重症监护病房获得性感染的传播途径及其相关因素

目的:探讨有效地预防和控制重症监护病房(ICU)获得性感染发生的措施。方法:对某教学医院ICU76例机械通气患者的获得性感染情况进行调查,并用质粒限制性内切酶图谱对有流行病学相关性感染及环境分离株进行分析。结果:ICU获得性感染39例,感染优势菌为铜绿假单胞菌(33.3%),肺炎克雷伯菌(28.2%),大肠埃希菌(10.3%),不动杆菌(7.7%),其中产ESBLs9株(25%),主要由肠杆菌科细菌产生。结论:患者之间交叉感染是ICU获得性感染的主要传播途径;污染的氧气湿化瓶、气管插管、呼吸机雾化器、床旁柜、公用洗涤池及导尿管等是造成交叉感染的重要传播因素。

毛里塔尼亚育龄期妇女人类免疫缺陷病毒感染情况调查(英文)

背景:数据报告非洲地区撒哈拉以南的16个国家艾滋病病毒感染者多达2450万。目的:了解居于撒哈拉腹地的毛里塔尼亚育龄期妇女人类免疫缺陷病毒的感染及类型,为艾滋病的防治工作提供研究方向和基本资料。设计:随机抽样调查。单位:苏州大学放射医学与公共卫生学院流行病与卫生统计学教研室,哈尔滨医科大学碘缺乏病研究所,哈尔滨医科大学公共卫生学院流行病与卫生统计学教研室。对象:调查于2001-03/2001-06在毛里塔尼亚14个行政区(省)进行,纳入标准:毛里塔尼亚14个行政区(省)育龄期妇女,年龄15～49岁,均知情同意。排除标准:拒绝调查及非育龄期妇女。总数为331548名,拟抽样调查4000～6000名,抽样率为1.2%～1.8%。方法:抽查育龄期妇女,采静脉血、分离血清;用酶联免疫吸附试验做初筛试验,用蛋白印迹试验做确证试验,检测人类免疫缺陷病毒的感染及其类型;用每个行政区人类免疫缺陷病毒感染的检出率乘以该行政区育龄期妇女数,即为该行政区育龄妇女人类免疫缺陷病毒感染的估计人数。主要观察指标:检测人类免疫缺陷病毒的感染及其类型;计算不同城市、不同人群的人类免疫缺陷病毒感染率,并加以分析。结果:艾卡欧特行政区(省)因故未调查,在13个行政区中抽查了4648名,抽样率为1.4%。在4648名15～49岁育龄期妇女中,检出人类免疫缺陷病毒感染者24例,总感染率为0.516%。其中,人类免疫缺陷病毒-1型22例,人类免疫缺陷病毒-2型2例;有5个城市感染率在0.50%～1.01%之间,有3个城市感染率在0～0.50%之间,有5个城市未检出;15～29岁人类免疫缺陷病毒感染23例,占95.83%;在全国13个主要城市中,人类免疫缺陷病毒感染者总数估计在1400例左右。结论:毛里塔尼亚13个主要城市育龄期妇女人类免疫缺陷病毒总感染率为0.516%;人类免疫缺陷病毒感染以人类免疫缺陷病毒-1型为主;人类免疫缺陷病毒感染有地区差异;15～29岁人类免疫缺陷病毒感染占95%以上;毛里塔尼亚艾滋病的流行态势属于传入后的传播扩散阶段。

母乳喂养与艾滋病毒的母婴传播

艾滋病毒(HIV)以每天5000名新感染者的速度传播,目前全世界已有1000万成人和100万儿童感染 HIV,估计至2000年将有4000万 HIV 感染者。HIV 感染者中3/4为异性性接触传播所致,妇女感染例数骤增且80%为育龄妇女,儿童 HIV 感染中80%为母婴传播,足见阻断母婴传播在控制艾滋病(AIDS)流行中具有十分重要的意义。可靠资料证实母乳可作为 HIV 母婴传播的媒介,本文简要综述母乳喂养在 HIV母婴传播中的意义、发生机理、影响因素和预防策略等方面的研究现状。

