Small Outbreaks Research Articles

A mini outbreak of human metapneumovirus infection with severe acute respiratory symptoms in a selected group of children presented to a teaching hospital in Sri Lanka.

Human metapneumovirus (hMPV) of the family Paramyxoviridae is a relatively new virus causing severe acute respiratory tract infections (SARI) in children. Data on hMPV infection in Asia including Sri Lanka is limited. We aimed to detect respiratory viruses including hMPV in a selected group of children affected by a small outbreak of SARI presented to the Teaching Hospital, Peradeniya (THP), Sri Lanka in 2014. Nasopharyngeal aspirates (NPA) were obtained from 21 children with SARI and tested for hMPV, influenza A and B, parainfluenza 1, 2 and 3 (PIV 1–3), adenovirus and respiratory syncytial virus (RSV) antigens using an immunofluorescence assay (IFA). In addition, a one step RT-PCR was done for the detection of hMPV from the viral RNA extracts. Of the 21 NPA samples tested for respiratory viral antigens by IFA, two were positive for RSV (9.5%), one was positive for influenza A (4.8%) and one was positive for both adenovirus and PIV-2 (4.8%). Of the 21 NPA viral RNA extracts tested by RT-PCR, 18 (86%) were positive for hMPV, in which 2 were co-infected with RSV and influenza A virus, respectively. hMPV was the predominant cause of SARI outbreak (2014) in children presented to the THP, Sri Lanka.

Difficulties in achieving and maintaining the goal of measles elimination in Bulgaria.

Measles is a disease with almost a hundred year history of existing registration in Bulgaria and has been subject to mass immunization since 1969. In 2017, after a three-year period with a low number of measles cases registered, an epidemic upsurge has been recorded affecting 3 of the total 28 regions in the country. The purpose of this study was to analyze the changes of measles morbidity in Bulgaria over the period of 1921-2017 and focus on the epidemiological characteristics of the last outbreak in the region of Plovdiv in 2017. For the whole period (1921-2017) the average measles morbidity amounts to 157.69%ооо, decreasing from 525.02%ооо in 1921 to 2.32%ооо in 2017, with 99.5% rate of reduction. In the period prior to vaccination the average morbidity was 247.14%ооо while in the vaccination period it was 70.08%ооо. The ARIMA model could be used as a short-term forecast to predict the morbidity rate. Against the background of the downward tendency in morbidity this study reports a small measles outbreak in Plovdiv, involving 141 cases, after three years of no local virus transmission in the country. An unvaccinated child who returned from abroad probably imported the disease. The measles cases were mainly Roma children and a large number of them were infants. The low intensity and prolong course of the outbreak was indicative of relatively high vaccination coverage of the population. To achieve measles elimination goals, efforts must be made to strengthen surveillance and increase the vaccination coverage, targeting children and especially Roma children.

Survey and genetic characterization of Vibrio cholerae in Apalachicola Bay, Florida (2012-2014).

A small outbreak of gastroenteritis in 2011 in Apalachicola Bay, FL was attributed to consumption of raw oysters carrying Vibrio cholerae serotype O75. To better understand possible health risks, V. cholerae was surveyed in oysters, fish and seawater, and results were compared to data for Vibrio vulnificus and Vibrioparahaemolyticus. Enrichment protocols were used to compare prevalence of V. cholerae (0, 48, 50%), V. vulnificus (89, 97, 100%) and V. parahaemolyticus (83, 83, 100%) in fish, seawater and oysters respectively. Compared to other species, Most probable number results indicated significantly (P<0·001) lower abundance of V. cholerae, which was also detected more frequently at lower salinity, near-shore sites; other species were more widely distributed throughout the bay. Genes for expression (ctxA, ctxB) and acquisition (tcpA) of cholera toxin were absent in all strains by PCR, which was confirmed by whole genome sequencing; however, other putative virulence genes (toxR, rtxA, hlyA, opmU) were common. Multi-locus sequence typing revealed 78% of isolates were genetically closer to V.cholerae O75 lineage or other non-O1 serogroups than to O1 or O139 serogroups. Resistance to amoxicillin, kanamycin, streptomycin, amikacin, tetracycline and cephalothin, as well as multidrug resistance, was noted. Results indicated minimal human health risk posed by V. cholerae, as all isolates recovered from Apalachicola Bay did not have the genetic capacity to produce cholera toxin. Vibrio cholerae was less prevalent and abundant relative to other pathogenic Vibrio species. These studies provide important baseline observations for V.cholerae virulence potential regarding: (i) genetic relatedness to V. cholerae O75, (ii) antibiotic resistance and (iii) prevalence of multiple virulence genes. These data will serve as a biomonitoring tool to better understand ecosystem status and management if bacterial densities and virulence potential are altered by environmental and climatic changes over time.

