Foodborne Illness Outbreaks at Retail Food Establishments - National Environmental Assessment Reporting System, 25 State and Local Health Departments, 2017-2019.

Problem/Condition: Each year, state and local public health departments report hundreds of foodborne illness outbreaks associated with retail food establishments (e.g., restaurants or caterers) to CDC. Typically, investigations involve epidemiology, laboratory, and environmental health components. Health departments voluntarily report epidemiologic and laboratory data from their foodborne illness outbreak investigations to CDC through the National Outbreak Reporting System (NORS); however, minimal environmental health data from outbreak investigations are reported to NORS. This report summarizes environmental health data collected during outbreak investigations and reported to the National Environmental Assessment Reporting System (NEARS). Period Covered: 2017-2019. Description of System: In 2014, CDC launched NEARS to complement NORS surveillance and to use these data to enhance prevention efforts. State and local health departments voluntarily enter data from their foodborne illness outbreak investigations of retail food establishments into NEARS. These data include characteristics of foodborne illness outbreaks (e.g., etiologic agent and factors contributing to the outbreak), characteristics of establishments with outbreaks (e.g., number of meals served daily), and food safety policies in these establishments (e.g., ill worker policy requirements). NEARS is the only available data source that collects environmental characteristics of retail establishments with foodborne illness outbreaks. Results: During 2017-2019, a total of 800 foodborne illness outbreaks associated with 875 retail food establishments were reported to NEARS by 25 state and local health departments. Among outbreaks with a confirmed or suspected agent (555 of 800 [69.4%]), the most common pathogens were norovirus and Salmonella, accounting for 47.0% and 18.6% of outbreaks, respectively. Contributing factors were identified in 62.5% of outbreaks. Approximately 40% of outbreaks with identified contributing factors had at least one reported factor associated with food contamination by an ill or infectious food worker. Investigators conducted an interview with an establishment manager in 679 (84.9%) outbreaks. Of the 725 managers interviewed, most (91.7%) said their establishment had a policy requiring food workers to notify their manager when they were ill, and 66.0% also said these policies were written. Only 23.0% said their policy listed all five illness symptoms workers needed to notify managers about (i.e., vomiting, diarrhea, jaundice, sore throat with fever, and lesion with pus). Most (85.5%) said that their establishment had a policy restricting or excluding ill workers from working, and 62.4% said these policies were written. Only 17.8% said their policy listed all five illness symptoms that would require restriction or exclusion from work. Only 16.1% of establishments with outbreaks had policies addressing all four components relating to ill or infectious workers (i.e., policy requires workers to notify a manager when they are ill, policy specifies all five illness symptoms workers need to notify managers about, policy restricts or excludes ill workers from working, and policy specifies all five illness symptoms requiring restriction or exclusion from work). Interpretation: Norovirus was the most commonly identified cause of outbreaks reported to NEARS, and contamination of food by ill or infectious food workers contributed to approximately 40% of outbreaks with identified contributing factors. These findings are consistent with findings from other national outbreak data sets and highlight the role of ill workers in foodborne illness outbreaks. Although a majority of managers reported their establishment had an ill worker policy, often these policies were missing components intended to reduce foodborne illness risk. Contamination of food by ill or infectious food workers is an important cause of outbreaks; therefore, the content and enforcement of existing policies might need to be re-examined and refined. Public Health Action: Retail food establishments can reduce viral foodborne illness outbreaks by protecting food from contamination through proper hand hygiene and excluding ill or infectious workers from working. Development and implementation of policies that prevent contamination of food by workers are important to foodborne outbreak reduction. NEARS data can help identify gaps in food safety policies and practices, particularly those concerning ill workers. Future analyses of stratified data linking specific outbreak agents and foods with outbreak contributing factors can help guide the development of effective prevention approaches by describing how establishments' characteristics and food safety policies and practices relate to foodborne illness outbreaks.

Development of an Empirically Derived Measure of Food Safety Culture in Restaurants.

