Using Case-Case Study Designs to Study Foodborne Enteric Infections

Case-control studies are the traditional ways in which foodborne enteric diseases are studied and outbreaks are investigated. This method has some significant limitations and biases for diseases with low efficiency reporting rates, such as Campylobacter, a common foodborne disease. Case-case methodologies have been explored for these studies but have been implemented without any clear strategy. This dissertation aims to first, determine the common risk factors for Campylobacter in Arizona using the traditional case-control study design, second, to systematically compare case-case studies to the more common case-control studies, and third, to simultaneously compare the results of a community outbreak of Campylobacter using both case-control and case-case study designs. Results from these studies identified some unique risk factors for routine Campylobacter infection in Arizona that will be used to enhance surveillance for the disease in the state. A systematic review of case-case studies used for enteric diseases found that there are specific recommendations that can be put into place in determining what comparison cases should be selected based on the primary aims and goals of the study. Finally, the results of the simultaneous case-case and case-control studies of a Campylobacter outbreak showed that these methods may work best in conjunction with one another and in doing so, the most accurate depiction of the source of infection can be determined

Field Team Syndromic Surveillance for Mass Gatherings: NCAA Final Four 2017

ObjectiveTo describe and present results of field-based near-real time syndromic surveillance conducted at first aid stations during the 2017 National Collegiate Athletic Association Division I Men’s College Basketball Championship (Final Four) events, and the use of field team data to improve situational awareness for Mass Gathering events.IntroductionFinal Four-associated events culminated in four days of intense activity from 3/31/17-4/3/17, which attracted an estimated 400,000 visitors to Maricopa County (population 4.2 million). Field teams of staff and volunteers were deployed to three days of Music Fest, four days of Fan Fest, and three Final Four games (Games) as part of an enhanced epidemiologic surveillance system.MethodsAttendees presenting to first aid stations were requested to complete an electronic questionnaire which captured illness and injury syndromes (after needed care was given). Emergency Medical Services technicians and nurses (EMS) conducted patient care. These were submitted and epidemiologically assessed in near-real-time to rapidly identify threats. Syndrome-specific data were mapped during events to identify spatial clustering. Field Teams were provided with case contact log sheets, suspicious substance investigation and exposure registry forms to allow rapid investigation of significant public health events. Patient Presentation Rates (PPR) and Transport to Hospital Rates (TTHR) were calculated per 10,000 attendees. Patients presenting per hour of event and transports per hour of event were calculated. Field reports were included in daily reports to inter-disciplinary partners, and shared during regular Multi-Agency Coordination Center briefings.Results301 field questionnaires were completed, including 146 from Final Four games (Games), 127 from the Music Fest, and 28 from the Fan Fest (see Figure).Among the 153,780 attendees of the three Games, there were 146 cases who presented to one of five first aid stations (over 12 hours). There were 27 illness cases who sought care (18.5% of Games cases), among whom 21 (78%) were assessed by EMS. Illness cases not assessed by EMS (n=6) included mostly allergy symptoms/medication needs. There were 50 injury cases who sought care (34.2% of Games cases), among whom 10 (20%) were assessed by EMS. Sixty (41.1%) persons presented seeking a pain reliever, and 9 (6.2%) presented seeking an antacid. Games experienced a PPR of 9.5, and a TTHR of 0.52. Patients presented at 12.2 per hour on average and there were eight transports to medical facilities (0.66 per hour).There were 127 cases among an estimated 135,000 Music Fest attendees who presented to one of two first aid stations (and at times 2 roving teams) over 3 days (22.5 hours) from 3/31 to 4/2. Illnesses accounted for 29 cases (22.8% of Music Fest cases) and 28 of 29 were assessed by EMS. There were 68 injury cases who sought care (53.5% of Music Fest cases), among whom 22 (32.4%) were assessed by EMS. Twenty-seven persons (21.3%) presented seeking a pain reliever and 2 (1.6%) sought an antacid. Music Fest results included a PPR of 9.4, and a TTHR of 0.15. There were 5.6 patients presenting per hour on average, and there were two transports to the hospital (0.09 per hour).At the Fan Fest there were 28 cases among an estimated 50,803 attendees presenting to the first aid station (or roving teams) from 3/31-4/3 (over 37 hours). Most cases sought care for an injury (n=22, 78.6% of cases). Four persons sought care for an illness (14.3%), all with relatively minor complaints. For the Fan Fest, there was a PPR of 5.5, and a TTHR of 0 (there were no transports to the hospital). There were 0.76 patient presentations per hour on average.No geographic clustering or public health threats requiring investigation were identified at any of the three sites. Interdisciplinary partners requested additional field data during the response.ConclusionsInjuries were more common than illnesses at all three sites. Visits requiring pain relievers only were more common at Games (41.1%) than at Music Fest (21.3%) or Fan Fest (3.6%).A greater percentage of visits requiring EMS assessment were seen at the Fan Fest (78.6%) than at the Music Fest (40.2%) or the Games (21.2%).The PPRs per 10,000 attendees were highest at the Games (9.5) and Music Fest (9.4), compared to the Fan Fest (5.5). The TTHR per 10,000 attendees was highest at the Games (0.52), compared to the Music Fest (0.15) and Fan Fest (0.0). The Music Fest field team reported greater effectiveness at fixed first aid stations compared to traveling with roving EMS teams. Field reports enhanced health and medical situational awareness and information sharing as evidenced by requests from interdisciplinary partners for additional field data. 

