Invasive Haemophilus influenzae disease: an ecological study of sociodemographic risk factors before and after the introduction of Hib conjugate vaccine

This study examines the impact of H. influenzae type b (Hib) conjugate vaccine on sociodemographic risk factors for invasive H. influenzae disease in the 2 years before and immediately after the introduction of Hib conjugate vaccine. An ecological study design was used and cases were identified using active surveillance employing several surveillance systems. The study population comprised all children aged <5 years resident in the West Midlands, an English health region, with laboratory confirmed invasive disease 2 years before (1990–1992) and 2 years after (1992–1994) the introduction of Hib conjugate vaccine. Selected sociodemographic variables derived from the UK census were obtained for all census enumeration districts in the region. Each variable was then ranked and divided into six categories. Linear associations between disease rates and sociodemographic variables were examined. Overall, there was a significant reduction in the incidence of invasive H. influenzae disease. In the pre-conjugate vaccine era there were trends of decreasing disease incidence with increasing child population density (p = 0.012) and total population density (p = 0.0023). In the post-conjugate vaccine period, total population density (p = 0.0275) remained significant and a trend of increasing disease incidence with increasing population mobility (p = 0.0012) was seen. Although Hib conjugate vaccine has resulted in a dramatic reduction in disease incidence changes in sociodemographic risk factors were identified in the post-conjugate vaccine period, particularly population mobility. Our results may have implications for current and future vaccine strategies.     

Salmonella in slaughter pigs of German origin: An epidemiological study

The Salmonella prevalence in slaughter pigs of German origin was determined in seven abattoirs located in different regions of the country between February and June 1996. A total of 11,942 pigs delivered to the abattoirs in 752 batches, most of them comprised of pigs from individual finishing farms, was investigated by the bacteriological examination of faecal and gut lymph node samples, as well as of surface swabs taken from the carcasses. Salmonellae were isolated from 3.7% of the faecal samples, 3.3% of the lymph nodes and 4.7% of the surface swabs. The estimated overall prevalence of Salmonellae was 6.2% in the slaughter pigs, ranging between 1.9% and 12% in individual abattoirs. In the samples taken from carcasses, the estimated prevalence of Salmonellae reached 10.3%. 648 out of 752 batches could be included in a statistical analysis. No Salmonellae were detected in nearly 70 percent of the batches included in this analysis (n = 648). High Salmonella prevalences of more than 50 percent positive animals were detected only in 13 batches (2.0%). A statistically significant influence of the duration of the transport of slaughter pigs to the abattoirs or the waiting period in the abattoirs prior to slaughter could not be detected.     

Random meticillin-resistant Staphylococcus aureus carrier surveillance at a district hospital and the impact of interventions to reduce endemic carriage

Colonisation with meticillin-resistant Staphylococcus aureus (MRSA) has previously been described as a risk factor for subsequent infection. MRSA colonisation reached endemic proportions in most healthcare institutions in the UK during the 1990s. Bacteraemia due to MRSA is associated with increased mortality and morbidity compared with meticillin-susceptible S. aureus and national targets have been set for reduction. We present our findings of regular random colonisation surveillance and systematic decolonisation of MRSA carriers over a five-year period with the aim of reducing the pool of carriers and number of MRSA bacteraemia cases. Interventions to reduce the rate of colonisation included assurance of decolonisation and follow up, targeting wards with the highest carriage rates using enhanced screening and education, and screening all admissions aged >65 years. There was a statistically significant reduction in the proportion of patients colonised from 14.6% to 7.0% (P < 0.001) and the total number of bacteraemia cases from 42 to 22 (P = 0.012) in the initial 24 months of surveillance compared to the most recent 24 months. Regular surveillance of MRSA carriage is useful for monitoring the effects of control measures on MRSA carriage among inpatients. Interventions to reduce carriage are able to reduce the pool of MRSA carriers, thereby reducing cases of bacteraemia.     