胃癌高发区儿童幽门螺杆菌感染及传播途径

目的研究胃癌高发区儿童幽门螺杆菌（Ｈｐ）和ｃａｇＡ＋亚型感染状况及细菌传播方式，探讨儿童早期感染Ｈｐ与胃癌的关系．方法用１３Ｃ尿毒酶呼吸实验（１３ＣＵＢＴ）方法检测（山东省临朐县）９８名儿童Ｈｐ感染状况，用ＥＬＩＳＡ方法检测７０名儿童抗ＣａｇＡ抗体及成人抗Ｈｐ抗体．结果胃癌高发区儿童Ｈｐ感染率为６９４％，其中３岁～４岁儿童Ｈｐ感染率为５２６％．９岁～１０岁上升为８５％，１１岁～１２岁下降为６６７％，接近于成人水平．儿童ｃａｇＡ＋亚型感染率为７１４％．Ｈｐ感染有明显的家族聚集性，其中父母双方或一方Ｈｐ感染阳性的子女Ｈｐ感染率（８５％）明显高于父母Ｈｐ感染均阴性者（２２％，Ｐ＜００５）．结论胃癌高发区儿童Ｈｐ、特别是ｃａｇＡ＋亚型感染率很高，且有家族聚集性，表明儿童阶段即可感染Ｈｐ，并且与当地胃癌高发有明显关系．

Relationship of hepatitis B virus infection of placental barrier and hepatitis B virus intra-uterine transmission mechanism

AIM: To explore the mechanism of intra-uterine transmission,the HBV infection status of placental tissue and in vitro cultured placental trophoblastic cells was tested through in vivo and in vitro experiments. METHODS: A variety of methods,such as ELISA,RT- PCR,IHC staining and immunofluorescent staining were employed to test the HBV marker positive pregnant women's placenta and in vitro cultured placental trophoblastic cells. RESULTS: The HBV DNA levels in pregnant women's serum and fetal cord blood were correlated. For those cord blood samples positive for HBV DNA,their maternal blood levels of HBV DNA were at a high level. The HBsAg IHC staining positive cells could be seen in the placental tissues and the presence of HBV DNA detected. After co-incubating the trophoblastic cells and HBV DNA positive serum in vitro,the expressions of both HBsAg and HBV DNA could be detected. CONCLUSION: The mechanism of HBV intra-uterine infection may be due to that HBV breaches the placental barrier and infects the fetus.

Injection drug use and HIV/AIDS transmission in China

After nearly three decades of being virtually drug free, use of heroin and other illicit drugs has re-emerged in China as a major public health problem. One result is that drug abuse, particularly heroin injection, has come to play a predomi- nant role in fueling China’s AIDS epidemic. The first outbreak of HIV among China’s IDUs was reported in the border area of Yunnan province between China and Myanmar where drug trafficking is heavy. Since then drug-related HIV has spread to all 31 provinces, autonomous regions and municipalities. This paper provides an overview to HIV/AIDS transmission through injection drug use in China. It begins with a brief history of the illicit drug trade in China, followed by a discussion of the emergence of drug related AIDS, and a profile of drug users and their sexual partners who have contracted the virus or who are vulnerable to infection. It ends by summarizing three national strategies being used by China to address both drug use and AIDS as major health threats.

Epidemiology of hepatitis C virus infection

Globally, hepatitis C virus (HCV) has infected an estimated 130 million people, most of whom are chronically infected. HCV-infected people serve as a reservoir for transmission to others and are at risk for developing chronic liver disease, cirrhosis, and primary hepatocellular carcinoma (HCC). It has been estimated that HCV accounts for 27% of cirrhosis and 25% of HCC worldwide. HCV infection has likely been endemic in many populations for centuries. However, the wave of increased HCV-related morbidity and mortality that we are now facing is the result of an unprecedented increase in the spread of HCV during the 20th century. Two 20th century events appear to be responsible for this increase; the widespread availability of injectable therapies and the illicit use of injectable drugs.

