沙门氏菌快速增菌培养的实验研究

用改良的沙门氏菌增菌培养基与02快速增菌培养基,比较研究了鼠伤寒沙门氏菌、伤寒沙门氏菌、甲型副伤寒沙门氏菌、乙型副伤寒沙门氏菌、猪霍乱沙门氏菌及纽因吞沙门氏菌的增殖能力。以OD值测定菌量,改良法较02法增长1.43—3.97倍。尤其是对鼠伤寒沙门氏菌和伤寒沙门氏菌的菌量增殖较多,生长速度较快,分别为02法的3.97和3.7倍。改良法可适合于这两种菌的增殖培养,其次是纽因吞沙门氏菌和乙型副伤寒沙门氏菌的培养,但对甲型副伤寒沙门氏菌和猪霍乱沙门氏菌的增长欠佳。改良的增菌培养基尚有抑制葡萄球菌和大肠杆菌生长的作     

微柱凝胶技术诊断伤寒及副伤寒的临床应用

目的 比较微柱凝胶技术(MGT)与肥达反应法(WR)在诊断伤寒及副伤寒中的意义.方法 采用微柱凝胶技术及肥达反应法分别检测317例疑似伤寒及副伤寒患者.结果 317例疑似患者中,通过对已被临床确诊或得到血培养和(或)粪便培养阳性报告的患者血清标本检测,微柱凝胶法要比肥达反应法平均提高1～2个滴度.统计学差异有显著性.结论 微柱凝胶技术检测伤寒杆菌抗体方法简便快速,灵敏度高,便于观察,能为临床早期诊断,快速诊断提供重要的参考依据.     

2004-2013年玉溪市麻疹病例与人群抗体的监测分析

目的监测分析2004-2013年玉溪市麻疹病例与人群血清抗体,为预防控制麻疹提供科学依据。方法对玉溪市2004-2013年麻疹病例进行流行病学调查分析,采集人群血样标本,并用ELISA检测血清麻疹IgG抗体。结果全市共报告麻疹疑似病例1 086例和确诊病例457例,年均发病率为1.99/10万,发病率高峰在每年12月至次年2月,占总病例的43.55%(199/457),最高发病率(5.11/10万)、最低发病率(0.13/10万)分别在2005和2010年,发病率最高为红塔区5.75/10万,最低为通海县0.65/10万;2004-2008年病例数占83.81%,2009-2013年病例数占16.19%;散居儿童病例占发病数的42.67%,年龄小于14岁病例占78.34%。常住人口、流动人口病例数分别为222例和235例,年均发病率分别为1.06/10万和11.75/10万(χ2=1047.43,P<0.05)。19 010人群各年麻疹血清抗体阳性率范围是90.06%~97.62%,保护率范围为71.60%~87.72%;麻疹组份疫苗免疫1、2、3和4剂次保护率分别为74.49%、87.38%、87.72%和95.01%(χ2=462.402,P<0.05),接种1剂次与2、3、4剂次和2、3剂次与4剂次差异有统计学意义(P<0.05)。结论麻疹病例数总体呈下降趋势,有季节、区域、人群分布差异,增加人群麻疹组分疫苗免疫剂次的策略有预防意义,强化免疫的成本效益值得探讨。     

上海新泾社区50岁以上居民足癣患病情况调查

皮肤癣菌病是临床常见皮肤病,包括体癣、股癣、头癣、甲癣及手足癣等,其中足癣发病率最高.足癣在全世界广为流行,在热带和亚热带地区更为普遍.在我国,足癣的发病率甚高,据1975年上海市对11万人普查,足癣的发病率为36.76％.在一些职业和集体中,甚至可高达80％～100％.随着经济发展及人们生活水平的提高,足癣引起人们越来越多的重视,关于足癣在运动员、军人、矿工及青少年人群中的调查研究已有不少[1-4].     