A poor food safety culture has been described as an emerging risk factor for foodborne illness outbreaks, yet there has been little research on this topic in the retail food industry. The purpose of this study was to identify and validate conceptual domains around food safety culture and develop an assessment tool that can be used to assess food workers' perceptions of their restaurant's food safety culture. The study, conducted from March 2018 through March 2019, surveyed restaurant food workers for their level of agreement with 28 statements. We received 579 responses from 331 restaurants spread across eight different health department jurisdictions. Factor analysis and structural equation modeling supported a model composed of four primary constructs. The highest rated construct was Resource Availability (x¯=4.69, sd=0.57), which assessed the availability of resources to maintain good hand hygiene. The second highest rated construct was Employee Commitment (x¯=4.49, sd=0.62), which assessed workers' perceptions of their coworkers' commitment to food safety. The last two constructs were related to management. Leadership (x¯=4.28, sd=0.69) assessed the existence of food safety policies, training, and information sharing. Management Commitment (x¯=3.94, sd=1.05) assessed whether food safety was a priority in practice. Finally, the model revealed one higher-order construct, Worker Beliefs about Food Safety Culture (x¯=4.35, sd=0.53). The findings from this study can support efforts by the restaurant industry, food safety researchers, and health departments to examine the influence and effects of food safety culture within restaurants.

Longitudinal serologic and viral testing post-SARS-CoV-2 infection and post-receipt of mRNA COVID-19 vaccine in a nursing home cohort-Georgia, October 2020‒April 2021.

There are limited data describing SARS-CoV-2-specific immune responses and their durability following infection and vaccination in nursing home residents. We conducted a prospective longitudinal evaluation of 11 consenting SARS-CoV-2-positive nursing home residents to evaluate the quantitative titers and durability of binding antibodies detected after SARS-CoV-2 infection and subsequent COVID-19 vaccination. The evaluation included nine visits over 150 days from October 25, 2020, through April 1, 2021. Visits included questionnaire administration, blood collection for serology, and paired anterior nasal specimen collection for testing by BinaxNOW™ COVID-19 Ag Card (BinaxNOW), reverse transcription polymerase chain reaction (RT-PCR), and viral culture. We evaluated quantitative titers of binding SARS-CoV-2 antibodies post-infection and post-vaccination (beginning after the first dose of the primary series). The median age among participants was 74 years; one participant was immunocompromised. Of 10 participants with post-infection serology results, 9 (90%) had detectable Pan-Ig, IgG, and IgA antibodies, and 8 (80%) had detectable IgM antibodies. At first antibody detection post-infection, two-thirds (6/9, 67%) of participants were RT-PCR-positive, but none were culture- positive. Ten participants received vaccination; all had detectable Pan-Ig, IgG, and IgA antibodies through their final observation ≤90 days post-first dose. Post-vaccination geometric means of IgG titers were 10-200-fold higher than post-infection. Nursing home residents in this cohort mounted robust immune responses to SARS-CoV-2 post-infection and post-vaccination. The augmented antibody responses post-vaccination are potential indicators of enhanced protection that vaccination may confer on previously infected nursing home residents.

Repeated antigen testing among severe acute respiratory coronavirus virus 2 (SARS-CoV-2)-positive nursing home residents.

Repeated antigen testing of 12 severe acute respiratory coronavirus virus 2 (SARS-CoV-2)-positive nursing home residents using Abbott BinaxNOW identified 9 of 9 (100%) culture-positive specimens up to 6 days after initial positive test. Antigen positivity lasted 2-24 days. Antigen positivity might last beyond the infectious period, but it was reliable in residents with evidence of early infection.

Performance Evaluation of Serial SARS-CoV-2 Rapid Antigen Testing During a Nursing Home Outbreak.

