Estimating foodborne gastroenteritis, Australia

We estimated for Australia the number of cases, hospitalizations, and deaths due to foodborne gastroenteritis in a typical year, circa 2000. The total amount of infectious gastroenteritis was measured by using a national telephone survey. The foodborne proportion was estimated from Australian data on each of 16 pathogens. To account for uncertainty, we used simulation techniques to calculate 95% credibility intervals (CrI). The estimate of incidence of gastroenteritis in Australia is 17.2 million (95% confidence interval 14.5-19.9 million) cases per year. We estimate that 32% (95% CrI 24%-40%) are foodborne, which equals 0.3 (95% CrI 0.2-0.4) episodes per person, or 5.4 million (95% CrI 4.0-6.9 million) cases annually in Australia. Norovirus, enteropathogenic Escherichia coli, Campylobacter spp., and Salmonella spp. cause the most illnesses. In addition, foodborne gastroenteritis causes approximately 15,000 (95% CrI 11,000-18,000) hospitalizations and 80 (95% CrI 40-120) deaths annually. This study highlights global public health concerns about foodborne diseases and the need for standardized methods, including assessment of uncertainty, for international comparison.     

Sequelae of Foodborne Illness Caused by 5 Pathogens,Australia, Circa 2010

In Australia circa 2010, 4.1 million (90% credible interval [CrI] 2.3–6.4 million) episodes of foodborne gastroenteritis occurred, many of which might have resulted in sequelae. We estimated the number of illnesses, hospitalizations, and deaths from Guillain-Barré syndrome, hemolytic uremic syndrome, irritable bowel syndrome, and reactive arthritis that were associated with contaminated food in Australia. Data from published studies, hospital records, and mortality reports were combined with multipliers to adjust for different transmission routes. We used Monte Carlo simulation to estimate median estimates and 90% CrIs. In Australia, circa 2010, we estimated that 35,840 (90% CrI 25,000–54,000) illnesses, 1,080 (90% CrI 700–1,600) hospitalizations, and 10 (90% CrI 5–14) deaths occurred from foodborne gastroenteritis–associated sequelae. Campylobacter spp. infection was responsible for 80% of incident cases. Reducing the incidence of campylobacteriosis and other foodborne diseases would minimize the health effects of sequelae.     

Foodborne illness acquired in the United States--unspecified agents

Each year, 31 major known pathogens acquired in the United States caused an estimated 9.4 million episodes of foodborne illness. Additional episodes of illness were caused by unspecified agents, including known agents with insufficient data to estimate agent-specific illness, known agents not yet recognized as causing foodborne illness, substances known to be in food but of unproven pathogenicity, and unknown agents. To estimate these additional illnesses, we used data from surveys, hospital records, and death certificates to estimate illnesses, hospitalizations, and deaths from acute gastroenteritis and subtracted illnesses caused by known gastroenteritis pathogens. If the proportions acquired by domestic foodborne transmission were similar to those for known gastroenteritis pathogens, then an estimated 38.4 million (90% credible interval [CrI] 19.8-61.2 million) episodes of domestically acquired foodborne illness were caused by unspecified agents, resulting in 71,878 hospitalizations (90% CrI 9,924-157,340) and 1,686 deaths (90% CrI 369-3,338).     

Direct healthcare costs of selected diseases primarily or partially transmitted by water

SUMMARY Despite US sanitation advancements, millions of waterborne disease cases occur annually, although the precise burden of disease is not well quantified. Estimating the direct healthcare cost of specific infections would be useful in prioritizing waterborne disease prevention activities. Hospitalization and outpatient visit costs per case and total US hospitalization costs for ten waterborne diseases were calculated using large healthcare claims and hospital discharge databases. The five primarily waterborne diseases in this analysis (giardiasis, cryptosporidiosis, Legionnaires' disease, otitis externa, and non-tuberculous mycobacterial infection) were responsible for over 40 000 hospitalizations at a cost of $970 million per year, including at least $430 million in hospitalization costs for Medicaid and Medicare patients. An additional 50 000 hospitalizations for campylobacteriosis, salmonellosis, shigellosis, haemolytic uraemic syndrome, and toxoplasmosis cost $860 million annually ($390 million in payments for Medicaid and Medicare patients), a portion of which can be assumed to be due to waterborne transmission.     