6种沙门菌单克隆抗体的制备和效能评价

目的：制备稳定、特异、高亲和性的分别针对甲型副伤寒沙门菌、乙型副伤寒沙门菌、丙型副伤寒沙门菌、肠炎沙门菌、伤寒沙门菌和猪霍乱沙门菌的单克隆抗体。方法：用甲醛灭活的菌液抗原免疫BALB／c小鼠,取脾细胞与SP2／0骨髓瘤细胞融合;用灭活的菌液包被酶标板,ELISA筛选阳性克隆株,建立细胞系;选取高效分泌杂交瘤细胞,常规制备腹水并纯化,进行单抗特异性与亲和性评价。结果：筛选得到分泌6种沙门菌相应单克隆抗体的杂交瘤细胞株,获得高亲和性单抗;所有单抗与大部分病原菌（包括7种沙门菌、3株志贺菌、2株李斯特菌、4株致病性大肠杆菌、2株霍乱弧菌）无交叉反应,但由于同类型O抗原的广泛分布,抗乙型副伤寒沙门菌单抗与鼠伤寒沙门菌、抗伤寒沙门菌单抗与肠炎沙门菌有明显的交叉反应。结论：沙门菌单抗的制备,为感染性腹泻的监测、诊断奠定了基础。     

1999‒2015年红塔区伤寒与副伤寒流行特征和 气象变量的研究

摘要：目的 分析1999?2015年红塔区伤寒与副伤寒（typhoid and paratyphoid fever，TPF）地方病区域流行特征和气象变量的关系，为TPF监测控制和危险因素评价提供科学依据。方法 采用描述流行病学方法和自主研发计算机软件建立中国疾病预防控制信息系统红塔区TPF病例分布与流行特征数据库，用Pearson相关分析和多元线性逐步回归分析研究TPF发病和气象变量关系。结果 1999?2015年报告TPF病例数为8 398例，1999、2015年分别报告23、44例。1999?2015年期间每年3~5月、6~10月、11月~次年2月分别为发病上升期（月均增长率63.8%）、高峰期（月均降低率2.0%）和下降期（月均降低率25.7%），每年度病例数都呈现3月~10月季节性升高和11月~次年2月季节性降低；2000年8月至2010年12月每月病例数都大于8例，2000?2002、2004?2005、2005?2007、2007?2008、2008?2010年出现五个高强度流行峰，峰期范围是12～24个月，周期范围是11～40个月；2001、2004、2006、2007、2009年五个高峰年度6~10月病例数范围分别为86～217、67～215、125～216、97～131、63～95例；1999、2000、2002、2003、2005、2008、2010、2015年八个低峰年度6月~10月病例数范围分别为1～3、1～17、32～60、30～43、46～55、43～78、22～61、2～11例。单因素分析TPF月平均发病率与月平均降雨量（r=0.825，P<0.01）、月平均气温（r=0.797，P<0.01）和月平均相对湿度（r=0.706，P<0.05）呈正相关；经多元逐步回归分析建立TPF月平均发病率（Y）与月平均降雨量（X）的拟合模型方程Y=4.563+0.051X。结论 红塔区TPF发病呈现季节性升高与降低、周期性流行、长期趋势特点；发病率与降雨量、气温、相对湿度呈正相关；传染源积累、重污染源形成、暴露人群增加驱动着流行特征与气象变量关系；相应规律、机制、政策、评估有助TPF的监测控制。     

沙门氏伤寒菌荚膜多糖抗伤寒的研究-尼泊尔现场报告

<正> 伤寒在发展中国家是一种多发的烈性病。过去通过使用清洁水、污水处理和对患者及未发病的病菌携带者进行及时诊断、隔离和治疗等方法控制这种病的流行,但今后几十年内,局部或大面积流行此病的国家仅用这些方法还不够。对发展中国家来说,伤寒是最常见的烈性传染病。从病原学角度看,沙门氏菌属中唯有沙门氏伤寒菌具有荚膜多糖(Vi抗原),而沙门氏副伤寒菌C株偶尔才有同样的荚膜抗原。     

伤寒沙门菌致病物质的研究进展

伤寒沙门菌(Salmonella typhi)是引起人类伤寒的病原体,人类是其唯一宿主.伤寒是一种严重的侵袭性细菌性疾病,以热带及亚热带地区为多,在不发达国家常引起流行.全球每年有约2 160万人感染伤寒,其中死亡人数超过21万,且所有年龄段人群均可罹患[1].伤寒沙门菌是革兰阴性兼性胞内菌,有菌毛和周身鞭毛,有较强的内毒素,并有一定的侵袭力.现将近年来其重要的致病物质研究进展综述如下.     

