Infectivity of Severe Acute Respiratory Syndrome during Its Incubation Period

Objective To evaluate the infectivity of severe acute respiratory syndrome （SARS） during its incubation period by investigating chains of transmission and individuals isolated for medical observation with a view to providing scientific evidence for updating protocols of medical isolation. Methods Individuals related with the two SARS chains of transmission in Beijing in 2003 and a group of individuals isolated for medical observation in Haidian district of Beijing during the SARS outbreak were selected as subjects of study. Contactors with SARS patients and those with symptom development following the contacts were investigated via questionnaire. Serum samples were collected from super transmitters and tested for SARS-CoV antibody by neutralization test and enzyme linked immunosorbent assay （ELISA）. Results A total of 1 112 contactors were investigated in three surveys. Of them, 669 had a history of close contact with symptomatic SARS patients, 101 developed symptoms with a rate of 15.1%, 363 had a history of close contact with patients in their incubation period, none of whom developed symptoms （0%）. Serum samples were collected fi＇om 32 highly-exposed individuals, of whom 13 developing SARS symptoms atter contact had serum samples positive for SARS-CoV antibody. Samples collected from the asymptomatic contactors were all negative for SARS-CoV antibody. Conclusion SARS cases are infectious only during their symptomatic period and are non-infectious during the incubation period. Isolation for medical observation should be placed for individuals who are in close contact with symptomatic SARS patients. The results of our study are of decisive significance for the Ministry of Health to the definition of SARS close contactor.

Targeted montoring to surgical site infection and investigation of standard application of antibiotics during perioperative period

Objective To investigate current surgical site infection and perioperative antibiotics in inpatients and explore the controlling aim and methods. Methods The infection rates of surgical sites of 287 operated cases from May to Dec 31,2007 were studied and compared with

Treatment of postoperative infectious complications in patients with human immunodef iciency virus infection

BACKGROUND: Antibiotics are widely given for surgical patients to prevent infection. Because of the lack of study on the rational use of antibiotics in patients with human immunodef iciency virus(HIV)-infected during surgical procedures, we analyzed the risk factors affecting postoperative infectious complications in HIV-infected patients and explore the rational use of perioperative antibiotics.METHODS: This retrospective study consisted of 308 HIV-infected patients, 272 males and 36 females, who had undergone operation at the Shanghai Public Health Clinical Center from November 2008 to April 2012. The patients were divided into postoperative infection and non-infection groups. Their age and clinical variables were compared. The correlation between surgical incision, surgical site infection(SSI) and postoperative sepsis was analyzed. Prophylactic antibiotics were used for patients with type I and II incisions for less than 2 days. Patients with type III incisions were given antibiotics until the infection was controlled. Antiretroviral therapy(ART) was prescribed preoperatively for patients whose preoperative CD4 count was <350 cells/μL. For those patients whose preoperative CD4 count was <200 cells/μL, sulfamethoxazole and fluconazole were given preoperatively as prophylactic agents controlling Pneumocystis carinii pneumonia and fungal infection.RESULTS: A total of 196 patients developed postoperative infectious complications, and 7 patients died. Preoperative CD4 counts, ratio of CD4/CD8 cells, hemoglobin level, and postoperative CD4 counts, hemoglobin and albumin levels were risk factors of perioperative infection in HIV-infected patients. Patients with a preoperative CD4 count <200 cell/μL, anemia, a postoperative CD4 count <200 cell/μL or albumin levels <35 g/L were correlated with a higher rate of perioperative infection. There was a signif icant correlation between SSI and the type of surgical incision. The rate of SSI in patients with type I surgical incision was 2% and in those with type II surgical incision was 38%. All the patients who received type III surgical incision developed SSI, and they were more likely to develop postoperative sepsis.CONCLUSIONS: HIV-infected patients are more likely to develop postoperative infectious complications. The rational use of antibiotics in HIV-infected patients could help to reduce the rate of postoperative infectious complications in these patients.

