Edward Velasco

Social Media and Internet-Based Data in Global Systems for Public Health Surveillance: A Systematic Review

Context: The exchange of health information on the Internet has been heralded as an opportunity to improve public health surveillance. In a field that has traditionally relied on an established system of mandatory and voluntary reporting of known infectious diseases by doctors and laboratories to governmental agencies, innovations in social media and so-called user-generated information could lead to faster recognition of cases of infectious disease. More direct access to such data could enable surveillance epidemiologists to detect potential public health threats such as rare, new diseases or early-level warnings for epidemics. But how useful are data from social media and the Internet, and what is the potential to enhance surveillance? The challenges of using these emerging surveillance systems for infectious disease epidemiology, including the specific resources needed, technical requirements, and acceptability to public health practitioners and policymakers, have wide-reaching implications for public health surveillance in the 21st century. Methods: This article divides public health surveillance into indicator-based surveillance and event-based surveillance and provides an overview of each. We did an exhaustive review of published articles indexed in the databases PubMed, Scopus, and Scirus between 1990 and 2011 covering contemporary event-based systems for infectious disease surveillance. Findings: Our literature review uncovered no event-based surveillance systems currently used in national surveillance programs. While much has been done to develop event-based surveillance, the existing systems have limitations. Accordingly, there is a need for further development of automated technologies that monitor health-related information on the Internet, especially to handle large amounts of data and to prevent information overload. The dissemination to health authorities of new information about health events is not always efficient and could be improved. No comprehensive evaluations show whether event-based surveillance systems have been integrated into actual epidemiological work during real-time health events. Conclusions: The acceptability of data from the Internet and social media as a regular part of public health surveillance programs varies and is related to a circular challenge: the willingness to integrate is rooted in a lack of effectiveness studies, yet such effectiveness can be proved only through a structured evaluation of integrated systems. Issues related to changing technical and social paradigms in both individual perceptions of and interactions with personal health data, as well as social media and other data from the Internet, must be further addressed before such information can be integrated into official surveillance systems.

Burden of Six Healthcare-Associated Infections on European Population Health: Estimating Incidence-Based Disability-Adjusted Life Years through a Population Prevalence-Based Modelling Study

Background Estimating the burden of healthcare-associated infections (HAIs) compared to other communicable diseases is an ongoing challenge given the need for good quality data on the incidence of these infections and the involved comorbidities. Based on the methodology of the Burden of Communicable Diseases in Europe (BCoDE) project and 2011–2012 data from the European Centre for Disease Prevention and Control (ECDC) point prevalence survey (PPS) of HAIs and antimicrobial use in European acute care hospitals, we estimated the burden of six common HAIs. Methods and Findings The included HAIs were healthcare-associated pneumonia (HAP), healthcare-associated urinary tract infection (HA UTI), surgical site infection (SSI), healthcare-associated Clostridium difficile infection (HA CDI), healthcare-associated neonatal sepsis, and healthcare-associated primary bloodstream infection (HA primary BSI). The burden of these HAIs was measured in disability-adjusted life years (DALYs). Evidence relating to the disease progression pathway of each type of HAI was collected through systematic literature reviews, in order to estimate the risks attributable to HAIs. For each of the six HAIs, gender and age group prevalence from the ECDC PPS was converted into incidence rates by applying the Rhame and Sudderth formula. We adjusted for reduced life expectancy within the hospital population using three severity groups based on McCabe score data from the ECDC PPS. We estimated that 2,609,911 new cases of HAI occur every year in the European Union and European Economic Area (EU/EEA). The cumulative burden of the six HAIs was estimated at 501 DALYs per 100,000 general population each year in EU/EEA. HAP and HA primary BSI were associated with the highest burden and represented more than 60% of the total burden, with 169 and 145 DALYs per 100,000 total population, respectively. HA UTI, SSI, HA CDI, and HA primary BSI ranked as the third to sixth syndromes in terms of burden of disease. HAP and HA primary BSI were associated with the highest burden because of their high severity. The cumulative burden of the six HAIs was higher than the total burden of all other 32 communicable diseases included in the BCoDE 2009–2013 study. The main limitations of the study are the variability in the parameter estimates, in particular the disease models’ case fatalities, and the use of the Rhame and Sudderth formula for estimating incident number of cases from prevalence data. Conclusions We estimated the EU/EEA burden of HAIs in DALYs in 2011–2012 using a transparent and evidence-based approach that allows for combining estimates of morbidity and of mortality in order to compare with other diseases and to inform a comprehensive ranking suitable for prioritization. Our results highlight the high burden of HAIs and the need for increased efforts for their prevention and control. Furthermore, our model should allow for estimations of the potential benefit of preventive measures on the burden of HAIs in the EU/EEA.