Hepatitis A in Poland in 2017 - epidemic increase cases

The aim of this article is to describe and assess changes in epidemiological situation of Hepatitis A in Poland in 2017. The assessment was based on the information from the individual case questionnaires, aggregated data from the bulletins “Infectious diseases and poisonings in Poland in 2017” and reports from epidemiological investigations in outbreaks of hepatitis A, submitted by the sanitary-epidemiological stations to the Department of Epidemiology of Infectious Diseases and Surveillance in NIPH-NIH. In 2017 a large increase of HAV cases and hepatitis A incidence was observed in Poland (3006 cases, incidence 7.8 per 100 000) in comparison to 2016 (35; 0.09). Majority of the cases were registered in large cities, where incidence was 3 times higher than in rural areas. Among reported there were 501 cases (16.6% of all cases) selfdeclaring as man who have sex with man (MSM). In course of the year an increasing trend in the number of cases was observed until September and the increase of male to female ratio (m/f) until May. Moreover 251 HAV outbreaks were reported, number of which increased until October and with the increase of m/f ratio in these outbreaks until April. From July to October there was an increase in the number of small outbreaks with m/f ratio equal 1. There were 178 imported cases reported, most of them from European countries- especially Germany and Spain. In 2017 over 80-fold increase of HAV cases and hepatitis A incidence was observed in comparison to previous years. Available epidemiological data indicate that ongoing HAV outbreak among MSM in Europe reached also Poland, and data from the second part of the year suggest infection spreading in non-MSM part of the population. It is therefore highly indicated that the list of risk groups for which vaccination against hepatitis A is recommended should also be expanded for MSM. To avoid such increase in the number of cases in future it is recommended to introduce vaccinations in risk groups as soon as large international outbreak occurs.

Epidemiology of carbapenemase-producing Enterobacteriaceae in a pediatric hospital in a country with high endemicity

BackgroundLittle is known about epidemiology of carbapenemase-producing Enterobacteriaceae (CPE) in children. Aim of this study was to describe CPE epidemiology in a tertiary care pediatric hospital in Italy that admits patients coming from geographic areas with high diffusion of CPE. MethodsProspective evaluation of the proportion and rates per 100,000 hospital discharges (D) or hospitalization-days (HD) of invasive infections due to CPE from 2013 to 2017 and of CPE infections and colonizations from 2014 to 2017. Disease-preventing strategies comprised patients’ screening at admission, pre-emptive contact isolation precautions pending cultures results, and bundles for prevention of healthcare associated infections. ResultsFrom 2013 to 2017 CPE represented 3.5% of all invasive infections due to Enterobacteriaceae, with rates ranging 7.30–14.33 for D and 1.03–2.06 for HD, without major changes over time. On the contrary, overall rates of isolates increased from 83.03 to 191.34 for D and from 12.21 to 28.35 for HD. The intra-hospital diffusion consisted of 2 small outbreaks without invasive diseases in 2014–2015, and sporadic, not epidemiologically-related cases in 2016–2017. Globally, Escherichia coli and Klebsiella pneumoniae represented 64% of identified CPE, while 70% of carbapenemases identified were metallo-beta-lactamases (VIM or NDM), with changes over time. ConclusionsIn our center metallo-beta lactamases were the most frequently identified carbapenemases in Enterobacteriaceae and E. coli and K. pneumoniae the most frequently isolated pathogens carrying these enzymes. A proactive management strategy was effective in containing in-hospital spreading.

Outbreak of Burkholderia Cepacia Infection: a Systematic Study in a Hematolooncology Unit of a Tertiary Care Hospital from Eastern India.