Knowledge and practices of primary care physicians or general practitioners treating post-infectious Irritable Bowel Syndrome

Background Post-infectious Irritable Bowel Syndrome (PI-IBS) is a functional bowel disorder which has significant impacts to a patient's quality of life. No IBS-specific biomarker or treatment regimen for PI-IBS currently exists, therefore understanding practice patterns and variance is of interest. Methods This online survey of primary care physicians and general practitioners in the USA aimed to understand the knowledge and treatment of PI-IBS within the physician's current practice. Summary statistics are provided with a commentary on implications for practices and treatment of PI-IBS. Results Most physician survey respondents (n = 50) were aware of PI-IBS, but less than half discussed this condition as a possible outcome in their patients with a recent gastrointestinal infection. Most physicians indicated that they would treat the patients themselves with a focus on managing IBS through different treatment modalities based on severity. Treatment for PI-IBS followed IBS recommendations, but most physicians also prescribed a probiotic for therapy. Physicians estimated that 4 out of 10 patients who develop PI-IBS will have life-long symptoms and described significant impacts to their patient's quality of life. Additionally, physicians estimated a significant financial burden for PI-IBS patients, ranging from $100-1000 (USD) over the course of their illness. Most physicians agreed that they would use a risk score to predict the probability of their patients developing PI-IBS, if available. Conclusions While this survey is limited due to sample size, physician knowledge and treatment of PI-IBS was consistent across respondents. Overall, the physicians identified significant impacts to patient's quality of life due to PI-IBS.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Surveillance for Mass Gatherings: NCAA Final Four 2017 in Maricopa County, Arizona

Objective: To describe and present results for the enhanced epidemiologic surveillance system established during the 2017 National Collegiate Athletic Association Division I Men’s College Basketball Championship (Final Four) events.Introduction: Final Four-associated events culminated in four days of intense activity from March 31st through April 3rd, and added an estimated 400,000 visitors to Maricopa County's 4.2 million residents.Methods: Preparation included: refinements in enhanced surveillance for previous events (including Super Bowl XLII); a rehearsal on information sharing for team leads; just in time training for field team members; a tabletop exercise on 2/22; and solicitation of lessons learned from jurisdictions recently hosting the Final Four.Enhanced surveillance began on 3/24 and continued through 4/10 (one week before the first major event until one week after the championship game) with intensified surveillance from 3/31-4/3. Subject matter experts for each enhanced surveillance component functioned as team leads. A surveillance coordinator was assigned to review data and prepare reports. Team members were sent a plan of the day detailing daily surveillance activities.An enhanced surveillance (SURV) alert requesting an increased index of suspicion for events of public health significance was sent to pre-established lists of healthcare providers. Urgent care clinics within five miles of venues were asked to report influenza-like, gastrointestinal, rash, and neurological illness visits daily. Emergency department records in the National Syndromic Surveillance Program, Electronic Surveillance System for Early Notification of Community-Bases Epidemics (ESSENCE) were monitored daily for influenza-like illness, gastrointestinal illness, injury, records of interest, heat-related illness and event-specific terms. Mumps and meningitis were added after outbreak reports were received from home jurisdictions of Final Four teams. Death certificate data, Office of the Medical Examiner line lists and preliminary reports of death were reviewed daily for reportable diseases or circumstances of public health significance. Communicable disease data was reviewed daily for notifiable disease cases of concern, aberration detection as compared to the previous four years, outbreak review, and Influenza-like-illness.Field teams of staff and volunteers were deployed to three days of Music Fest, four days of Fan Fest, and three Final Four games. Attendees presenting to first aid stations were requested to complete an electronic questionnaire capturing illness and injury syndromes. These were submitted and epidemiologically assessed in near-real-time. Syndrome-specific data were geo-located on venue maps during events to identify spatial clustering. Patient Presentation Rates (PPR) and Transport to Hospital Rates (TTHR) per 10,000 attendees were calculated.To enhance animal health system surveillance, veterinarians and agencies that work with animals were notified to increase the index of suspicion for unusual animal disease, keep alert for outbreaks with zoonotic potential, and update 24/7 emergency contact lists.Health-related media reports, Final-Four-specific reports, health-aggregated Twitter reports, and breaking news alert subscriptions were monitored. Poison Control Center (PCC) reports were assessed by conducting regular queries of the National Poison Data System (NPDS). Reports from the 24/7 Disease Reporting Line were monitored.A one page enhanced surveillance report was developed for daily distribution to inter-disciplinary partners; a more detailed report was distributed to health and medical partners. Physicians overseeing the health/medical care of teams were included in information sharing. Public health intelligence information was exchanged with epidemiologists from home jurisdictions of Final Four teams.Results: 301 field questionnaires were completed, including 146 from Final Four games, 127 from the Music Fest, and 28 from the Fan Fest. Final Four games experienced a PPR of 9.5, and a TTHR of 0.52. Music Fest results were a PPR of 9.4, and a TTHR of 0.15. For the Fan Fest, there was a PPR of 5.5, and a TTHR of 0.PCC data review resulted in investigation of four cases for potential ricin exposure. These reports were determined to be exposure to castor beans and the castor bean plant (Ricinus communis) only. One report indicating potential phosgene occupational exposure to an air conditioning system worker was reviewed, and judged unlikely to cause noted symptoms.Outbreak information from home jurisdictions of Final Four teams resulted in increased index of suspicion for mumps, additional surveillance and mentions in media surveillance reports.Review of communicable disease, mortality, and ESSENSE data resulted only in routine investigations.Conclusions: Surveillance information from disparate surveillance systems was synthesized into reports which enhanced health and medical situational awareness and information sharing; interdisciplinary partners highlighted the utility of the one-page report. Enhanced surveillance allowed the rapid identification and characterization of potential threats, and provided an evidence base for public health decisions. Establishment of field teams allowed for near-real-time tracking of patient presentations and transports and rapid identification and characterization of syndromes of concern and potential threats. Public health intelligence information exchange with home jurisdictions of Final Four teams resulted in targeted surveillance for mumps and meningitis

