Intention to vaccinate for Lyme disease using the Health Belief Model

AIMS

Lyme disease (LD) cases in the United States are estimated to be approaching 500,000 annually. Protective measures, such as repellent use and wearing protective clothing are recommended by public health officials. However, no protective measure has been proven to be consistently effective, partly because they require consistent and persistent behaviour change. While safe and effective vaccines are in development, it is unclear what factors influence the intention to vaccinate against LD. This study uses the Health Belief Model (HBM) framework to determine key drivers associated with vaccine intention. The HBM is widely applied in public health research and uses the following constructs: perceived susceptibility and severity of disease, perceived benefits and barriers to disease prevention, and cues to action for disease prevention to predict health behaviours. To date, the HBM framework has not been applied to vaccination intention for LD.

METHODS AND RESULTS

Data were collected from 874 adults and 834 caregivers of children residing in US states endemic to LD. Sampling adults and caregivers allows us to explore how the intention to vaccinate differs among those at-risk. Estimates from structural equation modelling (SEM) show that the HBM constructs explain much of the variation in intention to vaccinate against LD. Both adult and caregiver intentions to vaccinate are positively influenced by cues to action, perceived susceptibility of LD, and perceived benefits to vaccination. However, there is variation in the influence of constructs across the samples. Caregiver's intention to vaccinate is positively influenced by the perceived severity of LD and negatively influenced by safety concerns about the vaccine, whereas adult intention is negatively influenced by perceived barriers to vaccination.

CONCLUSION

A strong relationship of cues to action on vaccine intention in samples of adults and caregivers suggests the importance of a recommendation from a healthcare provider or the Centers for Disease Control and Prevention (CDC).

Using the health belief model to understand intention to vaccinate for Lyme disease in the United States

AIMS

A growing number of Lyme disease (LD) cases in the U.S. are reported in states neighbouring those with high-incidence (>10 cases per 100,000 population) rates. Considering the evolving epidemiology, high-incidence counties in many of these "neighbouring states," and the forthcoming vaccines, understanding the drivers of vaccination intention is critical, particularly how drivers of intention in neighbouring states vary relative to regions currently classified as high incidence. This study uses the Health Belief Model (HBM) to determine the key drivers associated with vaccine intention for U.S. adults and caregivers of children residing in neighbouring states.

METHODS AND RESULTS

Using an established panel with quotas for age, sex, race/ethnicity and urbanity, we surveyed 887 adults and 822 caregivers of children residing in U.S. neighbouring states. Survey items included measures of intention and HBM constructs, all of which were assessed using 5-point Likert scales. We subsequently used structural equation modelling to understand the influence of the HBM constructs on LD vaccine intention. Estimates from structural equation modelling show that the HBM constructs explain much of the variation in intention to vaccinate against LD. Intentions to vaccinate for both adults and caregivers are positively influenced by cues to action, perceived susceptibility of LD, and perceived benefits to vaccination. Both are also negatively influenced by perceived barriers to vaccination. The caregiver's intention to vaccinate is also positively influenced by the perceived severity of LD.

CONCLUSION

The intention to vaccinate for respondents residing in LD neighbouring states is strongly influenced by recommendations from healthcare providers or the Centers for Disease Control and Prevention (CDC). As incidence rises in neighbouring states and the need to prevent disease becomes more overt, public health officials should strongly recognize the influence of healthcare providers and CDC recommendations on intention to vaccinate against LD.

Racial and ethnic disparities in Lyme disease in the United States

INTRODUCTION

Lyme disease (LD), caused by the spirochete Borrelia burgdorferi, is the most common vector-borne disease in the United States. Although most surveillance-reported cases are in people who are White, data suggest worse outcomes among people from racial and ethnic minority groups.

METHODS

We conducted a systematic literature review to describe racial disparities in LD. We described the epidemiology of LD by race and ethnicity, including clinical presentation at diagnosis, and summarised the literature on knowledge, attitudes and practices related to LD and ticks by race and ethnicity.

RESULTS

Overall, the incidence and prevalence of LD were 1.2-3.5 times higher in White persons than in persons who identified as Asian or Pacific Islander and 4.5-6.3 times higher in White persons than in persons who identified as Black. Across multiple studies, people from racial and ethnic minority groups were more likely than White people to have disseminated manifestations of LD, including neurological manifestations and arthritis, and less likely to have erythema migrans. People from racial and ethnic minority groups were also more likely to report disease onset in the fall and less likely to report disease onset in the summer. Possible reasons for these disparities include lack of recognition of the disease in people with darker skin tones, lack of knowledge of disease risk for some groups and differences in exposure risk.

CONCLUSIONS

Taken together, these results reinforce that all people residing in high-incidence areas are at risk of LD, regardless of race or ethnicity. Future prevention measures should be broadly targeted to reach all at-risk populations.

Descriptive study of causes of death and COVID-19-associated morbidities from the New York City electronic death record: first wave of the pandemic March-July 2020

OBJECTIVE

Assessing excess deaths from benchmarks across causes of death during the first wave of the COVID-19 pandemic and identifying morbidities most frequently mentioned alongside COVID-19 deaths in the death record.

METHODS

Descriptive study of death records between 11 March 2020 and 27 July 2020, from the New York City Bureau of Vital Statistics. Mortality counts and percentages were compared with the average for the same calendar period of the previous 2 years. Distributions of morbidities from among forty categories of conditions were generated citywide and by sex, race/ethnicity and four age groups. Causes of death were assumed to follow Poisson processes for Z-score construction.

RESULTS

Within the study period, 46 563 all-cause deaths were reported; 132.9% higher than the average for the same period of the previous 2 years (19 989). Of those 46 563 records, 19 789 (42.5%) report COVID-19 as underlying cause of death. COVID-19 was the most prevalent cause across all demographics, with respiratory conditions (prominently pneumonia), hypertension and diabetes frequently mentioned morbidities. Black non-Hispanics had greater proportions of mentions of pneumonia, hypertension, and diabetes. Hispanics had the largest proportion of COVID-19 deaths (52.9%). Non-COVID-19 excess deaths relative to the previous 2-year averages were widely reported.

CONCLUSION

Mortality directly due to COVID-19 was accompanied by significant increases across most other causes from their reference averages, potentially suggesting a sizable COVID-19 death undercount. Indirect effects due to COVID-19 may partially account for some increases, but findings are hardly dispositive. Unavailability of vaccines for the time period precludes any impact over excess deaths. Respiratory and cardiometabolic-related conditions were most frequently reported among COVID-19 deaths across demographic characteristics.

