Control Of Such Outbreaks Research Articles

The Outbreak of SARS-CoV-2 in a Medical Ward and Its Containment: An Experience From a Tertiary Care Centre in North India.

Background Periodic outbreaks of SARS-CoV-2 in hospital settings amidst the recent pandemic are well known. However, the timely control of such outbreaks was key to preventing morbidity among vulnerable patients as well as reducing sickness absenteeism among healthcare workers. This is the first study of its kind in India. Methods An outbreak investigation was conducted between June 12 and July 18, 2020, at the All India Institute of Medical Sciences, New Delhi, India, during the first wave of COVID-19. Results A total of 27 individuals were infected during this time, including people visiting the hospital and healthcare workers. A thorough investigation led us to the epidemiological link between cases and allowed us to bring reforms to the existing hospital policy of screening and admission of COVID-19 patients and those suspected to have the infection. This experience helped us avoid future outbreaks during the second wave of COVID-19 in our hospital. Conclusion The SARS-CoV-2 virus is highly transmissible, especially in hospital settings due to the high burden of patients and close proximity between patients. Timely intervention is the key to effective control of hospital outbreaks, as it can avoid morbidity in patients and reduce sickness absenteeism among healthcare workers.

Marburg virus disease: lesson learned from the first outbreak encounter in Tanzania

Marburg virus disease: lesson learned from the first outbreak encounter in Tanzania

Commercial Transport During a Pandemic: Network Analysis to Reconcile COVID-19 Diffusion and Vital Supply Chain Resilience.

Commercial Transport During a Pandemic: Network Analysis to Reconcile COVID-19 Diffusion and Vital Supply Chain Resilience.

Collaborative emergency preparedness and response to cross-institutional outbreaks of multidrug-resistant organisms: a scenario-based approach in two regions of the Netherlands

BackgroundThe likelihood of large-scale outbreaks of multidrug-resistant organisms (MDRO) is growing. MDRO outbreaks can affect a wide range of healthcare institutions. Control of such outbreaks requires structured collaboration between professionals from all involved healthcare institutions, but guidelines for cross-institutional procedures are, however, often missing. Literature indicates that such multi-actor collaboration is most promising when effective network brokers are present, and when the collaborative actors have clarity about the different roles and responsibilities in the outbreak response network, including collaborative structures and coordination roles. Studying these factors in an imaginary MDRO outbreak scenario, we gained insights into the expectations that health professionals in the Netherlands have in regard to the procedures required to best respond to any future cross-institutional MDRO outbreaks.MethodsFor exploration purpose, a focus group discussion with ten healthcare professionals was held. Subsequently, an online-survey was conducted among 56 healthcare professionals in two Dutch regions. The survey data was analysed using social network analyses (clique analysis and centrality analysis), which provided insights into the collaborative structures and potential brokers in the outbreak response networks. Additionally, respondents were asked which healthcare institutions and which professions they would prefer as coordinating actors in the collaborative network.ResultsOur results show a relatively high level of perceived clarity about the roles and responsibilities that healthcare professionals have during a joint outbreak response. The regional outbreak response networks which were studied appeared inclusive and integrated, with many overlapping groups of fully-connected healthcare actors. Social network analyses resulted in the identification of several central actors from different healthcare institutions with the potential to take on a brokerage role in the collaboration. Actors in the outbreak response networks also showed to prefer several healthcare professionals to take on the coordination roles.ConclusionExpected collaborative structures during an imaginary regional MDRO outbreak response are relatively dense and integrated. In regard to the coordination of an MDRO outbreak response, based on both the network analysis results and the preferred coordination roles, our findings support a governance structure with several healthcare institutions involved in responding to future cross-institutional MDRO outbreaks.

Control of a Mycoplasma pneumoniae Outbreak in an Institutional Setting Using Azithromycin Prophylaxis.