Probability Distribution of SARS-Cov-2 (COVID) Infectivity Following Onset of Symptoms: Analysis from First Principles

The phasing out of protective measures by governments and public health agencies, despite continued seriousness of the coronavirus pandemic, leaves individuals who are concerned for their health with two basic options over which they have control: 1) minimize risk of infection by being vaccinated and by wearing a face mask when appropriate, and 2) minimize risk of transmission upon infection by self-isolating. For the latter to be effective, it is essential to have an accurate sense of the probability of infectivity as a function of time following the onset of symptoms. Epidemiological considerations suggest that the period of infectivity follows a lognormal distribution. This proposition is tested empirically by construction of the lognormal probability density function and cumulative distribution function based on quantiles of infectivity reported by several independent investigations. A comprehensive examination of a prototypical ideal clinical study, based on general statistical principles (the Principle of Maximum Entropy and the Central Limit Theorem) reveals that the probability of infectivity is a lognormal random variable. Subsequent evolution of new variants may change the parameters of the distribution, which can be updated by the methods in this paper, but the form of the probability function is expected to remain lognormal as this is the most probable distribution consistent with mathematical requirements and available information.

北京妇产医院围产期孕妇B族链球菌感染及妊娠结局的概况分析

目的分析在北京妇产医院就诊的围产期孕妇B族链球菌(GBS)感染以及妊娠结局新生儿受累感染的概况。方法收集2022年1月至2024年3月在我院就诊的围产期孕妇26351例,新生儿2015例,对其进行B族链球菌核酸检测分析。结果在26351例围产期孕妇中,有2906例为GBS阳性感染者,感染率为11.03%。其中18~24岁孕妇GBS感染率为10.70%,25~35岁孕妇GBS感染率为11.22%,36~45岁孕妇GBS感染率为10.35%,46~52岁孕妇GBS感染率为13.33%,4组年龄段B族链球菌感染率差异无统计学意义(P>0.05);根据季节分组发现春季围产期孕妇GBS感染率为10.41%,夏季孕妇GBS感染率为11.51%,秋季孕妇GBS感染率为11.83%,冬季孕妇GBS感染率为10.74%,围产期孕妇B族链球菌在不同季节的感染率差异存在统计学意义(P<0.05)。在2015例新生儿中,有124例为B族链球菌阳性感染者,感染率为6.15%;B族链球菌阳性感染孕妇中正常新生儿913例(45.31%)、不良妊娠结局1102例(54.69%),包括新生儿早产715例(53.48%)、新生儿感染108例(5.36%)、新生儿呼吸困难99例(4.91%)、胎膜早破116例(5.7%)、新生儿宫内窘迫11例(0.55%)、新生儿低血糖13例(0.65%)、新生儿代谢性酸中毒2例(0.1%)。结论北京地区围产期孕妇B族链球菌感染率为11.03%,其中以46岁至52岁年龄段感染率最高(13.33%),夏秋季节孕妇GBS感染高发,GBS阳性感染孕妇娩出新生儿的GBS感染率为6.15%,不良妊娠结局中以新生儿早产发生率最高(53.48%)。通过本研究为临床对于围产期孕妇B族链球菌感染的概况、诊疗、预防、把控妊娠结局提供可靠的数据支持。

具有非局部感染和周期治疗的HIV感染模型的时空动力学分析

该文建立了一类非自治反应扩散HIV细胞模型来研究周期治疗、非局部感染对HIV感染时空动力学的影响.具体地,首先推导出模型基本再生数R0,其由下一代再生算子R的谱半径所定义.然后对模型的动力学行为进行分析,其中包括无感染平衡态的全局稳定性、HIV感染的一致持久性以及周期正平衡态的存在性.最后,通过数值模拟验证了理论结果的正确性并分析了相关重要因素对HIV感染进程的影响,为HIV的临床治疗提供有价值的参考建议.

