Plasmid typing of Shigella sonnei epidemic strains and molecular relationship of their R-plasmids

We conducted a surveillance program on epidemic and/or endemic Shigella strains in Asturias (Spain), their frequency and dispersion in our community, and their R-plasmids. We analyzed initial isolates of Shigella sonnei from two epidemic outbreaks using antibiotic resistance patterns and plasmid profile analysis as epidemiological markers. We found that the 2 outbreaks were caused by different S. sonnei strains, which respectively carried one and two R-plasmids together with other plasmids. The molecular relationship among these and three other R-plasmids from two S. sonnei strains isolated during a previous outbreak, were studied by restriction enzyme analysis and DNA-DNA hybridizations. We were able to establish different levels of relationship among the six R-plasmids.Corresponding author.     

Tinea corporis caused by Microsporum canis: Report of a Nosocomial outbreak

In an unusual nosocomial outbreak, 13 staff and 11 patients in an acute and chronic health care facility were infected with the zoophilic dermatophyte, Microsporum canis. The dermatophyte was apparently introduced into the facility by a single infected patient. Likely modes of subsequent disease transmission include person-to-person contact, handling of contaminated laundry, and use of a shared razor. Infection control measures for managing such outbreaks are discussed.     

Hospital outbreak of Salmonella virchow possibly associated with a food handler

A foodborne outbreak of salmonella infection at a private hospital in London in 1994 was found to be associated with eating turkey sandwiches prepared by a food handler. One patient, nine staff, and a foodhandler's baby were confirmed to have Salmonella enterica serotype virchow, phage type 26 infection. The attack rate was estimated to be 5% among the approximately 200 patients and staff at risk. A food handler reportedly became ill days after, but her baby days before, the first hospital case. Although it appeared to be a single outbreak, antibiogram analysis, supplemented by plasmid profile typing, demonstrated that there were two strains of S. virchow involved, one with resistance to sulphonamides and trimethoprim and a second sensitive to these antimicrobial drugs. Mother and child had different strains. The investigation demonstrated the importance of full phenotypic characterization of putative outbreak strains including antimicrobial susceptibility testing.Outbreaks of foodborne infection in hospitals are preventable and are associated with high attack rates and disruption of services. There is a need for good infection control policies and training of all staff involved in patient care as well as in catering services. Consultants in Communicable Disease (CCDCs) should include private hospitals in their outbreak control plans. Good working relations between Infection Control Doctors (ICDs) in the private health sector and their local CCDCs are important if outbreaks are to be properly investigated.     

Environmental contamination during a carbapenem-resistant Acinetobacter baumannii outbreak in an intensive care unit

During a three-month period in 1999, 25 strains of carbapenem resistant Acinetobacter baumannii were isolated from 12 of 170 hospitalized intensive care unit (ICU) patients, of which 16 were considered to be clinically significant. These strains were indistinguishable by biotyping and antibiograms, but genotyping was not performed. Appropriate antibiotic treatment, isolation precautions, and infection control education of the staff failed to halt the outbreak. Environmental contamination was therefore investigated, and A. baumannii was found out in 22 (39.3%) of 56 environmental samples obtained by swabbing. Different antibiotic sensitivity patterns were obtained in the majority of these isolates, but four (7.1%) of the strains were found to have the same sensitivity pattern as the strain causing the outbreak. As a result the ICU was closed, equipment and the environment cleaned, with hypochlorite and terminal disinfection carried out. No bacteria were grown on repeat environmental cultures. Environmental contamination has an important reservoir role in outbreaks ofA. baumannii in ICUs and must be eradicated in order to overcome such outbreaks.     