Methicillin resistant Staphylococcus aureus (MRSA) isolated in Saudi Arabia: epidemiology and antimicrobial resistance patterns

Methicillin resistant Staphylococcus aureus (MRSA) comprised about 7·5% per annum of all S. aureus isolated in a general hospital in Jeddah, Saudi Arabia during the 3 year period 1990–1992. Most isolates were from wound sites (71%). Resistance to gentamicin (83%) and tetracycline (93%) was frequently observed whilst resistance to ciprofloxacin (1%) and rifampicin (6%) was uncommon. Low levels of mupirocin resistance (MIC 8 mg 1⁻¹), were detected in 3% of all MRSA isolates.     

建设部门协同机制和监测网络应对沙门菌感染疫情

沙门菌病为常见的食源性疾病, 经常发生局部和跨地区的暴发流行, 随着全球经贸往来的日益频繁, 沙门菌跨境传播的风险也在不断增加。近期多国出现巧克力相关单相鼠伤寒沙门菌感染暴发疫情, 对我国食源性疾病特别是沙门菌病的监测和预警提出了更高的要求。加强临床机构与疾控和食品安全监测机构的合作、提升沙门菌基因组测序分析以及应用于流行病学监测和暴发溯源的能力、加强食品安全相关各部门间信息沟通及协作, 是及时发现暴发及传播、预防和控制传播的主要手段, 也是食源性疾病监测亟待加强的地方。     

Results of the three-year surveillance by the Italian SALM-NET System: Human isolates of Salmonella serotypes

Within the wide framework of the European Community Human Salmonella Surveillance Project (SALM-NET), the data on the most commonly isolated serotypes in Italy from January 1994 to December 1996 are reported. The total data included in the Italian SALM-NET data base account for 34,412 Salmonella isolates. In the list of the most frequent isolates, S. enteritidis ranked always first in the years 1994, 1995 and 1996 with 5435 (43.4%), 4589 (37.1%) and 4044 (42.4%), respectively, over the total number of Salmonella isolates. This serotype is followed by S. typhimurium in the list of the top ten isolates, with 2236 (17.9%), 2831 (22.9%) and 2239 (23.5%). The other serotypes included in this list accounted for a much lower number and percentages ranging from 505 isolates of S. derby (4.0%) to 99 isolates of S. brandenburg (0.8%).     

Sequential emergence of multi-resistant Klebsiella pneumoniae in Bahrain

During the mid-1980s, nosocomial infections due to aminoglycoside-resistant Klebsiella pneumonia were prevalent in the intensive care unit (ICU) of the Salamanya Medical Centre, Bahrain. In an attempt to control the spread of such organisms, the third-generation cephalosporins were introduced in early 1987. Subsequently there was a marked increase in the incidence of cephalosporin resistance among Klebsiella spp. isolated in the ICU. In 1990, over 60% of Klebsiella isolates were resistant to both cephalosporins and aminoglycosides. Cephalosporin resistance was due to production of extended-spectrum β-lactamases encoded on the same plasmid as aminoglycoside resistance. The incidence of cephalosporin resistance declined during 1991–1992, which was coincident with severe restrictions on the use of third-generation cephalosporins and the preferential use of ciprofloxacin and imipenem for nosocomial klebsiella infections. Sequential overuse of aminoglycosides and cephalosporins for nosocomial klebsiella infection may select for organisms resistant to both classes of antibiotics.     

Surveillance of multidrug-resistant strains of Salmonella enterica serotype Typhimurium in southern Italy in the years 1992–1997

Spread of multidrug-resistant strains of Salmonella enterica serotype Typhimurium (S. typhimurium) is increasingly reported worldwide. The presence of a pattern of resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in some cases associated to trimethoprim and infrequently to quinolones, is of particular concern. This resistance pattern appears to be chromosomally encoded and, in most epidemiological studies, closely related to definitive type 104 (DT104).In southern Italy multidrug-resistant isolates of S. typhimurium had been identified since 1980, but only during 1992 S. typhimurium strains with chromosomally encoded drug resistance were first isolated from domestic animals.One hundred fifty-five isolates – 52.5% of the multidrug-resistant strains identified in the years 1992–1997 – were submitted to phage typing and plasmid profile analysis. Ribotyping was also performed in comparison with a random sample of 150 strains susceptible or resistant to three or less antibiotics identified in the same interval of time.Four ribotypes (RTs) -1, 5, 8, and 48 – included approximately 90% of the multiresistant strains, RT8 accounting for 61.2%. Phage type (PT) 193 is the most prevalent phage type.Phage typing and ribotyping suggest that few bacterial clones are involved in spread of multi- drug-resistant S. typhimurium strains in southern Italy.     