Application of the Probability Model for Starting Period to Initiate to Take Palivizumab by Prefecture Using National Official Sentinel Surveillance in Japan

Background: Palivizumab were used for the premature infant or a high-risk infant with congenital heart disease. However, recently outbreak pattern of respiratory syncytial (RS) virus infection has been varying year by year. Moreover, it also has some regional difference. Therefore, the object of the present study was to develop early detection of the timing of that outbreak had started in each prefecture. Method: We used data in National Official Sentinel Surveillance for Infectious Diseases (NOSSID). Study period was March 16th, 2011 to December 30th, 2018. We defined stating period to initiate to take palivizumab as 8 - 12 weeks before from the peak of outbreak. We estimated whether the week is included in starting period or not from April 1st to the peak of outbreak by the past number of patients of RS virus infection on week and its squared. Additionally, we have to take delay in NOSSID into consideration. Results: In nationwide, the last two seasons, the model predicted precisely the starting period. At prefectural level, the model predicted the starting period precisely in 16.6% of all year and prefectures pairs. When we consider the delay in NOSSID into consideration, the patients can start to take in 14.9% of all year and prefectures pairs. Discussion and Conclusion: The result of the probability model was not good, and thus we have to develop more sophisticated model for prediction at prefecture level.

围术期预防护理应用于产科手术患者中的效果分析

目的:分析围术期预防护理应用于产科手术患者中的效果。方法:选取2022年10月—2023年10月于泰安市妇幼保健院手术室行产科手术的80例患者作为研究对象,随机分为观察组、对照组,各40例。对照组实施常规护理,观察组实施围术期预防护理。比较两组护理效果。结果:观察组总感染率低于对照组,差异有统计学意义(P=0.048)。观察组无菌操作、消毒程度及器械灭菌评分高于对照组,差异有统计学意义(P<0.001)。观察组总满意度高于对照组,差异有统计学意义(P=0.048)。结论:围术期预防护理应用于产科手术患者中的效果较好,可提高护理质量,积极控制感染,患者满意度高。

围产期解脲脲原体感染的诊治进展

解脲脲原体是女性生殖道的常见共生体,可通过垂直传播导致胎儿感染,是绒毛膜羊膜炎和早产的主要致病菌。产前、围产期或产后传播可能导致新生儿脲原体感染。这可能表现为急性侵袭性感染,例如肺炎和败血症,也可能表现为慢性炎症如支气管肺发育不良等。解脲脲原体种类的检测有一定困难,且临床上不作为常规检测项目。目前对于早产儿解脲脲原体感染的治疗尚无统一标准,足月新生儿解脲脲原体定植、妊娠期解脲脲原体定植是否需要治疗尚无定论。本文通过复习既往文献,讨论解脲脲原体感染的致病机制、临床结局和目前的诊断及治疗进展。

肝移植围手术期脑卒中的研究进展

肝移植是目前治疗终末期肝病的标准手段之一,随着手术技术的发展以及围手术期管理的优化,肝移植术后并发症的发生率有所下降,但围手术期神经系统并发症仍较为常见,其中脑卒中的发生率差异较大,病因复杂多样,且起病隐匿、进展迅速、病死率高。对肝移植围手术期脑卒中进行早期识别及诊断,及时进行有效治疗,对于改善患者预后具有重要意义。因此,本文就肝移植围手术期脑卒中的概念、发生情况、危险因素、诊断、治疗及预防进行综述,探讨肝移植围手术期脑卒中的研究进展,以期为肝移植围手术期脑卒中的诊治提供参考。