Serological evidence of Cryptosporidium infections in southern Europe

Although cryptosporidiosis outbreaks have been frequently reported in the United States, Canada and the United Kingdom, few outbreaks have been reported on the European continent. The reasons for this are unclear. To ascertain whether a European population has been previously exposed to Cryptosporidium, we conducted a survey of 100 resident blood donors in a northern Italian city for IgG serological response to two oocyst antigen groups. A serological response to the 15/17-kDa antigen group was detected in 83% of blood donors and response to the 27-kDa antigen group in 62%. Donors who traveled outside of Italy during the prior 12 months were less likely to have had a response to the 15/17-kDa antigen group (p < 0.04) and to have a less intense response (p < 0.05). Older age was predictive of a more intense response to each antigen group (p < 0.01). The fraction of Italian blood donors with a serological response to either antigen group was higher than in four United States blood donor populations, with differences more pronounced for response to the 15/17-kDa antigen group (p < 0.01). A lower fraction of Italian donors had a serological response to either antigen group than persons tested at the time of a cryptosporidiosis outbreak in the United States or blood donors tested six months after that outbreak (p < 0.05). Since the presence of serological responses to these antigen groups predicts a reduced risk of cryptosporidiosis, the high prevalence of serological responses in these Italian blood donors may explain the infrequent occurrences of clinically detectable cryptosporidiosis in this city.     

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。     

Viral gastrointestinal outbreaks in residential care facilities: an examination of the value of public health unit involvement

Objective : To evaluate the value of notification to public health units (PHUs) in the management of viral gastrointestinal outbreaks in residential care facilities (RCFs) in Queensland. Methods : Routine outbreak characteristics and control measures were collected at notification and conclusion of outbreaks notified between May and August 2008. This was supplemented with detailed interviews with RCFs and PHUs, including perceptions of the value of the RCF‐PHU interaction. Results : Norovirus was the confirmed aetiological agent in 39 (68%) of 60 outbreaks. A significant association was found between increased outbreak duration and longer (≥4 days) time to outbreak notification (p<0.01) and larger facility size (≥150 people; p<0.05). Increased attack rate was not significantly associated with either time to outbreak notification or facility size, but was significantly associated with difficulty in cohorting (p<0.05). Most (92%) RCFs considered that outbreak notification was important and that PHU support was useful (97%). Most PHUs (77%) also considered that outbreak notification was important. Conclusions : This study demonstrates an association between prompt notification of viral gastroenteritis outbreaks to PHUs and shorter duration of outbreaks. Implications : This study provides evidence to support recommendations in current Australian guidelines that notification of outbreaks should occur promptly.     

Involvement of closely related strains of a new clonal group of Listeria monocytogenes in the 1998-99 and 2002 multistate outbreaks of foodborne listeriosis in the United States

In 1998-99, a multistate outbreak of listeriosis in the United States was associated with contaminated hot dogs and was caused by a strain of Listeria monocytogenes serotype 4b that had been only rarely encountered before in the national PulseNet database. Upon further characterization, the strains from this outbreak were designated as Epidemic Clone II (ECII). ECII isolates exhibited diversification in a genomic region ("region 18") that was otherwise conserved among L. monocytogenes of serotype 4b. Additional unique genetic markers were identified through genome sequencing of one of the isolates from the 1998-99 outbreak. In 2002, another multistate outbreak of listeriosis also involved bacteria of serotype 4b and was attributed to contaminated turkey deli meats. Molecular subtyping data revealed that the macrorestriction patterns of the isolates from the 1998-99 and 2002 outbreaks were closely related. In addition, the 2002 outbreak isolates harbored chromosomal genetic markers found to be unique to, and typical of, the 1998-99 outbreak isolates, including diversification in genomic region 18. Macroarray- based subtyping using chromosomal sequences confirmed the close genetic relatedness between the isolates from the two outbreaks. Genomic content was highly conserved among isolates from each outbreak, with differences detected only in prophage and internalin-like gene sequences. However, since these differences were observed among isolates from each of the outbreaks, they did not differentiate the 1998-99 isolates as a group from those of the 2002 outbreak. Two of 15 randomly chosen serotype 4b clinical isolates from a non-outbreak period (calendar year 2003) appeared to be closely related to the 1998-99 and 2002 outbreak isolates. These findings suggest that both multistate outbreaks of listeriosis in the United States involved closely related members of a single clonal group (ECII) that had not been identified in outbreaks prior to 1998. Since the outbreaks involved different food vehicles and processing plants, the findings suggest establishment of ECII in a still unidentified reservoir in the United States, from which the organisms were introduced to different processing plants.     

