Organizational support of investigation of Legionnaires' disease outbreak in town Verkhnyaya Pyshma

Materials on organizational support of preventive and antiepidemic measures during outbreak of Legionnaires' disease in town Verkhnyaya Pyshma (Sverdlovsk region) in July-August 2007 are presented. Thanks to collaborative efforts of Federal Service for Surveillance for Protection of Consumers Rights and Human Welfare, Ministry of Health of Sverdlovsk region, health-care services in Verkhnyaya Pyshma, near located municipalities, and others it was able to establish in short term the hospital for treatment, identify source of the infection and factor of its transmission, and terminate the outbreak. Operative implementation of the mentioned measures both allowed to provide good quality medical care to all patients and to prevent occurrence of such situations on other towns of Sverdlovsk region.     

Experience of information sharing between local healthcare management and regional Administration of Federal Service for Surveillance for Protection of Consumers Rights and Human Welfare in Sverdlovsk region during outbreak of Legionnaires' disease in town Verkhnyaya Pyshma in July-August 2007

Issues of reliability, uniformity, and timeliness of reporting and sharing of information during outbreaks of infectious diseases are basic for establishment of tactics and strategy of organizational, antiepidemic, and clinical measures. Analysis of experience in sharing of information between medical care organization service and services ensuring sanitary-epidemiological welfare of population during outbreak of Legionnaires' disease in town Verkhnyaya Pyshma in July-August 2007 was performed in the article.     

Epidemiologic versions in investigation of Legionnaires' disease outbreak in town Verkhnyaya Pyshma

Materials of investigation of Legionnaires' disease outbreak in one of the town of Sverdlovsk region in summer 2007 are presented. Outbreak arose in situation of epidemiologic welfare on majority of registered infectious diseases. Epidemiologic diagnostics of the outbreak has been performed in maximal shorttime interval, during which it was necessary to investigate variety of miscellaneous versions. Active search of the source of the infection and its transmission factors resulted in desired result and allowed to terminate the outbreak in 14 days.     

PCR-diagnostics in investigation of Legionnaires' disease outbreak

Results of studies of biological samples from patients with community-acquired pneumonia and samples from environment during Legionnaires' disease outbreak in town Verkhnyaya Pyshma (Sverdlovsk region) in July-August 2007 performed by PCR analysis are presented.     

Epidemiologic characteristic of Legionnaires' disease outbreak in town Verkhnyaya Pyshma

Materials of investigation of Legionnaires' disease outbreak in town Verkhnyaya Pyshma (Sverdlovsk region) are presented. Features of epidemic process during this outbreak were reflected, its epidemiologic characteristics were described. Effectiveness of timely antiepidemic measures directed at elimination of main factor of infection's transmissibility was shown.     

Diagnostic role of different immunologic methods for laboratory diagnostics of legionellosis

The aim of the study was a comparative analysis of diagnostic value of different laboratoty methods conducted on the basis of results of examination of patients during Legionnaires' disease outbreak in town Verkhnyaya Pyshma. Retrospective analysis of laboratory data from 74 patients with diagnosis of Legionnaires' disease was performed. Complex of laboratory methods was used (polymerase chain reaction (PCR), enzyme immunoassay (EIA), immunochromatography). In group of patients with Legionnaires' disease, the highest proportion of positive results (73%) was obtained by the EIA determining total specific antibodies in urine. Determination of antigen in urine by immunochromatographic express-test yielded 52% of positive results. PCR testing of blood specimens yielded positive results in 65% of samples but was low specific, due to that in 19% of patients from control group false-positive results were obtained. Testing of 3 autopsy samples showed that all specimens contained DNA of the causative agent. Performed analysis allowed to recommend complex use of immunochromatographic express-test of antigen detection and identification of total specific antibodies by EIA during mass people examination.     