Current treatment options and response rates in children with chronic hepatitis C

Vertical transmission has become the most common mode of transmission of hepatitis C virus (HCV) in children.The rate of perinatal transmission from an HCVinfected mother to her child ranges from 2% to 5% and the prevalence of HCV in children in developed countries ranges between 0.1% and 0.4%.Spontaneous viral clearance seems to be dependent on the genotype and has been reported between 2.4%-25%.For chronically infected patients,treatment with recombinant polyethylene glycol (PEG)-interferon α-2b and daily ribavirin has now been approved as standard treatment for children 2-17 years of age.In five large prospective studies,a total of 318 children and adolescents aged 3-17 years were treated either with subcutaneous PEG-interferon α-2b at a dose of 1-1.5 μg/kg or 60 μg/m2 once a week in combination with oral ribavirin (15 mg/kg per day) or PEG-interferon α-2a with ribavirin.Subjects with genotype 1 and 4 received the medication for 48 wk and individuals with genotype 2 and 3 mainly for 24 wk.Overall sustained viral response (SVR) was achieved in 193/318 (60.7%) of treated patients.Stratified for genotype;120/234 (51%) with genotype 1,68/73 (93%) with genotype 2/3,and 6/11 (55%) with genotype 4 showed SVR.Relapse rate was between 7.7% and 17%.Overall,treatment was well tolerated;how-ever,notable side effects were present in approximately 20%.According to recent experiences in the treatment of chronic hepatitis C in children and adolescents,a combination of PEG-interferon α with ribavirin has been found to be well tolerated and highly efficacious,particularly in individuals with genotype 2/3.Thus,this treatment can be recommended as standard of care until more effective treatment options will become available for genotype 1 patients.

Study on the blood-borne virus co-infection and T lymphocyte subset among intravenous drug users

AIM： To investigate the features of various blood- borne virus infections and co-infection in intravenous drug users （IDUs）, and to examine the correlation of T lymphocyte subsets with virus co-infection. METHODS： Four hundred and six IDUs without any clinical manifestation of hepatitis and 102 healthy persons were enrolled in this study. HBV-DNA and HCV-RNA were detected by fluorescence quantitative PCR. HBsAg, HBeAg, anti-HBc, anti-HCV, HDV-Ag, anti-HGV, anti-HIV, and HCMV-IgM were assayed by enzyme-linked immunosorbent assay （ELISA） and immunochromatographic tests. The levels of Th1 and Th2 cytokines were measured by ELISA and radioactive immune assay （RIA）. The T lymphocyte subpopulation was detected by using fluorescence immunoassay. The similar indices taken from the healthy persons served as controls. RESULTS： The viral infection rate among IDUs was 36.45% for HBV, 69.7% for HCV, 47.3% for HIV, 2.22% for HDV, 1.97% for HGV, and 3.45% for HCMV. The co- infection rate of blood-borne virus was detected in 255 of 406 （62.81%） IDUs. More than 80% （161/192） of subjects infected with HIV were co-infected with the other viruses, such as HBV, HCV. In contrast, among the controls, the infection rate was 17.65% for HBV and 0% for the other viruses. Our investigation showed that there was a profound decrease in the proportion of CD4/CD8 and the percentage of CD3 and CD4, but not in the percentage of CD8. The levels of PHA-induced cytokines （IFN-γ and IL-4） and serum IL-2 were obviously decreased in IDUs. On the other hand, the level of serum IL-4 was increased. The level of IFN-γ and the percentage of CD4 were continuously decreased when the IDUs were infected with HIV or HIV co-infection. IDUs with HIV and HBV co-infection was 15.1% （29/192）. Of those 29 IDU with HIV and HBV co-infection, 51.72% （15/29） and 37.93% （11/29） were HBV-DNA-positive and HBeAg-positive, respectively. But, among IDUs without HIV infection, only 1.68% （2/119） of cases were HBV- DNA-positive.CONCLUSION： HCV, HBV and HIV infections are common in this population of IDU, leading to a high incidence of impaired Thl cytokine levels and CD4 lymphocyte. IDUs with HIV and HBV/HCV co-infection have lower expression of Th1 cytokine with enhancement of the Th2 response. HIV may be causing HBV replication by decreasing Thl function.

Scanning Electron Microscopically Study of Sesame Seeds Infected with Macrophomina phaseolina

The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, including saprophytes and very weak parasites, may lower the quality of seeds by causing discoloration which may seriously depreciate the commercial value of seeds, particularly of grain when graded for consumption. Studies by using scanning electron microscopy （SEM） confirmed the importance of the seed coat, and seed cells as infection sites as well as location of the mycelium of the investigated fungus. Macrophominaphaseolina The present investigation is undertaken to study the colonization, infection and fungal establishment on different sesame seed parts by （SEM）. A successful colonization of M. phaseolina to seed tissues was also detected. Different forms of pycnidial shapes were also observed.