BACKGROUND: To address high COVID-19 burden in U.S. nursing homes, rapid SARS-CoV-2 antigen tests have been widely distributed in those facilities. However, performance data are lacking, especially in asymptomatic people. OBJECTIVE: To evaluate the performance of SARS-CoV-2 antigen testing when used for facility-wide testing during a nursing home outbreak. DESIGN: A prospective evaluation involving 3 facility-wide rounds of testing where paired respiratory specimens were collected to evaluate the performance of the BinaxNOW antigen test compared with virus culture and real-time reverse transcription polymerase chain reaction (RT-PCR). Early and late infection were defined using changes in RT-PCR cycle threshold values and prior test results. SETTING: A nursing home with an ongoing SARS-CoV-2 outbreak. PARTICIPANTS: 532 paired specimens collected from 234 available residents and staff. MEASUREMENTS: Percentage of positive agreement (PPA) and percentage of negative agreement (PNA) for BinaxNOW compared with RT-PCR and virus culture. RESULTS: BinaxNOW PPA with virus culture, used for detection of replication-competent virus, was 95%. However, the overall PPA of antigen testing with RT-PCR was 69%, and PNA was 98%. When only the first positive test result was analyzed for each participant, PPA of antigen testing with RT-PCR was 82% among 45 symptomatic people and 52% among 343 asymptomatic people. Compared with RT-PCR and virus culture, the BinaxNOW test performed well in early infection (86% and 95%, respectively) and poorly in late infection (51% and no recovered virus, respectively). LIMITATION: Accurate symptom ascertainment was challenging in nursing home residents; test performance may not be representative of testing done by nonlaboratory staff. CONCLUSION: Despite lower positive agreement compared with RT-PCR, antigen test positivity had higher agreement with shedding of replication-competent virus. These results suggest that antigen testing could be a useful tool to rapidly identify contagious people at risk for transmitting SARS-CoV-2 during nascent outbreaks and help reduce COVID-19 burden in nursing homes. PRIMARY FUNDING SOURCE: None.

Hospitalizations and Deaths Associated with EVALI.

BACKGROUND: As of January 7, 2020, a total of 2558 hospitalized patients with nonfatal cases and 60 patients with fatal cases of e-cigarette, or vaping, product use-associated lung injury (EVALI) had been reported to the Centers for Disease Control and Prevention (CDC). METHODS: In a national study, we compared the characteristics of patients with fatal cases of EVALI with those of patients with nonfatal cases to improve the ability of clinicians to identify patients at increased risk for death from the condition. Health departments reported cases of EVALI to the CDC and included, when available, data from medical-record abstractions and patient interviews. Analyses included all the patients with fatal or nonfatal cases of EVALI that were reported to the CDC as of January 7, 2020. We also present three case reports of patients who died from EVALI to illustrate the clinical characteristics common among such patients. RESULTS: Most of the patients with fatal or nonfatal cases of EVALI were male (32 of 60 [53%] and 1666 of 2498 [67%], respectively). The proportion of patients with fatal or nonfatal cases was higher among those who were non-Hispanic white (39 of 49 [80%] and 1104 of 1818 [61%], respectively) than among those in other race or ethnic groups. The proportion of patients with fatal cases was higher among those 35 years of age or older (44 of 60 [73%]) than among those younger than 35 years, but the proportion with nonfatal cases was lower among those 35 years of age or older (551 of 2514 [22%]). Among the patients who had an available medical history, a higher proportion of those with fatal cases than those with nonfatal cases had a history of asthma (13 of 57 [23%] vs. 102 of 1297 [8%]), cardiac disease (26 of 55 [47%] vs. 115 of 1169 [10%]), or a mental health condition (32 of 49 [65%] vs. 575 of 1398 [41%]). A total of 26 of 50 patients (52%) with fatal cases had obesity. Half the patients with fatal cases (25 of 54 [46%]) were seen in an outpatient setting before hospitalization or death. CONCLUSIONS: Chronic conditions, including cardiac and respiratory diseases and mental health conditions, were common among hospitalized patients with EVALI.

The Public Health Response to a Large Poisoning Outbreak Involving an Illicit Substance: Synthetic Cannabinoids Contaminated With a Long-Acting Anticoagulant Rodenticide, Illinois, March-July, 2018.

During March-July 2018, the Illinois Department of Public Health responded to an acute outbreak of severe coagulopathy among patients with recent synthetic cannabinoid use. Toxicological testing indicated that cases were exposed to brodifacoum, a long-acting anticoagulant rodenticide. A total of 174 confirmed and probable cases, including 5 deaths, were linked to this outbreak. On the basis of the experience of responding to this complex outbreak, we recommend several steps for consideration to improve health department preparation for acute outbreaks involving illicit substances including strengthening communication between public health and law enforcement agencies, reviewing legal authority to investigate noninfectious acute disease outbreaks, continuing strong partnerships with state poison control centers, partnering with substance abuse and mental health agencies to provide services to patients, and determining health department ability to rapidly enter into public-private partnership agreements.

An outbreak of severe coagulopathy from synthetic cannabinoids tainted with Long-Acting anticoagulant rodenticides.