Mycoplasma pneumoniae is a major cause of respiratory infection of varying severity. Outbreaks of M. pneumoniae infection commonly occur in closed or semi-closed communities and settings. The control of such outbreaks is challenging, owing to delayed detection, long incubation period, and paucity of infection control guidelines. Between May and July 2015, a residential facility for adults with developmental disabilities in Southern Israel witnessed an outbreak of acute respiratory infection, subsequently diagnosed as associated with M. pneumoniae. All relevant data were collected as a part of a formal outbreak investigation. Strict infection control procedures were implemented, and azithromycin prophylaxis was provided to all residents. Out of 215 residents, there were 29 suspected cases, 23 of which were confirmed as M. pneumoniae infection by serology or nucleic acid testing, for an attack rate of 11%. There were no cases of severe or fatal illness. An infection control strategy, including implementation of strict case isolation, enforcement of hygiene measures, a high index of suspicion for case detection, and use of azithromycin prophylaxis for all residents, led to rapid cessation of the outbreak. The use of azithromycin prophylaxis may be worthwhile in closed institutional settings in which M. pneumoniae infections are documented. The dynamics of this outbreak suggest that if spread between wards is anticipated, expanding prophylaxis beyond immediate contacts of affected individuals should be considered.

Outbreaks of virulent diarrheagenic Escherichia coli- are we in control?

Shiga toxin-producing Escherichia coli (STEC) are the most virulent diarrheagenic E. coli known to date. They can be spread with alarming ease via food as exemplified by a large sprout-borne outbreak of STEC O104:H4 in 2011 that was centered in northern Germany and affected several countries. Effective control of such outbreaks is an important public health task and necessitates early outbreak detection, fast identification of the outbreak vehicle and immediate removal of the suspected food from the market, flanked by consumer advice and measures to prevent secondary spread.In our view, opportunities to improve control of STEC outbreaks lie in early clinical suspicion for STEC infection, timely diagnosis of all STEC at the serotype-level and integrating molecular subtyping information into surveillance systems. Furthermore, conducting analytical studies that supplement patients' imperfect food history recall and performing, as an investigative element, product tracebacks, are pivotal but underutilized tools for successful epidemiologic identification of the suspected vehicle in foodborne outbreaks. As a corollary, these tools are amenable to tailor microbiological testing of suspected food.Please see related article: http://www.biomedcentral.com/1741-7015/10/12

Investigation of a spatiotemporal cluster of verotoxin-producing Escherichia coli O157 infections in eastern England in 2007

An outbreak of verotoxin-producing Escherichia coli O157 (VTEC O157) infections linked to an open farm occurred in eastern England in April and May 2007. This paper describes the investigation and highlights the importance of multidisciplinary collaboration for successful control of such outbreaks. There was a temporal cluster of 12 confirmed symptomatic cases of VTEC O157 and one asymptomatic carrier, from five families. The investigation revealed that four of these cases formed part of an outbreak involving two families who visited an open farm. The phenotypic and genotypic characteristics of the isolates from the two families and the putative farm animal contacts were indistinguishable, indicating that the animals were the source of the primary infections. No epidemiological link could be established between the remaining three families affected and the open farm or people having visited the farm. Control measures included improved hand washing facilities on the farm, information for visitors and staff, restricted access and suspended petting and feeding of animals, and thorough cleaning and disinfection of affected areas.