Biovars and Serotypes of Ureaplasma Urealyticum among Chinese Women Undergoing Routine Gynecologic Exam, Women with Sexually Transmitted Infections, and Female Sex Workers

Objectives: To characterize the distribution pattern of biovars and scrotypes or Ureaplasma urealyyicum in normalhealthy women, sexually transmitted infections clinic clients,and in sex workers. Methods: We cultured cervical swabs taken from 261physical check-up clients, 599 STI clinic outpatients and 98 sexworkers using commercial selective medium. Some positivecultures were further biotyped and serotyped by PCR. Results: (1) U. urealyticum is more commonly isolated in sexworkers (90.8%) than in the physical check-up group (60.9%)or the STI outpatient group (61.3%) (P<0.001). (2) Biovar 1of U. 'realyticum (95.0%), especially single infection ofserotype 1. 3, and 6 of biovar 1, is commonly found in healthywomen. (3) Biovar 2 infection of U urealyticum is moreprevalent in sex workers (28.1%) and STI outpatients group(26.6%) than that in the physical check-up group (4.9%) (P<0.001). (4) Mixed infection caused by more than one serotypeof U urealyticum increased from physical check-up group(8.6%) to STI utpatients (12.4%) to sex workers (23.9%) (P<0.01). (5) There is no statistically significant difference in thedistribution of serotype 1, 3, and 6 of biovar 1 among thesethree groups (P=0.763). (6) The PCR method described here isrelatively simple, rapid and specific for the biotyping andserotyping of biovar 1 of U urealyticum. Conclusion: We should pay more attention to biovar 2 andmixed infections of U. urealyticum than single infection ofhiovar 1 in clinic practice. PCR is a good method for biotypingand serotvping.

Partner's Sexual Behaviora are an Important Risk Factor for Chlamydia Trachomatis Infection among STD Patients

Risk factors for genitourinary Chlamydia trachomatis (Ct) infection were investigated using an STD elative risk factor questionnaire among 176 patients and theirregular sexual partners. Twenty-four independent variableswere selected for analysis, nine of which were confirmed asfactors associated with C. trachomatis. Four of the nine factorswere significantly correlated to infection using a multifactorialunconditional logistic regression model which included: levelof education (odds ratios [ORs]: 2.144 for below junior middleschool), number of sexual partners (ORs: 4.503 for≥5),number of regular partner's sexual partner (ORs: 16.333 for≥5), STD history of regular partner (ORs: 18.417 for theirSTD history). These data demonstrate that regular partner'ssexual behaviors are also an important risk factor for Ctinfection among STD clinic clients.

Risk of Getting Nosocomial Water-Borne Infections from the Main Water Systems in Hospitals

Drinking water may be a risk factor for human infections if the water supply is contaminated with biofilm producing bacteria such as Legionella pneumophilae or Pseudomonas aeruginosa. Several situations have to be considered when water supply to new buildings is planned. The aim of this paper is to review situations that have to be considered in new buildings and give an example on a new water supply contaminated with biofilm producing water bacteria and the precautions introduced to eliminate the contamination. When new buildings are planned it should be considered where to get the water and what is the microbiological quality of the water. If the water is contaminated there will be troubles from the beginning. The material for the pipes should be considered as biofilm which is produced in greater amounts and faster in PEG pipes than in stainless steel pipes. The choice of material depends on the expected lifetime of the building, the dimensions of the pipes, and the choice of forceps, how often the taps are used and thereby the flow in the system. The higher flow the less and slower biofilm formation. It is important to reduce the number of taps to a minimum to ovoid ＂dead ends＂ if they are not or only seldom used. Alternatively all taps could be opened automatically regularly. It is important to establish precautions to ovoid contamination of the water system in the period from when it is established until the building is taken in use. The period can be several months during which the system can act as a ＂dead end＂ if no precautions, such as regularly opening of all taps, are taken. The microbiological quality of the water in the system should be controlled before the building is taken in use. In a new building, where the water supply and the water in the building was not controlled before the building was taken in use, extremely high total and Legionella germ counts were found. The water was disinfected with low concentrations of chloride with very little effect. After disinfection with high concentrations of chloride for few hours and placing a sterile filter at the water entrance both the total and Legionella germ count decreased to an acceptable level.