Can changing neighborhoods influence mental health? An ecological analysis of gentrification and neighborhood-level serious psychological distress-New York City, 2002-2015

Neighborhood conditions influence people's health; sustaining healthy neighborhoods is a New York City (NYC) Health Department priority. Gentrification is characterized by rapid development in historically disinvested neighborhoods. The gentrification burden, including increased living expenses, and disrupted social networks, disproportionally impacts certain residents. To ultimately target health promotion interventions, we examined serious psychological distress time trends in gentrifying NYC neighborhoods to describe the association of gentrification and mental health overall and stratified by race and ethnicity. We categorized NYC neighborhoods as hypergentrifying, gentrifying, and not-gentrifying using a modified New York University Furman Center index. Neighborhoods with ≥100% rent growth were hypergentrifying; neighborhoods with greater than median and <100% rent growth were gentrifying; and neighborhoods with less than median rent growth were not-gentrifying. To temporally align neighborhood categorization closely with neighborhood-level measurement of serious psychological distress, data during 2000-2017 were used to classify neighborhood type. We calculated serious psychological distress prevalence among adult populations using data from 10 NYC Community Health Surveys during 2002-2015. Using joinpoint and survey-weighted logistic regression, we analyzed serious psychological distress prevalence time trends during 2002-2015 by gentrification level, stratified by race/ethnicity. Among 42 neighborhoods, 7 were hypergentrifying, 7 were gentrifying, and 28 were not gentrifying. In hypergentrifying neighborhoods, serious psychological distress prevalence decreased among White populations (8.1% to 2.3%, β = -0.77, P = 0.02) and was stable among Black (4.6% to 6.9%, β = -0.01, P = 0.95) and Latino populations (11.9% to 10.4%, β = -0.16, P = 0.31). As neighborhoods gentrified, different populations were affected differently. Serious psychological distress decreased among White populations in hypergentrifying neighborhoods, no similar reductions were observed among Black and Latino populations. This analysis highlights potential unequal mental health impacts that can be associated with gentrification-related neighborhood changes. Our findings will be used to target health promotion activities to strengthen community resilience and to ultimately guide urban development policies.

Collateral Impacts of the COVID-19 Pandemic: The New York City Experience

OBJECTIVE

To adapt an existing surveillance system to monitor the collateral impacts of the COVID-19 pandemic on health outcomes in New York City across 6 domains: access to care, chronic disease, sexual/reproductive health, food/economic insecurity, mental/behavioral health, and environmental health.

DESIGN

Epidemiologic assessment. Public health surveillance system.

SETTING

New York City.

PARTICIPANTS

New York City residents.

MAIN OUTCOME MEASURES

We monitored approximately 30 indicators, compiling data from 2006 to 2022. Sources of data include clinic visits, surveillance surveys, vital statistics, emergency department visits, lead and diabetes registries, Medicaid claims, and public benefit enrollment.

RESULTS

We observed disruptions across most indicators including more than 50% decrease in emergency department usage early in the pandemic, which rebounded to prepandemic levels by late 2021, changes in reporting levels of probable anxiety and depression, and worsening birth outcomes for mothers who identified as Asian/Pacific Islander or Black. Data are processed in SAS and analyzed using the R Surveillance package to detect possible inflections. Data are updated monthly to an internal Tableau Dashboard and shared with agency leadership.

CONCLUSIONS

As the COVID-19 pandemic continues into its third year, public health priorities are returning to addressing non-COVID-19-related diseases and conditions, their collateral impacts, and postpandemic recovery needs. Substantial work is needed to return even to a suboptimal baseline across multiple health topic areas. Our surveillance framework offers a valuable starting place to effectively allocate resources, develop interventions, and issue public communications.

Listeria monocytogenes Illness and Deaths Associated With Ongoing Contamination of a Multiregional Brand of Ice Cream Products, United States, 2010-2015

BACKGROUND

Frozen foods have rarely been linked to Listeria monocytogenes illness. We describe an outbreak investigation prompted by both hospital clustering of illnesses and product testing.

METHODS

We identified outbreak-associated listeriosis cases using whole-genome sequencing (WGS), product testing results, and epidemiologic linkage to cases in the same Kansas hospital. We reviewed hospital medical and dietary records, product invoices, and molecular subtyping results. Federal and state officials tested product and environmental samples for L. monocytogenes.

RESULTS

Kansas officials were investigating 5 cases of listeriosis at a single hospital when, simultaneously, unrelated sampling for a study in South Carolina identified L. monocytogenes in Company A ice cream products made in Texas. Isolates from 4 patients and Company A products were closely related by WGS, and the 4 patients with known exposures had consumed milkshakes made with Company A ice cream while hospitalized. Further testing identified L. monocytogenes in ice cream produced in a second Company A production facility in Oklahoma; these isolates were closely related by WGS to those from 5 patients in 3 other states. These 10 illnesses, involving 3 deaths, occurred from 2010 through 2015. Company A ultimately recalled all products.

CONCLUSIONS

In this US outbreak of listeriosis linked to a widely distributed brand of ice cream, WGS and product sampling helped link cases spanning 5 years to 2 production facilities, indicating longstanding contamination. Comprehensive sanitation controls and environmental and product testing for L. monocytogenes with regulatory oversight should be implemented for ice cream production.

Data for Equity: Creating an Antiracist, Intersectional Approach to Data in a Local Health Department

OBJECTIVE

To develop recommendations to embed equity into data work at a local health department and a framework for antiracist data praxis.

DESIGN

A working group comprised staff from across the agency whose positions involved data collection, analysis, interpretation, or communication met during April-July 2018 to identify and discuss successes and challenges experienced by staff and to generate recommendations for achieving equitable data practices.

SETTING

Local health department in New York City.

RESULTS

The recommendations encompassed 6 themes: strengthening analytic skills, communication and interpretation, data collection and aggregation, community engagement, infrastructure and capacity building, and leadership and innovation. Specific projects are underway or have been completed.

CONCLUSIONS

Improving equity in data requires changes to data processes and commitment to racial and intersectional justice and process change at all levels of the organization and across job functions. We developed a collaborative model for how a local health department can reform data work to embed an equity lens. This framework serves as a model for jurisdictions to build upon in their own efforts to promote equitable health outcomes and become antiracist organizations.

Psychological and Physical Intimate Partner Violence, Measured by the New York City Community Health Survey - New York City, 2018

Purpose

Intimate partner violence (IPV) can damage long-term physical and mental health, yet IPV prevalence in New York City (NYC) is unknown. We described prevalence and health correlates of psychological and physical IPV in NYC.

Method

The 2018 NYC Community Health Survey, a representative telephone survey among adult residents, asked about lifetime psychological or physical IPV experiences. We estimated age-adjusted physical and psychological prevalence, stratified by demographic variables, and created log-linear multivariable models with 95% CIs to measure the association of each IPV type with health conditions and behaviors.

Results

Overall, 10,076 surveys were completed. We excluded responses with missing IPV values. Of 9,945 adults, 16.7% reported ever having experienced psychological IPV; higher prevalence among females (18.6%; CI:17.0-20.2) than males (14.5%; CI:13.1-16.2). Prevalence of not getting needed mental health treatment (PR: 4.5; CI:3.3-6.1) and current depression (PR:2.6 CI:2.1-3.1) was higher among adults who had ever experienced psychological IPV, compared with those who had not. Of 9,964 adults, 9.8% reported ever having experienced physical IPV; higher prevalence among females (12.4%; CI:11.1-13.8) than males (6.8%; CI:5.8-8.0). Prevalence of not getting needed mental health treatment (PR:3.9, CI:2.8-5.4) and current depression (PR:2.6, CI:2.1-3.2) was higher among adults who had ever experienced physical IPV, compared with those who had not.