BackgroundBurkholderia cepacia, an aerobic gram-negative bacillus, is a frequent colonizer of fluids used in the hospital ward. It poses little risk of infection to healthy people; however it is a known important opportunistic pathogen causing morbidity and mortality due to its intrinsic resistance to most of the antibiotics in hospitalized patients. Small hospital outbreaks are frequent. B. cepacia may occur as an opportunistic infection in hemato-oncology patients. Here we present an outbreak of Burkholderia cepacia infection in hematology ward of our institute.MethodsFebrile episodes as defined by IDSA guideline, 2010 were followed, and blood for culture and sensitivity was sent in all the events. The culture was done by an automated method using Bactalert 3d Biomeriux & sensitivity pattern by Microscan Siemens method and subsequently detected by PCR based method.ResultsDuring September 2016 to February 2017 (six months), a total of 498 blood cultures were sent during febrile episodes. Out of which 60 (12%) came out to be positive for different microorganisms. Out of all positive cultures, Burkholderia cepacia was detected in 29 (48%) patients, which reduced drastically following the change in antibiotic administration practice. All isolates showed sensitivity to pipercillin+tazobactum, cefoperazone+sulbactum, fluoroquinolones, cotrimoxazole and carbapenems and resistance to polymyxin B and colistin. With timely intervention by appropriate intravenous antibiotics as per culture sensitivity result and change in antibiotic preparation practice, overall mortality was low 1 (4%) out of 29 culture positive episodes.ConclusionChange of antibiotic preparation practice was the key to control this outbreak, and overall mortality was low.

Modeling cost-effectiveness of risk-based bovine tuberculosis surveillance in Minnesota

In the United States, slaughter surveillance combined with other measures has effectively maintained a very low prevalence of bovine tuberculosis (bTB). However, bTB continues to be sporadically detected, causing substantial economic burden to the government and cattle producers. To detect the infection earlier and reduce sudden economic losses, additional risk-based surveillance of live animals might be more cost-effective than slaughter surveillance alone to detect and prevent bTB infection. The objective of this study was to evaluate alternative risk-based surveillance strategies targeting high-risk herds to complement slaughter surveillance in a region with very low bTB prevalence. We developed an integrated within- and between-herd bTB transmission model with simulated premises-level cattle movements among beef and dairy herds in Minnesota for 10 years. We constructed ten risk-based surveillance strategies for beef herds and dairy herds, and predicted the epidemiological outcomes and costs for each strategy in combination with slaughter surveillance. Our models showed that slaughter surveillance alone resulted in low risk of between-herd transmission with typically small outbreak sizes, and also cost less compared to alternative risk-based surveillance measures. However, risk-based surveillance strategies could reduce the time to detect infection and the time to reach disease freedom by up to 9 months. At a higher initial prevalence, alternative risk-based surveillance could reduce the number of infected herds and shorten the time to disease freedom by almost 3 years (34–35 months). Our findings suggest that risk-based surveillance could detect infection more quickly and allow affected regions to reach disease freedom faster. If the bTB status of the affected regions changes after an outbreak happens, the reduced time to disease freedom could reduce the economic impact on the affected region.

Transit time inside a mosquito

Dengue Dengue virus genetic variation and ambient temperature influence the rate of transmission by mosquitoes and thus the risk and magnitude of an outbreak. Virus in a blood meal within the vector mosquito's gut takes several days—roughly a quarter of the short life of an Aedes mosquito—to transition from the gut to the salivary gland, ready for inoculation into the next host. So, 1 day's difference can mean success or failure for ongoing transmission. Fontaine et al. found that eight strains of recently circulating dengue virus have different gut–salivary gland transit times. In an agent-based model, this parameter translated into a roughly 20% difference in the probability of a subsequent human infection, with a Haitian strain being the slowest, resulting in smaller outbreaks. PLOS Pathog. 10.1371/journal.ppat.1007187 (2018).

Population structure of OXA-48-producing Klebsiella pneumoniae ST405 isolates during a hospital outbreak characterised by genomic typing.

The aim of this study was to investigate the structure of a broad and sustained hospital outbreak of OXA-48-producing Klebsiella pneumoniae (KpO48) belonging to sequence type 405 (ST405). Whole-genome sequencing and comparison of ten ST405 KpO48 isolates obtained from clinical samples in our hospital was performed. Using stringent criteria, 36 single nucleotide polymorphisms (SNPs) were detected (range 0-21 in pairwise comparisons), and allele-specific PCR was used to call the SNPs among a larger set of isolates. Several haplotypes were identified within the population. The haplotypes did not show a spatial structure, but a temporal evolution of sequential haplotype replacements was observed. The dispersed spatial distribution suggests a reservoir formed by a large pool of colonised patients, and the temporal replacement pattern suggests that the sustained outbreak was composed of several small outbreaks that appeared and rapidly dispersed to several units.