Environmental survey to assess viral contamination of air and surfaces in hospital settings

This report describes an outbreak of Clostridium difficile infection (CDI) in a vascular surgery ward in 2009 caused by a high-level clindamycin-resistant ribotype 106. A case of CDI was defined as a patient with diarrhoea, positive for C. difficile toxin and negative for other enteric pathogens. Cultures were sent to the Scottish Salmonella Shigella and Clostridium difficile Reference Laboratory (SSSCDRL) for PCR ribotyping, antibiotic susceptibility testing and PCR detection of ermB. The mean age of the nine patients was 73 years (range: 38–90 years). All had received clindamycin and ciprofloxacin. All cases were typed as PCR ribotype 106 and they showed high-level resistance to clindamycin. Five of these isolates were tested by PCR for the presence of the ermB gene and no amplification was detected. This strain has rarely been isolated from patients on this ward. The outbreak was controlled successfully by closure of the ward with terminal cleaning, reinforcement of infection control precautions and the introduction of a new antibiotic policy. It is notable that this outbreak was caused by a strain with high-level clindamycin resistance not mediated by ermB. It also re-emphasizes that outbreaks of CDI can be caused by C. difficile PCR ribotypes other than 027. The outbreak was most likely associated with the use of clindamycin and ciprofloxacin cross-infection with spores in this environment. Implementation of strict infection control precautions, antimicrobial stewardship and enhanced environmental cleaning are key components in managing such an outbreak successfully. The number of meticillin-resistant Staphylococcus aureus acquisitions also fell substantially after these interventions.     

广东省2013年副溶血弧菌暴发与散发菌株的病原学特征

目的 了解2013年广东省副溶血弧菌暴发与散发分离株的血清型别、抗菌药物耐药性、毒力基因携带情况以及分子分型特征.方法 对36株暴发分离株和43株散发分离株进行血清分型、药敏试验以及耐热直接溶血毒素基因(tdh)、耐热相关溶血毒素基因(trh)、GS-PCR和orf8基因的PCR检测,并进行脉冲场凝胶电泳(PFGE)分型.结果 36株暴发分离株全部为O3:K6血清型,43株散发分离株的优势血清型为O3:K6型(23株,53.49%).药敏检测结果显示,对氨苄西林(96.20%)和头孢噻吩(40.50%)的耐药率较高;对复方新诺明和氯霉素则高度敏感,敏感性均为100%.多重耐药分析显示,83.33%(30/36)的暴发分离株同时耐受≥3种抗菌药,37.21%(16/43)的散发分离株同时耐受≥3种抗菌药物.毒力基因PCR检测显示,36株暴发分离株均为tdh⁺tdh^-型菌株.86.05%(37/43)的散发分离株为tdh⁺tdh^-型菌株,11.63%(5/43)为tdh^-tdh⁺型菌株,仅1株为tdh⁺tdh⁺型菌株.暴发分离株全部携带GS-PCR和/或orf8基因,51.16%(22/43)的散发分离株携带GS-PCR和/或orf8基因.PFGE显示,79株副溶血弧菌经NotⅠ酶切后的PFGE图谱可分为3个聚类,32种PFGE型别,相似值为59.8%～100.0%.暴发菌株聚集在同一个聚类中,散发菌株散布在各个聚类中.结论 2013年广东省副溶血弧菌优势血清型为O3:K6型,菌株对多数抗菌药物仍然比较敏感,但存在多重耐药现象,多数菌株携带tdh基因,大部分O3:K6型菌株携带GS-PCR和/或orf8基因;PFGE结果提示广东省副溶血弧菌存在遗传多样性.     

SurvNet electronic surveillance system for infectious disease outbreaks, Germany

In 2001, the Robert Koch Institute (RKI) implemented a new electronic surveillance system (SurvNet) for infectious disease outbreaks in Germany. SurvNet has captured 30,578 outbreak reports in 2001-2005. The size of the outbreaks ranged from 2 to 527 cases. For outbreaks reported in 2002-2005, the median duration from notification of the first case to the local health department until receipt of the outbreak report at RKI was 7 days. Median outbreak duration ranged from 1 day (caused by Campylobacter) up to 73 days (caused by Mycobacterium tuberculosis). The most common settings among the 10,008 entries for 9,946 outbreaks in 2004 and 2005 were households (5,262; 53%), nursing homes (1,218; 12%), and hospitals (1,248; 12%). SurvNet may be a useful tool for other outbreak surveillance systems because it minimizes the workload of local health departments and captures outbreaks even when causative pathogens have not yet been identified.     