What caused the outbreak of ESBL-producing Klebsiella pneumoniae in a neonatal intensive care unit, Germany 2009 to 2012? Reconstructing transmission with epidemiological analysis and whole-genome sequencing

Objective We aimed to retrospectively reconstruct the timing of transmission events and pathways in order to understand why extensive preventive measures and investigations were not sufficient to prevent new cases. Methods We extracted available information from patient charts to describe cases and to compare them to the normal population of the ward. We conducted a cohort study to identify risk factors for pathogen acquisition. We sequenced the available isolates to determine the phylogenetic relatedness of Klebsiella pneumoniae isolates on the basis of their genome sequences. Results The investigation comprises 37 cases and the 10 cases with ESBL (extended-spectrum beta-lactamase)-producing K. pneumoniae bloodstream infection. Descriptive epidemiology indicated that a continuous transmission from person to person was most likely. Results from the cohort study showed that ‘frequent manipulation’ (a proxy for increased exposure to medical procedures) was significantly associated with being a case (RR 1.44, 95% CI 1.02 to 2.19). Genome sequences revealed that all 48 bacterial isolates available for sequencing from 31 cases were closely related (maximum genetic distance, 12 single nucleotide polymorphisms). Based on our calculation of evolutionary rate and sequence diversity, we estimate that the outbreak strain was endemic since 2008. Conclusions Epidemiological and phylogenetic analyses consistently indicated that there were additional, undiscovered cases prior to the onset of microbiological screening and that the spread of the pathogen remained undetected over several years, driven predominantly by person-to-person transmission. Whole-genome sequencing provided valuable information on the onset, course and size of the outbreak, and on possible ways of transmission.

Ecological analysis of social risk factors for Rotavirus infections in Berlin, Germany, 2007–2009

BackgroundSocioeconomic factors are increasingly recognised as related to health inequalities in Germany and are also identified as important contributing factors for an increased risk of acquiring infections. The aim of the present study was to describe in an ecological analysis the impact of different social factors on the risk of acquiring infectious diseases in an urban setting. The specific outcome of interest was the distribution of Rotavirus infections, which are a leading cause of acute gastroenteritis among infants and also a burden in the elderly in Germany. The results may help to generate more specific hypothesis for infectious disease transmission.MethodsWe analysed the spatial distribution of hospitalized patients with Rotavirus infections in Berlin, Germany. The association between the small area incidence and different socio-demographic and economic variables was investigated in order to identify spatial relations and risk factors. Our spatial analysis included 447 neighbourhood areas of similar population size in the city of Berlin. We included all laboratory-confirmed cases of patients hospitalized due to Rotavirus infections and notified between 01/01/2007 and 31/12/2009. We excluded travel-associated and nosocomial infections. A spatial Bayesian Poisson regression model was used for the statistical analysis of incidences at neighbourhood level in relation to socio-demographic variables.ResultsAltogether, 2,370 patients fulfilled the case definition. The disease mapping indicates a number of urban quarters to be highly affected by the disease. In the multivariable spatial regression model, two risk factors were identified for infants (<4 year olds): Rotavirus incidence increased by 4.95% for each additional percent of unemployed inhabitants in the neighbourhood (95% credibility interval (CI): 3.10%-6.74%) and by 0.53% for each additional percent of children attending day care in the neighbourhood (95% CI: 0.00%-1.06%). We found no evidence for an association with the proportion of foreign residents, population density, the residential quality of accommodations and resident changes in the neighbourhood.ConclusionsNeighbourhoods with a high unemployment rate and high day care attendance rate appear to be particularly affected by Rotavirus in the population of Berlin. Public health promotion programs should be developed for the affected areas. Due to the ecological study-design, risk pathways on an individual patient level remain to be elucidated.

