Harnessing landrace diversity empowers wheat breeding.

Harnessing genetic diversity in major staple crops through the development of new breeding capabilities is essential to ensure food security1. Here we examined the genetic and phenotypic diversity of the A.E. Watkins landrace collection2 of bread wheat (Triticum aestivum), a major global cereal, through whole-genome re-sequencing (827 Watkins landraces and 208 modern cultivars) and in-depth field evaluation spanning a decade. We discovered that modern cultivars are derived from just two of the seven ancestral groups of wheat and maintain very long-range haplotype integrity. The remaining five groups represent untapped genetic sources, providing access to landrace-specific alleles and haplotypes for breeding. Linkage disequilibrium (LD) based haplotypes and association genetics analyses link Watkins genomes to the thousands of high-resolution quantitative trait loci (QTL), and significant marker-trait associations identified. Using these structured germplasm, genotyping and informatics resources, we revealed many Watkins-unique beneficial haplotypes that can confer superior traits in modern wheat. Furthermore, we assessed the phenotypic effects of 44,338 Watkins-unique haplotypes, introgressed from 143 prioritised QTL in the context of modern cultivars, bridging the gap between landrace diversity and current breeding. This study establishes a framework for systematically utilising genetic diversity in crop improvement to achieve sustainable food security.

Effect of Ground Beef Irradiation on Annual Nontyphoidal Salmonella and Escherichia coli O157 Burden and Direct Healthcare Costs in the United States: A Simulation Study.

Over 20% of E. coli O157 illnesses and over 5% of Salmonella illnesses are estimated to be attributable to beef consumption in the United States. Irradiating ground beef is one possible method to reduce disease burden. We simulated the effect of ground beef irradiation on illnesses, hospitalizations, deaths, and direct healthcare costs from ground beef-associated E. coli O157 and Salmonella illnesses in the United States. To estimate the fraction of illnesses, hospitalizations, deaths, and direct healthcare costs preventable by ground beef irradiation, we multiplied the disease burden attributable to ground beef; the estimated percentage of ground beef sold that is not currently irradiated; the percentage of unirradiated ground beef that would be irradiated; and the percentage reduction in risk of illness after irradiation. We multiplied this fraction by estimates of burden and direct healthcare costs to calculate the numbers or amounts averted. Model inputs were obtained from the literature and expert opinion. We used Monte Carlo simulation to incorporate uncertainty in inputs into model estimates. Simulation outcomes were summarized with means and 95% uncertainty intervals (UI). Irradiating 50% of the currently unirradiated ground beef supply would avert 3,285 (95% UI: 624-9,977) E. coli O157 illnesses, 135 (95% UI: 24-397) hospitalizations, 197 (95% UI: 34-631) hemolytic uremic syndrome cases, 2 (95% UI: 0-16) deaths, and $2,972,656 (95% UI: $254,708-$14,496,916) in direct healthcare costs annually. For Salmonella, irradiation would avert 20,308 (95% UI: 9,858-38,903) illnesses, 400 (95% UI: 158-834) hospitalizations, 6 (95% UI: 0-18) deaths, and $7,318,632 (95% UI: $1,436,141-$26,439,493) in direct healthcare costs. Increasing ground beef irradiation could reduce E. coli O157 and Salmonella burden in the United States. Additional studies should assess whether targeted irradiation of higher-risk ground beef products could prevent similar numbers of illnesses with less total product irradiated.

A thematic analysis of staff perspectives on the impact of a mental health nurse (RMN) in a critical care unit.

Background: Recent guidelines in the UK have shaped Critical Care Units (CCUs) to bring the mental health needs of patients, and staff wellbeing to the forefront of service provision. A health board based in NHS Wales has trialled the secondment of a Mental Health Nurse (RMN) within a CCU to help service provision adhere to such guidelines. Methods: Critical care staff were invited to attend focus groups to share their experiences of how the RMN influenced service provision. Results: Thematic analysis identified five main themes; including 'smoother care pathways', 'a holistic approach to care', 'co-production', 'knowledge and confidence' and 'staff wellbeing'. Each of these themes reflected how the RMN had both direct and indirect benefits on patient and staff wellbeing. Conclusion: This qualitative exploration suggests that staff perceived value in the role of the RMN for both staff and patient outcomes, although further measures were considered necessary to improve staff-wellbeing within a critical care environment. This service evaluation supports recommendations for commissioning a RMN permanently in a CCU.

