江苏省有肾综合征出血热自然疫源地综合调查报告

1982年9至11月选择江苏省不同流行强度的HFRS疫区及非疫区计11个点进行了包括疫源地地貌、鼠类种群及密度、革螨种群及指数、鼠类带毒率、健康人群隐性感染率等项内容的综合调查。结果表明：
1.黑线姬鼠是各疫区的野外优势鼠种。其密度在高发区为3.90%，在中发区为2.54%。在低发区为0.80%，而在非疫区为0.56%；其HFRS抗原检出率在高发区为4.61%，中发区为3.96%，低发区为2.01%，非疫区为0。
2.流行前期黑线姬鼠密度与带毒率的乘积，同各调查点的发病率呈明显正相关；与调查点所在县1981、1982两年总发病率的相关系数为rs=0.8334，P<0.01；与调查点所在公社1981、1982两年总发病率的相关系数为rs=0.9524，P<0.0025。认为可将此指标纳入HFRS监测内容。
3.各疫区黑线姬鼠窝巢的优势螨种均为格式血厉螨，但其指数差异不显著。
4.疫区健康人群HFRS隐形感染率很低，高发区为1.02%，中发区为1.10%，低发区为0.60%，不足以构成影响本病流行的自然免疫屏障。     

周宁县31年流脑流行病学分所

为了解我县流脑流行概况，掌握其流行规律和特点，以搞好疫情预测，并制定有效的预防政策，我们对1951~81年流脑资料的分析结果如下：
1.周期性：自1951年起共发生三次流行，1960年发生第一次小流行，历时一年，发病率为15.90/10万，1967~69年及1978~80年分别发生二、三次大流行，各历时三年，发病率分别为26.99~428.31/10万及85.79~161.69/10万之间；每次流行间隔8~10年；尚有13年呈散发，发病率在0.74~10.65/10万之间；另11年无病例。     

沈阳市1975~1982年流行性乙型脑炎流行病学监测报告

本文报告了1975~1982年有关因素与乙脑发病关系的结果。流行年采到三带喙库蚊时间早（7月初），8月上、中旬的密度指数高（可达250只/人工小时以上），年平均密度也高（130只/人工小时以上）。首次检出病毒时间亦较早（8月8日），检毒持续时间较长（49天）。另外，三带喙库蚊带毒指数与乙脑发病率呈正相关。
猪HI抗体50%阳转日在8月下旬或100%阳转日在9月下旬的年份发病率皆低。当分别提前到8月上旬以前和8月下旬以前时，则发病率增高或出现流行。
本调查未看到人群抗体水平对乙脑发病率有明显影响。     

一起溶组织内阿米巴感染的流行病学调查

本文报告了山东省章丘县两个村庄1977~1984年发生溶组织内阿米巴流行的情况,并作了初步分析,共调查3,829人,人群感染率为6.35%,女性高于男性;阿米巴痢疾发病率为2.82%;阿米巴肝脓肿发病率为0.89%,病死率为32.35%。该病分布有明显的家庭聚集性;并发现猪可携带本原虫,且与家庭内有、无感染者有关。灭滴灵治疗效果显著,经一疗程,阴转率为88.07%。     

鼠伤寒沙门氏菌院内交叉感染的流行病学调查

本文报告德州地区自1981年10月23日发现首例鼠伤寒菌病患者，至1982年2月底，共发生40例经细菌学证实的患者。均为住院病人。统计其中38例，17例为原发感染，21例为院内儿科病房内交叉感染。主要症状为发热，腹泻。全部菌株对庆大霉素均敏感，符合临床治疗效果。对氯霉素等常用药物的耐药率高达82.5%~100.0%。
从儿科病房的窗、木凳、床头桌、病床、病历牌、陪人手和医护人员的手标本中培养出鼠伤寒菌。并从2例病人的咽及口腔粘膜检出该菌。空气中未检出。
最后，初步分析了鼠伤寒菌病广泛流行的原因，提出了一般预防措施，并对常用消毒剂进行了实验观察。     