福氏志贺菌4c型暴发和散发菌株的脉冲场凝胶电泳分型

目的了解杭州地区福氏志贺菌4c型暴发菌株和散发菌株的分子分型特征。方法对2003和2005年杭州地区的2次食物中毒暴发分离的福氏志贺菌菌株（暴发1和暴发2,菌株数分别为13株和12株）和2005年1例散发腹泻患者分离的福氏志贺菌4c型离株（1株）进行生化鉴定和血清分型,PCR检测侵袭性抗原基因ipaH,改良Kirby-Bauer纸片法检测菌株的耐药谱及脉冲场凝胶电泳（pulse field gel electrophoresis,PFGE）进行分子分型。结果暴发1中分离的13株菌株均为福氏4c型,但检测的6株菌株间的PFGE图谱存在着相当的差异,Dice系数为0．78至0．92。暴发2中分离的菌株有10株福氏4c型和2株福氏x型,所有菌株的PFGE图谱几乎完全一致。暴发2分离株和暴发1的部分分离株可能存在着一定相关性（Dice系数大于0．8）,而散发菌株与2起暴发的绝大部分菌株间的距离较远（Dice系数小于0．8）。暴发1、暴发2的分离株和1株散发菌株对14种抗生素的耐药谱略呈差异,暴发2中分离的福氏4c型和x型菌株的耐药谱一致。结论PFGE能够很好地辨别福氏志贺菌4c型的两起暴发菌株和1株散发菌株。福氏志贺菌4c型菌株具有易变性,可在暴发流行过程中产生PFGE图谱的差异、血清亚型的转换、耐药谱的变化等。     

Investigation of an outbreak of Enterobacter cloacae in a neonatal unit and review of the literature

Enterobacter cloacae has emerged as an important pathogen in neonatal units, with several outbreaks of infection being reported. The aim of this study was to investigate an outbreak of sepsis due to E. cloacae in a neonatal unit and to review the literature. A retrospective cohort study was conducted in which cases were compared with all newborns hospitalised for more than 48h in the neonatal intensive care unit (NICU). Cohorting of infected patients and work reorganisation were implemented. Pulsed-field gel electrophoresis was performed. The retrospective cohort included the six cases and 13 control patients that had been in the NICU during April 2006. Univariate analysis showed that the use of dobutamine was significantly associated with infection (P=0.036) and that enteral feeding was a protective factor (P=0.02). Multivariate analysis did not find any independent risk factor. Bed occupancy rate in March 2006 was 109.6%, indicating overcrowding. PFGE identified indistinguishable patterns among isolates from all six newborns. PubMed and OVID was search from 1 January 1983 to 15 January 2008 for papers including the terms 'E. cloacae', 'outbreaks', 'clusters' in combination with 'neonate', 'newborn', and 'infant'.We found 26 reports of outbreaks due to E. cloacae in neonate patients: sixteen (52%) were bloodstream infection outbreaks, of which two (12.5%) were related to multiple-dose medications. The source for our outbreak was not identified. Reinforcement of hygiene practices, restrictions on new admissions and the establishment of single-dose medications helped to control the outbreak.     

Serotypes of Bacillus cereus from outbreaks of food poisoning and from routine foods.

A provisional serotyping scheme was used to type cultures of Bacillus cereus from 84 outbreaks of food poisoning in seven countries; 283 of the 337 (84%) cultures tested were typable. In 35 of the 61 outbreaks associated with a vomiting-type syndrome, foods, clinical specimens or both yielded H-serotype 1 only. Type 1 strains together with other sterotypes were isolated in seven outbreaks. In 14 outbreaks types 3, 4, 5, 8 or a mixture of serotypes were present. Untypable strains were isolated in five outbreaks. Two of the nine diarrhoeal-type outbreaks yielded serotype 1 only. Types 2, 6, 8, 9, 10 and a mixture of type 12 and an untypable strain appeared to be responsible for one outbreak each. Although 16 of the 18 recognized serotypes were present among cultures of B. cereus from various routine foods, only 156 of the 400 (39%) isolates tested were typable.     