Occurrence of different genospecies ofBorrelia burgdorferi sensu lato in ixodid ticks of Valais,Switzerland

A total of 825 adult ticks (727Ixodes ricinus, 72Dermacentor marginatus and 26Haemaphysalis punctata) was collected from vegetation in Valais (Switzerland) in 1987 to 1992. They were examined for the presence ofBorrelia burgdorferi sensu lato, the etiologic agent of Lyme borreliosis.B. burgdorferi sensu lato was detected by indirect immunofluorescence assay, dark field microscopy and/or culture in 221 out of 727I. ricinus (30.4%) and none in the other two species. From these 221 infected ticks we obtained 50 isolates. Indirect immunofluorescence assay and culture were used for all ticks but dark field examination has also been performed and compared to the two above mentioned methods for 231I. ricinus. Indirect immunofluorescence was found the most efficient method for the detection of Borrelia in ticks with 54 positive out of 231, followed by dark field examination with 35 positive and culture with 12 isolates. We found no site free of Borrelia whereI. ricinus is present. The rate of infection varied from 9.7 to 47.5%, as detected by the addition of the three methods. Typing of the 50 isolates revealed also a nonhomogeneous distribution of the Borrelia species. Based on the electrophoretic mobility of the OspA and B and immunostaining with species specific monoclonal antibodies (H3TS forB. burgdorferi sensu stricto, D6 forB. garinii and J8.3 forB. afzelii) 4 groups could be observed. Half of the isolates (n=26) were typed asB. burgdorferi sensu stricto, 19 asB. garinii, 3 asB. afzelii and 2 as group VS116. This forth group formed of two isolates from one location is genetically distinct from the 3 former species described in Europe so far. The Borreliae of this group are unreactive with any of the three monoclonal antibodies used.     

Changes in serotype distribution of Haemophilus influenzae meningitis isolates identified through laboratory-based surveillance following routine childhood vaccination against H. influenzae type b in Brazil

Following routine childhood vaccination against Haemophilus influenzae type b (Hib) disease in Brazil in 1999, passive laboratory surveillance reported increasing numbers of non-b serotypes and nontypeable H. influenzae (NTHi) from meningitis cases. To characterize this increase, we analyzed data on 3910 H. influenzae isolated from cerebrospinal fluid or blood from meningitis cases that were sent to the national reference laboratory for serotyping from 1990 to 2008. Hib accounted for 98% of H. influenzae meningitis isolates received during 1990-1999 versus 59% during 2000-2008, while non-b serotypes increased from 1% to 19% and NTHi increased from 2% to 22% of H. influenzae isolates received during the two periods. Higher proportions of non-b serotypes and NTHi than Hib were isolated from blood rather than cerebrospinal fluid. Estimated incidence rates for H. influenzae meningitis for Sao Paulo state remained below 1 case per million population during 2000-2008, although annual incidence of NTHi meningitis (mean, 0.03 cases per 100,000 population) increased in several age groups. Changes in surveillance for H. influenzae following introduction of Hib conjugate vaccine likely contributed to increased numbers of non-b and nontypeable H. influenzae meningitis isolates received at the national reference laboratory.     

中国幽门螺杆菌基因组多样性与种群结构分析

目的 了解中国幽门螺杆菌（Helicobacter pylori,HP）基因组特征及种群结构。方法 利用中国不同地域不同疾病分离的10株HP的基因组序列,并整合公共数据库中其他地域的HP基因组数据,通过比较基因组和生物信息学方法分析中国HP的基因组与种群结构特征。结果 中国HP核心基因为1 203个。菌株特异基因为19～32个,这些基因可能与中国HP在不同地域、不同疾病宿主中的适应性进化有关。基因组变异较大区域主要集中在编码限制修饰系统的基因和编码四型分泌系统的基因。基于核心基因组单核苷酸多态性（SNP）的种群分析确定中国菌株均属于hpEastAsia群,hspEAsia亚群,且不同地域菌株具有地域聚集性特点。在3株中国HP基因组序列中发现了前噬菌体序列,携带噬菌体组装所需的必要元件。结论 基于核心基因组SNP分析中国菌株均属于hpEastAsia群,hspEAsia亚群,且具有地域聚集性。为深入挖掘中国不同地域不同疾病相关HP的遗传特征及研究噬菌体在HP进化与致病中的作用奠定了基础。     