Objective: To describe a large regional poison center's experience managing an outbreak of long-acting anticoagulant rodenticide (LAAR) poisoning associated with synthetic cannabinoid (SC) use.Methods: This is a retrospective review of exposures reported to the Illinois Poison Center between March 10 and August 1, 2018. All cases coded as exposure to Δ9-tetrahydrocannabinol homologs were identified. Patients with suspected SC use, positive LAAR testing, and coagulopathy (signs or symptoms of bleeding or international normalized ratio [INR] > 2) were included. If confirmatory LAAR testing was performed and resulted as negative, the patient was excluded from this analysis. In the absence of LAAR testing, patients with suspected SC use, an INR >2, and no alternative explanation of coagulopathy were included. Suspected SC use was defined as use suspected by a member of the treating team or reported by the patient. Presenting signs and symptoms, laboratory findings, management, healthcare utilization, outcomes, and disposition of patients affected by this outbreak were reported.Results: One hundred seventy-eight cases met inclusion criteria. Most patients were male (73%) and young to middle-aged (median age 32, IQR 25-40). Most presented to hospitals in Peoria (35%) and Cook (31%) counties. Median hospitalization was three days (IQR 2-4). Eighty-eight percent of patients presented with an INR >10. Eighteen cases had qualitative anticoagulant testing, all of which were positive for brodifacoum. Other identified LAARs included difenacoum (10/18) and bromadiolone (1/18). Sixty-three percent of patients had back, flank or abdominal pain; 70% of patients presented with hematuria. One hundred six cases received IV vitamin K1; no adverse or anaphylactoid reactions were reported. Forty-one (22%) patients left AMA. Thirty-eight patients (21%) were re-hospitalized during the study period. Patients leaving AMA were 1.6 times more likely to be re-hospitalized than patients with other dispositions. Intracranial hemorrhage, present in 3% of total cases, was present in 4 of 5 fatalities.Conclusions: We describe an outbreak of multiple LAARs contaminating SCs. Patients presented with bleeding from varied sites, often required blood products, factor replacement, and high dose vitamin K1 for stabilization.

Update: Characteristics of Patients in a National Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injuries - United States, October 2019.

CDC, the Food and Drug Administration, state and local health departments, and other public health and clinical stakeholders are investigating a national outbreak of electronic-cigarette (e-cigarette), or vaping, product use-associated lung injury (EVALI) (1). As of October 22, 2019, 49 states, the District of Columbia (DC), and the U.S. Virgin Islands have reported 1,604 cases of EVALI to CDC, including 34 (2.1%) EVALI-associated deaths in 24 states. Based on data collected as of October 15, 2019, this report updates data on patient characteristics and substances used in e-cigarette, or vaping, products (2) and describes characteristics of EVALI-associated deaths. The median age of EVALI patients who survived was 23 years, and the median age of EVALI patients who died was 45 years. Among 867 (54%) EVALI patients with available data on use of specific e-cigarette, or vaping, products in the 3 months preceding symptom onset, 86% reported any use of tetrahydrocannabinol (THC)-containing products, 64% reported any use of nicotine-containing products, and 52% reported use of both. Exclusive use of THC-containing products was reported by 34% of patients and exclusive use of nicotine-containing products by 11%, and for 2% of patients, no use of either THC- or nicotine-containing products was reported. Among 19 EVALI patients who died and for whom substance use data were available, 84% reported any use of THC-containing products, including 63% who reported exclusive use of THC-containing products; 37% reported any use of nicotine-containing products, including 16% who reported exclusive use of nicotine-containing products. To date, no single compound or ingredient used in e-cigarette, or vaping, products has emerged as the cause of EVALI, and there might be more than one cause. Because most patients reported using THC-containing products before symptom onset, CDC recommends that persons should not use e-cigarette, or vaping, products that contain THC. In addition, because the specific compound or ingredient causing lung injury is not yet known, and while the investigation continues, persons should consider refraining from the use of all e-cigarette, or vaping, products.

Update: Interim Guidance for Health Care Providers Evaluating and Caring for Patients with Suspected E-cigarette, or Vaping, Product Use Associated Lung Injury - United States, October 2019.