Two separate outbreaks of Salmonella enteritidis phage type 14b food poisoning linked to the consumption of the same type of frozen food

OBJECTIVES: To ascertain, using a combination of epidemiological, environmental and microbiological methods of investigation, a possible link between two outbreaks of salmonella food poisoning. METHODS: Case-control studies were carried out on the known at-risk populations. Environmental investigations took place in the food preparation areas used for the social functions and microbiological examinations were carried out on faecal specimens obtained from cases, environmental swabs, and food specimens when these were available. RESULTS: In both outbreaks, illness was associated with the consumption of sesame prawn toast (outbreak one P<0.004; outbreak two P<0.0001). Salmonella enteritidis phage type 14b was cultured from the faecal specimens of cases in both outbreaks and from a packet of sesame prawn toast used for the second outbreak function. Molecular typing methods indicated that the salmonella cultures obtained in both outbreaks were indistinguishable from each other and from cultures obtained from imported Spanish eggs in a previous survey. Imported Spanish eggs were used in the manufacture of the sesame prawn toast. CONCLUSIONS: Adequate cooking must take place of raw food products, which should be clearly labelled as such. Manufacturers should consider, when possible, the use of pasteurized egg in the preparation of food products.     

Factors associated with adverse outcomes during influenza outbreaks in aged care facilities

Objective : To explore factors associated with adverse outcomes during influenza outbreaks in residential aged care facilities. Methods : A retrospective cohort study of all outbreaks reported to three Sydney metropolitan Public Health Units during 2017. Results : A total of 123 outbreaks affected 1,787 residents and 543 staff. Early notification to a Public Health Unit was associated with shorter outbreak duration (p<0.001; B=0.674). Resident attack rates and resident mortality rates were lower in outbreaks notified early, on univariate analysis (p=0.034 and p=0.048 respectively) but not on an adjusted model. Staff attack rates were significantly associated with resident attack rates (p=0.001; B=0.736). Data on staff vaccination rates was incomplete and reported coverage rates were low (median 39%). Resident vaccination coverage ≥95% was associated with shorter outbreak duration in univariate testing but not on an adjusted model. Conclusions : Early public health notification is associated with improved outbreak parameters; sick staff may pose a risk to residents, yet vaccination rates are low. Resident vaccination may also be valuable. Implications for public health : Measures that facilitate early PHU involvement in influenza outbreaks should be implemented, such as compulsory reporting requirements and processes that permit easier notification through technology. Actions that enhance staff and resident vaccination coverage should also be undertaken.     

A school-based measles outbreak: the effect of a selective revaccination policy and risk factors for vaccine failure

Persons who received measles vaccine between 12 and 14 months of age have been found to be at increased risk of measles compared with those vaccinated at greater than or equal to 15 months of age. Because of this, in 1987 the Immunization Practices Advisory Committee of the US Public Health Service recommended that, during measles outbreaks, revaccination of persons vaccinated at 12-14 months of age be considered. During a school-based outbreak in New Mexico in 1987, the authors evaluated the effect of a mandatory revaccination policy in affected schools. Before the effect of revaccination, the overall attack rate in persons vaccinated at greater than or equal to 12 months of age was 4.1 cases/1,000 students; afterward, the risk was significantly reduced by 73%, to 1.1/1,000 students. The attack rate among students targeted for revaccination declined 100%, compared with 41% among those not revaccinated. Overall, attack rates were significantly lower in schools conducting revaccination early compared with schools holding later revaccination. In a retrospective cohort study of single-dose vaccines in one school, age at vaccination was not associated with risk of disease; however, persons vaccinated greater than or equal to 10 years before the outbreak were at increased risk, independently of age at vaccination. Revaccination of persons whose most recent vaccination was between 12 and 14 months of age appeared to control transmission in this outbreak. Further studies are needed to confirm these observations and to evaluate the effect of other revaccination efforts during outbreaks.     