Conclusions

One in six (16.7%) and one in 10 (9.8%) NYC adults reported ever experiencing psychological IPV and ever experiencing physical IPV, respectively. Key implications suggest that IPV potentially underlies public health priority health conditions and behaviors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10896-022-00442-1.

Racial and Ethnic Disparities in COVID-19-Like Illness and Impacts of Social Distancing and Working from Home

Objectives

To examine racial and ethnic disparities in COVID-19-like illness (CLI) during March - August 2020 in New York City, and to test effect modification by age, nativity, and working from home vs outside the home, and mediation via social distancing behavior.

Design

Analysis of the monthly Community Health Survey datasets.

Setting

New York City.

Participants

5,305 adults living in New York City.

Main Outcome Measures

A binary indicator of having new onset of CLI in the past 30 days.

Methods

Prevalence of having CLI was compared among racial and ethnic groups using multivariable log-linear regression. Stratified and causal mediation analyses were conducted to test effect modification and mediation, respectively.

Results

Overall percentage of CLI decreased from 25% during March-May to 14% during June-August. In both periods, there was no increased prevalence of CLI among Black or Latino New Yorkers compared with White New Yorkers. However, in stratified analyses, Latino vs White New Yorkers had 2.05 times (95%CI=1.09, 3.83) higher prevalence of CLI among adults working outside the home. Mediation via social distancing was not statistically significant.

Conclusions

Excess burden of CLI among Latino adults working outside the home underscores inequitable impacts of COVID-19 in New York City.

Adapting Survey Data Collection to Respond to the COVID-19 Pandemic: Experiences From a Local Health Department

The New York City (NYC) Department of Health and Mental Hygiene ("Health Department") conducts routine surveys to describe the health of NYC residents. During the COVID-19 pandemic, the Health Department adjusted existing surveys and developed new ones to improve our understanding of the impact of the pandemic on physical health, mental health, and social determinants of health and to incorporate more explicit measures of racial inequities. The longstanding Community Health Survey was adapted in 2020 to ask questions about COVID-19 and recruit respondents for a population-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey. A new survey panel, Healthy NYC, was launched in June 2020 and is being used to collect data on COVID-19, mental health, and social determinants of health. In addition, 7 Health Opinion Polls were conducted from March 2020 through March 2021 to learn about COVID-19-related knowledge, attitudes, and opinions, including vaccine intentions. We describe the contributions that survey data have made to the emergency response in NYC in ways that address COVID-19 and the profound inequities of the pandemic. (Am J Public Health. 2021;111(12):2176-2185. https://doi.org/10.2105/AJPH.2021.306515).

Population-Based Estimates of Coronavirus Disease 2019 (COVID-19)-like Illness, COVID-19 Illness, and Rates of Case Ascertainment, Hospitalizations, and Deaths-Noninstitutionalized New York City Residents, March-April 2020

Using a population-based, representative telephone survey, ~930 000 New York City residents had COVID-19 illness beginning 20 March–30 April 2020, a period with limited testing. For every 1000 persons estimated with COVID-19 illness, 141.8 were tested and reported as cases, 36.8 were hospitalized, and 12.8 died, varying by demographic characteristics.

Prevalence of SARS-CoV-2 Antibodies in New York City Adults, June-October 2020: A Population-Based Survey

Background

Serosurveys are important to ascertain burden of infection. Prior SARS-CoV-2 serosurveys in New York City (NYC) have used nonrandom samples. During June–October 2020, the NYC Health Department conducted a population-based survey to estimate SARS-CoV-2 antibody prevalence in NYC adults.

Methods

Participants were recruited from the NYC 2020 Community Health Survey. We estimated citywide and stratified antibody prevalence using a hybrid design: serum tested at the NYC Health Department using the DiaSorin LIAISON ^® SARS-CoV-2 S1/S2 IgG assay and self-reported antibody test results were used together. Prevalence was estimated using univariate frequencies and 95% confidence intervals (CI), accounting for complex survey design. Two-sided P-values ≤0.05 were statistically significant.

Results

There were 1074 respondents overall; 497 provided blood and 577 provided only a self-reported antibody test result. Weighted prevalence was 24.3% overall (95% CI: 20.7–28.3). Latino (30.7%, 95% CI: 24.1–38.2, p<0.01) and Black (30.7%, 95% CI: 21.9–41.2, p=0.02) respondents had a higher weighted prevalence compared with White respondents (17.4%, 95% CI: 12.5–23.7).

Conclusions

By October 2020, nearly 1 in 3 Black and 1 in 3 Latino NYC adults had SARS-CoV-2 antibodies, highlighting unequal impacts of the COVID-19 pandemic on Black and Latino adults in NYC.

Impact of law enforcement-related deaths of unarmed black New Yorkers on emergency department rates, New York 2013-2016

BACKGROUND

Law enforcement-related deaths of unarmed black Americans may lead black communities to distrust public institutions. Our study quantifies the impact of law enforcement-related deaths of black New York residents on the use of hospital emergency departments (ED) during 2013-2016.

METHODS

We used regression discontinuity models stratified by race and time period (2013-2015 and 2015-2016) to estimate the impact of law enforcement-related deaths on ED rates. Dates of deaths and media reports were from the Mapping Police Violence database. We calculated the daily overall and condition-specific ED visit rates from the New York's Statewide Planning and Research Cooperative System.

RESULTS

There were 14 law enforcement-related deaths of unarmed black New York residents from 2013 to 2016. In 2013-2014, the ED rate among black New Yorkers decreased by 7.7 visits per 100 000 black New Yorkers (5% less than the average ED rate) using the date of media report as the cut-off with a 2-week exposure window. No changes in ED rates were noted for black New Yorkers in 2015-2016 or for white New Yorkers in either time period. Models using the date of death followed a similar pattern.

CONCLUSION

The decrease in ED rates among black New Yorkers immediately following media reports of law enforcement-related deaths involving unarmed black New Yorkers during 2013-2014 may represent potentially harmful delays in healthcare. Reforms implemented during 2015-2016 might have modified the impact of these deaths. Further investigation into the population health impacts of law enforcement-related deaths is needed.

ZIP Code-Level Estimates from a Local Health Survey: Added Value and Limitations

We assessed the added value and limitations of generating directly estimated ZIP Code-level estimates by aggregating 5 years of data from an annual cross-sectional survey, the New York City Community Health Survey (n = 44,886) from 2009 to 2013, that were designed to provide reliable estimates only of larger geographies. Survey weights generated directly-observed ZIP Code (n = 128) level estimates. We assessed the heterogeneity of ZIP Code-level estimates within coarser United Hospital Fund (UHF) neighborhood areas (n = 34) by using the Rao-Scott Chi-Square test and one-way ANOVA. Orthogonal linear contrasts assessed whether there were linear trends at the UHF level from 2009 to 2013. 22 of 37 health indicators were reliable in over 50% of ZIP Codes. 14 of the 22 variables showed heterogeneity in ≥4 UHFs. Variables for drinking, nutrition, and HIV testing showed heterogeneity in the most UHFs (9-24 UHFs). In half of the 32 UHFs, >20% variables had within-UHF heterogeneity. Flu vaccination and sugary beverage consumption showed significant time trends in the largest number of UHFs (12 or more UHFs). Overall, heterogeneity of ZIP Code-level estimates suggests that there is value in aggregating 5 years of data to make direct small area estimates.