Estimating Waterborne Infectious Disease Burden by Exposure Route, United States, 2014.

More than 7.15 million cases of domestically acquired infectious waterborne illnesses occurred in the United States in 2014, causing 120,000 hospitalizations and 6,600 deaths. We estimated disease incidence for 17 pathogens according to recreational, drinking, and nonrecreational nondrinking (NRND) water exposure routes by using previously published estimates. In 2014, a total of 5.61 million (95% credible interval [CrI] 2.97-9.00 million) illnesses were linked to recreational water, 1.13 million (95% CrI 255,000-3.54 million) to drinking water, and 407,000 (95% CrI 72,800-1.29 million) to NRND water. Recreational water exposure was responsible for 36%, drinking water for 40%, and NRND water for 24% of hospitalizations from waterborne illnesses. Most direct costs were associated with pathogens found in biofilms. Estimating disease burden by water exposure route helps direct prevention activities. For each exposure route, water management programs are needed to control biofilm-associated pathogen growth; public health programs are needed to prevent biofilm-associated diseases.

(Mis)perception and Use of Unsterile Water in Home Medical Devices, PN View 360+ Survey, United States, August 20211.

Tap water is not sterile, and its use in home medical devices can result in infections from waterborne pathogens. However, many participants in a recent survey in the United States said tap water could safely be used for home medical devices. These results can inform communication materials to reduce the high consequence of infections.

More than Our Enemy: Making Space for the Microbiome in Pharmacy Education.

The microbiome is the collection of commensal microorganisms along with their genomes inhabiting the human body. Despite the many known beneficial effects of these microbes on human health, the 2016 ACPE Standards for Doctor of Pharmacy curricula describe Medical Microbiology in Appendix 1 with a pathogen-centered focus. Over the last twenty years, evolving biotechnology has enabled a deeper understanding of the microbiome in the context of both wellness and disease. Retail stores are allocating increasing shelf space to commercial probiotic products, while the approach to PharmD training on the selection and use of these natural care products remains static, creating a disproportionate footprint between PharmD curricula and consumer markets. Looking to the future of patient care, we brief pharmacy educators on the current evidence and invite discussion around a proposed revision to the 2025 ACPE Standards that would add language recognizing the beneficial role of the commensal microbiota and expanding therapeutic applications of microbiome supplementation. We suggest a variety of opportunities within Doctor of Pharmacy curricula as leverage points for including relevant aspects of the microbiome in the training of future pharmacists.

Community structured model for vaccine strategies to control COVID19 spread: A mathematical study.

Initial efforts to mitigate the COVID-19 pandemic have relied heavily on non-pharmaceutical interventions (NPIs), including physical distancing, hand hygiene, and mask-wearing. However, an effective vaccine is essential to containing the spread of the virus. We developed a compartmental model to examine different vaccine strategies for controlling the spread of COVID-19. Our framework accounts for testing rates, test-turnaround times, and vaccination waning immunity. Using reported case data from the city of Toronto, Canada between Mar-Dec, 2020 we defined epidemic phases of infection using contact rates as well as the probability of transmission upon contact. We investigated the impact of vaccine distribution by comparing different permutations of waning immunity, vaccine coverage and efficacy throughout various stages of NPI's relaxation in terms of cases and deaths. The basic reproduction number is also studied. We observed that widespread vaccine coverage substantially reduced the number of cases and deaths. Under phases with high transmission, an early or late reopening will result in new resurgence of the infection, even with the highest coverage. On the other hand, under phases with lower transmission, 60% of coverage is enough to prevent new infections. Our analysis of R0 showed that the basic reproduction number is reduced by decreasing the tests turnaround time and transmission in the household. While we found that household transmission can decrease following the introduction of a vaccine, public health efforts to reduce test turnaround times remain important for virus containment.

Antibiotic prescribing for acute gastroenteritis during ambulatory care visits-United States, 2006-2015.