CDC, the Food and Drug Administration (FDA), state and local health departments, and public health and clinical partners are investigating a multistate outbreak of lung injury associated with the use of electronic cigarette (e-cigarette), or vaping, products. In late August, CDC released recommendations for health care providers regarding e-cigarette, or vaping, product use associated lung injury (EVALI) based on limited data from the first reported cases (1,2). This report summarizes national surveillance data describing clinical features of more recently reported cases and interim recommendations based on these data for U.S. health care providers caring for patients with suspected or known EVALI. It provides interim guidance for 1) initial clinical evaluation; 2) suggested criteria for hospital admission and treatment; 3) patient follow-up; 4) special considerations for groups at high risk; and 5) clinical and public health recommendations. Health care providers evaluating patients suspected to have EVALI should ask about the use of e-cigarette, or vaping, products in a nonjudgmental and thorough manner. Patients suspected to have EVALI should have a chest radiograph (CXR), and hospital admission is recommended for patients who have decreased blood oxygen (O2) saturation (<95%) on room air or who are in respiratory distress. Health care providers should consider empiric use of a combination of antibiotics, antivirals, or steroids based upon clinical context. Evidence-based tobacco product cessation strategies, including behavioral counseling, are recommended to help patients discontinue use of e-cigarette, or vaping, products. To reduce the risk of recurrence, patients who have been treated for EVALI should not use e-cigarette, or vaping, products. CDC recommends that persons should not use e-cigarette, or vaping, products that contain tetrahydrocannabinol (THC). At present, CDC recommends persons consider refraining from using e-cigarette, or vaping, products that contain nicotine. Irrespective of the ongoing investigation, e-cigarette, or vaping, products should never be used by youths, young adults, or women who are pregnant. Persons who do not currently use tobacco products should not start using e-cigarette, or vaping, products.

Cases of transfusion-transmitted babesiosis occurring in nonendemic areas: a diagnostic dilemma.

BACKGROUND: Transfusion-transmitted babesiosis (TTB) has been rapidly increasing in incidence since the beginning of the 21st century. Asymptomatic individuals with Babesia infection are able to donate blood in the United States because of the lack of specific blood donation testing. Blood products collected in Babesia-endemic areas are distributed nationally; thus, clinicians in nonendemic states may fail to include babesiosis in the differential diagnosis of a patient who had a recent transfusion history and a fever of unknown origin. STUDY DESIGN AND METHODS: We report the details of two cases of clinical transfusion-transmitted babesiosis and one asymptomatic infection identified in red blood cell recipients in two nonendemic states (South Carolina and Maryland), which, when combined with three recent additional cases in nonendemic states, totals six recipient infections in three nonendemic states. RESULTS: Delayed diagnosis of transfusion-transmitted babesiosis places patients at risk for increased morbidity and mortality and may result in clinical mismanagement or unnecessary treatments. A peripheral blood smear should be reviewed in any patient with a recent transfusion and a fever of unknown origin. Prompt communication of the diagnosis among physicians is key to ensuring that patients with transfusion-transmitted babesiosis are treated expeditiously, and a transfusion service investigation is necessary to identify additional recipients from the same donor. CONCLUSION: TTB is appearing in traditionally nonendemic states because of blood product distribution patterns. Clinicians should include TTB on the differential diagnosis in any patient presenting who had a recent transfusion history and a fever of unknown origin, regardless of where the transfusion took place.

Across state lines: Fulminant Babesia microti infection in a liver transplant recipient.

The potential for transmission of Babesia microti by blood transfusion is well recognized. Physicians may be unaware that products used for transfusion may be collected from geographically diverse regions. We describe a liver transplant recipient in South Carolina who likely acquired B. microti infection from a unit of blood collected in Minnesota.

Description of 15 DNA-positive and antibody-negative "window-period" blood donations identified during prospective screening for Babesia microti.

BACKGROUND: Blood donation screening detecting only antibodies fails to identify donors in the earliest stage of infection, before a detectable immunologic response, that is, the "window period" (WP). We present data on WP donations identified during prospective screening for Babesia microti, a transfusion-transmissible parasite of increasing concern in the United States. STUDY DESIGN AND METHODS: Blood donations collected in Connecticut, Massachusetts, Minnesota, and Wisconsin were screened using polymerase chain reaction (PCR) and arrayed fluorescence immunoassay (AFIA) to detect B. microti DNA and antibodies, respectively. Parasite loads were estimated using quantitative PCR. Red blood cell (RBC) samples were inoculated into hamsters to assess infectivity. Donors screening reactive were indefinitely deferred, tested by supplemental methods, and followed to assess DNA and antibody clearance. Demographic data from WP donors (i.e., those screening PCR positive and AFIA negative) were compared to data from other positive donors. RESULTS: Of 220,479 donations screened from June 2012 to August 2016, a total of 700 were positive, of which 15 (2% of positive donations or 1 per 14,699 screened donations) were confirmed WP donations. The median estimated parasite load in WP donations was 350 parasites/mL, no different than AFIA-positive and PCR-positive donors. Parasite loads in RBC samples from WP units ranged from 14 to 11,022 parasites/mL; RBC samples from three of 10 (30%) WP donations infected hamsters. The mean age of WP donors was 48 years (range, 17-75 years); three (20%) were female. WP donor demographics did not differ significantly from demographics of other donors. CONCLUSIONS: We report one per 15,000 B. microti WP infections in blood donors in endemic areas, demonstrating the importance of nucleic acid testing to mitigate the risk of transfusion-transmitted babesiosis.