Supportive Housing and Its Relationship With Diabetes Diagnosis and Management Among Homeless Persons in New York City

Supportive housing addresses a fundamental survival need among homeless persons, which can lead to reduced risk of diabetes mellitus and improved diabetes care. We tested the association between supportive housing and diabetes outcomes among homeless adults who were eligible for New York City's supportive housing program in 2007-2012. We used multiple administrative data sources, identifying 7,525 Medicaid-eligible adults. The outcomes included receiving medical evaluation and management services, hemoglobin A1C and lipid testing (n = 1,489 persons with baseline diabetes), and incidence of new diabetes diagnoses (n = 6,036 persons without baseline diabetes) in the 2 years postbaseline. Differences in these outcomes by placement were estimated using inverse-probability-of-treatment weighting. Placed persons were more likely to receive evaluation and management services (relative risk (RR) = 1.03, 95% confidence interval (CI): 1.01, 1.04) than unplaced persons. For those with baseline diabetes, placed persons were more likely to receive hemoglobin A1C tests (RR = 1.10, 95% CI: 1.02, 1.19) and lipid tests (RR = 1.09, 95% CI: 1.02, 1.17). For those without baseline diabetes, placement was also associated with lower risk of new diabetes diagnoses (RR = 0.87, 95% CI: 0.76, 0.99). These findings show that benefits of supportive housing may be extended to diabetes care and prevention.

Detection of Avian Influenza A(H7N2) Virus Infection Among Animal Shelter Workers Using a Novel Serological Approach-New York City, 2016-2017

BACKGROUND

In 2016, an influenza A(H7N2) virus outbreak occurred in cats in New York City's municipal animal shelters. One human infection was initially detected.

METHODS

We conducted a serological survey using a novel approach to rule out cross-reactive antibodies to other seasonal influenza viruses to determine whether additional A(H7N2) human infections had occurred and to assess exposure risk.

RESULTS

Of 121 shelter workers, one had serological evidence of A(H7N2) infection, corresponding to a seroprevalence of 0.8% (95% confidence interval, .02%-4.5%). Five persons exhibited low positive titers to A(H7N2) virus, indicating possible infection; however, we could not exclude cross-reactive antibody responses to seasonal influenza viruses. The remaining 115 persons were seronegative. The seropositive person reported multiple direct cat exposures without using personal protective equipment and mild illness with subjective fever, runny nose, and sore throat.

CONCLUSIONS

We identified a second case of A(H7N2) infection from this outbreak, providing further evidence of cat-to-human transmission of A(H7N2) virus.

Long-Term Supportive Housing is Associated with Decreased Risk for New HIV Diagnoses Among a Large Cohort of Homeless Persons in New York City

It is unknown whether providing housing to persons experiencing homelessness decreases HIV risk. Housing, including access to preventive services and counseling, might provide a period of transition for persons with HIV risk factors. We assessed whether the new HIV diagnosis rate was associated with duration of supportive housing. We linked data from a cohort of 21,689 persons without a previous HIV diagnosis who applied to a supportive housing program in New York City (NYC) during 2007-2013 to the NYC HIV surveillance registry. We used time-dependent Cox modeling to compare new HIV diagnoses among recipients of supportive housing (defined a priori, for program evaluation purposes, as persons who spent > 7 days in supportive housing; n = 6447) and unplaced applicants (remainder of cohort), after balancing the groups on baseline characteristics with propensity score weights. Compared with unplaced applicants, persons who received ≥ 3 continuous years of supportive housing had decreased risk for new HIV diagnosis (HR 0.10; CI 0.01-0.99). Risk of new HIV diagnosis decreased with longer duration placement in supportive housing. Supportive housing might aid in primary HIV prevention.

Salmonella enterica Serotype Newport Infections in the United States, 2004-2013: Increased Incidence Investigated Through Four Surveillance Systems

Newport is the third most common Salmonella enterica serotype identified among the estimated 1.2 million human salmonellosis infections occurring annually in the United States. Risk factors for infection and food items implicated in outbreaks vary by antimicrobial resistance pattern. We conducted a descriptive analysis of data from four enteric disease surveillance systems capturing information on incidence, demographics, seasonality, geographic distribution, outbreaks, and antimicrobial resistance of Newport infections over a 10-year period from 2004 through 2013. Incidence increased through 2010, then declined to rates similar to those in the early years of the study. Incidence was highest in the South and among children <5 years old. Among isolates submitted for antimicrobial susceptibility testing, 88% were susceptible to all antimicrobials tested (pansusceptible) and 8% were resistant to at least seven agents, including ceftriaxone. Rates of pansusceptible isolates were also highest in the South and among young children, particularly in 2010. Pansusceptible strains of Newport have been associated with produce items and environmental sources, such as creek water and sediment. However, the role of environmental transmission of Newport in human illness is unclear. Efforts to reduce produce contamination through targeted legislation, as well as collaborative efforts to identify sources of contamination in agricultural regions, are underway.

Listeriosis Outbreaks Associated with Soft Cheeses, United States, 1998-20141

Since 2006, the number of reported US listeriosis outbreaks associated with cheese made under unsanitary conditions has increased. Two-thirds were linked to Latin-style soft cheese, often affecting pregnant Hispanic women and their newborns. Adherence to pasteurization protocols and sanitation measures to avoid contamination after pasteurization can reduce future outbreaks.

Impact of a New York City Supportive Housing Program on Housing Stability and Preventable Health Care among Homeless Families

OBJECTIVE

To assess the impact of a New York City supportive housing program on housing stability and preventable emergency department (ED) visits/hospitalizations among heads of homeless families with mental and physical health conditions or substance use disorders.

DATA SOURCES

Multiple administrative data from New York City and New York State for 966 heads of families eligible for the program during 2007-12.

STUDY DESIGN

We captured housing events and health care service utilization during 2 years prior to the first program eligibility date (baseline) and 2 years postbaseline. We performed sequence analysis to measure housing stability and compared housing stability and preventable ED visits and hospitalizations between program participants (treatment group) and eligible applicants not placed in the program (comparison group) via marginal structural modeling.

DATA COLLECTION/EXTRACTION METHODS

We matched electronically collected data.

PRINCIPAL FINDINGS

Eighty-seven percent of supportive housing tenants experienced housing stability in 2 years postbaseline. Compared with unstably housed heads of families in the comparison group, those in the treatment group were 0.60 times as likely to make preventable ED visits postbaseline (95% CI = 0.38, 0.96).

CONCLUSIONS

Supportive housing placement was associated with improved housing stability and reduced preventable health care visits among homeless families.

Outbreaks of Disease Associated with Food Imported into the United States, 1996-20141

The proportion of US food that is imported is increasing; most seafood and half of fruits are imported. We identified a small but increasing number of foodborne disease outbreaks associated with imported foods, most commonly fish and produce. New outbreak investigation tools and federal regulatory authority are key to maintaining food safety.