郑州市惠济区2005—2012年NGU疫情流行病学分析

目的通过分析郑州市惠济区2005—2012年非淋菌性尿道炎(NGU)的流行特征,提出惠济区今后对NGU的防治措施。方法采用描述流行病学方法,对惠济区NGU疫情的三间分布及传播途径进行描述。结果2005—2012年惠济区共报告NGU患者450例,疫情呈上升趋势,发病率由3.75/10万上升到30.00/10万。女性发病率明显高于男性,男女之比为1∶8,25~34岁为高发年龄段,占总病例数的80.44%。职业分布以商业服务、农民工、企业工人为主要发病人群,结论惠济区NGU疫情日趋严重,应加强对重点人群的监测和管理,强化各项干预措施,降低发病率。     

肠道传染病的予防

<正> 肠道传染病在苏联登记的所有传染病中占有相当大的比重。痢疾、埃希氏杆病和其他急性腹泻病,沙门氏菌病、传染性肝炎BoTkNH病)发病率处于较高的状态。只有伤寒和副伤寒甲、乙的发病率规律地下降,而在多数城市中,这些疾病以散发性病例的形式出现。 为么什予防伤寒获得较大的成就,且其发病率处于完全良好的趋势,而在痢疾、沙门氏菌病及传染性肝炎发病率方面,虽然传染源的传播机制相同(粪便经口腔感染),为何发病率截然不同呢? 按照我们的见解:痢疾通过粪便经口腔传播感染的机制比伤寒容易。这是因为第一:痢疾病人出现腹泻,存在广泛污染周围环境的可能性;其次是因为40％的痢疾病人是幼龄儿童,这些病人成为周围环境的传染源是极其现实的。     

The Application of the Grey Disaster Model to Forecast Epidemic Peaks of Typhoid and Paratyphoid Fever in China

Objective

The objectives of this study were to forecast epidemic peaks of typhoid and paratyphoid fever in China using the grey disaster model, to evaluate its feasibility of predicting the epidemic tendency of notifiable diseases.

Methods

According to epidemiological features, the GM(1,1) model and DGM model were used to build the grey disaster model based on the incidence data of typhoid and paratyphoid fever collected from the China Health Statistical Yearbook. Model fitting accuracy test was used to evaluate the performance of these two models. Then, the next catastrophe date was predicted by the better model.

Results

The simulation results showed that DGM model was better than GM(1,1) model in our data set. Using the DGM model, we predicted the next epidemic peak time will occur between 2023 to 2025.

Conclusion

The grey disaster model can predict the typhoid and paratyphoid fever epidemic time precisely, which may provide valuable information for disease prevention and control.     

Descriptive Epidemiology of Typhoid Fever during an Epidemic in Harare,Zimbabwe, 2012

Background

Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare.

Methods

A typhoid fever case-patient register was analysed to describe the epidemic. To explore clustering, we constructed a dataset comprising GPS coordinates of case-patient residences and randomly sampled residential locations (spatial controls). The scale and significance of clustering was explored with Ripley K functions. Cluster locations were determined by a random labelling technique and confirmed using Kulldorff''s spatial scan statistic.

Principal Findings

We analysed data from 2570 confirmed and suspected case-patients, and found significant spatiotemporal clustering of typhoid fever in two non-overlapping areas, which appeared to be linked to environmental sources. Peak relative risk was more than six times greater than in areas lying outside the cluster ranges. Clusters were identified in similar geographical ranges by both random labelling and Kulldorff''s spatial scan statistic. The spatial scale at which typhoid fever clustered was highly localised, with significant clustering at distances up to 4.5 km and peak levels at approximately 3.5 km. The epicentre of infection transmission shifted from one cluster to the other during the course of the epidemic.