松材线虫潜育期延长导致红松越年枯死

【目的】探究红松越年枯死的病理学过程和产生原因,以期为有效除治无松材线虫病症状的携带者松树提供理论依据。【方法】统计抚顺市大伙房实验林场自然侵染红松越年枯死比例,观测自然侵染和人工接种红松病症病状,测定红松当年显症的松材线虫数量阈值。实验室内不同温度下测定松材线虫虫口增长情况,以及媒介昆虫羽化后适宜松材线虫虫口有效增长的时期(虫口增长期),计算从寄生关系的建立到症状开始出现的时间(潜育期),并揭示红松感染松材线虫后越年枯死的原因。【结果】截至6月,自然侵染红松的越年枯死比例为41.4%。观测的自然侵染和低剂量人工接种红松在被侵染或接种当年均未出现显著外部、内部症状变化,而是到翌年松脂分泌停止,树干水分低,针叶变红褐色,只有进行高剂量饱和接种才出现当年半数显症。病症表现为松材线虫能够正常侵染红松,可有效繁殖但在低温时繁殖受阻,可成功越冬但越冬后虫口数量骤减。红松显症的全株阈值St1=(163±22)条·g^(-1),局部阈值St2=(621±20)条·g^(-1)。以每株50000条的接种量接种38年生红松,在当年虫口增长期内全株松材线虫数量仅为(90±8)条·g^(-1),低于St1、局部松材线虫数量最高为(350±18)条·g^(-1),也低于St2。抚顺的虫口增长期(141天)比大连(154天)和南京(173天)短。经计算,抚顺市松材线虫的潜育期为146天,长于虫口增长期。【结论】云杉花墨天牛携带的松材线虫数量相对较低,导致初始侵染量低。松材线虫生命周期受温度特性的影响,表现为非增长期长、虫口增长期短,最终导致在虫口增长期内未能达到红松显症的松材线虫数量阈值。这些综合作用导致松材线虫潜育期延长,其中41.4%的死亡红松表现出越年枯死现象。

脑出血恢复期患者发生肺部感染的临床预测模型建立和验证

目的探讨脑出血恢复期患者发生肺部感染(PI)的主要危险因素,构建并验证预测PI发生风险的列线图预测模型。方法回顾性收集2020年9月1日至2022年12月31日住院于合肥市第二人民医院高压氧医学科的761例脑出血恢复期患者临床资料。根据临床表现与胸片确定发生肺部感染情况,将患者分为PI组[257例,其中女116例、男141例,年龄60(53,70)岁]与非PI组[504例,其中女204例、男300例,年龄58.5(51,69)岁]。统计学方法采用Mann-Whitney U检验、χ^(2)检验。采用单因素logistic回归初筛出危险因素,随后采用最小绝对收缩和选择运算(LASSO)回归进行危险因素优化,最终将优化过的危险因素纳入多因素logistic回归中筛选出独立危险因素并构建列线图。采用受试者操作特征曲线(ROC)的曲线下面积(AUC)、校准曲线以及决策曲线分析(DCA)来确定模型的区分度、校准度和临床实用性。结果年龄、抗菌药物使用、意识障碍、气管切开、吞咽障碍、卧床时间、鼻饲均是脑出血恢复期患者并发肺部感染的独立危险因素(OR=2.406、5.507、8.878、8.931、2.709、3.402、2.528,均P<0.05),高压氧治疗是减少肺部感染的保护因素(OR=0.202,P<0.05)。预测模型ROC的AUC为0.901(95%CI 0.878~0.924),采Bootstrap法从原始数据中重复抽样1000次后AUC为0.900(95%CI 0.877~0.923);Hosmer–Lemeshow检验:χ^(2)=4.28,P=0.982。结论本研究构建的列线图预测模型具有较高的准确性,方便识别脑出血恢复期患者并发肺部感染的早期识别和风险预测。

一类潜伏期和染病期具有不同传染率的SEIQR传染病模型的稳定性

文章研究了一类潜伏期具有饱和传染率且染病期具有双线性传染率的SEIQR流行病模型,求得了模型的基本再生数R_(0),并证明了当R_(0)<1时,模型存在唯一的无病平衡点P_(0)且P_(0)全局渐近稳定;当R_(0)>1时,模型存在两个平衡点,无病平衡点P_(0)不稳定,且当2Aβ1<md时,地方病平衡点P^(*)全局渐近稳定.最后,利用数值模拟验证了结论的正确性并讨论了隔离对传染病模型的影响.