Screening for Babesia microti in the U.S. Blood Supply.

BACKGROUND: Babesia microti, a tickborne intraerythrocytic parasite that can be transmitted by means of blood transfusion, is responsible for the majority of cases of transfusion-transmitted babesiosis in the United States. However, no licensed test exists for screening for B. microti in donated blood. We assessed data from a large-scale, investigational product-release screening and donor follow-up program. METHODS: From June 2012 through September 2014, we performed arrayed fluorescence immunoassays (AFIAs) for B. microti antibodies and real-time polymerase-chain-reaction (PCR) assays for B. microti DNA on blood-donation samples obtained in Connecticut, Massachusetts, Minnesota, and Wisconsin. We determined parasite loads with the use of quantitative PCR testing and assessed infectivity by means of the inoculation of hamsters and the subsequent examination for parasitemia. Donors with test-reactive samples were followed. Using data on cases of transfusion-transmitted babesiosis, we compared the proportions of screened versus unscreened donations that were infectious. RESULTS: Of 89,153 blood-donation samples tested, 335 (0.38%) were confirmed to be positive, of which 67 (20%) were PCR-positive; 9 samples were antibody-negative (i.e., 1 antibody-negative sample per 9906 screened samples), representing 13% of all PCR-positive samples. PCR-positive samples were identified all through the year; antibody-negative infections occurred from June through September. Approximately one third of the red-cell samples from PCR-positive or high-titer AFIA-positive donations infected hamsters. Follow-up showed DNA clearance in 86% of the donors but antibody seroreversion in 8% after 1 year. In Connecticut and Massachusetts, no reported cases of transfusion-transmitted babesiosis were associated with screened donations (i.e., 0 cases per 75,331 screened donations), as compared with 14 cases per 253,031 unscreened donations (i.e., 1 case per 18,074 unscreened donations) (odds ratio, 8.6; 95% confidence interval, 0.51 to 144; P=0.05). Overall, 29 cases of transfusion-transmitted babesiosis were linked to blood from infected donors, including blood obtained from 10 donors whose samples tested positive on the PCR assay 2 to 7 months after the implicated donation. CONCLUSIONS: Blood-donation screening for antibodies to and DNA from B. microti was associated with a decrease in the risk of transfusion-transmitted babesiosis. (Funded by the American Red Cross and Imugen; ClinicalTrials.gov number, NCT01528449 .).

Hepatitis E virus: seroprevalence and frequency of viral RNA detection among US blood donors.

BACKGROUND: Hepatitis E virus (HEV) is a nonenveloped emerging virus of increasing worldwide interest. Antibody prevalence, RNA frequencies, and transfusion transmissions have been reported. We investigated the HEV RNA and antibody frequencies in US blood donors. STUDY DESIGN AND METHODS: Individual-donation HEV RNA testing was performed on 18,829 donations from six US geographic regions using a CE-marked nucleic acid test (95% limit of detection, 7.9 IU/mL). Repeat-reactive donations were confirmed by in-house, real-time polymerase chain reaction (PCR; 10.3 IU/mL). Total HEV seroprevalence in a randomly selected subset of donations (n = 4499) was assessed by a direct, double-antigen sandwich assay; reactives were further tested for immunoglobulin (Ig)G and IgM. As part of the total antibody confirmatory algorithm, the cutoff was adjusted. RESULTS: Two donations tested confirmed-positive for RNA (PCR not quantifiable, IgM/IgG positive; and 14 IU/mL, antibody negative) for a frequency of 1 in 9500 (95% confidence interval [CI], 1:2850-1:56,180) and 99.96% specificity (95% CI, 99.92%-99.98%); both donors were from the Midwest United States. Antibody prevalence was 9.5% (95% CI, 8.7-10.5) before the cutoff adjustment and 7.7% (95% CI, 7.0%-8.5%) after adjustment; 0.58% (95% CI, 0.39%-0.85%) were IgM positive. CONCLUSIONS: We confirmed comparatively low rates and low viral loads of HEV RNA in US blood donors indicating the need for individual-donation testing if screening is implemented. Antibody prevalence rates were comparable to those reported by one US study using a different assay, but lower than those reported in another study using yet a third assay. We did not answer the question of whether US blood donation screening is warranted. Selective strategies involving providing HEV-negative blood to severely immunosuppressed patients at risk of developing hepatitis may be considered.