Conclusions

This study demonstrated highly localised clustering of typhoid fever during an epidemic in an urban African setting, and highlights the importance of spatiotemporal analysis for making timely decisions about targetting prevention and control activities and reinforcing treatment during epidemics. This approach should be integrated into existing surveillance systems to facilitate early detection of epidemics and identify their spatial range.     

Estimating the Burden of Paratyphoid A in Asia and Africa

Despite the increasing availability of typhoid vaccine in many regions, global estimates of mortality attributable to enteric fever appear stable. While both Salmonella enterica serovar Typhi (S. Typhi) and serovar Paratyphi (S. Paratyphi) cause enteric fever, limited data exist estimating the burden of S. Paratyphi, particularly in Asia and Africa.We performed a systematic review of both English and Chinese-language databases to estimate the regional burden of paratyphoid within Africa and Asia. Distinct from previous reviews of the topic, we have presented two separate measures of burden; both incidence and proportion of enteric fever attributable to paratyphoid. Included articles reported laboratory-confirmed Salmonella serovar classification, provided clear methods on sampling strategy, defined the age range of participants, and specified the time period of the study.A total of 64 full-text articles satisfied inclusion criteria and were included in the qualitative synthesis. Paratyphoid A was commonly identified as a cause of enteric fever throughout Asia. The highest incidence estimates in Asia came from China; four studies estimated incidence rates of over 150 cases/100,000 person-years. Paratyphoid A burden estimates from Africa were extremely limited and with the exception of Nigeria, few population or hospital-based studies from Africa reported significant Paratyphoid A burden.While significant gaps exist in the existing population-level estimates of paratyphoid burden in Asia and Africa, available data suggest that paratyphoid A is a significant cause of enteric fever in Asia. The high variability in documented incidence and proportion estimates of paratyphoid suggest considerable geospatial variability in the burden of paratyphoid fever. Additional efforts to monitor enteric fever at the population level will be necessary in order to accurately quantify the public health threat posed by S. Paratyphi A, and to improve the prevention and treatment of enteric fever.     

Spatial and Temporal Distribution of West Nile Virus in Horses in Israel (1997–2013) - from Endemic to Epidemics

With the rapid global spread of West Nile virus (WNV) and the endemic state it has acquired in new geographical areas, we hereby bring a thorough serological investigation of WNV in horses in a longstanding endemic region, such as Israel. This study evaluates the environmental and demographic risk factors for WNV infection in horses and suggests possible factors associated with the transition from endemic to epidemic state. West Nile virus seroprevalence in horses in Israel was determined throughout a period of more than a decade, before (1997) and after (2002 and 2013) the massive West Nile fever outbreak in humans and horses in 2000. An increase in seroprevalence was observed, from 39% (113/290) in 1997 to 66.1% (547/827) in 2002 and 85.5% (153/179) in 2013, with persistent significantly higher seroprevalence in horses situated along the Great Rift Valley (GRV) area, the major birds'' migration route in Israel. Demographic risk factors included age and breed of the horse. Significantly lower spring precipitation was observed during years with increased human incidence rate that occurred between 1997–2007. Hence, we suggest referring to Israel as two WNV distinct epidemiological regions; an endemic region along the birds'' migration route (GRV) and the rest of the country which perhaps suffers from cyclic epidemics. In addition, weather conditions, such as periods of spring drought, might be associated with the transition from endemic state to epidemic state of WNV.     

Combined rapid (TUBEX) test for typhoid-paratyphoid A fever based on strong anti-O12 response: design and critical assessment of sensitivity