肾综合征出血热血清流行病学的研究 Ⅲ 隐性感染和家庭聚集性

本文指出，通过对38户有阳性家族史和102户无阳性家族史的302个家庭成员的调查发现：
1.在农村型HFRS的流行区，普通人群存在隐性感染，其中男的隐性感染率为11.39%；女的为17.36%从年龄分布来看，29岁以下和60岁以上较高，而30~59岁者较低。其总体人群的隐性感染率为14.24%。
2.用间接荧光技术检查38户有阳性家族史的家庭成员131人，其中隐性感染者为28人，隐性感染率为21.37%，而无阳性家族史的171人中，隐性感染者为15人，隐性感染率为8.87%；卡方检验结果，P<0.01，即存在阳性家族史与家庭成员的隐性感染有极为明显的联系。
3.用二项分布式的原理进行家庭聚集性分析的结果提示，该病的感染（包括显性和隐性）具有极为明显的家庭聚集性。χ²检验P<0.01，均衡性检验可排除性别和年龄构成差异的混杂影响。     

不同免疫程序接种钩端螺旋体菌苗的血清学效果观察

本文报道了1977~1980年桃源县部分钩体病疫区菌苗免疫效果的观察结果。
分别设四个组，以不同的免疫方法接种钩体菌苗。连年免疫组（每年加强一针）；间隔一年免疫组；间隔二年免疫组和间隔三年免疫组。
经过基础免疫后一年，抗体水平较高，滴度为1：34.89~179.6。再免疫后抗体可大幅度上升，最高可达1：129~1646。另外自然隐性感染亦可得到较强的免疫力。
根据检测结果我们认为在钩体病流行区，如果已查明宿主动物和流行株，易感人群必需进行相应群的钩体菌苗作基础免疫后，再继续加强免疫两年，抗体在机体中可保持较高水平甚至终身。但必须密切监测钩体流行株的变迁。     

六安市一起伤寒病爆发流行的调查分析

通过对128例病人的临床分析和流行病学调查，确认这是一起水型伤寒病爆发流行。发病始于1981年11月中旬，翌年元月下旬达到发病高峰，历时4月余，波及18个单位，患病率为590.1/10万。患者主要是青少年学生，占59.4%。
水源污染的原因是病人隔离治疗不当、粪便、污水未经处理排入枯水期河水，人们因饮用污染河水而发病。流行期间，从三处河水中分离到伤寒沙门氏菌与病人分离菌一致。
经过隔离收治病人，加强粪便管理、卫生宣传、饮用水消毒、菌苗注射及开放水闸加大河水流量等综合处理，流行终止。     

广东广西两省、区部分地区登革病毒感染血清流行病学调查报告

通过对广东和广西省区部分地区登革病毒感染的血清流行病学调查,得知处于登革热流行当年的海南地区临高县的人群抗体阳性率为74%。而两年前(1978年)曾发生过本病流行的佛山地区海南县人群抗体阳性率为50.4%。而从未发生过本病流行的广东省连山壮族瑶族自治县在其人群中没查到抗体。但同属于非流行区的广西自治区的南宁市和桂林市人群抗体阳性率却有10%和7.2%。
在同一个流行区,不同年龄和不同性别人群的抗体阳性率尚未看出显著性差别。
流行当年的病人抗体阳性率为100%。而两年前患过本病者的抗体阳性率只有52%。     