Cost-effectiveness of Babesia microti antibody and nucleic acid blood donation screening using results from prospective investigational studies.

BACKGROUND: Babesia microti causes transfusion-transmitted babesiosis (TTB); currently, blood donor screening assays are unlicensed but used investigationally. STUDY DESIGN AND METHODS: We developed a decision tree model assessing the comparative- and cost-effectiveness of B. microti blood donation screening strategies in endemic areas compared to the status quo (question regarding a history of babesiosis), including testing by: (1) universal antibody (Ab), (2) universal polymerase chain reaction (PCR), (3) universal Ab/PCR, and (4) recipient risk-targeted Ab/PCR. The model predicted the number of TTB cases, complicated TTB cases, cases averted, and quality-adjusted life years (QALYs). Economic outcomes included each strategy's per-donation cost, waste (number of infection-free units incorrectly discarded), and waste index (number wasted units/number true positives). Sensitivity analyses examined uncertainty in transmission probabilities, prevalence rates, and other key model inputs. RESULTS: Universal PCR in four endemic states would prevent 24 to 31 TTB cases/100,000 units transfused (pht) at an incremental cost-effectiveness ratio (ICER) of $26,000 to $44,000/QALY (transmission probability dependent) and waste index of zero. Universal Ab/PCR would prevent 33 to 42 TTB cases pht at an ICER of $54,000 to $83,000/QALY and waste index of 0.05. The questionnaire is most wasteful (99.62 units wasted pht; 208.62 waste index), followed by the risk-targeted strategy (76.27 units wasted pht; 0.68 waste index). The model predicted zero cases of TTB or complicated TTB with universal Ab/PCR (versus [33, 42] and [13, 18] pht, respectively [no screening]). Results are highly sensitive to transmission probabilities. CONCLUSIONS: Universal PCR in endemic states is an effective blood donation screening strategy at a threshold of $50,000/QALY. Using a higher cost-effectiveness ratio, universal Ab/PCR is the most effective strategy.

Molecular characteristics of Staphylococcus aureus isolated from employees, children, and environmental surfaces in Iowa child daycare facilities.

BACKGROUND: Infectious agents have the potential to thrive in child daycare facilities. Asymptomatic Staphylococcus aureus carriage is a risk factor for developing infection and contributes to transmission. METHODS: We collected swabs from 110 employees, 111 unexposed adults, 81 children, and 214 environmental surfaces at 11 Iowa daycare facilities. S aureus isolates were characterized using antibiotic resistance profiles and Staphylococcal protein A typing. Staphylococcal protein A types were grouped into cluster complexes using the Based Upon Repeat Pattern algorithm. RESULTS: All isolates (from 38 employees, 37 unexposed adults, 16 children, and 19 surfaces) were characterized. Daycare employees were more likely to carry erythromycin-resistant S aureus than unexposed adults (odds ratio, 3.7; 95% confidence interval, 1.1-12.7; P = .033). Isolates were genetically heterogeneous, although isolates from employees appeared more clonal than those from unexposed adults. Strains associated with ST8 were identified in 5 daycare facilities and 3 unexposed adults. CONCLUSIONS: S aureus isolates collected from employees, children, and surfaces of daycare facilities are genetically heterogeneous, but contain strains associated with community-associated methicillin-resistant S aureus. This suggests that daycare facilities can serve as reservoirs for community-associated methicillin-resistant S aureus and facilitate genetic exchange. Employees may be at increased risk of carrying antibiotic-resistant strains, indicating more research is necessary into this occupational group.