迈向消除阶段我国血吸虫病突发疫情应急响应

当前,我国血吸虫病防治从传播控制、传播阻断迈向消除阶段.由于血吸虫病传播环节多、流行因素复杂,加之受社会、经济和自然环境等多种因素影响,目前尚未达到血吸虫病传播阻断及已经达到传播阻断甚至消除的地区,都面临出现血吸虫病突发疫情的威胁,严重影响血吸虫病防治成效的巩固和消除目标的实现.本文通过梳理历年发生的血吸虫病突发疫情,...     

Norovirus outbreaks in a teaching hospital: the role of infection control

In January 2004, 20 patients and 19 staff in one ward became ill in an outbreak of norovirus-related gastroenteritis over a 12-day period. The epidemic curve indicated person-to-person transmission. Infection control measures were instituted in consultation with the government health authorities. A prompt rigorous response may have prevented spread to other wards. In March 2004, 54 staff and 1 member of a patient's family became ill in an outbreak of gastroenteritis. The source of norovirus contamination was associated with food served at the hospital restaurant. Secondary infection was prevented because the outbreak was recognized early and staff members with gastroenteritis symptoms were asked to stay home. Immediate control measures, such as identification and announcement of the outbreak, isolation of symptomatic individuals from others, personal protection, helped control the infection.     

Management of enteroviral conjunctivitis outbreaks in the Singapore military in 2005

Between 8 August and 9 October 2005, tropical Singapore experienced a national epidemic of acute viral conjunctivitis. We report the epidemiological and virological findings of outbreaks of viral conjunctivitis in military facilities during the same time period, and the outbreak control measures taken. Outbreaks of viral conjunctivitis were identified by medical officers in military medical facilities. Epidemiological and virological investigations were carried out, and a standard set of control measures was instituted for each outbreak upon detection. Eight outbreaks of viral conjunctivitis occurred in the time period, corresponding to the national outbreak. Delayed detection and institution of preventive measures during the outbreaks were associated with delayed effectiveness of the control measures. Every delay in outbreak detection by one day resulted in a delay in terminating the outbreak by 0.82 days (p = 0.01). Coxsackievirus A24 was identified from some of the conjunctival swab samples taken.     

Hepatitis A outbreaks--methods of intervention in South-East Asian countries.

INTRODUCTION: In many Asian countries, improved hygiene standards and socio-economic conditions have led to a reduction in exposure to the hepatitis A virus (HAV) in childhood. However, the persistence of circulating HAV may lead to hepatitis A outbreaks, particularly in adolescents and adults. In other countries and specific areas, where socio-economic conditions have not improved as markedly, HAV endemicity remains medium-to-high. A systematic approach to outbreak control is therefore urgently needed. METHODS: The Steering Committee for Prevention and Control of Infectious Diseases reviewed reports on recent hepatitis A outbreaks in South-East Asian countries and determined that there is no systematic regional plan for the containment of such outbreaks. By contrast, on reviewing reports on outbreaks in several North American and European countries, it was found that the most important elements of successful outbreak control are a plan of action, rapid and widespread communication, public education and vaccination of household contacts to prevent secondary cases. RESULTS: This investigation proposes an outbreak control programme consisting of six key stages -- initiation, planning, set-up, implementation, vaccination of at-risk populations and evaluation. Outbreak control requires the formation of an outbreak management team, plus a task force to implement intervention and educate the public. The vaccination of family members and close contacts is a central element of the programme. CONCLUSION: This model programme for hepatitis A outbreak control provides a framework for action in countries and specific areas where the disease remains a problem.     

Disinfectant contaminated with Klebsiella oxytoca as a source of sepsis in babies

We report an outbreak of sepsis from contaminated disinfectant in a neonatal and paediatric intensive-care unit. 28 infants were infected with Klebsiella oxytoca and basic measures to control the outbreak failed. The resistance of K. oxytoca against the disinfectant was probably mediated by capsule formation, visible as mucoid colonies.     