Workers not Paid for Sick Leave after Implementation of the New York City Paid Sick Leave Law

This study examined factors associated with being paid for sick leave after implementation of the New York City (NYC) paid sick leave law. A random sample of NYC residents was surveyed by telephone multiple times over a 2-year period. Participants (n = 1195) reported socio-demographics, awareness of the law, income, work hours per week, and payment for sick time off work. In the year after implementation of the law, part-time workers were significantly more likely to attend work while sick than full-time workers (relative risk = 1.25, 95% CI = 1.1, 1.4). Seventy percent of workers who missed work due to illness (n = 249) were paid for sick leave. Part-time workers, respondents not aware of the benefit (30% of workers), and workers without a college degree were the least likely to be paid for sick days. More than one third (37%) of persons not paid for sick leave worked in retail, food service, or health care. Although 70% of respondents were paid for sick leave after implementation of the law, part-time workers and workers with low education were least likely to access the benefit and more likely to work while sick. The disparity in paid sick leave may have public health consequences as many persons not paid for sick leave had occupations that carry a high risk of disease transmission to others.

Impact of residential displacement on healthcare access and mental health among original residents of gentrifying neighborhoods in New York City

OBJECTIVES

As gentrification continues in New York City as well as other urban areas, residents of lower socioeconomic status maybe at higher risk for residential displacement. Yet, there have been few quantitative assessments of the health impacts of displacement. The objective of this paper is to assess the association between displacement and healthcare access and mental health among the original residents of gentrifying neighborhoods in New York City.

METHODS

We used 2 data sources: 1) 2005-2014 American Community Surveys to identify gentrifying neighborhoods in New York City, and 2) 2006-2014 Statewide Planning and Research Cooperative System. Our cohort included 12,882 residents of gentrifying neighborhoods in 2006 who had records of emergency department visits or hospitalization at least once every 2 years in 2006-2014. Rates of emergency department visits and hospitalizations post-baseline were compared between residents who were displaced and those who remained.

RESULTS

During 2006-2014, 23% were displaced. Compared with those who remained, displaced residents were more likely to make emergency department visits and experience hospitalizations, mainly due to mental health (Rate Ratio = 1.8, 95% confidence interval = 1.5, 2.2), after controlling for baseline demographics, health status, healthcare utilization, residential movement, and the neighborhood of residence in 2006.

CONCLUSIONS

These findings suggest negative impacts of displacement on healthcare access and mental health, particularly among adults living in urban areas and with a history of frequent emergency department visits or hospitalizations.

Foodborne Disease Outbreaks Associated with Organic Foods in the United States

Consumer demand for organically produced foods is increasing in the United States as well as globally. Consumer perception often credits organic foods as being safer than conventionally produced foods, although organic standards do not directly address safety issues such as microbial or chemical hazards. We reviewed outbreaks reported to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System where the implicated food was reported to be organic. Information collected for each outbreak included the year, state, number of illnesses, pathogen, and implicated food. We identified 18 outbreaks caused by organic foods from 1992 to 2014, resulting in 779 illnesses, 258 hospitalizations, and 3 deaths; 56% of outbreaks occurred from 2010 to 2014. Nine outbreaks occurred in a single state, and nine outbreaks were multistate. Salmonella sp. (44% of outbreaks) and Escherichia coli O157:H7 (33%) were the most commonly occurring pathogens. Eight of the outbreaks were attributed to produce items, four to unpasteurized dairy products, two to eggs, two to nut and seed products, and two to multi-ingredient foods. Fifteen (83%) outbreaks were associated with foods that were definitely or likely U.S. Department of Agriculture certified. More foodborne outbreaks associated with organic foods in the United States have been reported in recent years, in parallel with increases in organic food production and consumption. We are unable to assess risk of outbreaks due to organic foods compared with conventional foods because foodborne outbreak surveillance does not systematically collect food production method. Food safety requires focused attention by consumers, regardless of whether foods are produced organically or conventionally. Consumers should be aware of the risk of milk and produce consumed raw, including organic.

A State-by-State Assessment of Food Service Regulations for Prevention of Norovirus Outbreaks

Noroviruses are the leading cause of foodborne disease in the United States. Foodborne transmission of norovirus is often associated with contamination of food during preparation by an infected food worker. The U.S. Food and Drug Administration's Food Code provides model food safety regulations for preventing transmission of foodborne disease in restaurants; however, adoption of specific provisions is at the discretion of state and local governments. We analyzed the food service regulations of all 50 states and the District of Columbia (i.e., 51 states) to describe differences in adoption of norovirus-related Food Code provisions into state food service regulations. We then assessed potential correlations between adoption of these regulations and characteristics of foodborne norovirus outbreaks reported to the National Outbreak Reporting System from 2009 through 2014. Of the 51 states assessed, all (100%) required food workers to wash their hands, and 39 (76%) prohibited bare-hand contact with ready-to-eat food. Thirty states (59%) required exclusion of staff with vomiting and diarrhea until 24 h after cessation of symptoms. Provisions requiring a certified food protection manager (CFPM) and a response plan for contamination events (i.e., vomiting) were least commonly adopted; 26 states (51%) required a CFPM, and 8 (16%) required a response plan. Although not statistically significant, states that adopted the provisions prohibiting bare-hand contact (0.45 versus 0.74, P =0.07), requiring a CFPM (0.38 versus 0.75, P =0.09), and excluding ill staff for ≥24 h after symptom resolution (0.44 versus 0.73, P =0.24) each reported fewer foodborne norovirus outbreaks per million person-years than did those states without these provisions. Adoption and compliance with federal recommended food service regulations may decrease the incidence of foodborne norovirus outbreaks.

Implementation of Nationwide Real-time Whole-genome Sequencing to Enhance Listeriosis Outbreak Detection and Investigation

Listeria monocytogenes (Lm) causes severe foodborne illness (listeriosis). Previous molecular subtyping methods, such as pulsed-field gel electrophoresis (PFGE), were critical in detecting outbreaks that led to food safety improvements and declining incidence, but PFGE provides limited genetic resolution. A multiagency collaboration began performing real-time, whole-genome sequencing (WGS) on all US Lm isolates from patients, food, and the environment in September 2013, posting sequencing data into a public repository. Compared with the year before the project began, WGS, combined with epidemiologic and product trace-back data, detected more listeriosis clusters and solved more outbreaks (2 outbreaks in pre-WGS year, 5 in WGS year 1, and 9 in year 2). Whole-genome multilocus sequence typing and single nucleotide polymorphism analyses provided equivalent phylogenetic relationships relevant to investigations; results were most useful when interpreted in context of epidemiological data. WGS has transformed listeriosis outbreak surveillance and is being implemented for other foodborne pathogens.

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

Beef and leafy vegetables were the most common sources of these outbreaks.

Increased outbreaks associated with nonpasteurized milk, United States, 2007-2012

The number of US outbreaks caused by nonpasteurized milk increased from 30 during 2007–2009 to 51 during 2010–2012. Most outbreaks were caused by Campylobacter spp. (77%) and by nonpasteurized milk purchased from states in which nonpasteurized milk sale was legal (81%). Regulations to prevent distribution of nonpasteurized milk should be enforced.

Increase in Multistate Foodborne Disease Outbreaks-United States, 1973-2010

INTRODUCTION

Changes in food production and distribution have increased opportunities for foods contaminated early in the supply chain to be distributed widely, increasing the possibility of multistate outbreaks. In recent decades, surveillance systems for foodborne disease have been improved, allowing officials to more effectively identify related cases and to trace and identify an outbreak's source.