Towards personalized learning to rank for epidemic intelligence based on social media streams

In the presence of sudden outbreaks, how can social media streams be used to strengthen surveillance capabilities? In May 2011, Germany reported one of the largest described outbreaks of Enterohemorrhagic Escherichia coli (EHEC). By end of June, 47 persons had died. After the detection of the outbreak, authorities investigating the cause and the impact in the population were interested in the analysis of micro-blog data related to the event. Since Thousands of tweets related to this outbreak were produced every day, this task was overwhelming for experts participating in the investigation. In this work, we propose a Personalized Tweet Ranking algorithm for Epidemic Intelligence (PTR4EI), that provides users a personalized, short list of tweets based on the users context. PTR4EI is based on a learning to rank framework and exploits as features, complementary context information extracted from the social hash-tagging behavior in Twitter. Our experimental evaluation on a dataset, collected in real-time during the EHEC outbreak, shows the superior ranking performance of PTR4EI. We believe our work can serve as a building block for an open early warning system based on Twitter, helping to realize the vision of Epidemic Intelligence for the Crowd, by the Crowd.

MRSA-surveillance in Germany: data from the Antibiotic Resistance Surveillance System (ARS) and the mandatory surveillance of MRSA in blood

Data from the German Antibiotic Resistance Surveillance system (ARS) and statutory notification of methicillin-resistant Staphylococcus aureus (MRSA) in blood cultures are presented. ARS is a voluntary laboratory-based surveillance system providing resistance data of all clinical pathogens and sample types from hospitals and ambulatory care. Statutory notification includes MRSA detected in blood and cerebrospinal fluid by microbiological laboratories. Resistance data from 2008 to 2010 and MRSA-bacteraemia incidences from 2010 are presented. From 2008 to 2010, resistance data from 70,935 Staphylococcus aureus isolates were transferred to the national health institution. MRSA proportions in hospitals and outpatient care account for 19.2% and 10.6%, respectively. In hospital care high proportions of MRSA were found in nephrological, geriatric, neurological general wards and surgical ICUs (49.4%, 45.8%, 34.2%, and 27.0%, respectively), while in community outpatient care urological practices (29.2%) account for the highest values. In both healthcare settings urinary tract samples stand out with high proportions of MRSA (hospitals, 32.9%; outpatients, 20.5%). In 2010, 3900 cases of MRSA bacteraemia were reported, accounting for an incidence of MRSA bacteraemia of 4.8/100,000 inhabitants/year. Stratification by federal states shows considerable regional differences (range, 1.0–8.3/100,000 inhabitants/year). Vulnerable areas in hospitals and outpatient care have been pointed out as subjects for further inquiries.

A Survey of Outpatient Antibiotic Prescribing for Cystitis

BACKGROUND In view of the currently increasing rates of antibiotic resistance, we studied the factors that affect the prescribing of specific antibiotics for uncomplicated cystitis in outpatient care. METHODS A nationwide cross-sectional survey of physicians in private practice in various specialties (internal medicine, general medicine, surgery, obstetrics/gynecology, child and adolescent medicine, otorhinolaryngology, dermatology, urology) was carried out in 2008. The sample was derived from the German state directories of medical specialists. RESULTS 1810 (60%) of the physicians surveyed reported that they made decisions about antibiotic treatment every day, with uncomplicated urinary tract infection as the most common diagnosis (715 physicians). The antibiotics that they prescribed most commonly for it were cotrimoxazole (61%) and fluoroquinolones (21%). The following factors were significantly associated with a preference for fluoroquinolones: being a gynecologist (odds ratio [OR] 0.47, 95% confidence interval [CI] 0.27-0.80), location of practice in the former East Germany (OR 2.01, CI 1.16-3.46), a treatment strategy incorporating a switch from empirical to targeted treatment (OR 1.72, CI 1.02-2.90), and the stated intention of avoiding inconvenience to the patient (OR 2.14, CI 1.25-3.68). DISCUSSION Fluoroquinolones are no longer recommended as the drug of first choice for uncomplicated urinary tract infections because of the development of resistance, but are still commonly prescribed for it. ARS (Antibiotic Resistance Surveillance in Germany) publishes current regional and patient-group-specific resistance rates to promote good clinical practice and improve prescribing behavior.