Morbidity, cost and role of health care worker transmission in an influenza outbreak in a tertiary care hospital

An influenza A outbreak involving 17 health care workers (HCWs) and 16 chronic geriatric patients on a ward in a tertiary care hospital was reviewed. Thirty-seven per cent of all HCWs and 47% of patients on the affected wards became ill with influenza. Three patients died during the outbreak. The majority of health care workers became ill prior to detecting the first patient case of influenza, suggesting that nosocomial spread from HCWs to patients may have occurred. Only 13.7% of the staff and 5.9% of the patients had been vaccinated prior to the outbreak. Lost time due to HCW absenteeism, outbreak-related medication costs and additional staff time involved in outbreak control resulted in considerable cost to the hospital. It is suggested that much of this cost, as well as morbidity and possibly mortality, could have been avoided by increased immunization of HCWs and patients.     

Nosocomial outbreak of scabies in a hospital in Spain

An outbreak of scabies occurred in a ward of a local hospital in Barbastro (Huesca, Spain), between November 2002 and January 2003. The outbreak was linked to a patient infested with mites when he was admitted to the ward on 1 November 2002. The first case had onset of symptoms on 5 November and the last one on 5 January 2003. Seventeen cases were reported: 11 healthcare workers (HCWs) and six patients. The outbreak was attributed to a delay in diagnosis, and lack of individual protection measures by caregivers. The use of short-sleeved coats is an habitual risk practice in this ward. Contact with fomites, animals, infested clothes or intimate contact with people other than their usual partners were dismissed as risk factors for the infestation. The different groups of caregivers in this ward presented a similar risk of becoming infested, and the mechanism of transmission was probably person to person contact. The implementation of specific guidelines for scabies prevention and treatment, as well as an active surveillance system, were fundamental to the control of this outbreak.     

The potential of targeted antibody prophylaxis in SARS outbreak control: a mathematic analysis

BACKGROUND: Severe acute respiratory syndrome (SARS) coronavirus-like viruses continue to circulate in animal reservoirs. If new mutants of SARS coronavirus do initiate another epidemic, administration of prophylactic antibodies to risk groups may supplement the stringent isolation procedures that contained the first SARS outbreak. METHOD: We developed a mathematical model to investigate the effects of hospital admission and targeted antibody prophylaxis on the reproduction number R, defined as the number of secondary cases generated by an index case, during different SARS outbreak scenarios. RESULTS: Assuming a basic reproduction number R(0)=3, admission of patients to hospital within 4.3 days of symptom onset is necessary to achieve outbreak control without the need to further reduce community-based transmission. Control may be enhanced by providing pre-exposure prophylaxis to contacts of hospitalized patients, and through contact tracing and provision of post-exposure prophylaxis. Antibody prophylaxis may also be employed to reduce R below one and thereby restrict outbreak size and duration. CONCLUSIONS: Patient isolation alone can be sufficient to control SARS outbreaks provided that the time from onset to admission is short. Antibody prophylaxis as supplemental measure generally allows for containment of higher R(0) values and restricts both the size and duration of an outbreak.     

Rapid control of a hospital-wide outbreak caused by extensively drug-resistant OXA-72-producing Acinetobacter baumannii