MATERIALS AND METHODS

We reviewed multistate foodborne disease outbreaks reported to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System during 1973-2010. We calculated the percentage of multistate foodborne disease outbreaks relative to all foodborne disease outbreaks and described characteristics of multistate outbreaks, including the etiologic agents and implicated foods.

RESULTS

Multistate outbreaks accounted for 234 (0.8%) of 27,755 foodborne disease outbreaks, 24,003 (3%) of 700,600 outbreak-associated illnesses, 2839 (10%) of 29,756 outbreak-associated hospitalizations, and 99 (16%) of 628 outbreak-associated deaths. The median annual number of multistate outbreaks increased from 2.5 during 1973-1980 to 13.5 during 2001-2010; the number of multistate outbreak-associated illnesses, hospitalizations, and deaths also increased. Most multistate outbreaks were caused by Salmonella (47%) and Shiga toxin-producing Escherichia coli (26%). Foods most commonly implicated were beef (22%), fruits (13%), and leafy vegetables (13%).

CONCLUSIONS

The number of identified and reported multistate foodborne disease outbreaks has increased. Improvements in detection, investigation, and reporting of foodborne disease outbreaks help explain the increasing number of reported multistate outbreaks and the increasing percentage of outbreaks that were multistate. Knowing the etiologic agents and foods responsible for multistate outbreaks can help to identify sources of food contamination so that the safety of the food supply can be improved.

Factors contributing to decline in foodborne disease outbreak reports, United States

The number of foodborne disease outbreaks reported in the United States declined substantially in 2009, when the surveillance system transitioned from reporting only foodborne disease outbreaks to reporting all enteric disease outbreaks. A 2013 survey found that some outbreaks that would have been previously reported as foodborne are now reported as having other transmission modes.

Outbreaks associated with cantaloupe, watermelon, and honeydew in the United States, 1973-2011

Fresh fruits and vegetables are an important part of a healthy diet. Melons have been associated with enteric infections. We reviewed outbreaks reported to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System during 1973-2011 in which the implicated food was a single melon type. We also reviewed published literature and records obtained from investigating agencies. During 1973-2011, 34 outbreaks caused by a single melon type were reported, resulting in 3602 illnesses, 322 hospitalizations, 46 deaths, and 3 fetal losses. Cantaloupes accounted for 19 outbreaks (56%), followed by watermelons (13, 38%) and honeydew (2, 6%). Melon-associated outbreaks increased from 0.5 outbreaks per year during 1973-1991 to 1.3 during 1992-2011. Salmonella was the most common etiology reported (19, 56%), followed by norovirus (5, 15%). Among 13 outbreaks with information available, melons imported from Mexico and Central America were implicated in 9 outbreaks (69%) and domestically grown melons were implicated in 4 outbreaks (31%). The point of contamination was known for 20 outbreaks; contamination occurred most commonly during growth, harvesting, processing, or packaging (13, 65%). Preventive measures focused on reducing bacterial contamination of melons both domestically and internationally could decrease the number and severity of melon-associated outbreaks.

Outbreaks attributed to cheese: differences between outbreaks caused by unpasteurized and pasteurized dairy products, United States, 1998-2011

INTRODUCTION

The interstate commerce of unpasteurized fluid milk, also known as raw milk, is illegal in the United States, and intrastate sales are regulated independently by each state. However, U.S. Food and Drug Administration regulations allow the interstate sale of certain types of cheeses made from unpasteurized milk if specific aging requirements are met. We describe characteristics of these outbreaks, including differences between outbreaks linked to cheese made from pasteurized or unpasteurized milk.

METHODS

We reviewed reports of outbreaks submitted to the Foodborne Disease Outbreak Surveillance System during 1998-2011 in which cheese was implicated as the vehicle. We describe characteristics of these outbreaks, including differences between outbreaks linked to cheese made from pasteurized versus unpasteurized milk.

RESULTS

During 1998-2011, 90 outbreaks attributed to cheese were reported; 38 (42%) were due to cheese made with unpasteurized milk, 44 (49%) to cheese made with pasteurized milk, and the pasteurization status was not reported for the other eight (9%). The most common cheese-pathogen pairs were unpasteurized queso fresco or other Mexican-style cheese and Salmonella (10 outbreaks), and pasteurized queso fresco or other Mexican-style cheese and Listeria (6 outbreaks). The cheese was imported from Mexico in 38% of outbreaks caused by cheese made with unpasteurized milk. In at least five outbreaks, all due to cheese made from unpasteurized milk, the outbreak report noted that the cheese was produced or sold illegally. Outbreaks caused by cheese made from pasteurized milk occurred most commonly (64%) in restaurant, delis, or banquet settings where cross-contamination was the most common contributing factor.

CONCLUSIONS

In addition to using pasteurized milk to make cheese, interventions to improve the safety of cheese include limiting illegal importation of cheese, strict sanitation and microbiologic monitoring in cheese-making facilities, and controls to limit food worker contamination.

Vital signs: foodborne norovirus outbreaks - United States, 2009-2012

INTRODUCTION

Norovirus is the leading cause of acute gastroenteritis and foodborne disease in the United States, causing an estimated one in 15 U.S. residents to become ill each year as well as 56,000-71,000 hospitalizations and 570-800 deaths, predominantly among young children and the elderly. Whereas noroviruses often spread through person-to-person contact, foodborne transmission can cause widespread exposures and presents important prevention opportunities.

METHODS

CDC analyzed 2009–2012 data on suspected and confirmed norovirus outbreaks reported by state, local, and territorial health departments through the National Outbreak Reporting System (NORS) to characterize the epidemiology of foodborne norovirus outbreaks.

RESULTS

During 2009–2012, a total of 1,008 foodborne norovirus outbreaks were reported to NORS, constituting 48% of all foodborne outbreaks with a single known cause. Outbreaks were reported by 43 states and occurred year round. Restaurants were the most common setting (64%) of food preparation reported in outbreaks. Of 520 outbreaks with factors contributing to contamination reported, food workers were implicated as the source in 70%. Of 324 outbreaks with an implicated food, most resulted from food contaminated during preparation (92%) and food consumed raw (75%). Specific food categories were implicated in only 67 outbreaks; the most frequently named were vegetable row crops (e.g., leafy vegetables) (30%), fruits (21%), and mollusks (19%).

CONCLUSIONS

Noroviruses are the leading cause of reported foodborne disease outbreaks and most often associated with contamination of food in restaurants during preparation by infected food workers.

IMPLICATIONS FOR PUBLIC HEALTH PRACTICE

Improved adherence to appropriate hand hygiene, excluding ill staff members from working until ≥48 hours after symptom resolution, and supervision by certified kitchen managers are all recommended to reduce the incidence of foodborne norovirus disease.

Swine flu in college: early campus response to outbreak control measures

OBJECTIVES

To describe student and faculty attitudes towards and adherence to nonpharmaceutical control measures during the first-known university outbreak of 2009 pandemic influenza A (H1N1).

METHODS

Preferred information sources, control measure adherence and likelihood of adherence during future out-breaks, and perceived illness risk, were explored through focus groups and patient interviews.