Application of molecular genetic methods during Legionnaires' disease outbreak in town Verkhnyaya Pyshma

The aim of the study was to perform molecular genetic analysis based on multi-locus sequence typing in order to identify source of Legionnaires' disease outbreak in town Verkhnyaya Pyshma in July 2007 and genetic profile of the causative agent. Sequence-based typing protocol recommended by European Working Group on Legionella infection (EWGLI) was used. It was not possible to obtain satisfactory results of Fla gene sequencing for all samples. Obtained allelic profiles of other genes were typical for L. pneumophila. Allelic profiles of L. pneumophila isolated from patients were identical and matched with L. pneumophila DNA detected in water from hot water supply of domestic building, but differed from cooling tower's isolates and isolates from showerhead in apartment of one patient. Identity of 5 genes of L. pneumophila isolated from autopsy samples and from hot water of central hot water supply of domestic building confirms aspiration route of infection through hot water contaminated by the microorganism. L. pneumophila detected in water from cooling tower, showerhead in apartment of one patient, and from drainage canal of hot water supply station belonged to other allelic variants and, therefore, are not related with the outbreak.     

Experience of microbiologic diagnostics of acute pneumonia cases arose in town Verkhnyaya Pyshma in July-August 2007

Bacteriologic, serologic, and PCR tests of blood, sputum, serum and autopsy samples from 91 patients were performed during outbreak of pneumonia in town Verkhnyaya Pyshma in July-August 2007. Streptococcus pneumoniae was isolated from 20% of diagnostically meaningful samples of sputum and from 50% of autopsy samples. Diagnosis of Legionnaires' disease was confirmed in 48% of cases. It was shown that association of Streptococcus pneumoniae and Legionella pneumophila determined the affect during such pneumonia. Need for establishment of diagnostic procedure for patients with pneumonia including those caused by atypical agents was revealed.     

Pathologic anatomy of pneumonia caused by Legionella: on the materials of outbreak in town Verkhnyaya Pyshma

Data on postmortem examination of five patients deceased during Legionnaires' outbreak in town Verkhnyaya Pyshma are presented in the article. Feature of course of the disease was severe affection of the lungs with development of toxic shock. Pathomorphological picture in lungs was characterized by polymorphism, presence of shock reaction and ventilator-associated pneumonia (atelectases, distelectases, tracheobronchitis). In autopsy material from four fatal cases Legionella pneumophila serogroup 1 was detected. Causative agent of pneumonia was not determined in one fatal case although comparison of clinical and morphological characteristics of this case with other four cases as well as detection of Gram-negative bacillus in alveolar macrophages allowed to consider this case of pneumonia as caused by Legionella. In studied fatal cases postmortem diagnoses were ascertained in which main disease was bilateral pneumonia caused by Legionella pneumophila serogroup 1 complicated by toxic shock.     

Work with public in foci of infection during outbreaks of pneumonia caused by Legionella in town Verkhnyaya Pyshma in July-August 2007

One of the key elements in epidemiologic control for infectious diseases is timely and active identification of contacts, which results in in-time hospitalization of patients that are needed it and allows to conduct educational work with the public. Measures for outpatient medical and preventive help in Legionella infection which were developed on the experience of termination of outbreak of pneumonia caused by Legionella in town Verkhnyaya Pyshma in July-August, 2007 are presented.     

Legionnaires' disease outbreaks and cooling towers with amplifiedLegionella concentrations

This study was designed to investigate the possible association of high colony counts of legionellae from cooling towers and evaporative condensers with Legionnaires' disease outbreaks. We obtained legionellae counts from samples of cooling towers and evaporative condensers that were the likely sources of two different Legionnaires' disease outbreaks and compared these counts with those from cooling towers that were not associated with reports of human disease. Among 675 potential control cooling tower that were samples from 258 facilities, 136 facilities had one or more cooling towers that met our criteria for inclusion into the study. Samples taken from buildings where an outbreak had occurred had much higherLegionella counts than did samples from other buildings. Colony counts from the two outbreak-associated facilities were significantly higher than colony counts from other facilities [Wilcoxon Rank Sum Test (Exact), p<0.01]. The results of the study suggest that, among cooling towers that test positive for the presence of legionellae, higher colony counts are associated with higher risk of Legionnaires' disease.     

Infection of cultured human endothelial cells by Legionella pneumophila

Legionella pneumophila is a gram-negative pathogen that causes a severe pneumonia known as Legionnaires' disease. Here, we demonstrate for the first time that L. pneumophila infects and grows within cultured human endothelial cells. Endothelial infection may contribute to lung damage observed during Legionnaires' disease and to systemic spread of this organism.     