Economic burden of seasonal influenza in the United States

BackgroundSeasonal influenza is responsible for a large disease and economic burden. Despite the expanding recommendation of influenza vaccination, influenza has continued to be a major public health concern in the United States (U.S.). To evaluate influenza prevention strategies it is important that policy makers have current estimates of the economic burden of influenza.ObjectiveTo provide an updated estimate of the average annual economic burden of seasonal influenza in the U.S. population in the presence of vaccination efforts.MethodsWe evaluated estimates of age-specific influenza-attributable outcomes (ill-non medically attended, office-based outpatient visit, emergency department visits, hospitalizations and death) and associated productivity loss. Health outcome rates were applied to the 2015 U.S. population and multiplied by the relevant estimated unit costs for each outcome. We evaluated both direct healthcare costs and indirect costs (absenteeism from paid employment) reporting results from both a healthcare system and societal perspective. Results were presented in five age groups (<5 years, 5–17 years, 18–49 years, 50–64 years and ≥65 years of age).ResultsThe estimated average annual total economic burden of influenza to the healthcare system and society was $11.2 billion ($6.3–$25.3 billion). Direct medical costs were estimated to be $3.2 billion ($1.5–$11.7 billion) and indirect costs $8.0 billion ($4.8–$13.6 billion). These total costs were based on the estimated average numbers of (1) ill-non medically attended patients (21.6 million), (2) office-based outpatient visits (3.7 million), (3) emergency department visit (0.65 million) (4) hospitalizations (247.0 thousand), (5) deaths (36.3 thousand) and (6) days of productivity lost (20.1 million).ConclusionsThis study provides an updated estimate of the total economic burden of influenza in the U.S. Although we found a lower total cost than previously estimated, our results confirm that influenza is responsible for a substantial economic burden in the U.S.     

The economic impact of pandemic influenza in the United States: priorities for intervention.

We estimated the possible effects of the next influenza pandemic in the United States and analyzed the economic impact of vaccine-based interventions. Using death rates, hospitalization data, and outpatient visits, we estimated 89,000 to 207,000 deaths; 314,000 to 734,000 hospitalizations; 18 to 42 million outpatient visits; and 20 to 47 million additional illnesses. Patients at high risk (15% of the population) would account for approximately 84% of all deaths. The estimated economic impact would be US$71.3 to $166.5 billion, excluding disruptions to commerce and society. At $21 per vaccinee, we project a net savings to society if persons in all age groups are vaccinated. At $62 per vaccinee and at gross attack rates of 25%, we project net losses if persons not at high risk for complications are vaccinated. Vaccinating 60% of the population would generate the highest economic returns but may not be possible within the time required for vaccine effectiveness, especially if two doses of vaccine are required.     

The 2006 California Heat Wave: Impacts on Hospitalizations and Emergency Department Visits

Background

Climate models project that heat waves will increase in frequency and severity. Despite many studies of mortality from heat waves, few studies have examined morbidity.

Objectives

In this study we investigated whether any age or race/ethnicity groups experienced increased hospitalizations and emergency department (ED) visits overall or for selected illnesses during the 2006 California heat wave.

Methods

We aggregated county-level hospitalizations and ED visits for all causes and for 10 cause groups into six geographic regions of California. We calculated excess morbidity and rate ratios (RRs) during the heat wave (15 July to 1 August 2006) and compared these data with those of a reference period (8–14 July and 12–22 August 2006).

Results

During the heat wave, 16,166 excess ED visits and 1,182 excess hospitalizations occurred statewide. ED visits for heat-related causes increased across the state [RR = 6.30; 95% confidence interval (CI), 5.67–7.01], especially in the Central Coast region, which includes San Francisco. Children (0–4 years of age) and the elderly (≥ 65 years of age) were at greatest risk. ED visits also showed significant increases for acute renal failure, cardiovascular diseases, diabetes, electrolyte imbalance, and nephritis. We observed significantly elevated RRs for hospitalizations for heat-related illnesses (RR = 10.15; 95% CI, 7.79–13.43), acute renal failure, electrolyte imbalance, and nephritis.

Conclusions

The 2006 California heat wave had a substantial effect on morbidity, including regions with relatively modest temperatures. This suggests that population acclimatization and adaptive capacity influenced risk. By better understanding these impacts and population vulnerabilities, local communities can improve heat wave preparedness to cope with a globally warming future.     

Foodborne illness acquired in the United States--major pathogens

Estimates of foodborne illness can be used to direct food safety policy and interventions. We used data from active and passive surveillance and other sources to estimate that each year 31 major pathogens acquired in the United States caused 9.4 million episodes of foodborne illness (90% credible interval [CrI] 6.6-12.7 million), 55,961 hospitalizations (90% CrI 39,534-75,741), and 1,351 deaths (90% CrI 712-2,268). Most (58%) illnesses were caused by norovirus, followed by nontyphoidal Salmonella spp. (11%), Clostridium perfringens (10%), and Campylobacter spp. (9%). Leading causes of hospitalization were nontyphoidal Salmonella spp. (35%), norovirus (26%), Campylobacter spp. (15%), and Toxoplasma gondii (8%). Leading causes of death were nontyphoidal Salmonella spp. (28%), T. gondii (24%), Listeria monocytogenes (19%), and norovirus (11%). These estimates cannot be compared with prior (1999) estimates to assess trends because different methods were used. Additional data and more refined methods can improve future estimates.     