Description and characterization of a novel live-attenuated tri-segmented Machupo virus in Guinea pigs

BackgroundMachupo virus (MACV) is a member of the Mammarenavirus genus, Arenaviridae family and is the etiologic agent of Bolivian hemorrhagic fever, which causes small outbreaks or sporadic cases. Several other arenaviruses in South America Junín virus (JUNV) in Argentina, Guanarito in Venezuela, Sabiá in Brazil and Chapare in Bolivia, also are responsible for human hemorrhagic fevers. Among these arenaviruses, JUNV caused thousands of human cases until 1991, when the live attenuated Candid #1 vaccine, was used. Other than Candid #1 vaccine, few other therapeutic or prophylactic treatments exist. Therefore, new strategies for production of safe countermeasures with broad spectrum activity are needed.FindingsWe tested a tri-segmented MACV, a potential vaccine candidate with several mutations, (r3MACV). In cell culture, r3MACV showed a 2-log reduction in infectious virus particle production and the MACV inhibition of INF-1β was removed from the construct and produced by infected cells. Furthermore, in an animal experiment, r3MACV was able to protect 50% of guinea pigs from a simultaneous lethal JUNV challenge. Protected animals didn’t display clinical symptoms nor were virus particles found in peripheral blood (day 14) or in organs (day 28 post-inoculation). The r3MACV provided a higher protection than the Candid #1 vaccine.ConclusionsThe r3MACV provides a potential countermeasure against two South America arenaviruses responsible of human hemorrhagic fever.

A methodological framework for the evaluation of syndromic surveillance systems: a case study of England

BackgroundSyndromic surveillance complements traditional public health surveillance by collecting and analysing health indicators in near real time. The rationale of syndromic surveillance is that it may detect health threats faster than traditional surveillance systems permitting more timely, and hence potentially more effective public health action. The effectiveness of syndromic surveillance largely relies on the methods used to detect aberrations. Very few studies have evaluated the performance of syndromic surveillance systems and consequently little is known about the types of events that such systems can and cannot detect.MethodsWe introduce a framework for the evaluation of syndromic surveillance systems that can be used in any setting based upon the use of simulated scenarios. For a range of scenarios this allows the time and probability of detection to be determined and uncertainty is fully incorporated. In addition, we demonstrate how such a framework can model the benefits of increases in the number of centres reporting syndromic data and also determine the minimum size of outbreaks that can or cannot be detected. Here, we demonstrate its utility using simulations of national influenza outbreaks and localised outbreaks of cryptosporidiosis.ResultsInfluenza outbreaks are consistently detected with larger outbreaks being detected in a more timely manner. Small cryptosporidiosis outbreaks (<1000 symptomatic individuals) are unlikely to be detected. We also demonstrate the advantages of having multiple syndromic data streams (e.g. emergency attendance data, telephone helpline data, general practice consultation data) as different streams are able to detect different outbreak types with different efficacy (e.g. emergency attendance data are useful for the detection of pandemic influenza but not for outbreaks of cryptosporidiosis). We also highlight that for any one disease, the utility of data streams may vary geographically, and that the detection ability of syndromic surveillance varies seasonally (e.g. an influenza outbreak starting in July is detected sooner than one starting later in the year). We argue that our framework constitutes a useful tool for public health emergency preparedness in multiple settings.ConclusionsThe proposed framework allows the exhaustive evaluation of any syndromic surveillance system and constitutes a useful tool for emergency preparedness and response.

Outbreak of Invasive Wound Mucormycosis in a Burn Unit Due to Multiple Strains of Mucor circinelloides f. circinelloides Resolved by Whole-Genome Sequencing.