Neurological sequelae of healthcare-associated sepsis in very-low-birthweight infants: Umbrella review and evidence-based outcome tree

Sepsis is a frequent cause of death in very-low-birthweight infants and often results in neurological impairment. Its attributable risk of sequelae has not been systematically assessed. To establish an outcome tree for mapping the burden of neonatal sepsis, we performed systematic literature searches to identify systematic reviews addressing sequelae of neonatal sepsis. We included cohort studies and performed meta-analyses of attributable risks. Evidence quality was assessed using GRADE. Two systematic reviews met inclusion criteria. The first included nine cohort studies with 5,620 participants and five outcomes (neurodevelopmental impairment, cerebral palsy, vision impairment, hearing impairment, death). Pooled risk differences varied between 4% (95% confidence interval (CI):2-10) and 13% (95% CI:5-20). From the second review we analysed four studies with 472 infants. Positive predictive value of neurodevelopmental impairment for later cognitive impairment ranged between 67% (95% CI:22-96) and 83% (95% CI:36-100). Neonatal sepsis increases risk of permanent neurological impairment. Effect size varies by outcome, with evidence quality being low to very low. Data were used to construct an outcome tree for neonatal sepsis. Attributable risk estimates for sequelae following neonatal sepsis are suitable for burden estimation and may serve as outcome parameters in interventional studies.

The FIFA Women's World Cup in Germany 2011 - A practical example for tailoring an event-specific enhanced infectious disease surveillance system

BackgroundMass gatherings require a decision from public health authorities on how to monitor infectious diseases during the event. The appropriate level of enhanced surveillance depends on parameters like the scale of the event (duration, spatial distribution, season), participants’ origin, amount of public attention, and baseline disease activity in the host country. For the FIFA Men’s World Cup 2006, Germany implemented enhanced surveillance. As the scale of the FIFA Women’s World Cup (June 26 – July 17, 2011) was estimated to be substantially smaller in size, visitors and duration, it was not feasible to simply adopt the previously implemented measures. Our aim was therefore to develop a strategy to tailor an event-specific enhanced surveillance for this smaller-scale mass gathering.MethodsBased on the enhanced surveillance measures during the Men’s Cup, we conducted a needs assessment with the district health authorities in the 9 host cities in March 2011. Specific measures with a majority consent were implemented. After the event, we surveyed the 9 district and their corresponding 7 state health authorities to evaluate the implemented measures.ResultsAll 9 district health authorities participated in the pre-event needs assessment. The majority of sites consented to moving from weekly to daily (Monday-Friday) notification reporting of routine infectious diseases, receiving regular feedback on those notification reports and summaries of national/international World Cup-relevant epidemiological incidents, e.g. outbreaks in countries of participating teams. In addition, we decided to implement twice-weekly reports of “unusual events” at district and state level. This enhanced system would commence on the first day and continue to one day following the tournament. No World Cup-related infectious disease outbreaks were reported during this time period. Eight of 9 district and 6 of 8 state health authorities participated in the final evaluation. The majority perceived the implemented measures as adequate.ConclusionsOur approach to tailor an event-specific enhanced surveillance concept worked well. Involvement of the participating stakeholders early-on in the planning phase secured ownership of and guaranteed support for the chosen strategy. The enhanced surveillance for this event resulted as a low-level surveillance. However, we included mechanisms for rapid upscaling if the situation would require adaptations.

Die telefonische infektionsepidemiologische Bund-Länder-Lagekonferenz in Deutschland

Public health threats are increasingly triggered by events which span across international, national and state level jurisdictions. Innovative surveillance methods are needed to ensure adequate and timely response to such threats. In January 2009 the Department of Infectious Disease Epidemiology at the Robert Koch Institute (RKI) established a system of weekly telephone conferences with all competent authorities of the German federal states to identify, discuss and respond to infectious disease events in real-time. A regular and structured platform was developed for use between participants from state level public health authorities, the military and the RKI. During the first three quarters, 46 infectious diseases were covered, including mandatory reports of measles and meningococcal meningitis and outbreaks of cowpox, which does not have to be notified in Germany. Results of a targeted evaluation and a consistently high attendance rate both indicate that the teleconference has met additional needs for supplemental information exchange among participants. The telephone conference has proven to be a useful resource for rapid and direct communication, coordination and evaluation of signals for public health events in Germany.