The rise in cases of mucormycosis,candidiasis and aspergillosis amidst COVID19

The Coronavirus outbreak globally has changed the medical system and also led to a shortage of medical facilities in both developing and underdeveloped countries. The COVID19 disease, being novel in nature along with high infectivity and frequent mutational rate, has been termed to be fatal across the globe. The advent of infection by SARS-CoV-2 has brought a myriad of secondary complications and comorbidities resulting in additional challenges to the health care system induced by novel therapeutic procedures. The emerging variant with respect to the Indian subcontinent and the associated genetic mutations have worsened the situation at hand. Proper clinical management along with epidemiological studies and clinical presentations in scientific studies and trials is necessary in order to combat the simultaneous waves of emerging strains. This article summarizes three of the major fungal outbreaks in India namely mucormycosis, candidiasis and aspergillosis, and elaborates their subtypes, pathogenesis, symptoms and treatment and detection techniques. A detail of future therapeutics under consideration are also elaborated along with a general hypothesis on how COVID19 is related to immunological advances leading to major widespread fungal infection in the country. The factors that contribute in promoting virus proliferation and invasive fungal infections include cell-mediated immunity, associated immunocompromised conditions and treatment protocols that slows down immune mechanisms. To better comprehend a fungal or bacterial outbreak, it is very important to conduct audits mediated through multicenter national and state research teams for recognizing patterns and studying current cases of fungal infection in both healthy and comorbid groups of COVID19 patients.     

Ebola Outbreak Response; Experience and Development of Screening Tools for Viral Haemorrhagic Fever (VHF) in a HIV Center of Excellence Near to VHF Epicentres

Introduction

There have been 3 outbreaks of viral hemorrhagic fever (VHF) in Uganda in the last 2 years. VHF often starts with non-specific symptoms prior to the onset of haemorrhagic signs. HIV clinics in VHF outbreak countries such as Uganda see large numbers of patients with HIV 1/2 infection presenting with non-specific symptoms every day. Whilst there are good screening tools for general health care facilities expecting VHF suspects, we were unable to find tools for use in HIV or other non-acute clinics.

Methods

We designed tools to help with communication to staff, infection control and screening of HIV patients with non-specific symptoms in a large HIV clinic during the outbreaks in Uganda. We describe our experiences in using these tools in 2 Ebola Virus Disease outbreaks in Uganda.

Results

During the Ebola Virus Disease (EVD) outbreaks, enhanced infection control and communication procedures were implemented within 24 hours of the WHO/Ministry of Health announcement of the outbreaks. During course of these outbreaks the clinic saw 12,544 patients with HIV 1/2 infection, of whom 3,713 attended without an appointment, suggesting new symptoms. Of these 4 were considered at risk of EVD and seen with full infection procedures; 3 were sent home after further investigation. One patient was referred to the National Referral Hospital VHF unit, but discharged on the same day. One additional VHF suspect was identified outside of a VHF outbreak; he was transferred to the National Referral Hospital and placed in isolation within 2 hours of arriving at the HIV clinic.

Discussion

Use of simple screening tools can be helpful in managing large numbers of symptomatic patients attending for routine and non-routine medical care (including HIV care) within a country experiencing a VHF outbreak, and can raise medical staff awareness of VHF outside of the epidemics.     

Effect of supplementall-tyrosine on pigment production in cultures of the Legionnaires' disease bacterium

The etiologic agent of Legionnaires' disease grows on certain agar media. Cultures of this organism on supplemented Mueller-Hinton agar are characterized by the appearance of brown pigment in and around areas of bacterial growth. The major peptone source in Mueller-Hinton agar is an acid hydrolysate of casein. Legionnaires' disease bacterium also grows on a medium in which the peptone source is 0.25% yeast extract, but no pigment is produced. If the yeast extract agar is enriched withl-tyrosine, pigment formation can occur. Pigmentation of cultures of Legionnaires' disease bacterium may be mediated by a phenolo-monooxygenase, or tyrosinase.     

急诊重症监护病房耐甲氧西林金黄色葡萄球菌定植与感染调查分析

目的 调查急诊重症监护病房( EICU)耐甲氧西林金黄色葡萄球菌(MRSA)定植与感染状况,为实时控制医院感染暴发流行提供参考依据.方法 对临床资料进行分析,环境卫生学监测采样方法参照卫生部《消毒技术规范》,制定干预措施.结果 6例MRSA定植和感染病例平均年龄62.5岁,原发性基础疾病重;41份环境标本和16份来自接触阳性患者的医务人员手部标本中均分离到病原菌,阳性率分别为24.39％和18.75％.结论MRSA定植是造成医院感染的源头,将仅出现定植的病例并入感染病例进行统计分析,可实时监控院内医院感染的暴发.     