ABSTRACTMucorales are ubiquitous environmental molds responsible for mucormycosis in diabetic, immunocompromised, and severely burned patients. Small outbreaks of invasive wound mucormycosis (IWM) have already been reported in burn units without extensive microbiological investigations. We faced an outbreak of IWM in our center and investigated the clinical isolates with whole-genome sequencing (WGS) analysis. We analyzed M. circinelloides isolates from patients in our burn unit (BU1, Hôpital Saint-Louis, Paris, France) together with nonoutbreak isolates from Burn Unit 2 (BU2, Paris area) and from France over a 2-year period (2013 to 2015). A total of 21 isolates, including 14 isolates from six BU1 patients, were analyzed by whole-genome sequencing (WGS). Phylogenetic classification based on de novo assembly and assembly free approaches showed that the clinical isolates clustered in four highly divergent clades. Clade 1 contained at least one of the strains from the six epidemiologically linked BU1 patients. The clinical isolates were specific to each patient. Two patients were infected with more than two strains from different clades, suggesting that an environmental reservoir of clonally unrelated isolates was the source of contamination. Only two patients from BU1 shared one strain, which could correspond to direct transmission or contamination with the same environmental source. In conclusion, WGS of several isolates per patients coupled with precise epidemiological data revealed a complex situation combining potential cross-transmission between patients and multiple contaminations with a heterogeneous pool of strains from a cryptic environmental reservoir.

Inminente Hibernación Solar 2020

El Ciclo solar 23º, es el vigésimo tercer ciclo, registrado cuidadosamente desde que iniciaron las observaciones de manchas solares en occidente, en el siglo XVII. En este trabajo se pretende demostrar estadísticamente, la tendencia hacia una hibernación solar, donde pueden ser muchos años en que el Sol no produzca ninguna mancha solar, en este caso específico se estudió la actividad solar final del ciclo 23 y comienzos del ciclo 24. Planteando la tendencia de baja actividad en el Sol y que continuará por varios años, como se ha visto que sucedieron, en los cinco periodos, con espacios aproximados a 200 años o menos cada uno, diversos períodos excepcionales de baja actividad solar durante el último milenio. Estos períodos son: el de Norman (1010) el de Wolf (hacia el año 1300), Spoerer (1500), Maunder (1645 - 1715) y Dalton (1800-1830). Por lo que no resultaría extraño otro acontecimiento característico similar, en un futuro cercano; porque han transcurrido 186 años a la fecha, desde el último mínimo, el de Dalton desde el año 1800 a 1830. Se ha observado que la actividad solar, volvió a descender desde el año 2011 y ocurrió un pequeño rebrote en 2013. Así una buena parte de la comunidad científica espera que cuando finalice este ciclo 24 de manchas solares, es muy posible que el astro entre en hibernación. De seguir con la tendencia a la baja actividad solar, consecuentemente puede bajar la temperatura en nuestro planeta Tierra, como se ha visto en el pasado y arrojada por los resultados estadísticos de esta investigación.

Dynamic network measures reveal the impact of cattle markets and alpine summering on the risk of epidemic outbreaks in the Swiss cattle population

BackgroundLivestock herds are interconnected with each other via an intricate network of transports of animals which represents a potential substrate for the spread of epidemic diseases. We analysed four years (2012–2015) of daily bovine transports to assess the risk of disease transmission and identify times and locations where monitoring would be most effective. Specifically, we investigated how the seasonal dynamics of transport networks, driven by the alpine summering and traditional cattle markets, affect the risk of epidemic outbreaks.ResultsWe found strong and consistent seasonal variation in several structural network measures as well as in measures for outbreak risk. Analysis of the consequences of excluding markets, dealers and alpine pastures from the network shows that markets contribute much more to the overall outbreak risk than alpine summering. Static descriptors of monthly transport networks were poor predictors of outbreak risk emanating from individual holdings; a dynamic measure, which takes the temporal structure of the network into account, gave better risk estimates. A stochastic simulation suggests that targeted surveillance based on this dynamic network allows a higher detection rate and smaller outbreak size at detection than compared to other sampling schemes.ConclusionsDynamic measures based on time-stamped data—the outgoing contact chain—can give better risk estimates and could help to improve surveillance schemes. Using this measure we find evidence that even in a country with intense summering practice, markets continue being the prime risk factor for the spread of contagious diseases.

Varicella Outbreak Surveillance in Schools in Sentinel Jurisdictions, 2012-2015.