OBJECTIVE: To describe national antibiotic prescribing for acute gastroenteritis (AGE). SETTING: Ambulatory care. METHODS: We included visits with diagnoses for bacterial and viral gastrointestinal infections from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey (NAMCS/NHAMCS; 2006-2015) and the IBM Watson 2014 MarketScan Commercial Claims and Encounters Database. For NAMCS/NHAMCS, we calculated annual percentage estimates and 99% confidence intervals (CIs) of visits with antibiotics prescribed; sample sizes were too small to calculate estimates by pathogen. For MarketScan, we used Poisson regression to calculate the percentage of visits with antibiotics prescribed and 95% CIs, including by pathogen. RESULTS: We included 10,210 NAMCS/NHAMCS AGE visits; an estimated 13.3% (99% CI, 11.2%-15.4%) resulted in antibiotic prescriptions, most frequently fluoroquinolones (28.7%; 99% CI, 21.1%-36.3%), nitroimidazoles (20.2%; 99% CI, 14.0%-26.4%), and penicillins (18.9%; 99% CI, 11.6%-26.2%). In NAMCS/NHAMCS, antibiotic prescribing was least frequent in emergency departments (10.8%; 99% CI, 9.5%-12.1%). Among 1,868,465 MarketScan AGE visits, antibiotics were prescribed for 13.8% (95% CI, 13.7%-13.8%), most commonly for Yersinia (46.7%; 95% CI, 21.4%-71.9%), Campylobacter (44.8%; 95% CI, 41.5%-48.1%), Shigella (39.7%; 95% CI, 35.9%-43.6%), typhoid or paratyphoid fever (32.7%; (95% CI, 27.2%-38.3%), and nontyphoidal Salmonella (31.7%; 95% CI, 29.5%-33.9%). Antibiotics were prescribed for 12.3% (95% CI, 11.7%-13.0%) of visits for viral gastroenteritis. CONCLUSIONS: Overall, ∼13% of AGE visits resulted in antibiotic prescriptions. Antibiotics were unnecessarily prescribed for viral gastroenteritis and some bacterial infections for which antibiotics are not recommended. Antibiotic stewardship assessments and interventions for AGE are needed in ambulatory settings.

Direct Outpatient Health Care Costs Among Commercially Insured Persons for Common Foodborne Pathogens and Acute Gastroenteritis, 2012-2015.

Foodborne illness is common in the United States with most, but not all, foodborne pathogens causing symptoms of acute gastroenteritis (AGI). Outpatient care is the most frequent type of medical care sought; however, more accurate estimates of outpatient costs are needed to inform food safety policy decision. Using the U.S. MarketScan Commercial Claims and Encounters database, we quantified the per-visit cost of outpatient visits with any AGI-related diagnosis (including pathogen-specific and nonspecific or symptom-based diagnoses) and for those with a pathogen-specific diagnosis for 1 of 29 pathogens commonly transmitted through food (including pathogens that cause AGI and some that do not). Our estimates included the per-case cost of office visits and associated laboratory tests and procedures as well as the conservative estimates of prescription cost. Most AGI outpatient visits were coded using nonspecific codes (e.g., infectious gastroenteritis), rather than pathogen-specific codes (e.g., Salmonella). From 2012 to 2015, we identified more than 3.4 million initial outpatient visits with any AGI diagnosis and 45,077 with a foodborne pathogen-specific diagnosis. As is typical of treatment cost data, severe cases of illness drove mean costs above median. The mean cost of an outpatient visit with any AGI was $696 compared with the median of $162. The mean costs of visits with pathogen-specific diagnoses ranged from $254 (median $131; interquartile range [IQR]: $98-184) for Streptococcus spp. Group A (n = 22,059) to $1761 (median $161; IQR: $104-$1101) for Clostridium perfringens (n = 30). Visits with two of the most common causes of foodborne illness, nontyphoidal Salmonella and norovirus, listed as a diagnosis, had mean costs of $841 and $509, respectively. Overall, the median per-case costs of outpatient visits increased with age, with some variation by pathogen. More empirically based estimates of outpatient costs for AGI and specific pathogens can enhance estimates of the economic cost of foodborne illness used to guide food policy and focus prevention efforts.

Mathematical modelling of vaccination rollout and NPIs lifting on COVID-19 transmission with VOC: a case study in Toronto, Canada.