Cost-sharing for emergency care and unfavorable clinical events: findings from the safety and financial ramifications of ED copayments study

Objective. To evaluate the effect of emergency department (ED) copayment levels on ED use and unfavorable clinical events. Data Source/Study Setting. Kaiser Permanente–Northern California (KPNC), a prepaid integrated delivery system. Study Design. In a quasi‐experimental longitudinal study with concurrent controls, we estimated rates of ED visits, hospitalizations, ICU admissions, and deaths associated with higher ED copayments relative to no copayment, using Poisson random effects and proportional hazard models, controlling for patient characteristics. The study period began in January 1999; more than half of the population experienced an employer‐chosen increase in their ED copayment in January 2000. Data Collection/Extraction Methods. Using KPNC automated databases, the 2000 U.S. Census, and California state death certificates, we collected data on ED visits and unfavorable clinical events over a 36‐month period (January 1999 through December 2001) among 2,257,445 commercially insured and 261,091 Medicare insured health system members. Principal Findings. Among commercially insured subjects, ED visits decreased 12 percent with the $20–35 copayment (95 percent confidence interval [CI]: 11–13 percent), and 23 percent with the $50–100 copayment (95 percent CI: 23–24 percent) compared with no copayment. Hospitalizations, ICU admissions, and deaths did not increase with copayments. Hospitalizations decreased 4 percent (95 percent CI: 2–6 percent) and 10 percent (95 percent CI: 7–13 percent) with ED copayments of $20–35 and $50–100, respectively, compared with no copayment. Among Medicare subjects, ED visits decreased by 4 percent (95 percent CI: 3–6 percent) with the $20–50 copayments compared with no copayment; unfavorable clinical events did not increase with copayments, e.g., hospitalizations were unchanged (95 percent CI: ?3 percent to +2 percent) with $20–50 ED copayments compared with no copayment. Conclusions. Relatively modest levels of patient cost‐sharing for ED care decreased ED visit rates without increasing the rate of unfavorable clinical events.     

Foodborne Illness,Australia, Circa 2000 and Circa 2010

Foodborne disease is a major public health problem worldwide. To examine changes in foodborne illness in Australia, we estimated the incidence, hospitalizations, and deaths attributed to contaminated food circa 2010 and recalculated estimates from circa 2000. Approximately 25% of gastroenteritis cases were caused by contaminated food; to account for uncertainty we used simulation techniques to estimate 90% credible intervals. We estimate that circa 2010, 4.1 million foodborne gastroenteritis cases occurred, and circa 2000, 4.3 million cases occurred. Circa 2010, contaminated food was estimated to be responsible for 30,840 gastroenteritis-associated hospitalizations, 76 associated deaths, and 5,140 nongastrointestinal illnesses. Cases of salmonellosis and campylobacteriosis increased from 2000 to 2010 and were the leading causes of gastroenteritis-associated hospitalizations; Listeria monocytogenes and nontyphoidal Salmonella spp. infections were the leading causes of death. Although the overall incidence of foodborne illnesses declined over time in Australia, cases of foodborne gastroenteritis are still common.Keywords: foodborne illness, foodborne disease, gastroenteritis, epidemiology, estimate, incidence, hospitalization, death, norovirus, salmonella, campylobacter, toxin, bacteria, parasites, viruses, AustraliaFoodborne illness is a major public health problem and a common cause of illness and death worldwide. Outbreaks linked to contaminated food can affect the public’s trust and financially harm implicated businesses and associated food industries. Estimates of the effects of foodborne illnesses and individual pathogens provide evidence for policy interventions and food safety regulation. In addition, estimates of changes in the incidence of foodborne illnesses and hospitalizations over time provide information on the effectiveness of changes to food safety standards and regulation.Many agents can cause foodborne illness; some of these agents are transmitted to humans by other routes as well as by food. Most foodborne illnesses manifest as gastroenteritis, but other presentations, such as meningitis and hepatitis may also result from infection, and sequelae may occur weeks after the acute infection.Many countries have estimated the incidence of foodborne diseases (1–5). In Australia in 2000, foodborne incidence, hospitalizations, and deaths were estimated to cost 1.25 billion Australian dollars annually (6,7). However, since 2000, surveillance has substantially improved, data availability has increased, and methods have been refined. To inform current public health decisions and policies in Australia, we used new methods and datasets to estimate the incidence of infectious gastroenteritis and associated hospitalizations and deaths in Australia circa 2010. We then applied these refined methods to circa 2000 data so that estimates from the 2 periods could be directly compared.     

