新生儿接种乙型肝炎疫苗后的流行病学效果.方法收集接种人群历年的报告、现场调查接种情况;分析接种后历年来传染病疫情报告;采用多阶段随机抽样方法,收集接种儿童的血清标本,应用固相放射免疫法(SPRIA)检测血清中乙型肝炎表面抗原(HBsAg)、抗HBs和抗-HBc,并与接种初期的检测结果进行比较.结果新生儿接种乙型肝炎疫苗后,其乙型肝炎发病率由接种初期1 8.5 9～20.5 2/10万(x2=58.26,P＜0.01)降至0.39～2.38/10万;HBsAg携带率由2.82%降至0.60%,下降约80.00%(x2=10.75,P＜0.01).结论给新生儿接种乙型肝炎疫苗是预防和控制乙型肝炎病毒感染的有效手段.