Facilitating the Implementation of Sexually Transmitted Infection Syndromic Management in China

Objerctive: To introduce the current status of implementing sexually transmitted infection (STIs)syndromic management in China. Methods: Data werecollected and analyzed from the literature. Possiblesolutions were suggested for the obstacles encountered inthe implementation process. Results: Validation of revised flowcharts for themanagement of three syndromes (urethritis, vaginaldischarge, and genital ulcers) has been conducted in China.The feasibility, effectiveness and acceptance of using asyndromic STI approach were investigated in a large studyin Hainan, Zhejiang and Hubei Provinces. Chief obstaclesto implementation included the following: lack of supportfrom government authorities; negative reaction by hospitals;lack of critical thinking and innovation; perceivedover-emphasis on treatment at the expense of prevention;and lack of coverage for several important pathogens withintreatment algorithms. Possible solutions may include policyadvocacy, adopting syndromic management into a Chinesecontext, ssemination and promotion, training of providers, encouraging use of syndromic approach, and conductingoperational rescarch. Conclusions: Syndromic STI management provides afeasible approach for the diagnosis and treatment of STIs inChina. Further efforts should be made for scaling up itsapplication in clinical settings.

Investigation on Biovars and Serotypes of Ureaplasma Urealyticum in Cervix in Chinese Gynecologic Check-up Population, Sexually Transmitted Infections Clinic Clients and Sex Workers

Objectives: To characterize the distribution pattern biovars and serotypes of Ureaplasma urealyticum in normahealthy women, sexually transmitted infections clinic clienand in sex workers. Methods: We cultured cervical swabs taken from 26physical check-up clients, 599 STI clinic outpatients and 9sex workers using commercial selective medium. Sompositive cultures were further biotyped and serotyped bPCR. Results: (1) Biovar 1 of U urealyticum (95.0%), especiallsingle infection of serotype 1, 3, and 6 of biovar 1,commonly found in healthy women. (2) U urealyticummore commonly isolated in sex workers (90.8%) than iphysical check-up group (60.9%) and STI outpatients grou(61.3%) (P<0.001). (3) Biovar 2 infection of U urealyticuris more prevalent in sex workers (28.1%) and SToutpatients group (26.6%) than that in physical check-ugroup (4.9%) (P<0.001). (4) Mixed infection caused bmore than one serotype of U. urealyticum is increasing fromphysical check-up group (8.6%) to STI outpatients (12.4%and to sex wokers (23.9%) (P<0.01). (5) There is nstatistic difference in the distribution of serotype 1, 3, and of biovar 1 among these three groups (P=0.763). (6) ThPCR method described here is relatively simple, rapid anspecific for the biotyping and serotyping of biovar 1 of Uurealyticum. Conclusion: we should pay more attention to biovarand mixed infection than single infection of biovar 1 of Uurealyticum in clinic practice. PCR is a good method ibiotyping and serotyping.

Asymptomatic Herpes Simplex Virus Shedding in STI Patients

Objective: This study examined Herpes Simplex Virus (HSV) subclinical shedding in the genital tract of patients withgenital herpes (GH) or non-gonoccal urethritis (NGU). Method Swabs were collected after exposure to rash andgenital tract during GH relapse or remission on a weekly basisfor four to six weeks. NGU patients with negative chlamydiaand mycoplasma tests were also swabbed for a similarduration. All swabs underwent HSV DNA detection withquantitative PCR. Result: There was a significant difference in the rate ofasymptomatic HSV shedding in urinary tracts comparing GHand the control group and comparing NGU and the controlgroup (P<0.05). The rate of HSV shedding was 22%, 9.8%and 3.3% for GH, NGU and control groups respectively. Therate of HSV shedding was 21.7% (20/92) for patients withactive GH and 23% for those in remission. The HSV positiverate was significantly higher in the group with patients whohad more than six relapses within one year compared to thegroup of patients with less than six relapses.Conclusion: There is HSV subclinical shedding in theirgenital tract during active GH and remission. SubclinicalHSV shedding is more common in patients with more than sixGH relapses per year compared to GH patients with fewerrelapses. Approximately 9.9% of NGU patients with negativechlamydia mycoplasma testing was found to have subclinicalHSV infection.