新疆维吾尔自治区1960-2019年流行性脑脊髓膜炎流行病学及病原学特征分析

目的 了解新疆维吾尔自治区（新疆）流行性脑脊髓膜炎（流脑）的流行病学和病原学特征。方法 资料来源于中国疾病预防控制信息系统和新疆CDC保存的1960-2019年流脑发病数据,分析其流行病学特征。采用分离培养和荧光PCR对临床标本进行检测,并开展健康人群带菌调查。采用玻片凝集和荧光PCR方法检测菌株的血清群,采用多位点序列分型（multi-locus sequence typing,MLST）方法检测脑膜炎奈瑟菌（Nm）菌株分子分型特征。结果 1960-2019年新疆流脑年发病率为0.02/10万~81.32/10万,病死率为1.05%~20.78%。喀什地区、阿克苏地区、乌鲁木齐市、昌吉回族自治州与和田地区发病数位居前5位。1990年以前,病例和密切接触者均以A群为主（81.82%）;1990年以后,出现B、C、W和Y群病例（14.00%）,密切接触者没有明显优势的血清群,B、A、W、Y、C群分别为23.28%、18.53%、15.52%、9.91%、7.33%。健康人群带菌率为15.50%,16~岁带菌率最高（25.53%）,菌株主要血清群为B（52.11%）、W（20.66%）、C（12.21%）和Y（9.39%）。MLST分子分型结果显示,新疆Nm菌株主要克隆群为ST-4821、ST-175和ST-5克隆群,病例Nm菌株以ST-5和ST-4821克隆群为主。结论 1960-2019年新疆流脑发病率存在地区差异,健康人群带菌率高,Nm菌株血清群正在发生变迁。应在重点地区加强流脑疫情的防控,防止流脑的暴发流行。     

Rickettsiae and rickettsioses in Portugal

The only rickettsiae recorded in Portugal till now were Rickettsia conorii and Coxiella burnetii. Boutonneuse fever is one of the most important transmissible diseases in Portugal. Though the annual number of cases is not exactly known, it is estimated to be not far from 20,000 in some years. Q fever is the other rickettsiosis widely disseminated throughout the country. The serological prevalence and the incidence of those rickettsioses in Portugal are presented in this communication. In recent research in southern Portugal, about 4,000 adult ticks of nine species were screened by the haemocyte test for rickettsiae and rickettsia-like organisms (RLO). In addition to R. conorii three microscopically different RLO were observed. Two of them, i.e. ovoid and bacillary-like, were positive in the immunofluorescence test with spotted fever (R. conorii) antiserum. The first occurred mainly in Rhipicephalus sanguineus ticks, the second one also in other tick species. The latter agent was cultivated in half-engorged R. sanguineus females and in Vero cells. The third organism was found in R. sanguineus, where it exhibited a massive infestation in haemocytes resembling that seen in experimentally infected ticks with C. burnetii, but not being this agent. The investigation of the isolates and their identification and characterization are being continued.Presented at the 4th International Symposium on Rickettsiae and Rickettsial Diseases, Pietany, C.S.F.R., 1–6 October, 1990.     