Escherichia coli O157 Outbreaks in the United States, 2003–2012

Infections with the Shiga toxin–producing bacterium Escherichia coli O157 can cause severe illness and death. We summarized reported outbreaks of E. coli O157 infections in the United States during 2003–2012, including demographic characteristics of patients and epidemiologic findings by transmission mode and food category. We identified 390 outbreaks, which included 4,928 illnesses, 1,272 hospitalizations, and 33 deaths. Transmission was through food (255 outbreaks, 65%), person-to-person contact (39, 10%), indirect or direct contact with animals (39, 10%), and water (15, 4%); 42 (11%) had a different or unknown mode of transmission. Beef and leafy vegetables, combined, were the source of >25% of all reported E. coli outbreaks and of >40% of related illnesses. Outbreaks attributed to foods generally consumed raw caused higher hospitalization rates than those attributed to foods generally consumed cooked (35% vs. 28%). Most (87%) waterborne E. coli outbreaks occurred in states bordering the Mississippi River.Signs and symptoms of infection with Shiga toxin–producing Escherichia coli O157 can include diarrhea that is often bloody, severe stomach cramps, and vomiting; infection can progress to hemolytic uremic syndrome (HUS) and death (1). In the United States, these infections and related illnesses are estimated to cost >$405 million annually (2).E. coli O157 can be transmitted to humans through contaminated food and water, directly between persons, and through contact with animals or their environment. The most common reservoir is cattle, and ground beef is the most frequently identified vehicle of transmission to humans. E. coli O157 was first recognized as a foodborne pathogen after outbreaks during 1982 were linked to ground beef consumption (1). Since then, many other sources have been identified (3), mostly through outbreak investigations. We describe the epidemiology of E. coli O157 outbreaks during 2003–2012.     

Twenty-Year Public Health Impact of 7- and 13-Valent Pneumococcal Conjugate Vaccines in US Children

Pneumococcal conjugate vaccines (PCVs) have been used in the United States since 2000. To assess the cumulative 20-year effect of PCVs on invasive pneumococcal disease (IPD) incidence among children <5 years of age, we analyzed Active Bacterial Core Surveillance data, conducted a literature review, and modeled expected and observed disease. We found that PCVs have averted >282,000 cases of IPD, including ≈16,000 meningitis, ≈172,000 bacteremia, and ≈55,000 bacteremic pneumonia cases. In addition, vaccination has prevented 97 million healthcare visits for otitis media, 438,914–706,345 hospitalizations for pneumonia, and 2,780 total deaths. IPD cases declined 91%, from 15,707 in 1997 to 1,382 in 2019. Average annual visits for otitis media declined 41%, from 78 visits/100 children before PCV introduction to 46 visits/100 children after PCV13 introduction. Annual pneumonia hospitalizations declined 66%–79%, from 110,000–175,000 in 1997 to 37,000 in 2019. These findings confirm the substantial benefits of PCVs for preventing IPD in children.     

The Costs of Respiratory Illnesses Arising from Florida Gulf Coast Karenia brevis Blooms

Background

Algal blooms of Karenia brevis, a harmful marine algae, occur almost annually off the west coast of Florida. At high concentrations, K. brevis blooms can cause harm through the release of potent toxins, known as brevetoxins, to the atmosphere. Epidemiologic studies suggest that aerosolized brevetoxins are linked to respiratory illnesses in humans.

Objectives

We hypothesized a relationship between K. brevis blooms and respiratory illness visits to hospital emergency departments (EDs) while controlling for environmental factors, disease, and tourism. We sought to use this relationship to estimate the costs of illness associated with aerosolized brevetoxins.

Methods

We developed a statistical exposure–response model to express hypotheses about the relationship between respiratory illnesses and bloom events. We estimated the model with data on ED visits, K. brevis cell densities, and measures of pollen, pollutants, respiratory disease, and intra-annual population changes.

Results

We found that lagged K. brevis cell counts, low air temperatures, influenza outbreaks, high pollen counts, and tourist visits helped explain the number of respiratory-specific ED diagnoses. The capitalized estimated marginal costs of illness for ED respiratory illnesses associated with K. brevis blooms in Sarasota County, Florida, alone ranged from $0.5 to $4 million, depending on bloom severity.