妊娠期上呼吸道病毒感染对妊娠结局的影响及不同时期上呼吸道病毒感染对孕产妇及胎儿的影响

目的探讨妊娠期上呼吸道病毒感染对妊娠结局的影响,以及妊娠不同时期上呼吸道病毒感染对孕产妇及胎儿的影响。方法纳入183名孕产妇,分为上呼吸道病毒感染组99人,非上呼吸道病毒感染组84人,比较2组的基本资料及不良妊娠结局,进行统计学分析;将上呼吸道病毒感染组孕妇根据感染孕周分为孕早、中、晚期3组,比较不同时期上呼吸道病毒感染对孕产妇及胎儿的影响。结果上呼吸道病毒感染组孕期妊娠合并症的发病率为43.4%,高于非上呼吸道病毒感染组的21.4%(P<0.05);上呼吸道病毒感染组早产率为14.1%,显著高于非上呼吸道病毒感染组的4.8%(P<0.05);上呼吸道病毒感染组胎儿宫内窘迫、胎儿发育迟缓的发生率高于非上呼吸道病毒感染组(P<0.05);孕晚期感染上呼吸道病毒的剖宫产率高于其他时期感染的孕产妇。结论妊娠期上呼吸道病毒感染与不良妊娠结局具有相关性;不同孕周(孕早、中、晚期)的上呼吸道病毒感染,对剖宫产率的影响有显著差异。

鞘内注射万古霉素治疗脑出血患者术后颅内感染的疗效评价

目的分析鞘内注射万古霉素治疗脑出血患者术后颅内感染与美罗培南的效果差异。方法回顾分析2021年3月至2023年1月山西省晋中市第一人民医院收治的60例小骨窗脑内血肿清除术后颅内感染患者的临床资料。根据患者所接受的治疗方案不同分为研究组与对照组,每组各30例,研究组给予万古霉素输注+鞘内注射,对照组给予美罗培南输注+鞘内注射。比较2组治疗后的临床疗效、脑脊液葡萄糖、颅内压、体温及感染相关因子水平。结果研究组临床有效率97%,高于对照组73%,差异有统计学意义(χ^(2)=4.706,P=0.030);治疗前,研究组的脑脊液葡萄糖、颅内压及体温与对照组比较差异无统计学意义(P均>0.05);2组白细胞计数(WBC)、C反应蛋白(CRP)、白细胞介素(IL)-6、肿瘤坏死因子(TNF)-α比较差异无统计学意义(P均>0.05)。治疗后,2组脑脊液葡萄糖均升高,且研究组高于对照组(P<0.001)。2组治疗后颅内压(P=0.041)和体温(P=0.017)均降低,且研究组低于对照组;2组治疗后WBC(P<0.001)、CRP(P=0.017)、IL-6(P<0.001)、TNF-α(P=0.011)均降低,研究组低于对照组,差异有统计学意义。结论对脑出血术后颅内感染患者给予万古霉素+鞘内注射能有效控制感染,对临床工作具有一定指导价值。

孕妇早孕期血清ALT升高与TORCH感染的相关性研究

目的 分析孕妇早孕期血清谷丙转氨酶(ALT)升高与TORCH感染的相关性。方法 选取本院282例免费孕前优生及早孕TORCH感染患者和同期未感染的282例免费孕前优生及早孕建卡者为研究对象,所有入选对象均接受ALT检测,对比分析两组ALT水平,并应用Logistic多因素回归分析方法对血清ALT升高与TORCH感染的相关性进行分析。结果 不同类型TORCH感染者ALT水平相比差异无统计学意义(P>0.05)。感染组血清ALT水平显著高于健康组,差异有统计学意义(P<0.05)。Logistic多因素回归分析结果显示,孕期血清ALT升高是TORCH感染的影响因素(P<0.05)。结论 孕妇早孕期血清ALT升高与TORCH感染密切相关,孕妇在孕前及孕期需积极加强ALT、TORCH监测。