In 2007, a routine second dose of varicella vaccine was recommended in the United States for children aged 4 to 6 years to better control varicella-zoster virus circulation and outbreaks. Sentinel varicella outbreak surveillance was established to assess feasibility of surveillance and describe outbreaks that are occurring. Through the Centers for Disease Control and Prevention Epidemiology Laboratory Capacity funding, health departments conducted active surveillance for varicella outbreaks in schools from 2012 to 2015. Outbreaks of varicella were defined as ≥5 cases in a school within at least 1 incubation period (21 days). School nurses, healthcare providers, or laboratories reported cases and outbreaks of varicella to health departments; demographic, vaccination, and clinical data were collected. Georgia, Houston, Maine, Minnesota, New York City, and Philadelphia participated in all 3 years; Puerto Rico and West Virginia participated in 2012 to 2013; and Kansas and Arkansas participated in 2014 to 2015. Twenty-nine outbreaks including 262 cases were reported. The median size of the outbreaks was 7 cases (range, 5-31 cases), and the median duration was 31 days (range, 4-100 days). Of the case-patients associated with larger outbreaks (≥8 cases), 55.4% were unvaccinated, and 15.7% and 18.1% had received 1 or 2 doses of vaccine, respectively. In small outbreaks (5-7 cases), 33.3% of case-patients were unvaccinated, and 16.7% and 38.5% had received 1 or 2 doses of vaccine, respectively. The majority of cases associated with outbreaks occurred in undervaccinated children (unvaccinated and 1-dose vaccine recipients). Outbreaks with a greater proportion of 2-dose vaccine recipients were smaller. Varicella outbreak surveillance is feasible, and continued monitoring of outbreaks remains important for describing the epidemiology of varicella during the 2-dose varicella vaccination program.

The Role of Uncertainty During the Ebola Pandemic in Western Africa (2014–2016)

An Ebola outbreak in Western Africa escalated into a transboundary crisis in 2014. This escalation of a rather small outbreak, to unfold into an international health crisis, were caused by many socio-political factors, such as poverty, lack of resources, inaction by governments, the international community and the way the response systems for pandemics have been built. Drawing on literature reviews of reports and policy documents, this paper aims to study the influence of uncertainty as a facilitator for “non-decision-making” on actions which could have stopped the escalation of the outbreak. The responders faced uncertainty associated with the source, evolution and solutions to the pandemic — mainly because of inadequate understanding of the situation in Western Africa, inadequate information exchange from the field, and internal administrative structures within the World Health Organization (WHO). In addition, uncertainty was also deliberately spread due to fears of having the WHO impose a “Declaration of Public Health Emergency of International Concern” (PHEIC), which again could cause severe economic and political consequences.

A Systems Approach to Agricultural Biosecurity.

This article highlights the importance of systems approaches in addressing agricultural biosecurity threats. On the basis of documentary analysis and stakeholder interaction, a brief survey of agricultural biosecurity threats and vulnerabilities from global and Indian perspectives is provided, followed by an exploration of technological and institutional capabilities. Finally, a perspective on the agricultural disease diagnostic networks is provided, drawing instances from global developments. Technical barriers to agroterrorism are lower than those to human-targeted bioterrorism, and the sector is unique as even a very small disease outbreak could prompt international export restrictions. Key vulnerabilities in the agriculture sector stem from, among others, the structure of agricultural production; insufficient monitoring, surveillance, and controls systems at the borders and in the food chain; inefficient systems for reporting unusual occurrences and outbreaks of disease; and lack of sufficiently trained human resources capable of recognizing or treating transboundary pathogens and diseases. An assessment of technology and institutions pertaining to crop and animal protection management suggests certain gaps. Investment in developing new technologies for civilian application in agriculture, as well as for legitimate actions pertaining to defense, detection, protection, and prophylaxis, and in upgrading laboratory facilities can increase the agricultural sector's level of preparedness for outbreaks. To address potential threats and vulnerabilities of agroterrorism effectively requires the development of a comprehensive strategy and a combined, interagency approach, ideally on an international level. It is proposed that a systems-oriented approach for developing knowledge and innovation networks and strengthening skills and capacities would enable a more resilient agricultural biosecurity system.

The association between acute flaccid myelitis (AFM) and Enterovirus D68 (EV-D68) - what is the evidence for causation?