Conclusions

Blooms of K. brevis lead to significant economic impacts. The costs of illness of ED visits are a conservative estimate of the total economic impacts. It will become increasingly necessary to understand the scale of the economic losses associated with K. brevis blooms to make rational choices about appropriate mitigation.     

Norovirus Disease in the United States

Although recognized as the leading cause of epidemic acute gastroenteritis across all age groups, norovirus has remained poorly characterized with respect to its endemic disease incidence. Use of different methods, including attributable proportion extrapolation, population-based surveillance, and indirect modeling, in several recent studies has considerably improved norovirus disease incidence estimates for the United States. Norovirus causes an average of 570–800 deaths, 56,000–71,000 hospitalizations, 400,000 emergency department visits, 1.7–1.9 million outpatient visits, and 19–21 million total illnesses per year. Persons >65 years of age are at greatest risk for norovirus-associated death, and children <5 years of age have the highest rates of norovirus-associated medical care visits. Endemic norovirus disease occurs year round but exhibits a pronounced winter peak and increases by ≤50% during years in which pandemic strains emerge. These findings support continued development and targeting of appropriate interventions, including vaccines, for norovirus disease.     

Residential injuries in U.S. children and adolescents

OBJECTIVES: Injuries are the leading cause of death and disability for U.S. children, but little research exists on injury in the home environment. The purpose of this study was to estimate the rate and severity of and trends in unintentional residential injury for U.S. children <20 years for 1993-1999. METHODS: Data on emergency department (ED) visits were obtained from the National Hospital Ambulatory Medical Care Survey (NHAMCS). Rates and 95% confidence intervals (CIs) were calculated using SUDAAN. Chi-square analysis was used to test for differences among proportions. Time trends were analyzed using linear regression. RESULTS: Residential injuries accounted for an average of 4.01 million (95% CI 3.50 million, 4.56 million) ED visits each year for U.S. children, representing 39% of unintentional injury ED visits. There were an average of 531,000 (95% CI 456,000, 606,000) visits with moderate-to-severe injuries, resulting in 73,680 (95% CI 59,715, 87,645) hospital admissions annually. The rate of residential injury visits (excluding unknown locations) was 5.6 per 100 (95% CI 4.9 per 100, 6.4 per 100). The visit rates for children <5 years of age were higher than those for children >9 years (p<0.0001). Males had a higher rate of visits than females (p=0.01). Falls were the leading mechanisms, resulting in 1.5 million ED visits per year (95% CI 1.3 million, 1.8 million). Residential injury rates decreased by 28% over time (p<0.02), from 6.3 per 100 (95% CI 3.4, 9.2) in 1993 to 4.5 per 100 (95% CI 2.3, 6.7) in 1999. CONCLUSIONS: The predominant location of injury for U.S. children is the home, accounting for 4.01 million ED visits and more than 70,000 hospitalizations each year. Efforts targeted to the home environment are needed to reduce morbidity and mortality from unintentional injury in U.S. children.     

The annual impact of seasonal influenza in the US: measuring disease burden and costs

BACKGROUND: Despite preventive efforts, influenza epidemics are responsible for substantial morbidity and mortality every year in the United States (US). Vaccination strategies to reduce disease burden have been implemented. However, no previous studies have systematically estimated the annual economic burden of influenza epidemics, an estimate necessary to guide policy makers effectively. OBJECTIVE: We estimate age- and risk-specific disease burden, and medical and indirect costs attributable to annual influenza epidemics in the United States. METHODS: Using a probabilistic model and publicly available epidemiological data we estimated the number of influenza-attributable cases leading to outpatient visits, hospitalization, and mortality, as well as time lost from work absenteeism or premature death. With data from health insurance claims and projections of either earnings or statistical life values, we then estimated healthcare resource utilization associated with influenza cases as were their medical and productivity (indirect) costs in $2003. RESULTS: Based on 2003 US population, we estimated that annual influenza epidemics resulted in an average of 610,660 life-years lost (undiscounted), 3.1 million hospitalized days, and 31.4 million outpatient visits. Direct medical costs averaged $10.4 billion (95% confidence interval [C.I.], $4.1, $22.2) annually. Projected lost earnings due to illness and loss of life amounted to $16.3 billion (C.I., $8.7, $31.0) annually. The total economic burden of annual influenza epidemics using projected statistical life values amounted to $87.1 billion (C.I., $47.2, $149.5). CONCLUSIONS: These results highlight the enormous annual burden of influenza in the US. While hospitalization costs are important contributors, lost productivity from missed work days and lost lives comprise the bulk of the economic burden of influenza.