Genomic DNA fingerprints and phenotypic characteristics of serotype B Haemophilus influenzae isolates from Italy

Three different restriction enzymes (PstI, EcoRI, SspI) were used to analyze the total genomic DNA fingerprints of 52 Haemophilus influenzae type b (Hib) isolates collected between 1982 and 1992 from patients and carriers in central-northern Italy. The same isolates were also characterized by biotyping and antimicrobial agent susceptibility typing. In addition, 13 Hib reference strains from Sweden and the Netherlands were subjected to DNA fingerprinting and compared to Italian isolates.Both genotypic and phenotypic analysis revealed low variability among the Italian study isolates. Most were biotype I and all study isolates but one were susceptible to ampicillin, chloramphenicol, rifampin, third-generation cephalosporins and cotrimoxazole. Among the 52 Italian isolates, 3 distinct DNA patterns were identified, and 88.5% of study strains belonged to the same DNA group. There was sharing of the predominant DNA profile among isolates cultured in different years from different geographical areas and different invasive, respiratory and surface infections. However, another DNA pattern was only found in carrier isolates and in one surface infection isolate.Comparison by DNA fingerprinting showed that the majority of Italian isolates were closely related to most of the analyzed Swedish and Dutch reference strains, previously shown by other techniques to be predominant in those areas. This finding provides additional support for the hypothesis that there may be a dominant European Hib clone.The results show that DNA fingerprinting is a reliable method for Hib characterization and may be a useful additional epidemiological tool for this microorganism.     

健康人携带金黄色葡萄球菌耐药表型及基因型研究

目的 调查我国健康人携带的金黄色葡萄球菌药物敏感性及大环内酯类耐药基因分布情况.方法 应用E-test方法,对2009－2011年收集的100株健康从业人员携带菌株进行16种抗生素的药物敏感性分析,以D 试验测定红霉素对克林霉素的诱导耐药表型.采用spa分型对上述菌株进行分型分析.利用PCR检测基因:甲基化酶[erm(A),erm(B),erm(C),erm(F),erm(T),erm(Y),erm(33)和erm(G)]、ATP结合转运蛋白[msr(A)和msr(D)]、主要易化子[mef(A)]、酯酶[ere(A)]及磷酸化酶[mph(C)],并与猪来源菌株38株(31株MRSA,7株MSSA)和患者来源MRSA菌株20株进行比较.结果 健康人群携带菌株对红霉素和克林霉素耐药率较高,分别为52%和27%.克林霉素诱导耐药率为29%.共鉴定35个spa型别,其中51.0%的spa型别为t189、t571、t002、t796、t437、t034和t701.52株健康人菌株主要携带erm(C)(57.7%)和erm(B)(34.6%), 95.0%的临床分离菌株携带erm(A), 100.0%猪鼻拭子分离菌株均携带erm(C)菌株.结论 携带erm(C)和erm(B)耐药基因的大环内酯类耐药菌株在健康人群中广泛存在,这些耐药基因在金黄色葡萄球菌中呈散在克隆传播.     

Salmonella serovars identified at the centre for enterobacteriaceae of palermo over the 5-year period 1983-87

Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area.This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983–1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.     

Surveillance of laboratory based infections by biological and medical analyses: review of the literature

Infectious disease surveillance is one of the priorities of public health programmes. This review aims to describe laboratory-based infection surveillance systems. The following surveillance networks are described: the Belgian microbiology network, AIDS surveillance in Philadelphia, EPIBAC, and the Salm-Net network. Laboratory-based surveillance provides the advantage of constituting an easily accessible computerised data bank that allows for studying age-old tendencies and evaluating the effectiveness of certain prevention programmes. The main inconveniences remain with the difficulty of eliminating duplications as well as the lack of clinical information. These difficulties can be surmounted by improving communication systems among the diverse participants in the network with electronic mail. Such surveillance systems will facilitate information exchanges at both the national and international level.     

Nosocomial outbreak of vancomycin-resistant Enterococcus faecium at a German University Pediatric Hospital

Nosocomial Infections caused by vancomycin–resistant enterococci (VRE) are an emerging threat to critically ill patients. At the University Hospital Eppendorf, VRE were isolated from 38 patients between August 1993 and April 1997, of whom 32 were hospitalized at the Department of Pediatrics. Pulsed-field gel electrophoresis revealed that 26 Enterococcus faecium isolates from patients of the Department of Pediatrics were identical or closely related, and that isolates from three additional patients of the same department were possibly related. All of these isolates were of vanA genotype. They were resistant to glycopeptides, ampicillin, ciprofloxacin, clindamycin, and erythromycin. Most isolates displayed high–level resistance to gentamicin, but all remained susceptible to quinupristin/dalfopristin. Implementation of stringent hand disinfection and environmental disinfection policies, as well as measures for patient isolation contained this first outbreak of VRE at a German Children's hospital, which emphasizes the importance of hygienic measures for the control of nosocomial spread of these organisms.     