2015－2018年全国阿米巴痢疾发病特征分析

目的 了解2015-2018年全国阿米巴痢疾发病特征和变化趋势,探索高发县（市、区）可能的原因,为制定全国防控策略提供依据。方法 使用SPSS 16.0软件,采用描述性流行病学方法,分析传染病报告管理信息系统中2015-2018年全国阿米巴痢疾发病数据的季节性特征、人群特征和地区分布。结果 2015-2018年,全国累计报告阿米巴痢疾病例4 366例,无死亡,年均报告发病率为0.08/10万,其中确诊病例占68.23%（2 979/4 366）。阿米巴痢疾的流行季节为5-10月,2015和2017年发病高峰分别为7月和6月,2016和2018年为双高峰,为6月和10月。发病集中在<5岁儿童（占42.28%,1 846/4 366）,在<10岁儿童中发病率随年龄增长而降低,其中0~1岁婴幼儿发病率最高（1.28/10万）;广西、河南、广东、黑龙江和江西（省、自治区）的累计报告发病数居全国前5位,占全国病例总数的64.50%（2 816/4 366）;广西壮族自治区防城港市东兴市、河南省商丘市睢县、黑龙江省大庆市让胡路区累计病例数占所在省份病例总数的比例超过50.00%。结论 2015-2018年全国阿米巴痢疾报告发病率呈下降趋势,<5岁儿童高发,局部地区（市、县）病例数高发,提示可对重点地区阿米巴痢疾诊断和报告情况开展进一步的调查,推动阿米巴痢疾诊断标准的更新。     

DNA vaccination with the serine rich Entamoeba histolytica protein (SREHP) prevents amebic liver abscess in rodent models of disease

Amebiasis remains one of the leading parasitic causes of death worldwide. A vaccine that prevented amebic liver abscess would significantly reduce mortality from this disease. To test the feasibility of a DNA vaccine to prevent amebic liver abscess, we immunized both mice and gerbils with plasmid DNA encoding the serine rich Entamoeba histolytica protein (SREHP). Animals receiving the SREHP DNA vaccine developed both antibody and cell mediated immune responses that recognized amebic trophozoites. A single dose of the SREHP DNA vaccine protected 80% of vaccinated mice and 60% of vaccinated gerbils from developing amebic liver abscess after direct hepatic inoculation of amebic trophozoites. Our study indicates that DNA vaccination with SREHP can provide high levels of protection against amebic liver abscess in animal models of disease.     

Sensitivity of free-living amoeba trophozoites and cysts to water disinfectants

Free-living amoebae are naturally present in water. These protozoa could be pathogenic and could also shelter pathogenic bacteria. Thus, they are described as a potential hazard for health. Also, free-living amoebae have been described to be resistant to biocides, especially under their cyst resistant form. There are several studies on amoeba treatments but none of them compare sensitivity of trophozoites and cysts from different genus to various water disinfectants. In our study, we tested chlorine, monochloramine and chlorine dioxide on both cysts and trophozoites from three strains, belonging to the three main genera of free-living amoebae. The results show that, comparing cysts to trophozoites inactivation, only the Acanthamoeba cysts were highly more resistant to treatment than trophozoites. Comparison of the disinfectant efficiency led to conclude that chlorine dioxide was the most efficient treatment in our conditions and was particularly efficient against cysts. In conclusion, our results would help to adapt water treatments in order to target free-living amoebae in water networks.     

Risk factors for intestinal invasive amebiasis in Japan, 2003-2009

We determined yearly change in prevalence and risk factors for amebic colitis caused by intestinal invasive amebiasis among persons who underwent endoscopy and assessed differences between HIV-positive and HIV-negative persons in Japan. A total of 10,930 patients were selected for analysis, of whom 54 had amebic colitis. Prevalence was in 2009 (0.88%, 12/1360) compared with 2003 (0.16%, 3/1904). Male sex (odds ratio [OR] 8.39, 95% CI 1.99-35.40), age <50 years (OR 4.73, 95% CI 2.43-9.20), history of syphilis (OR 2.90, 95% CI 1.40-5.99), and HIV infection (OR 15.85, 95% CI 7.93-31.70) were independent risk factors. No differences in risk factors were identified between HIV-positive and HIV-negative patients. Contact with commercial sex workers was a new risk factor among HIV-negative patients. Homosexual intercourse, rather than immunosuppressed status, appears to be a risk factor among HIV-positive patients.     