BACKGROUND: Since December 2020, public health agencies have implemented a variety of vaccination strategies to curb the spread of SARS-CoV-2, along with pre-existing Nonpharmaceutical Interventions (NPIs). Initial strategies focused on vaccinating the elderly to prevent hospitalizations and deaths, but with vaccines becoming available to the broader population, it became important to determine the optimal strategy to enable the safe lifting of NPIs while avoiding virus resurgence. METHODS: We extended the classic deterministic SIR compartmental disease-transmission model to simulate the lifting of NPIs under different vaccine rollout scenarios. Using case and vaccination data from Toronto, Canada between December 28, 2020, and May 19, 2021, we estimated transmission throughout past stages of NPI escalation/relaxation to compare the impact of lifting NPIs on different dates on cases, hospitalizations, and deaths, given varying degrees of vaccine coverages by 20-year age groups, accounting for waning immunity. RESULTS: We found that, once coverage among the elderly is high enough (80% with at least one dose), the main age groups to target are 20-39 and 40-59 years, wherein first-dose coverage of at least 70% by mid-June 2021 is needed to minimize the possibility of resurgence if NPIs are to be lifted in the summer. While a resurgence was observed for every scenario of NPI lifting, we also found that under an optimistic vaccination coverage (70% coverage by mid-June, along with postponing reopening from August 2021 to September 2021) can reduce case counts and severe outcomes by roughly 57% by December 31, 2021. CONCLUSIONS: Our results suggest that focusing the vaccination strategy on the working-age population can curb the spread of SARS-CoV-2. However, even with high vaccination coverage in adults, increasing contacts and easing protective personal behaviours is not advisable since a resurgence is expected to occur, especially with an earlier reopening.

Comparison of National Vulnerability Indices Used by the Centers for Disease Control and Prevention for the COVID-19 Response.

OBJECTIVE: Vulnerability indices use quantitative indicators and geospatial data to examine the level of vulnerability to morbidity in a community. The Centers for Disease Control and Prevention (CDC) uses 3 indices for the COVID-19 response: the CDC Social Vulnerability Index (CDC-SVI), the US COVID-19 Community Vulnerability Index (CCVI), and the Pandemic Vulnerability Index (PVI). The objective of this review was to describe these tools and explain the similarities and differences between them. METHODS: We described the 3 indices, outlined the underlying data sources and metrics for each, and discussed their use by CDC for the COVID-19 response. We compared the percentile score for each county for each index by calculating Spearman correlation coefficients (Spearman ρ). RESULTS: These indices have some, but not all, component metrics in common. The CDC-SVI is a validated metric that estimates social vulnerability, which comprises the underlying population-level characteristics that influence differences in health risk among communities. To address risk specific to the COVID-19 pandemic, the CCVI and PVI build on the CDC-SVI and include additional variables. The 3 indices were highly correlated. Spearman ρ for comparisons between the CDC-SVI score and the CCVI and between the CCVI and the PVI score was 0.83. Spearman ρ for the comparison between the CDC-SVI score and PVI score was 0.73. CONCLUSION: The indices can empower local and state public health officials with additional information to focus resources and interventions on disproportionately affected populations to combat the ongoing pandemic and plan for future pandemics.

Characterization of reported legionellosis outbreaks associated with buildings served by public drinking water systems: United States, 2001-2017.

This study examined 184 legionellosis outbreaks in the United States reported to the Centers for Disease Control and Prevention's Waterborne Disease and Outbreak Surveillance System, from 2001 to 2017. Drinking water characteristics examined include source water type, disinfectant type, exposure setting, geographical distribution by U.S. Census Divisions, and the public water system size (population served). This study found that most of the reported drinking water-associated legionellosis outbreaks occurred in eastern United States, including 35% in the South Atlantic, 32% in the Middle Atlantic, and 16% in the East North Central Census Divisions were linked with building water systems in healthcare and hotel settings; and were associated with buildings receiving drinking water from public water systems serving >10,000 people. Targeted evaluations and interventions may be useful to further determine the combination of factors, such as disinfectant residual type and drinking water system size that may lead to legionellosis outbreaks.

Efficacy of a "stay-at-home" policy on SARS-CoV-2 transmission in Toronto, Canada: a mathematical modelling study.