Extensively drug-resistant Acinetobacter baumannii (XDRAb) emerges as an important pathogen of health care-associated infections and outbreaks worldwide. During January and February 2006, there was a hospital-wide outbreak of XDRAb at a medical center in Taiwan. Without limiting the usage of carbapenems or the closure of any ward, this outbreak was effectively controlled. We investigated the molecular epidemiology and reported the infection control experiences. XDRAb is defined as A baumannii that is resistant to multiple antibiotics but susceptible to tigecycline and polymyxin B. During the outbreak, the clinical and environmental XDRAb isolates were collected and studied by antimicrobial susceptibility testing, pulsed-field gel electrophoresis, and polymerase chain reaction for Verona integron-encoded metallo-beta-lactamases, imipenemases, and oxacillinases (OXA). Our measures to control the outbreak included private room isolation of patients until there were three successive negative cultures, reinforcement of contact precautions, daily environmental cleansing with room-dedicated cleaning tools and sodium hypochlorite, and careful auditing of adherence. During the outbreak, 32 clinical XDRAb isolates came from 13 patients who were hospitalized in four intensive care units and three wards. Most (7 of 13, 53.8%) cases were associated with a surgical intensive care unit. The results from pulsed-field gel electrophoresis study indicated that all isolates were of one genotype. All 32 isolates harbored ISAba1-bla(OxA-51-like) and bla(OxA-72) genes. After this outbreak till August 2010, further incidences of XDRAb were sporadic cases of XDRAb with different clones and did not reach the level of outbreak. To our knowledge, this is the first reported hospital-wide outbreak caused by OXA-72 carbapenemase-producing A baumannii in the Asia-Pacific region, with successful and sustained control. Although the source or vehicle of the outbreak was not identified, our results suggest that a hospital-wide outbreak can be successfully managed with strict infection control measures, and that the limitation of the use of carbapenems and closure of wards may not be necessary.     

The public health response to the re-emergence of syphilis in Wales, UK

During the 1990s, cases of infectious syphilis were uncommon in Wales. In 2002, an outbreak occurred in a sexual network of men who have sex with men (MSM) attending a sauna. A multidisciplinary outbreak control team was convened to raise awareness of the outbreak among MSM and health professionals, assess the extent of outbreak, and initiate surveillance measures. It is likely that early intensive control efforts dampened the epidemic curve. However, since 2006 the number of cases has increased steadily to a peak of four cases per 100,000 population in 2008. The majority of cases continue to occur in MSM (81% in 2009) and in those attending genitourinary (GU) medicine clinics in south east Wales (76%). Traditional sexual networks such as saunas, bars/clubs and cruising grounds remain frequently reported, but Internet-based networks are assuming increasing importance. Public health interventions have been sustained, using traditional partner notification, health promotion initiatives, and more innovative Internet network tracing methods.     

Experience with oseltamivir in the control of a nursing home influenza B outbreak.

Oseltamivir prophylaxis was very effective in protecting nursing home residents from ILI and in halting this outbreak of influenza B. A portion of the total ILI cases may have been due to influenza A, as this strain was isolated in one resident. The 10% attack rate in this facility, controlled with oseltamivir, compares favourably with another influenza B outbreak in a similar facility in the same region, over the same time frame (ILI onset 27 December to 17 January). Oseltamivir prophylaxis was not used to manage this second outbreak of laboratory-confirmed influenza B. Of the 236 residents, 45 developed ILI for an overall attack rate of 19%, nearly double the rate in the oseltamivir-controlled setting (10%). While oseltamivir was effective in controlling influenza B in this outbreak, further experience and evaluation is required before it can be routinely recommended for prophylaxis of influenza in nursing home outbreaks. Although earlier attempts by others using oseltamivir in the control of influenza A outbreaks have also met with success, it is not yet licensed for this purpose. Compared to amantadine, oseltamivir has a relatively high cost for the control of influenza A outbreaks and this may continue to limit its wider acceptance. The cost-effectiveness of oseltamivir in the control of influenza B outbreaks needs to be specifically addressed given the typically milder nature of influenza B strains. However, such a distinction is not clinically reliable and elderly residents of long-term care facilities remain vulnerable to serious complications associated with influenza infection in general. An alternate agent for influenza chemoprophylaxis that is effective against both influenza A and B, is easily administered and has few side effects, could greatly enhance current prevention and control measures and warrants serious assessment. The spread of this outbreak from the geographically separate ward to other areas of the facility in which residents had not received prophylaxis, underscores the likely role of staff as a vehicle for transmission during facility outbreaks. While accurate staff ILI rates could not be determined, their immunization rates were low, and many staff were ill during the outbreak. Isolation of residents with ILI and prophylaxis of non-ill residents on the initial outbreak wards was insufficient to prevent the spread of the outbreak, although it was subsequently halted once prophylaxis was extended to all residents. In view of the uncertainty over this medication's widespread use, in the absence of licensure or previous studies demonstrating its effectiveness in the prophylaxis and control of influenza B outbreaks, initiation of oseltamivir prophylaxis was staggered by ward. In a declared influenza A outbreak, the protocol in a long term care facility is to initiate amantadine prophylaxis on all residents, rather than ward-by-ward. While anti-viral prophylaxis may be an effective secondary control measure in the management of influenza outbreaks, optimal primary prevention would be more effective. This would require increased vaccine coverage of residents and particularly of staff, who play an important role in the importation and transmission of influenza within these facilities.     