军团菌与同一空调水环境中分离的自由生活阿米巴的共培养观察

目的：通过从同一环境的同一份水样中分别分离出自由生活阿米巴和军团菌，然后将两者在实验室条件下共培养，观察两者的形态，从而推测两者在自然环境下的相互关系。方法：用微孔滤膜过滤，盐酸处理和抗生素抑制杂菌的方法分别从同一份水样中分离军团菌和自由生活阿米巴，然后将两者在实验室条件下进行共培养；取片后Gimenes染色，普通光学显微镜下观察，72h后收集共培养物做超薄切片电镜下观察，研究两者的形态。结果：分别分离到1株Ⅰ型嗜肺军团菌和一株棘阿米巴。两者进行共培养发现军团菌可以感染阿米巴，光镜下观察，8h后阿米巴体内即可发现军团菌，24h后开始增多，72h后阿米巴滋养体呈高度寄生状态，玻片上可见被裂解的滋养体遗骸。电镜照片显示被吞食的军团菌被多层膜结构缠绕。结论：阿米巴吞噬细菌是一种缠绕吞噬的方式，水样中分离到的军团菌能在同样本中分离到的自由生活阿米巴内生长繁殖，从侧面证实环境水体中自由生活阿米巴是嗜肺军团菌的自然宿主。     

Different growth rates in amoeba of genotypically related environmental and clinical Legionella pneumophila strains isolated from a thermal spa

Two cases of legionellosis occurring 3 years apart were acquired in the same French thermal spa and were apparently due to the same strain of Legionella pneumophila serogroup 1, as shown by genomic macrorestriction analysis. Minor differences between the two isolates were found by random amplification PCR profiling which showed an additional band with one of the isolates. Analysis of 107 L. pneumophila strains isolated from the spa waters by genome macrorestriction failed to identify the infective strain, but a closely related L. pneumophila serogroup 3 strain differing from the clinical isolates by only one band was found. To determine if the clinical L. pneumophila serogroup 1 isolates was better adapted for intracellular multiplication than related serogroup 3 environmental isolates, the growth kinetics of six isolates were determined in co-culture with Acanthamoeba lenticulata. One clinical isolate failed to grow within amoeba, while the other clinical isolate yielded the highest increase in bacterial cell count per amoeba (1,200%) and the environmental isolates gave intermediate values. Genetic analysis of L. pneumophila isolates by DNA macrorestriction does not therefore appear to reflect their growth kinetics within amoeba, and is not sufficiently discriminatory to identify potentially virulent strains.     

Cytopathogenicity of entamoeba histolytica: The role of amebic adherence and contact-dependent cytolysis in pathogenesis

The mechanisms by which Entamoeba histolytica trophozoites adhere to and lyse target cells are reviewed from the perspective of pathogenesis. Adherence via the galactose and N-acetyl -galactosamine inhibitable amebic lectin and possible additional amebic adhesin molecules is followed by target cell death. Inhibition of the Gal/GaINAc lectin with GaINAc inhibits amebic cytolysis of target cells. Amebic activities implicated in the cytolysic event include vesicle exocytosis and maintenance of an acid pH, pore forming proteins, phospholipase A and proteases. Increased knowledge of the sequence of events leading to target cell lysis should lead to more effective treatment or prevention of infection by this enteric parasite and add to our basic understanding of eukaryotic cell-cell interactions.Corresponding author.     

Primary amebic meningoencephalitis caused by Naegleria fowleri, Karachi, Pakistan

We report 13 cases of Naegleria fowleri primary amebic meningoencephalitis in persons in Karachi, Pakistan, who had no history of aquatic activities. Infection likely occurred through ablution with tap water. An increase in primary amebic meningoencephalitis cases may be attributed to rising temperatures, reduced levels of chlorine in potable water, or deteriorating water distribution systems.     

Preparation and evaluation of standardized amoeba antigen from axenic cultures of Entamoeba histolytica

The successful mass cultivation of Entamoeba histolytica strains in pure culture has made it possible to produce pure amoeba antigens, which should improve the prospects for immunodiagnostic research and simplify the interpretation of the results obtained in tests for amoeba antibodies.