An evaluation of emerging vaccines for childhood meningococcal disease

BackgroundMeningococcal meningitis is a major cause of disease worldwide, with frequent epidemics particularly affecting an area of sub-Saharan Africa known as the “meningitis belt”. Neisseria meningitidis group A (MenA) is responsible for major epidemics in Africa. Recently W-135 has emerged as an important pathogen. Currently, the strategy for control of such outbreaks is emergency use of meningococcal (MC) polysaccharide vaccines, but these have a limited ability to induce herd immunity and elicit an adequate immune response in infant and young children. In recent times initiatives have been taken to introduce meningococcal conjugate vaccine in these African countries. Currently there are two different types of MC conjugate vaccines at late stages of development covering serogroup A and W-135: a multivalent MC conjugate vaccine against serogroup A,C,Y and W-135; and a monovalent conjugate vaccine against serogroup A. We aimed to perform a structured assessment of these emerging meningococcal vaccines as a means of reducing global meningococal disease burden among children under 5 years of age.MethodsWe used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In the first stage we systematically reviewed the literature related to emerging MC vaccines relevant to 12 criteria of interest. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). They answered questions from CHNRI framework and their “collective optimism” towards each criterion was documented on a scale from 0 to 100%.ResultsFor MenA conjugate vaccine the experts showed very high level of optimism (~ 90% or more) for 7 out of the 12 criteria. The experts felt that the likelihood of efficacy on meningitis was very high (~ 90%). Deliverability, acceptability to health workers, end users and the effect on equity were all seen as highly likely (~ 90%). In terms of the maximum potential impact on meningitis disease burden, the median potential effectiveness of the vaccines in reduction of overall meningitis mortality was estimated to be 20%; (interquartile range 20-40% and min. 8%, max 50 %). For the multivalent meningococcal vaccines the experts had similar optimism for most of the 12 CHNRI criteria with slightly lower optimism in answerability and low development cost criteria. The main concern was expressed over the cost of product, its affordability and cost of implementation.ConclusionsWith increasing recognition of the burden of meningococcal meningitis, especially during epidemics in Africa, it is vitally important that strategies are taken to reduce the morbidity and mortality attributable to this disease. Improved MC vaccines are a promising investment that could substantially contribute to reduction of child meningitis mortality world-wide.

Preserving the Effectiveness of Antibiotics

ANTIBIOTICS ARE EXTRAORDINARY MEDICINE AND ARE often curative. In general, antibiotics are remarkably free of adverse effects, eradicating the microorganism and usually leaving the host unaffected. Because antibiotics are typically well tolerated and effective, they are often used when the diagnosis of a bacterial infection is unclear. The liberal use of antibiotics has contributed to antibiotic resistance—a problem that has become a crisis. As a drug class, antibiotics are virtually unique because once an antibiotic is released for wide-scale use, its efficacy diminishes. In contrast, aspirin, one of the oldest drugs, is as effective an analgesic today as the first time it was used. The same cannot be said of penicillin. In the 1950s, the use and overuse of penicillin resulted in penicillin resistance. In the 1960s and 1970s, the use and overuse of gentamicin resulted in gentamicin resistance. In the 1980s and 1990s, the use and overuse of ciprofloxacin resulted in ciprofloxacin resistance. The observation has been repeatedly made, yet clinicians do not seem to be learning from the mistakes that continue to occur with each new antibiotic. In this issue of JAMA, Sanchez Garcia and colleagues described an outbreak of linezolid-resistant Staphylococcus aureus (LRSA) in an intensive care unit (ICU) and identified a rarely described mechanism of linezolid resistance. The authors demonstrated that use of linezolid was associated with this novel resistance mechanism in clinically significant ICU infections that affected 12 patients, causing ventilator-associated pneumonia in 6 and bacteremia in 3. Linezolid is a member of the oxazolidinone class of antibiotics used to treat a variety of gram-positive bacteria, including methicillin-resistant S aureus (MRSA). MRSA has limited therapeutic options, especially considering that susceptibility to vancomycin has become an increasing concern. Physicians hoped linezolid would help replete the inadequate arsenal of antibiotics for MRSA, but it is not a panacea. Chief among linezolid’s limitations has been adverse effects, which are most serious in the long term (ie, use 2 weeks) and include thrombocytopenia and neuropathy. The latter is often irreversible. Linezolid resistance among MRSA has been uncommon, restricted to isolated reports until this investigation. In the study by Sanchez Garcia and colleagues, the laboratory analysis suggested that some molecular evolution of the resistance mechanism may have occurred. The outbreak was associated largely with 1 clone of LRSA in a Spanish hospital. However, at least 1 patient harbored a clone of LRSA that was different than the predominant clone in the outbreak. Even more worrisome, the cfr gene that was responsible for the linezolid resistance in MRSA was found in 2 coagulase-negative Staphylococci isolates. The evolution and transmission of linezolid resistance to another species in the relatively short period of the outbreak suggest that other institutions may be managing their own version of LRSA in the near future, particularly if linezolid is frequently used. The feature that provides a measure of relief from the study by Sanchez Garcia et al is the apparent control of the outbreak both with infection-control measures and control of linezolid use. The authors described total ICU consumption of linezolid as 202 defined daily doses in April 2008. Following their investigation, use of linezolid declined to 25 defined daily doses in July 2008. The defined daily doses in April suggest liberal use of the drug, although there is no description of guidelines for linezolid use in the ICU and whether the use of linezolid was appropriate. The authors also did not describe how the substantial reduction in linezolid use was achieved, but such a significant decrease in linezolid use suggests that much of the use in April probably could have been changed to another antibiotic or even eliminated. No one doubts the importance of infection-control practices in limiting outbreaks with antibiotic-resistant organisms, but optimizing antibiotic use remains essential for successful control of such outbreaks. Several reasons support the need for controls over antibiotic use, also known as antibiotic stewardship. First, the supply of different types of antibiotics has dwindled. New antibiotics have never been easy to find. However, pharmaceutical companies have recently curtailed or eliminated antibiotic discovery. Since the beginning of 2008, the US Food and Drug Administration