Surveillance for sexually transmissible diseases in Victoria, 1983 to 1992

Abstract: Surveillance systems have been developed in Victoria to determine trends in sexually transmissible diseases (STDs). Notifications to the Health Department (including laboratory notification since May 1990) have been supplemented by data about strains of Nasseria gonorrhoeae and cultures for Chlamydia trachomatis processed by the Microbiological Diagnostic Unit, enhanced laboratory surveillance of syphilis, and data on genital herpes and genital warts from the Melbourne Sexual Health Centre. During the period under review the incidence of gonorrhoea declined, rapidly at first, and then more slowly. For women, this trend has continued, while gonorrhoea acquired abroad by men has become relatively more important. Since 1988, gonorrhoea in homosexual men has increased, and rectal isolates have increased concurrently, raising concerns about HIV risk behaviour. Cases of syphilis are likely to be ascertained through STD, antenatal and refugee screening, rather than because of symptoms or contact tracing. Chlamydia is a the most common notifiable STD, despite underreporting and under-diagnosis. In 1991, 832 cases were notified, increasing to 1377 in 1992. In 1992, of the 73 cases (65 per cent of notifications) where the doctor identified a risk, 15 per cent was attributed to homosexual contact, and 27.4 per cent to heterosexual exposure. Limitations in the data include inadequate standard case definitions for many STDs, changes in the statutory requirement for notifications in 1990, underreporting, changes in diagnostic and screening patterns, and lack of detailed demographic data. Education of general practitioners is needed to improve diagnosis and notification of chlamydia.     

The secretion of aspartyl proteinase,a virulence enzyme,by isolates of Candida albicans from the oral cavity of HIV-infected subjects

Prevalence, serotype and in vitro secretion of aspartyl proteinase, a virulence enzyme, were studied in Candida isolates from the oral cavity of 337 HIV-infected subjects. Controls were 95 age-sex-matched HIV- (seronegative) subjects, belonging to either HIV-risk categories (47) or to the normal, general population (48). Fungi were isolated from 155 HIV+ subjects. C. albicans was the most prevalent species (85.8% of all isolates). 94.6% of C. albicans isolates were serotype A and all were agglutinated by a monoclonal antibody (AF1) directed against a major mannoprotein immunogen of the candidal cell wall, confirming previous results with C. albicans isolates from non-immunodeficient subjects. With regard to the stage of HIV infection, there were no statistically significant differences in the incidence of oral Candida carriage between asymptomatic (stage II) HIV+ and HIV- subjects, and between stage II and lymphadenopathic (stage III) individuals. Also, the low (3.8%) incidence of oral candidiasis in the subjects of the latter stage was insignificant with respect to stage II subjects. However, the incidence of C. albicans in stage IV (AIDS) subjects (46.8%) was significantly higher than in all other subjects, and in almost all cases, fungal isolation was accompanied by oral thrush and lower CD4+ lymphocyte counts (< 400 × 10°/L).All isolates of C. albicans were proteolytic in vitro, as assessed by scoring the proteinase activity on BSA agar and monitoring the secreted proteinase antigen by a highly sensitive (1 ng) and specific immunoenzymatic assay. However, by both methods, the isolates from subjects at stages III and IV of infection produced more secretory proteinase than the isolates from either HIV+ asymptomatic subjects or HIV- controls. The differences could not be attributed to particular culture media or source of Candida isolation (carriage versus active infection). Thus, the isolates of C. albicans from advanced HIV infection are serologically similar but more proteolytic than the isolates from earlier stages of HIV infection or those from HIV-uninfected subjects. The apparently higher virulence of C. albicans from AIDS subjects may represent a co-factor in determining and/or aggravating oral candidiasis in these patients.