BACKGROUND: Globally, nonpharmaceutical interventions for COVID-19, including stay-at-home policies, limitations on gatherings and closure of public spaces, are being lifted. We explored the effect of lifting a stay-at-home policy on virus resurgence under different conditions. METHODS: Using confirmed case data from Toronto, Canada, between Feb. 24 and June 24, 2020, we ran a compartmental model with household structure to simulate the impact of the stay-at-home policy considering different levels of compliance. We estimated threshold values for the maximum number of contacts, probability of transmission and testing rates required for the safe reopening of the community. RESULTS: After the implementation of the stay-at-home policy, the contact rate outside the household fell by 39% (from 11.58 daily contacts to 7.11). The effective reproductive number decreased from 3.56 (95% confidence interval [CI] 3.02-4.14) on Mar. 12 to 0.84 (95% CI 0.79-0.89) on May 6. Strong adherence to stay-at-home policies appeared to prevent SARS-CoV-2 resurgence, but extending the duration of stay-at-home policies beyond 2 months had little added effect on cumulative cases (25 958 for 65 days of a stay-at-home policy and 23 461 for 95 days, by July 2, 2020) and deaths (1404 for 65 days and 1353 for 95 days). To avoid a resurgence, the average number of contacts per person per day should be kept below 9, with strict nonpharmaceutical interventions in place. INTERPRETATION: Our study demonstrates that the stay-at-home policy implemented in Toronto in March 2020 had a substantial impact on mitigating the spread of SARS-CoV-2. In the context of the early pandemic, before the emergence of variants of concern, reopening schools and workplaces was possible only with other nonpharmaceutical interventions in place.

School and community reopening during the COVID-19 pandemic: a mathematical modelling study.

Operating schools safely during the COVID-19 pandemic requires a balance between health risks and the need for in-person learning. Using demographic and epidemiological data between 31 July and 23 November 2020 from Toronto, Canada, we developed a compartmental transmission model with age, household and setting structure to study the impact of schools reopening in September 2020. The model simulates transmission in the home, community and schools, accounting for differences in infectiousness between adults and children, and accounting for work-from-home and virtual learning. While we found a slight increase in infections among adults (2.2%) and children (4.5%) within the first eight weeks of school reopening, transmission in schools was not the key driver of the virus resurgence in autumn 2020. Rather, it was community spread that determined the outbreak trajectory, primarily due to increases in contact rates among adults in the community after school reopening. Analyses of cross-infection among households, communities and schools revealed that home transmission is crucial for epidemic progression and safely operating schools, while the degree of in-person attendance has a larger impact than other control measures in schools. This study suggests that safe school reopening requires the strict maintenance of public health measures in the community.

Demographic differences in use of household tap water in a representative sample of US adults, FallStyles 2019.

Tap water that is safe to consume may cause respiratory illness (e.g., Legionnaires' disease) when water conditions allow for proliferation and aerosolization of biofilm-associated pathogens. This study assessed household tap water consumption, exposure to aerosolized tap water, and associated demographics. A nationally representative FallStyles survey administered by Porter Novelli Public Services was sent to 4,677 US adult panelists in October 2019. There were 3,624 adults who completed the survey (77.5% response rate). Respondents were asked about self-reported use of household tap water for consumption (i.e., drinking, rinsing produce, or making ice) and use through water-aerosolizing devices (e.g., showerheads, humidifiers). Demographics included gender, age, race/ethnicity, education, income, region, and health status. Weighted analyses using complex sample survey procedures were used to assess tap water exposure by route and demographics. Most US adults are exposed to aerosolized tap water through showering (80.6%), and one in five are exposed through other water-aerosolizing devices (20.3%). Consumption and showering were greatest among older, White, higher educated, and higher-income adults. Aerosolized tap water can transmit waterborne pathogens and cause respiratory illness, especially among older age groups and people with weakened immune systems. These results will help target health messages for using water-aerosolizing devices safely.