WTW—an algorithm for identifying “who transmits to whom” in outbreaks of interhuman transmitted infectious agents

The authors developed a computerized algorithm that estimates 'who transmits to whom'--that is, the likeliest transmission paths during an outbreak of person-to-person transmitted illness. This algorithm uses basic information about natural history of the disease, population structure, and chronology of observed symptoms. To assess the algorithm efficacy, the authors built a simulator with parameters describing the disease and the population to simulate random outbreaks of influenza. The algorithm's performance was compared with three reference methods that simulated how human operators would handle such situations. For any size of outbreak, the algorithm outperformed the reference methods and provided a higher proportion of cases for whom the source subject who transmitted infection was identified. The authors also illustrated applicability of the algorithm for describing outbreaks of influenza in nursing homes. The use of this algorithm to draw transmission maps in investigations of outbreaks with person-to-person transmitted agents could potentially guide public health measures regarding the control of such outbreaks.

Extensively Drug-ResistantAcinetobacter baumannii

To the Editor: In the 1990s, patients infected with vancomycin-resistant Enterococcus faecium were successfully treated with new antimicrobial drugs. However, it is unlikely that new antimicrobial drugs will be available in the near future to treat patients infected with gram-negative pathogens such as Acinetobacter baumannii (1). No new antimicrobial drugs active against this organism are currently in clinical trials (www.clinicaltrials.gov). We report a patient infected with A. baumannii that lacked susceptibility to all commercially available antimicrobial drugs. The patient, a 55-year-old woman, had a prolonged stay in an intensive care unit at the University of Pittsburgh Medical Center (Pittsburgh, PA, USA) after undergoing lung transplantation. In the tenth postoperative week, ventilator-associated pneumonia developed, which was caused by A. baumanni that lacked susceptibility to all antimicrobial drugs tested except colistin (MIC 0.5 μg/mL). Therapy with colistin and tigecycline was begun. Colistin was administered intravenously and by inhalation. Although the pneumonia showed radiographic response to the antimicrobial drug therapy, A. baumannii continued to be isolated from respiratory secretions on numerous occasions. Despite another course of therapy with colistin and cefepime, the patient never recovered from respiratory failure. She eventually died of sepsis caused by vancomycin-resistant E. faecium. An A. baumannii isolate obtained just before she died lacked susceptibility to all commercially available antimicrobial drugs (Table). Table MICs and antimicrobial drug susceptibility for an extensively drug-resistant strain of Acinetobacter baumannii* Multidrug-resistant A. baumannii has emerged as a substantial problem worldwide (2). Such strains are typically resistant to all β-lactams and fluoroquinolones and require salvage therapy with colistin, amikacin, or tigecycline. Unfortunately, notably high-level resistance to colistin and amikacin was found in the isolate we have described (Table). Tigecycline, a newly available glycylcycline antimicrobial drug, showed intermediate susceptibility. No randomized trials have been performed to specifically evaluate combination antimicrobial drug therapy for treatment of infection with A. baumannii. Considerable media attention has been paid to extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (3). Infections with XDR strains are extremely difficult to treat and pose considerable infection control issues. We recently proposed that gram-negative bacilli lacking susceptibility to all commercially available antimicrobial drugs also be referred to as XDR because no therapeutic options are available (4). Numerous outbreaks of A. baumannii infection have been reported worldwide (5). Unfortunately, multidrug-resistant A. baumannii strains have become endemic in some institutions. Experimental and clinical isolates lacking susceptibility to colistin, often considered the drug of last resort, are increasingly being reported (6–8). Therefore, we alert healthcare workers to the need for stringent care in adhering to infection control precautions when caring for patients infected with XDR A. baumannii. Use of contact isolation precautions, enhanced environmental cleaning, removal of sources of infection from the hospital environment, and prudent use of antimicrobial drugs can contribute to control of such outbreaks (5). Fortunately, no spread of the XDR strain affecting this patient occurred. A crisis is looming should XDR A. baumannii become established pathogens in hospitals.