儿童重症监护病房医院感染暴发白色念珠菌血流感染4例分析

摘要 目的：探讨儿童重症监护病房白色念珠菌血流感染暴发的临床表现、危险因素、控制措施等,为预防和控制院内白色念珠菌血流感染暴发提供科学依据。方法：以2018年7月我院儿童重症监护病房发生的4例白色念珠菌血流感染暴发患儿为研究对象,分析患儿临床情况、临床特征、危险因素、暴发原因以及采取的预防控制措施。结果：4例医院感染暴发白色念珠菌血流感染患儿均存在基础疾病、有机械通气史、存在中心静脉或动脉置管、静脉或动脉置管前后均使用碘伏消毒、曾使用广谱抗生素、输血制品,白色念珠菌血流感染后最突出的临床表现均是发热。药敏方面,医院感染暴发的4例白色念珠菌感染患儿对唑类及5-氟胞嘧啶均耐药,但对两性霉素B均敏感。经拔除血管置管、减少或者避免广谱抗菌药的应用,根据药敏使用卡泊芬净及两性霉素B抗真菌等积极治疗,1例患儿放弃治疗后死亡,3例患儿顺利出院。通过Fisher确切概率法分析可知,留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素（P<0.05）。结论：留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素,医院感染暴发白色念珠菌血流感染患儿最突出的临床表现是发热,唑类及5-氟胞嘧啶耐药的患儿使用卡泊芬净及两性霉素B可能获得较好的治疗效果。     

基于多源地理数据精细尺度的武汉市人居环境新型冠状病毒肺炎疫情传播风险评估

新型冠状病毒肺炎的迅速传播和扩散警示着疾病风险评估的重要性。但现有的风险评估方法受数据限制,缺少实时性和准确性。此外,多数研究以行政统计单元作为分析尺度,存在可变面元问题。为解决这些问题,耦合精细尺度下武汉市疫情数据及多源地理数据,基于随机森林算法构建社区尺度的市域疫情传播风险评估模型并进行了疫情风险制图。模型测试精度达到0.85,Kappa系数达到0.70。此外,本研究还建立基于随机森林算法的社区及场所尺度的"空间变量-感染风险"模型,评估了不同场所设施疫情传播的风险程度。研究表明,（1）武汉中心区域感染风险最高并呈现出向外围递减的趋势;（2）感染风险排名前五的一级场所类型分别为购物服务、医疗服务、金融服务、交通设施以及公共设施;（3）小学、中学的疫情传播风险较低,而高等院校传播风险较高;（4）社区尺度下的疫情风险程度,预测购物场所与交通场所是疫情传播风险最高的驱动因子。本研究基于精细尺度提出风险评估新方法,可为未来疾病风险评估提供新思路,为疫情防控提供决策支持,人民群众提供安全保障。     

Detection of Mycobacterium ulcerans in environmental samples during an outbreak of ulcerative disease.

Mycobacterium ulcerans is an environmental bacterium which causes chronic skin ulcers. Despite significant epidemiological evidence to suggest that water is the source of infection, the organism has never been identified in the environment. Environmental water samples were collected from a small town in which an outbreak of 29 cases had occurred in a 3-year period. These were examined by mycobacterial culture and PCR amplification. Similar to previous studies, M. ulcerans was not cultured from the water samples. However, five samples were positive for M. ulcerans by PCR. These samples were collected from a swamp and a golf course irrigation system within the outbreak area. This is the first time that M. ulcerans has been demonstrated to be present in the environment and supports the postulated epidemiology of disease due to this organism.     

Standards for laboratory diagnostics of legionellosis and their application during epidemic outbreak of pneumonia in town Verkhnyaya Pyshma

High effectiveness of application of international standards for legionellosis laboratory diagnostics was confirmed during investigation of pneumonia outbreak in town Verkhnyaya Pyshma. Use of immunochromatographic method and enzyme immunoassay for detection of Legionella antigen in urine of patients allows to confirm diagnosis of Legionella infection during several hours, promptly begin etiologic antibacterial treatment and reveal possible sources of infection in potentially dangerous environmental objects.