A Multi-Site Analysis of the Prevalence of Food Insecurity in the United States, before and during the COVID-19 Pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic profoundly affected food systems including food security. Understanding how the COVID-19 pandemic impacted food security is important to provide support and identify long-term impacts and needs. OBJECTIVE: The National Food Access and COVID research Team (NFACT) was formed to assess food security over different US study sites throughout the pandemic, using common instruments and measurements. This study presents results from 18 study sites across 15 states and nationally over the first year of the COVID-19 pandemic. METHODS: A validated survey instrument was developed and implemented in whole or part through an online survey of adults across the sites throughout the first year of the pandemic, representing 22 separate surveys. Sampling methods for each study site were convenience, representative, or high-risk targeted. Food security was measured using the USDA 6-item module. Food security prevalence was analyzed using ANOVA by sampling method to assess statistically significant differences. RESULTS: Respondents (n = 27,168) indicate higher prevalence of food insecurity (low or very low food security) since the COVID-19 pandemic, compared with before the pandemic. In nearly all study sites, there is a higher prevalence of food insecurity among Black, Indigenous, and People of Color (BIPOC), households with children, and those with job disruptions. The findings demonstrate lingering food insecurity, with high prevalence over time in sites with repeat cross-sectional surveys. There are no statistically significant differences between convenience and representative surveys, but a statistically higher prevalence of food insecurity among high-risk compared with convenience surveys. CONCLUSIONS: This comprehensive study demonstrates a higher prevalence of food insecurity in the first year of the COVID-19 pandemic. These impacts were prevalent for certain demographic groups, and most pronounced for surveys targeting high-risk populations. Results especially document the continued high levels of food insecurity, as well as the variability in estimates due to the survey implementation method.

Disparities in Incidence and Severity of Shigella Infections Among Children-Foodborne Diseases Active Surveillance Network (FoodNet), 2009-2018.

BACKGROUND: Shigella infections are an important cause of diarrhea in young children and can result in severe complications. Disparities in Shigella infections are well documented among US adults. Our objective was to characterize disparities in incidence and severity of Shigella infections among US children. METHODS: We analyzed laboratory-diagnosed Shigella infections reported to FoodNet, an active, population-based surveillance system in 10 US sites, among children during 2009-2018. We calculated the incidence rate stratified by sex, age, race/ethnicity, Shigella species, and disease severity. Criteria for severe classification were hospitalization, bacteremia, or death. The odds of severe infection were calculated using logistic regression. RESULTS: During 2009-2018, 10 537 Shigella infections were reported in children and 1472 (14.0%) were severe. The incidence rate was 9.5 infections per 100 000 child-years and the incidence rate of severe infections was 1.3 per 100 000 child-years. Incidence was highest among children aged 1-4 years (19.5) and lowest among children aged 13-17 years (2.3); however, children aged 13-17 years had the greatest proportion of severe infections (21.2%). Incidence was highest among Black (16.2 total; 2.3 severe), Hispanic (13.1 total; 2.3 severe), and American Indian/Alaska Native (15.2 total; 2.5 severe) children. Infections caused by non-sonnei species had higher odds of severity than infections caused by Shigella sonnei (adjusted odds ratio 2.58; 95% confidence interval 2.12-3.14). CONCLUSIONS: The incidence and severity of Shigella infections among US children vary by age, race/ethnicity, and Shigella species, warranting investigation of unique risk factors among pediatric subpopulations.

American Academy of Optometry Microbial Keratitis Think Tank.

SIGNIFICANCE: Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies. PURPOSE: The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting. METHODS: Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives. RESULTS: The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed. CONCLUSIONS: The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.

Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States.

Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million-12.0 million), results in 601,000 ED visits (95% CrI 364,000-866,000), 118,000 hospitalizations (95% CrI 86,800-150,000), and 6,630 deaths (95% CrI 4,520-8,870) and incurring US $3.33 billion (95% CrI 1.37 billion-8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, Pseudomonas, Legionella), costing US $2.39 billion annually.

Attribution of Illnesses Transmitted by Food and Water to Comprehensive Transmission Pathways Using Structured Expert Judgment, United States.

Illnesses transmitted by food and water cause a major disease burden in the United States despite advancements in food safety, water treatment, and sanitation. We report estimates from a structured expert judgment study using 48 experts who applied Cooke's classical model of the proportion of disease attributable to 5 major transmission pathways (foodborne, waterborne, person-to-person, animal contact, and environmental) and 6 subpathways (food handler-related, under foodborne; recreational, drinking, and nonrecreational/nondrinking, under waterborne; and presumed person-to-person-associated and presumed animal contact-associated, under environmental). Estimates for 33 pathogens were elicited, including bacteria such as Salmonella enterica, Campylobacter spp., Legionella spp., and Pseudomonas spp.; protozoa such as Acanthamoeba spp., Cyclospora cayetanensis, and Naegleria fowleri; and viruses such as norovirus, rotavirus, and hepatitis A virus. The results highlight the importance of multiple pathways in the transmission of the included pathogens and can be used to guide prioritization of public health interventions.