Containing a haemorrhagic fever epidemic: the Ebola experience in Uganda (October 2000-January 2001).

INTRODUCTION: The Ebola virus, belonging to the family of filoviruses, was first recognized in 1976 when it caused concurrent outbreaks in Yambuku in the Democratic Republic of Congo (DRC), and in the town of Nzara in Sudan. Both countries share borders with Uganda. A total of 425 cases and 224 deaths attributed to Ebola haemorrhagic fever (EHF) were recorded in Uganda in 2000/01. Although there was delayed detection at the community level, prompt and efficient outbreak investigation led to the confirmation of the causative agent on 14 October 2000 by the National Institute of Virology in South Africa, and the subsequent institution of control interventions. CONTROL INTERVENTIONS: Public health interventions to contain the epidemic aimed at minimizing transmission in the health care setting and in the community, reducing the case fatality rate due to the epidemic, strengthening co-ordination for the response and building capacity for on-going surveillance and control. Co-ordination of the control interventions was organized through the Interministerial Committee, National Ebola Task Force, District Ebola Task Forces, and the Technical Committees at national and district levels. The World Health Organization (WHO) under the Global Outbreak Alert and Response Network co-ordinated the international response. The post-outbreak control interventions addressed weaknesses prior to outbreak detection and aimed at improving preparations for future outbreak detection and response. Challenges to control efforts included inadequate and poor quality protective materials, deaths of health workers, numerous rumors and the rejection of convalescent cases by members of the community. CONCLUSIONS: This was recognized as the largest reported outbreak of EHF in the world. Control interventions were very successful in containing the epidemic. The community structures used to contain the epidemic have continued to perform well after containment of the outbreak, and have proved useful in the identification of other outbreaks. This was also the first outbreak response co-ordinated by the WHO under the Global Outbreak Alert and Response Network, a voluntary organization recently created to co-ordinate technical and financial resources to developing countries during outbreaks.     

Success in controlling a major outbreak of malaria because of Plasmodium falciparum in Jamaica

In 2006, after 44 years of eradication of malaria, Jamaica had an outbreak of Plasmodium falciparum: 406 confirmed cases between September 2006 and December 2009 with a peak of the epidemic in December 2006. In response to the outbreak, the Ministry of Health launched an emergency response through early detection and prompt treatment of cases, vector control, public education and intersectoral collaboration. Ninety percent (361) of cases were residents of Kingston, and 63.6% were identified through house to house surveillance visits. For 56% of the confirmed cases, treatment with chloroquine was initiated within a week of onset of symptoms. Only one (0.3%) of 358 cases who had a post-treatment smear on day 7 had a persistent asexual parasitaemia, while none of the 149 persons who had a follow-up smear on day 28 was positive. The outbreak highlighted the need for increased institutional capacity for surveillance, confirmation and treatment of malaria as well as effective prevention and control of outbreaks which can occur after elimination. Jamaica appears to have successfully eliminated malaria after its reintroduction.     