An outbreak of M serotype 1 group A Streptococcus in a neonatal intensive care unit

OBJECTIVE: To describe the investigation and control of an outbreak of M serotype 1, Streptococcus pyogenes (group A Streptococcus, GAS) infections in a neonatal intensive care unit (NICU). STUDY DESIGN: The study was conducted in an NICU in a large urban universityaffiliated hospital. Retrospective review was performed of all infants and health care workers in the NICU, especially those either colonized or infected with GAS during the outbreak and the prospective surveillance period (July through September 1994). Prospective epidemiologic investigation, including cultures of throat, umbilicus, and anorectum (infants), or throat and anus (NICU personnel), identified a possible common source of the disease in case infants. Antimicrobial susceptibility testing and serotyping of all GAS strains were performed; M serotype 1 isolates were examined by DNA analysis with restriction fragment length polymorphism. The M-1 GAS isolates were tested for streptococcal pyrogenic exotoxin (SPE) A and SPE B production. A retrospective chart review and analysis of infants with GAS infection or colonization was conducted. RESULTS: During a 1-week period, two very low birth weight infants more than 3 weeks of age had GAS septicemia and focal infection. Two additional very low birth weight infants with asymptomatic throat colonization were identified during the first week of surveillance. Benzathine penicillin G was administered to all NICU infants, but failed to eradicate throat colonization in the four case subjects. Seven days after completing parenteral antibiotic therapy, the index patient had a recurrence of GAS septicemia that was fatal. Eradication of throat colonization in the remaining three infants was achieved with a 10-day course of intravenous clindamycin therapy. Among 103 NICU personnel, five (4.9%) had asymptomatic GAS colonization with strains that were uniformly susceptible to penicillin. Each colonized adult was successfully treated with oral clindamycin therapy. Serotyping revealed that five isolates of GAS from four infants and one NICU respiratory therapist were M-1 isolates; DNA analysis confirmed that these were the same strain. The five M-1 isolates produced both SPE A and SPE B. CONCLUSIONS: The previously documented increase in prevalence of M-1 strains of GAS in the United States is likely to be associated with their introduction into closed populations including NICUs. Control of such outbreaks may be achieved by isolation, cohorting of case subjects and possible carriers, and successful eradication of colonization in case subjects and carriers. Although GAS organisms are uniformly susceptible to penicillin G, eradication may require agents other than penicillin. (J P EDIATR 1996;129:396-402)

A large outbreak of mumps in the postvaccine era.

During a county-wide mumps outbreak in Nashville, Tennessee, 332 cases of mumps were identified at a public high school (attack rate, 18.8%). A pep rally 17 d before the peak of the outbreak at a single public high school may have provided an opportunity for point-source exposure. A case-control study demonstrated that vaccine efficacy was 75% (we used provider-verified records and excluded students with a history of mumps disease). Although school records were nonuniform, mumps immunization status was correct, compared with provider-verified records, in at least 85% of both cases and controls. Parental reports were much less reliable. The cost of the outbreak was estimated at $154/case. Receiving mumps vaccine at a vaccine clinic held after the outbreak had peaked was associated with a decrease in risk of mumps disease. Thus, these clinics may have a role in the control of such outbreaks.

Rotavirus inactivation by chemical disinfectants and antiseptics used in hospitals.