Rapid diagnostics can be accurate but, often, those based on antibody detection for infectious diseases are unwittingly underrated for various reasons. Herein, we described the development of a combined rapid test for two clinically-indistinguishable bacterial diseases, typhoid and paratyphoid A fever, the latter fast emerging as a global threat. By using monoclonal antibodies (mAbs) to bacterial antigens of known chemical structures as probes, we were able to dissect the antibody response in patients at the level of monosaccharides. Thus, a mAb specific for a common lipopolysaccharide antigen (O12) found in both the causative organisms was employed to semi-quantify the amounts of anti-O12 antibodies present in both types of patients in an epitope-inhibition particle-based (TUBEX) immunoassay. This colorimetric assay detected not only anti-O12 antibodies that were abundantly produced, but also, by steric hindrance, antibodies to an adjoining epitope (O9 or O2 in the typhoid or paratyphoid bacillus, respectively). Sensitivity and, particularly, reaction intensities, were significantly better than those obtained using an anti-O9 or anti-O2 mAb-probe in the examination of paired sera from 22 culture-confirmed typhoid patients (sensitivity, 81.8% vs 75.0%) or single sera from 36 culture-confirmed paratyphoid patients (52.8% vs 28.6), respectively. Importantly, sensitivity was better (97.1% for typhoid, 75.0% for paratyphoid) if allowance was made for the absence of relevant antibodies in certain specimens as determined by an independent, objective assay (ELISA)--such specimens might have been storage-denatured (especially the older paratyphoid samples) or procured from non-responders. Benchmarking against ELISA, which revealed high concordance between the two tests, was useful and more appropriate than comparing with culture methods as traditionally done, since antibody tests and culture target slightly different stages of these diseases. Paired sera analysis was insightful, revealing 64% of typhoid patients who had no change in antibody titer over 4-16 days, and 14% with no IgM-IgG class-switching.     

Additive‐Multiplicative Regression Models for Spatio‐Temporal Epidemics

An extension of the stochastic susceptible–infectious–recovered (SIR) model is proposed in order to accommodate a regression context for modelling infectious disease data. The proposal is based on a multivariate counting process specified by conditional intensities, which contain an additive epidemic component and a multiplicative endemic component. This allows the analysis of endemic infectious diseases by quantifying risk factors for infection by external sources in addition to infective contacts. Inference can be performed by considering the full likelihood of the stochastic process with additional parameter restrictions to ensure non‐negative conditional intensities. Simulation from the model can be performed by Ogata's modified thinning algorithm. As an illustrative example, we analyse data provided by the Federal Research Centre for Virus Diseases of Animals, Wusterhausen, Germany, on the incidence of the classical swine fever virus in Germany during 1993–2004.     

Evaluation of a Typhoid/Paratyphoid Diagnostic Assay (TPTest) Detecting Anti-Salmonella IgA in Secretions of Peripheral Blood Lymphocytes in Patients in Dhaka,Bangladesh

Background

Rapid and reliable diagnostic assays for enteric (typhoid and paratyphoid) fever are urgently needed. We report the characterization of novel approach utilizing lymphocyte secretions, for diagnosing patients with enteric fever by the TPTest procedure.

Methodology

TPTest detects Salmonella-specific IgA responses in lymphocyte culture supernatant. We utilized TPTest in patients with suspected enteric fever, patients with other illnesses, and healthy controls. We also evaluated simplified modifications of TPTest for adaptation in laboratories with limited facilities and equipment.

Principal Findings

TPTest was positive in 39 (27 typhoid and 12 paratyphoid A) patients confirmed by blood culture and was negative in 74 healthy individuals. Among 32 individuals with other illnesses, 29 were negative by TPTest. Of 204 individuals with suspected enteric fever who were negative by blood culture, 44 were positive by TPTest and the patients were clinically indistinguishable from patients with confirmed bacteremia, except they were more likely to be under 5 years of age. We evaluated simplifications in TPTest, including showing that lymphocytes could be recovered using lysis buffer or buffy coat method as opposed to centrifugation, that incubation of cells at 37°C did not require supplemental CO₂, and that results were available for majority of samples within 24 hours. Positive results by TPTest are transient and revert to negative during convalescence, supporting use of the test in endemic areas. The results can also be read using immunodot blot approach as opposed to ELISA. Since no true gold standard currently exists, we used a number of definitions of true positives and negatives. TPTest had sensitivity of 100% compared to blood culture, and specificity that ranged from 78–97% (73–100, 95% CI), depending on definition of true negative.

Conclusion

The TPTest is useful for identification of patients with enteric fever in an endemic area, and additional development of simplified TPTest is warranted.     