BackgroundEnterovirus D68 (EV-D68) has historically been a sporadic disease, causing occasional small outbreaks of generally mild infection. In recent years, there has been evidence of an increase in EV-D68 infections globally. Large outbreaks of EV-D68, with thousands of cases, occurred in the United States, Canada and Europe in 2014. The outbreaks were associated temporally and geographically with an increase in clusters of acute flaccid myelitis (AFM). Aims: We aimed to evaluate a causal association between EV-D68 and AFM. Methods: Using data from the published and grey literature, we applied the Bradford Hill criteria, a set of nine principles applied to examine causality, to evaluate the relationship between EV-D68 and AFM. Based on available evidence, we defined the Bradford Hill Criteria as being not met, or met minimally, partially or fully. Results: Available evidence applied to EV-D68 and AFM showed that six of the Bradford Hill criteria were fully met and two were partially met. The criterion of biological gradient was minimally met. The incidence of EV-D68 infections is increasing world-wide. Phylogenetic epidemiology showed diversification from the original Fermon and Rhyne strains since the year 2000, with evolution of a genetically distinct outbreak strain, clade B1. Clade B1, but not older strains, is associated with AFM and is neuropathic in animal models. Conclusion: While more research is needed on dose–response relationship, application of the Bradford Hill criteria supported a causal relationship between EV-D68 and AFM.

Clinical, Bacteriologic, and Geographic Stratification of Melioidosis Emerges from the Sri Lankan National Surveillance Program.

.Melioidosis, a potentially fatal tropical infection, is said to be underdiagnosed in low-income countries. An increase in melioidosis cases in Sri Lanka allowed us to analyze the relationship among clinical outcome, bacteriology, epidemiology, and geography in the first 108 laboratory-confirmed cases of melioidosis from a nationwide surveillance program. The additional 76 cases of laboratory-confirmed melioidosis confirmed further associations between Burkholderia pseudomallei multilocus sequence typing (MLST) and infection phenotype; ST1137/unifocal bacteremic infection (χ2 = 3.86, P < 0.05), ST1136/multifocal infection without bacteremia (χ2 = 15.8, P < 0.001), and ST1132/unifocal nonbacteremic infection (χ2 = 6.34, P = 0.02). ST1137 infections were predominantly seen in the Western Province, whereas ST1132, 1135, and 1136 infections predominated in the Northwestern Province. Early participating centers in the surveillance program had a lower melioidosis-associated mortality than later participants (χ2 = 3.99, P < 0.05). The based upon related sequence types (eBURST) algorithm, a MLST clustering method that infers founding genotypes and patterns of descent for related isolates and clonal complexes in an unrooted tree, showed uneven distribution of sequence types (STs). There was spatial clustering of the commonest STs (ST1132, 1136, and 1137) in the Western, Northwestern, and Central provinces. The recent increase in melioidosis in Sri Lanka uncovered by laboratory-enhanced surveillance is likely to be the result of a combination of improved laboratory detection, increased clinician awareness, recruitment of clinical centers, and small outbreaks. Further development of the surveillance program into a national genotyping-supported melioidosis registry will improve melioidosis diagnosis, treatment, and prevention where underdiagnosis and mortality rates remain high.

The Epidemiology of Foodborne Botulism Outbreaks: A Systematic Review.

We performed a systematic review of foodborne botulism outbreaks to describe their clinical aspects and descriptive epidemiology in order to inform public health response strategies. We searched seven databases for reports of foodborne botulism outbreaks published in English from database inception to May 2015. We summarized descriptive characteristics and analyzed differences in exposure and toxin types by geographic region. We performed logistic regression to assess correlations between exposure source, implicated food, and outbreak size. There were 197 outbreaks reported between 1920 and 2014. The median number of cases per outbreak was 3 (range 2-97). The majority of reported outbreaks (109; 55%) occurred in the United States. Toxin types A, B, E, and F were identified as the causative agent in 34%, 16%, 17%, and 1% of outbreaks, respectively. The median duration between exposure and symptom onset was approximately 1 day. The mean percentage of cases requiring mechanical ventilation per outbreak was 34%. Seventy percent of all outbreaks and 77% of small outbreaks (≤11 cases) originated from point source exposures, while commercial foods were significantly (odds ratio, 6.9; 95% confidence interval, 2.2-21.1) associated with large outbreaks (≥12 cases). Toxin type A accounted for half of outbreaks, and these outbreaks had a higher proportion of patient ventilatory failure. Most outbreaks were due to point source exposures, while outbreaks due to commercial food were larger. For effective responses to foodborne botulism outbreaks, these findings demonstrate the need for timely outbreak investigation and hospital surge capacity.