An outbreak of multiply resistant Serratia marcescens: the importance of persistent carriage

An outbreak of multi-resistant Serratia marcescens involving 24 patients occurred in a bone marrow transplant and oncology unit, from September 1998 to June 1999, of whom 14 developed serious infection. This is the first such outbreak described in a BMT unit. All isolates demonstrated the same antimicrobial susceptibility pattern and were the same unusual serotype O21:K14. The antimicrobial susceptibility profile showed reduced susceptibility to ciprofloxacin, gentamicin and piperacillin-tazobactam. As the latter two antimicrobials are part of our empiric therapy for febrile neutropenia, they were substituted with meropenem and amikacin during the outbreak. Investigation revealed breaches in infection control practices. Subsequently, the outbreak was contained following implementation of strict infection control measures. A prominent feature of the outbreak was prolonged carriage in some patients. These patients may have acted as reservoirs for cross-infection. This report also indicates that patients who become colonised with Serratia marcescens may subsequently develop invasive infection during neutropenic periods.     

从2019新型冠状病毒病疫情谈新发传染病防控策略

2019年12月湖北省武汉市出现了2019新型冠状病毒病疫情,疫情在很短时间内席卷了中国的34个省级行政单位,中国境外多个国家也有病例报道。2019新型冠状病毒病疫情是由冠状病毒科β冠状病毒属的"SARS-CoV-2"所致,一种以前从未被发现的新型冠状病毒,目前研究显示SARS-CoV-2的传染性较强。本文基于目前我国2019新型冠状病毒病疫情及其防控,对疫情现阶段采取的主要防控措施进行梳理和总结,并基于One Health视角探讨新发传染病防控策略,以期为今后我国有效应对新发传染病提供宝贵的可借鉴经验。     

A study on dengue outbreak during 2009 in Bhopal and Indore districts of Madhya Pradesh, India

An outbreak of mysterious virus disease reported from Bhopal, Indore and adjoining districts of Madhya Pradesh (MP) state during 2009. The outbreak started in Bhopal in early September and then from Indore in last week of September. Subsequently cases were also reported from adjoining districts. On basis of Epidemiological, Clinical, Entomological and Laboratory findings dengue outbreak was declared in the area. A total of 620 IgM Elisa positive cases were reported from Bhopal and Indore district and adjoining areas. The outbreak involved 8 districts in the state. The control measures were undertaken in the area and the outbreak of dengue subsided in December 2009.     

Efficient management of a norovirus outbreak causing gastroenteritis in two hotels in Spain, 2014

ObjectivesTo determine the aetiological agent causing a gastroenteritis outbreak in two hotels in Majorca (Spain) on August and September 2014.MethodsAn epidemiological study was carried out. Environmental and stool samples were analyzed for different pathogens, including norovirus.ResultsEpidemiological analysis detected 79 cases among the tourists hosted in the affected hotels over the period 18th August to 3rd September. They included 52 (attack rate: 6.4%) and 27 (attack rate: 3.0%) cases in hotel A and B, respectively. Seven of the staff members were also affected. Microbiological analyses detected genotype 2 norovirus in patient's stool samples, in rooms and in common areas’ surfaces. The specific control plan rapidly implemented at the beginning of the outbreak, and further adapted for norovirus elimination, allowed to control the outbreak.ConclusionsOur study demonstrates that the outbreak was caused by genotype 2 norovirus, and reflects the importance of a rapid analysis and response for its control.     

Outbreak of hepatitis A in Korean military personnel

This report describes a hepatitis A outbreak among Korean military personnel. Each case of hepatitis A in this outbreak was defined as a person who had symptoms compatible with acute viral hepatitis A and had positive HAV IgM between May 2 and August 14, 2007 in Inje district, Gangwon, Korea. We tested 70 cases with symptoms for HAV IgM, and 67 cases showed positive results. They included 4 sergeants, 1 officer and 62 privates. A positive result for HAV IgG among asymptomatic military personnel was seen in 11.8% of cases. This epidemic occurred after a heavy rainfall in the military compound area where drinking water was supplied by the stream water. After the outbreak, the supply of drinking water was switched to a public water system. All of 178 military personnel who had no HAV IgG were vaccinated on July 26, 2007. The outbreak was resolved after the control measures were implemented.