Nosocomial outbreaks of rotaviral gastroenteritis are a common occurrence. Although proper disinfection practices in the hospital environment are considered to be important in the prevention and control of such outbreaks, very little information has been available on the rotavirus-inactivating capacity of chemical disinfectants and antiseptics commonly used in hospitals. In view of this, 11 such products were selected and screened for their capacity to bring about at least a 3 log10 reduction in the plaque titre of rotavirus SA-11 after a contact time of 1-30 min. Consept "D" (1:100), D.R.X. (1:80), Dustbane Germicidal (1:80), Hibitane, and Wescodyne (1:200) were found to be ineffective under these test conditions even in the absence of an added organic load. The virucidal capacity of Savlon (1:200) and Zephiran was completely neutralized when single-strength tryptose phosphate broth was added to the virus-disinfectant mixture to simulate an organic load. Cidex (2% acid glutaraldehyde), Proviodine (10% solution of povidone-iodine), Septisol (0.75% hexachlorophene), and Sana Rinse (70% isopropylalcohol, 0.1% hexachlorophene) were able to produce at least a 3 log10 (99.9%) reduction in the virus plaque titre even in the presence of added organic matter. These findings should be of help in the prevention and control of outbreaks of rotaviral diarrhea in the hospital environment.

Pseudomonas Species Bacteremia Caused by Contaminated Normal Human Serum Albumin

In May and June 1973, 11 patients on the surgical service at the University of Maryland Hospital had bacteremia caused by Pseudomonas species. Seven of the isolates recovered from blood cultures had the same antibiogram (sensitive only to chloramphenicol and tetracycline). Ten of the 11 patients were given 25% normal serum albumin (human) shortly before the onset of symptoms. In contrast, only two of seven patients with bacteremia due to Psuedomonas aeruginosa in May and June (P =0.013) and only nine of 20 patients located in surgical special care units during these months (P =0.014) were given this product. When cultured, the albumin in one of 54 previously unopened vials from the implicated lot yielded Pseudomonas cepacia sensitive only to chloramphenicol, tetracycline, and nalidixic acid. Subsequent investigation showed that five more patients in four other hospitals had symptoms of bacteremia shortly after the infusion of different lots of albumin from the same manufacturer, and in four cases P. cepacia was cultured from the suspect albumin. Since sterility testing by manufacturers may not detect low-frequency contamination, surveillance of nosocomial infections, investigation of unusual disease clusters, and prompt reporting of suspect reactions are essential in the control of such outbreaks.

Public Health Aspects of Cream-filled Pastries. A Review

In the United States foodborne disease outbreaks for which cream-filled pastry was identified as the vehicle have declined from 17.8% in the 1930's to 2.3% in the 1970's. Cream fillings or cream-filled pastries were usually contaminated with staphylococci and Salmonella typhi by workers and with salmonellae by ingredients such as eggs and milk. These contaminants multiplied as a result of favorable nutrients, water activity, temperature, and pH; and they survived the effects of competing organisms and processes. Prevention and control of such outbreaks have been based on formulating the product so it will not support bacterial growth, using pathogen-free ingredients, thorough cooking and reheating, sanitary handling of fillings and finished pastry, rapid cooling and storing at low temperature, establishing microbiological standards for the finished products, training food-processing and food-service personnel, and educating the consumer to refrigerate products after purchase.

Tuberculosis as a Military Epidemic Disease and its Control by the Navy Tuberculosis Control Program

1. That outbreaks of tuberculosis can and do occur in isolated, close contact situations as microepidemics is well authenticated by previous reported episodes. 2. In the United States, with a diminishing infection rate and an increasing number of negative tuberculin reactors, the setting exists for the development of such from an active case of tuberculosis. 3. The experiences of the U. S. Navy with six shipboard tuberculosis outbreaks is related, with illustration of their development, detection and control. 4. A broad tuberculosis control program, such as is in force in the U. S. Navy is the major factor in the early detection of and control of such outbreaks. 5. The U. S. Navy Tuberculosis Program is described, its implementation outlined, along with the implication of the importance of maintaining tuberculin skin test negativity in the Navy personnel for best control.