Advances on Syndromic Management of Sexually Transmitted Diseases

Research data showed that syndromic approach could successfully manage gonococcal and chlamydial infections in males and syphilis and chancroid in males and females. However, low sensitivity, specificity and positive predictive value were found in the syndromic management of vaginal discharge. It is recommended that the syndromic algorithm for management of vaginal discharge used when serving high-risk and symptomatic women.

Susceptible-Infected-Recovered-Susceptible Virus Spreading Model Based on Two Dimensional Sparse Lattice

In order to clarify the virus＇ spreading rules, a SIRS （Susceptible-Infected-Recovered-Susceptible） disease spread model based on sparsely distributed crowd is proposed. In this model, the effects of crowd-density, spread efficiency and the moving of individuals on the spreading of viruses are researched. The theoretical analysis and analog simulation shows that there exist a critical value, only when the product of spread efficiency and crowd density goes beyond the critical value, can viruses spread in crowd continuously and steadily. Besides, the moving of individuals can promote the spreading of viruses. These results are helpful guiding people to defense and control virus＇ spreading process.

Investigation on the Maternal-Infantile Infection with Human Parvovirus B19

To investigate the maternal-infantile infection with human parvovirus B19, the IgG and IgM antibodies against human parvovirus and the B19-DNA in serum and peripheral blood mononuclear cells (PBMC) of pregnant women as well as the serum IgM antibody against B19 and the B19-DNA in serum and cord blood nucleated cells (CBNC) of newborns were determined by ELISA and nested PCR respectively. It was found that the positive rate of the IgG antibody against human parvovirus B19 in sera of 92 pregnant women was 38.04% (35/92), and that of the IgM antibody in 720 pregnant women was 9.03% (65/720). However, the IgM antibody against human parvovirus B19 was negative in the cord blood sera of 95 newborns. As to the human parvovirus B19 DNA, none of 720 pregnant women and 95 newborns was proved to be positive in their sera. Nevertheless, the positive rate of the parvovirus B19 DNA in PBMC was 3.06% (3/98) in 98 pregnant women and 1.12% (1/89) in CBNC of 89 newborns. It is concluded that the history of infection with human parvovirus B19 exists in certain pregnant women with a small percentage of pregnant women infected with recent or acute infections of B19 virus. The detection rates of the B19 viral DNA in PBMC of pregnant women and CBNC of newborns were higher than those in sera, indicating that the risk for vertical transmission is very low.

Vidas CHL Assay in the Detection of Urogenital Chlamydia Trachomatis Infection

Objectives: To evaluate the Vidas Chlamydia (CHL) assayfor detecting C.Trachomatis with swabs and first catch urine(FCU) specimens from STD patients and high riskpopulations. Methods: A total of 383 pahents were tested with tissueculture (TC), Vidas CHL and polymerase chain reaction (PCR)for C.trachomatis on male and female swabs, with Vidas CHLtesting male FCU specimens. CHL positive and equivocalresults were confirmed with a blocking assay (CHB). Truepositive were defined as either TC positive, or TC negtive butCHL and PCR positive. The performance of TC, CHL andPCR were evaluated according to this expanded goldstandard. Results: Compared with the expanded gold standard, 54 ofthe 232 male specimens were true positive results. For maleswabs, TC, CHL and PCR had sensitivities of 90.7%, 96.3%and 94.4%, and specificities of 100%, 98.3% and 97.2%,respectively. Differences were not statistically significant. Formale FCU specimens, CHL sensitivity and specificity were83.3% and 98.3%; there was little difference between theseresults and that of matched swabs. Compared with theexpanded gold standard, 28 of the 151 female swabs were truepositive; TC, CHL and PCR had sensitivities of 82.1%, 100%and 96.4%, and specificities of 100%, 98.4% and 97.6%,respectively. The difference was also not significant. Conclusions: Vidas CHL assay is very scnsitive and specificfor C.trachomatis detection with swab specimens of male andfemale STD patients. For male FCU specimens, the assay alsohad high sensitivity and specificity. CHB may not be needed inthe routine detection or Chlamydia infections. Populationswith higher incidence of C.trachomatis infection.