RESULTS

We conducted 7 focus groups (N=48) and 9 patient inter- views. Measures (eg, hand hygiene, self-isolation while ill) were initially heeded. Limited information regarding A(H1N1) pdm09, insufficient understanding of university decisions, and perceived university alert overuse led to reports that future outbreaks would be regarded less seriously.

CONCLUSIONS

Reported concern and commitment to recommendations decreased rapidly. Initial university messaging and response was critical in shaping participants' later perceptions.

Acute gastroenteritis surveillance through the National Outbreak Reporting System, United States

Implemented in 2009, the National Outbreak Reporting System provides surveillance for acute gastroenteritis outbreaks in the United States resulting from any transmission mode. Data from the first 2 years of surveillance highlight the predominant role of norovirus. The pathogen-specific transmission pathways and exposure settings identified can help inform prevention efforts.

Contributing factors in restaurant-associated foodborne disease outbreaks, FoodNet sites, 2006 and 2007

An estimated 48 million cases of foodborne illness occur each year in the United States, resulting in approximately 128,000 hospitalizations and 3,000 deaths. Over half of all foodborne disease outbreaks reported to the Centers for Disease Control and Prevention are associated with eating in restaurants or delicatessens. We reviewed data from restaurant-associated foodborne disease outbreaks to better understand the factors that contribute to these outbreaks. Data on restaurant-associated foodborne disease outbreaks reported by sites participating in the Foodborne Diseases Active Surveillance Network (FoodNet) were analyzed to characterize contributing factors reported in foodborne disease outbreaks and the levels of evidence used to identify these factors. Of 457 foodborne disease outbreaks reported in 2006 and 2007 by FoodNet sites, 300 (66%) were restaurant associated, and of these 295 (98%) had at least one reported contributing factor. One to nine (with a median of two) contributing factors were reported per outbreak. Of the 257 outbreaks with a single etiology reported, contributing factors associated with food worker health and hygiene were reported for 165 outbreaks (64%), factors associated with food preparation practices within the establishment were reported for 88 outbreaks (34%), and factors associated with contamination introduced before reaching the restaurant were reported for 56 outbreaks (22%). The pronounced role of food workers in propagating outbreaks makes it clear that more work is needed to address prevention at the local level. Food workers should be instructed not to prepare food while ill to prevent the risk of transmitting pathogens.

Epidemiology of community-associated Clostridium difficile infection, 2009 through 2011

IMPORTANCE

Clostridium difficile infection (CDI) has been increasingly reported among healthy individuals in the community. Recent data suggest that community-associated CDI represents one-third of all C difficile cases. The epidemiology and potential sources of C difficile in the community are not fully understood.

OBJECTIVES

To determine epidemiological and clinical characteristics of community-associated CDI and to explore potential sources of C difficile acquisition in the community.

DESIGN AND SETTING

Active population-based and laboratory-based CDI surveillance in 8 US states.

PARTICIPANTS

Medical records were reviewed and interviews performed to assess outpatient, household, and food exposures among patients with community-associated CDI (ie, toxin or molecular assay positive for C difficile and no overnight stay in a health care facility within 12 weeks). Molecular characterization of C difficile isolates was performed. Outpatient health care exposure in the prior 12 weeks among patients with community-associated CDI was a priori categorized into the following 3 levels: no exposure, low-level exposure (ie, outpatient visit with physician or dentist), or high-level exposure (ie, surgery, dialysis, emergency or urgent care visit, inpatient care with no overnight stay, or health care personnel with direct patient care).

MAIN OUTCOMES AND MEASURES

Prevalence of outpatient health care exposure among patients with community-associated CDI and identification of potential sources of C difficile by level of outpatient health care exposure.

RESULTS

Of 984 patients with community-associated CDI, 353 (35.9%) did not receive antibiotics, 177 (18.0%) had no outpatient health care exposure, and 400 (40.7%) had low-level outpatient health care exposure. Thirty-one percent of patients without antibiotic exposure received proton pump inhibitors. Patients having CDI with no or low-level outpatient health care exposure were more likely to be exposed to infants younger than 1 year (P = .04) and to household members with active CDI (P = .05) compared with those having high-level outpatient health care exposure. No association between food exposure or animal exposure and level of outpatient health care exposure was observed. North American pulsed-field gel electrophoresis (NAP) 1 was the most common (21.7%) strain isolated; NAP7 and NAP8 were uncommon (6.7%).

CONCLUSIONS AND RELEVANCE

Most patients with community-associated CDI had recent outpatient health care exposure, and up to 36% would not be prevented by reduction of antibiotic use only. Our data support evaluation of additional strategies, including further examination of C difficile transmission in outpatient and household settings and reduction of proton pump inhibitor use.

Surveillance for foodborne disease outbreaks - United States, 1998-2008

PROBLEM/CONDITION

Foodborne diseases cause an estimated 48 million illnesses each year in the United States, including 9.4 million caused by known pathogens. Foodborne disease outbreak surveillance provides valuable insights into the agents and foods that cause illness and the settings in which transmission occurs. CDC maintains a surveillance program for collection and periodic reporting of data on the occurrence and causes of foodborne disease outbreaks in the United States. This surveillance system is the primary source of national data describing the numbers of illnesses, hospitalizations, and deaths; etiologic agents; implicated foods; contributing factors; and settings of food preparation and consumption associated with recognized foodborne disease outbreaks in the United States.

REPORTING PERIOD

1998-2008.

DESCRIPTION OF THE SYSTEM

The Foodborne Disease Outbreak Surveillance System collects data on foodborne disease outbreaks, defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. Public health agencies in all 50 states, the District of Columbia, U.S. territories, and Freely Associated States have primary responsibility for identifying and investigating outbreaks and use a standard form to report outbreaks voluntarily to CDC. During 1998-2008, reporting was made through the electronic Foodborne Outbreak Reporting System (eFORS).

RESULTS

During 1998-2008, CDC received reports of 13,405 foodborne disease outbreaks, which resulted in 273,120 reported cases of illness, 9,109 hospitalizations, and 200 deaths. Of the 7,998 outbreaks with a known etiology, 3,633 (45%) were caused by viruses, 3,613 (45%) were caused by bacteria, 685 (5%) were caused by chemical and toxic agents, and 67 (1%) were caused by parasites. Among the 7,724 (58%) outbreaks with an implicated food or contaminated ingredient reported, 3,264 (42%) could be assigned to one of 17 predefined commodity categories: fish, crustaceans, mollusks, dairy, eggs, beef, game, pork, poultry, grains/beans, oils/sugars, fruits/nuts, fungi, leafy vegetables, root vegetables, sprouts, and vegetables from a vine or stalk. The commodities implicated most commonly were poultry (18.9%; 95% confidence interval [CI] = 17.4-20.3) and fish (18.6%; CI = 17.2-20), followed by beef (11.9%; CI = 10.8-13.1). The pathogen-commodity pairs most commonly responsible for outbreaks were scombroid toxin/histamine and fish (317 outbreaks), ciguatoxin and fish (172 outbreaks), Salmonella and poultry (145 outbreaks), and norovirus and leafy vegetables (141 outbreaks). The pathogen-commodity pairs most commonly responsible for outbreak-related illnesses were norovirus and leafy vegetables (4,011 illnesses), Clostridium perfringens and poultry (3,452 illnesses), Salmonella and vine-stalk vegetables (3,216 illnesses), and Clostridium perfringens and beef (2,963 illnesses). Compared with the first 2 years of the study (1998-1999), the percentage of outbreaks associated with leafy vegetables and dairy increased substantially during 2006-2008, while the percentage of outbreaks associated with eggs decreased.