Persisting gastrointestinal symptoms and post-infectious irritable bowel syndrome following SARS-CoV-2 infection: Results from the Arizona CoVHORT

In this study we aimed to examine the association between gastrointestinal (GI) symptom presence during acute SARS-CoV-2 infection and the prevalence of GI symptoms and development of post-infectious irritable bowel syndrome (PI-IBS). We used data from a prospective cohort and logistic regression to examine the association between GI symptom status during confirmed SARS-CoV-2 infection and prevalence of persistent gastrointestinal symptoms at ≥45 days. We also report the incidence of PI-IBS following SARS-CoV-2 infection. Of the 1,475 participants in this study, 33.8% (n=499) had GI symptoms during acute infection. Cases with acute GI symptoms had an odds of persisting GI symptoms 4 times higher than cases without acute GI symptoms (OR=4.29, CI: 2.45, 7.53); symptoms lasted on average 8 months following infection. Of those with persisting GI symptoms, 67% sought care for their symptoms and incident PI-IBS occurred in 3.0% (n=15) of participants. Those with acute GI symptoms after SARS-CoV-2 infection are likely to have similar persistent symptoms 45 days and greater. These data indicate that attention to a potential increase in related healthcare needs is warranted.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

A critical analysis of recreational water guidelines developed from temperate climate data and applied to the tropics

Recreational water epidemiology studies are rare in settings with minimal wastewater treatment where risk may be highest, and in tropical settings where warmer temperature influences the ecology of fecal indicator bacteria commonly used to monitor recreational waters. One exception is a 1999 study conducted in Sao Paulo Brazil. We compared the risk and exposure characteristics of these data with those conducted in the United Kingdom (UK) in the early 1990s that are the basis of the World Health Organization's (WHO) guidelines on recreational water risks. We then developed adjusted risk difference models (excess gastrointestinal illness per swimming event) for children (= 10 years of age) across five Brazil beaches. We used these models along with beach water quality data from 2004 to 2015 to assess spatial and temporal trends in water quality and human risk. Risk models indicate that children in Brazil have as much as two times the risk of gastrointestinal illness than non-children. In Brazil, 11.8% of the weekly water samples from 2004 to 2015 exceeded 158 enterococci CFU/100 ml, the highest level of fecal streptococci concentration measured in the UK study. Risks associated with these elevated levels equated to median NEEAR-Gastrointestinal Illness (NGI) risks of 53 and 96 excess cases per 1000 swimmers in non-children and children, respectively. Two of the five beaches appear to drive the overall elevated NGI risks seen during this study. Distinct enteric pathogen profiles that exist in tropical settings as well as in settings with minimal wastewater treatment highlight the importance of regionally specific guideline development. (C) 2019 Elsevier Ltd. All rights reserved.24 month embargo; published online: 9 November 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]