Reported waterborne outbreaks of gastrointestinal disease in Australia are predominantly associated with recreational exposure

Objective: To examine the frequency and circumstances of reported waterborne outbreaks of gastroenteritis in Australia. Method: Examination of data reported to OzFoodNet between 2001 and 2007. Results: During these seven years, 6,515 gastroenteritis outbreaks were reported to OzFoodNet, most of which were classified as being transmitted person‐to‐person or from an unknown source. Fifty‐four (0.83%) outbreaks were classified as either ‘waterborne’ or ‘suspected waterborne’, of which 78% (42/54) were attributed to recreational water and 19% (10/54) to drinking water. Of the drinking water outbreaks, implicated pathogens were found on all but one occasion and included Salmonella sp. (five outbreaks), Campylobacter jejuni (three outbreaks) and Giardia (one outbreak). Conclusions: There have been few waterborne outbreaks detected in Australia, and most of those reported have been associated with recreational exposure. However, there are difficulties in identifying and categorising gastroenteritis outbreaks, as well as in obtaining microbiological and epidemiological evidence, which can result in misclassification or underestimation of water‐associated events. Implications: Gastroenteritis surveillance data show that, among reported water‐associated gastroenteritis outbreaks in Australia, recreational exposure is currently more common than a drinking water source. However, ongoing surveillance for waterborne outbreaks is important, especially as drought conditions may necessitate replacement of conventional drinking water supplies with alternative water sources, which could incur potential for new health risks.     

神经内科ICU耐碳青霉烯类肺炎克雷伯菌感染疑似暴发调查与控制

目的 调查神经内科重症监护病房(ICU)耐碳青霉烯类肺炎克雷伯菌(CRKP)感染暴发原因, 为有效控制多重耐药菌医院感染提供依据。 方法 对2021年6—7月某院神经内科ICU检出CRKP的患者进行现场流行病学调查和环境卫生学监测, 并采取控制措施, 评价防控效果。 结果 共发生CRKP医院感染7例, 罹患率为12.28%(7/57), 与2019、2020年同期罹患率相比, 差异有统计学意义(P＜0.05)。环境卫生学监测显示: 手标本CRKP检出率为6.67%(1/15), 为1名保洁员手; 环境物体表面CRKP检出率为5.45%(3/55), 分别为19床床头柜、19床输液泵、1号床手持电脑(PDA)。在采取集中隔离CRKP感染患者, 严格限制人员流动, 病区清洁与消毒, 加强手卫生监管等一系列针对性措施后, 此次事件得到有效控制。 结论 此次可判定为一起CRKP疑似医院感染暴发事件, 推测CRKP感染患者未采取集中隔离措施、环境消毒不彻底及手卫生执行不到位是此次暴发事件的主要原因。早期识别感染暴发, 调查原因, 及时采取有效的针对性措施是控制感染暴发的关键。     

Two Linked Enteroinvasive Escherichia coli Outbreaks,Nottingham, UK,June 2014

Enteroinvasive Escherichia coli (EIEC) outbreaks are uncommon in Europe. In June 2014, two EIEC outbreaks occurred in Nottingham, UK, within 2 days; outbreak A was linked to a takeaway restaurant and outbreak B to a wedding party. We conducted 2 analytical studies: a case–control study for outbreak A and a cohort study for outbreak B. We tested microbiological and environmental samples, including by using whole-genome sequencing. For both outbreaks combined, we identified 157 probable case-patients; 27 were laboratory-confirmed as EIEC O96:H19–positive. Combined epidemiologic, microbiological, and environmental findings implicated lettuce as the vehicle of infection in outbreak A, but the source of the organism remained unknown. Whole-genome sequencing identified the same organism in cases from both outbreaks, but no epidemiologic link was confirmed. These outbreaks highlight that EIEC has the capacity to cause large and severe gastrointestinal disease outbreaks and should be considered as a potential pathogen in foodborne outbreaks in Europe.