INTERPRETATION

Outbreak reporting rates and implicated foods varied by state and year, respectively; analysis of surveillance data for this 11-year period provides important information regarding changes in sources of illness over time. A substantial percentage of foodborne disease outbreaks were associated with poultry, fish, and beef, whereas many outbreak-related illnesses were associated with poultry, leafy vegetables, beef, and fruits/nuts. The percentage of outbreaks associated with leafy vegetables and dairy increased during the surveillance period, while the percentage associated with eggs decreased.

PUBLIC HEALTH ACTIONS

Outbreak surveillance data highlight the etiologic agents, foods, and settings involved most often in foodborne disease outbreaks and can help to identify food commodities and preparation settings in which interventions might be most effective. Analysis of data collected over several years of surveillance provides a means to assess changes in the food commodities associated most frequently with outbreaks that might occur following improvements in food safety or changes in consumption patterns or food preparation practices. Prevention of foodborne disease depends on targeted interventions at appropriate points from food production to food preparation. Efforts to reduce foodborne illness should focus on the pathogens and food commodities causing the most outbreaks and outbreak-associated illnesses, including beef, poultry, fish, and produce.

Vital signs: Listeria illnesses, deaths, and outbreaks--United States, 2009-2011

BACKGROUND

Older adults, pregnant women, and persons with immunocompromising conditions are at higher risk than others for invasive Listeria monocytogenes infection (listeriosis), a rare and preventable foodborne illness that can cause bacteremia, meningitis, fetal loss, and death.

METHODS

This report summarizes data on 2009-2011 listeriosis cases and outbreaks reported to U.S. surveillance systems. The Listeria Initiative and PulseNet conduct nationwide surveillance to rapidly detect and respond to outbreaks, the Foodborne Diseases Active Surveillance Network (FoodNet) conducts active, sentinel population-based surveillance to track incidence trends, and the Foodborne Disease Outbreak Surveillance System (FDOSS) receives reports of investigated outbreaks to track foods and settings associated with outbreaks.

RESULTS

Nationwide, 1,651 cases of listeriosis occurring during 2009-2011 were reported. The case-fatality rate was 21%. Most cases occurred among adults aged ≥65 years (950 [58%]), and 14% (227) were pregnancy-associated. At least 74% of nonpregnant patients aged <65 years had an immunocompromising condition, most commonly immunosuppressive therapy or malignancy. The average annual incidence was 0.29 cases per 100,000 population. Compared with the overall population, incidence was markedly higher among adults aged ≥65 years (1.3; relative rate [RR]: 4.4) and pregnant women (3.0; RR: 10.1). Twelve reported outbreaks affected 224 patients in 38 states. Five outbreak investigations implicated soft cheeses made from pasteurized milk that were likely contaminated during cheese-making (four implicated Mexican-style cheese, and one implicated two other types of cheese). Two outbreaks were linked to raw produce.

CONCLUSIONS

Almost all listeriosis occurs in persons in higher-risk groups. Soft cheeses were prominent vehicles, but other foods also caused recent outbreaks. Prevention targeting higher-risk groups and control of Listeria monocytogenes contamination in foods implicated by outbreak investigations will have the greatest impact on reducing the burden of listeriosis.

IMPLICATIONS FOR PUBLIC HEALTH PRACTICE

Careful attention to food safety is especially important to protect vulnerable populations. Surveillance for foodborne infections like listeriosis identifies food safety gaps that can be addressed by industry, regulatory authorities, food preparers, and consumers.

Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus--United States, 1998-2008

From 1998 to 2008, 1229 foodborne outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus were reported in the United States; 39% were reported with a confirmed etiology. Vomiting was commonly reported in B. cereus (median, 75% of cases) and S. aureus outbreaks (median, 87%), but rarely in C. perfringens outbreaks (median, 9%). Meat or poultry dishes were commonly implicated in C. perfringens (63%) and S. aureus (55%) outbreaks, and rice dishes were commonly implicated in B. cereus outbreaks (50%). Errors in food processing and preparation were commonly reported (93%), regardless of etiology; contamination by a food worker was only common in S. aureus outbreaks (55%). Public health interventions should focus on these commonly reported errors to reduce the occurrence of outbreaks caused by B. cereus, C. perfringens, and S. aureus in the United States.

Epidemiology of foodborne norovirus outbreaks, United States, 2001-2008

In the United States, the leading cause of foodborne illness is norovirus; an average of 1 foodborne norovirus outbreak is reported every day. The more we know about how this virus is spread and in which foods, the better we can ward off future outbreaks. A recent study identified the most common sources of foodborne norovirus outbreaks as ready-to-eat foods that contain fresh produce and mollusks that are eaten raw, such as oysters. Most implicated foods had been prepared in restaurants, delicatessens, and other commercial settings and were most often contaminated by an infected food worker. Although possible contamination during production, harvesting, or processing cannot be overlooked, food safety during meal preparation should be emphasized. Food handlers should wash their hands, avoid bare-handed contact with ready-to-eat foods, and not work when they are sick.

Keywords: norovirus, foodborne disease, outbreaks, attribution, United States, viruses

Epidemiology of foodborne disease outbreaks caused by Clostridium perfringens, United States, 1998-2010

Clostridium perfringens is estimated to be the second most common bacterial cause of foodborne illness in the United States, causing one million illnesses each year. Local, state, and territorial health departments voluntarily report C. perfringens outbreaks to the U.S. Centers for Disease Control and Prevention through the Foodborne Disease Outbreak Surveillance System. Our analysis included outbreaks confirmed by laboratory evidence during 1998-2010. A food item was implicated if C. perfringens was isolated from food or based on epidemiologic evidence. Implicated foods were classified into one of 17 standard food commodities when possible. From 1998 to 2010, 289 confirmed outbreaks of C. perfringens illness were reported with 15,208 illnesses, 83 hospitalizations, and eight deaths. The number of outbreaks reported each year ranged from 16 to 31 with no apparent trend over time. The annual number of outbreak-associated illnesses ranged from 359 to 2,173, and the median outbreak size was 24 illnesses. Outbreaks occurred year round, with the largest number in November and December. Restaurants (43%) were the most common setting of food preparation. Other settings included catering facility (19%), private home (16%), prison or jail (11%), and other (10%). Among the 144 (50%) outbreaks attributed to a single food commodity, beef was the most common commodity (66 outbreaks, 46%), followed by poultry (43 outbreaks, 30%), and pork (23 outbreaks, 16%). Meat and poultry outbreaks accounted for 92% of outbreaks with an identified single food commodity. Outbreaks caused by C. perfringens occur regularly, are often large, and can cause substantial morbidity yet are preventable if contamination of raw meat and poultry products is prevented at the farm or slaughterhouse or, after contamination, if these products are properly handled and prepared, particularly in restaurants and catering facilities.