成年人下呼吸道感染者痰液病原菌分布及多重耐药菌感染风险因素分析

目的探讨新型冠状病毒疾病(COVID-19)后疫情时期成人下呼吸道感染者痰标本中的病原菌分布、耐药性以及多重耐药菌(MDRO)感染的影响因素。方法回顾性分析2021年1月至2022年12月鹰潭184医院收治的316例成年人下呼吸道感染患者的临床资料,对其痰标本培养首次检出的107株病原菌进行菌种鉴定及药敏分析,依据药敏结果分为MDRO组(n=62)和非MDRO组(n=45),比较MDRO组和非MDRO组患者的临床资料,应用多因素Logistic回归分析探讨多重耐药菌感染的影响因素。结果107株病原菌中,检出比例位居前3的分别为肺炎克雷伯菌(29.91%)、大肠埃希菌(16.82%)、铜绿假单胞菌(14.95%),其中MDRO占比57.94%,非MDRO占比42.06%。肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌和鲍曼不动杆菌对头孢唑林的耐药率分别为90.63%、57.89%、88.89%和81.25%,对头孢噻肟的耐药率分别为59.38%、52.63%、72.22%和68.75%,对氨曲南的耐药率分别为46.88%、42.11%、44.44%和87.50%。多重耐药菌组患者年龄≥60岁、住院天数≥7 d、接受有创治疗、白球比值<1、血红蛋白(Hb)水平<100 g/L以及C反应蛋白(CRP)≥30 mg/L的患者比例明显高于非多重耐药组,差异均有统计学意义(P<0.05)。患者年龄≥60岁、住院天数≥7 d是成年人下呼吸道感染MDRO的危险因素(P<0.05),而Hb水平≥100 g/L是保护性因素(P<0.05)。结论COVID-19后疫情时期,成人下呼吸道感染患者病原菌分布发生变化,对第一、二代头孢菌素普遍耐药严重,MDRO占比高。患者年龄、住院天数和Hb水平是后疫情时期成人下呼吸道MDRO感染的独立风险因素,合理干预这些风险因素,有利于临床控制MDRO传播。

抗生素不同用药方法在剖宫产术围手术期的应用效果比较

目的探讨抗生素不同用药方法在剖宫产围手术期的应用效果。方法选取2022年6月至2023年12月我院收治的行剖宫产术产妇100例,随机数字表法分组,各50例。对照组产后常规应用头孢唑林钠,观察组在手术开展前30 min预防性应用头孢唑林钠,术后6 h重复使用头孢唑林钠,比较两组抗生素总使用时间、住院时间、药物费用、术后炎性因子水平与术后发热和切口感染发生率情况。结果观察组抗生素总使用时间与住院时间短于对照组,抗生素使用费用低于对照组(均P<0.05);观察组术后6 h、12 h的白细胞介素(IL)-6、C反应蛋白(CRP)与肿瘤坏死因子(TNF)-α水平均低于对照组(均P<0.05);观察组术后发热与切口感染率均低于对照组(均P<0.05)。结论采用抗生素在剖宫产术前预防性应用联合术后重复使用,可缩短抗生素的使用时间,减轻患者炎性反应,降低术后发热与切口感染的风险。

苹果轮纹病枝条侵染时期研究

通过不同时期人工接种苹果轮纹病菌菌丝,观察其对苹果当年生新梢和多年生枝条的侵染。结果表明5-8月份是苹果轮纹病菌侵染当年新梢的时期,其中5-7月份是侵染的高峰期,8月处于低谷,9月以后病菌不再侵染。同时看出5月病菌对各种枝龄枝条均能侵染,并且枝龄越小越易侵染;7月病菌对1～2年生枝条能够侵染,但对3年生以及多于3年生枝条难以侵染;9月病菌对各种枝龄枝条均不能侵染。

基于稻曲球结构分析稻曲菌的侵染部位和侵染时期

对田间采集的稻曲病病粒进行解剖分析,结果显示厚垣孢子层未形成的稻曲病病粒可分离出完整雌雄蕊;典型的稻曲球均可解剖出完整子房,且子房绿色未见明显膨大。雄性不育的水稻品系受稻曲病为害产生典型症状,其解剖结果与正常水稻品系相同。由此推测稻曲菌侵染水稻雌蕊发生在水稻开花之前,并直接从子房获得营养形成稻曲球。