Neglected Tropical Diseases in Sub-Saharan Africa: Review of Their Prevalence,Distribution, and Disease Burden

The neglected tropical diseases (NTDs) are the most common conditions affecting the poorest 500 million people living in sub-Saharan Africa (SSA), and together produce a burden of disease that may be equivalent to up to one-half of SSA''s malaria disease burden and more than double that caused by tuberculosis. Approximately 85% of the NTD disease burden results from helminth infections. Hookworm infection occurs in almost half of SSA''s poorest people, including 40–50 million school-aged children and 7 million pregnant women in whom it is a leading cause of anemia. Schistosomiasis is the second most prevalent NTD after hookworm (192 million cases), accounting for 93% of the world''s number of cases and possibly associated with increased horizontal transmission of HIV/AIDS. Lymphatic filariasis (46–51 million cases) and onchocerciasis (37 million cases) are also widespread in SSA, each disease representing a significant cause of disability and reduction in the region''s agricultural productivity. There is a dearth of information on Africa''s non-helminth NTDs. The protozoan infections, human African trypanosomiasis and visceral leishmaniasis, affect almost 100,000 people, primarily in areas of conflict in SSA where they cause high mortality, and where trachoma is the most prevalent bacterial NTD (30 million cases). However, there are little or no data on some very important protozoan infections, e.g., amebiasis and toxoplasmosis; bacterial infections, e.g., typhoid fever and non-typhoidal salmonellosis, the tick-borne bacterial zoonoses, and non-tuberculosis mycobaterial infections; and arboviral infections. Thus, the overall burden of Africa''s NTDs may be severely underestimated. A full assessment is an important step for disease control priorities, particularly in Nigeria and the Democratic Republic of Congo, where the greatest number of NTDs may occur.     

Environmental Transmission of Typhoid Fever in an Urban Slum

BackgroundEnteric fever due to Salmonella Typhi (typhoid fever) occurs in urban areas with poor sanitation. While direct fecal-oral transmission is thought to be the predominant mode of transmission, recent evidence suggests that indirect environmental transmission may also contribute to disease spread.MethodsData from a population-based infectious disease surveillance system (28,000 individuals followed biweekly) were used to map the spatial pattern of typhoid fever in Kibera, an urban informal settlement in Nairobi Kenya, between 2010–2011. Spatial modeling was used to test whether variations in topography and accumulation of surface water explain the geographic patterns of risk.ResultsAmong children less than ten years of age, risk of typhoid fever was geographically heterogeneous across the study area (p = 0.016) and was positively associated with lower elevation, OR = 1.87, 95% CI (1.36–2.57), p <0.001. In contrast, the risk of typhoid fever did not vary geographically or with elevation among individuals less than 6b ten years of age.ConclusionsOur results provide evidence of indirect, environmental transmission of typhoid fever among children, a group with high exposure to fecal pathogens in the environment. Spatially targeting sanitation interventions may decrease enteric fever transmission.     

Dengue hemorrhagic fever epidemiology in Thailand: description and forecasting of epidemics

Despite the use of a variety of control strategies, dengue hemorrhagic fever (DHF) control is a major and permanent challenge for public health services in Thailand and in Southeast Asia. In order to improve the efficiency of DHF control in Thailand, these activities have to concentrate on areas and populations at higher risk, which implies early identification of higher incidence periods. A retrospective study of spatial and temporal variations of DHF incidence in all 73 provinces of Thailand (1983-1995) allowed discrimination between seasonal (endemic) transmission dependent on climatic variations and vector density and non-seasonal (epidemic) transmission, mainly due to the occurrence of a new virus serotype in a population with low immunity. To identify epidemic months, which appear significantly clustered, a significant deviation from the monthly average incidence was defined. The occurrence of two consecutive epidemic months in a given area has a high probability (P = 0.66) of being followed by a cluster of 2-18 epidemic months (average: 7.7 months). This observation is proposed as a warning of epidemic outbreak enabling an early launch of control activities. As an example, when this method is retrospectively applied to the studied period, 11,388 province months (73 provinces x 156 months), 579 epidemic outbreaks (5.1% of the total) are identified. Control activities can thus be improved through early management and prevention of the 308,636 supplementary cases occurring during epidemics (37.0% of the total recorded).