Unfractionated heparin versus enoxaparin for venous thromboembolism prophylaxis in intensive care units: a propensity score adjusted analysis.

Venous thromboembolism (VTE) is a common complication in hospitalized patients. Pharmacologic prophylaxis is used in order to reduce the risk of VTE events. The main purpose of this study is to compare the prevalence of deep vein thrombosis (DVT) and pulmonary embolism (PE) in patients admitted to the intensive care unit (ICU) who received unfractionated heparin (UFH) versus enoxaparin as VTE prophylaxis. Mortality was evaluated as a secondary outcome. This was a Propensity Score Adjusted Analysis. Patients admitted to neurology, surgical, or medical ICUs and screened with venous doppler ultrasonography or computed tomography angiography for detection of VTE were included in the analysis. We identified 2228 patients in the cohort, 1836 (82.4%) patients received UFH and 392 (17.6%) patients received enoxaparin. Propensity score matching yielded a well-balanced cohort of 950 (74% UFH, 26% enoxaparin) patients. After matching, there was no difference in prevalence of DVT (RR 1.05; 95% CI 0.67-1.64, p = 0.85) and PE (RR 0.76; 95% CI, 0.44-1.30, p = 0.31). No significant differences in location and severity of DVT and PE between the two groups were detected. Hospital and intensive care unit stay was similar between the two groups. Unfractionated heparin was associated with a higher rate of mortality, (HR 2.04; 95% CI, 1.13-3.70; p = 0.019). The use of UFH as VTE prophylaxis in ICU patients was associated with a similar prevalence of DVT and PE compared with enoxaparin, and the site and degree of occlusion were similar. However, a higher mortality rate was seen in the UFH group.

Comparison of polyspecific versus IgG specific ELISA in predominately cardiac patients with suspected heparin induced thrombocytopenia.

A diagnosis of heparin induced thrombocytopenia (HIT) must often be made based on clinical and laboratory evidence. This was a quasi-experimental study of patients admitted from June 2016 to October 2017. The primary endpoint was the incidence of false positive results in polyspecific and IgG specific enzyme-linked immunosorbent assay (ELISA); then we compared the sensitivity and specificity of each assays in predominately cardiac patients with suspected HIT. A sensitivity/specificity analysis was conducted using serotonin release assay (SRA) as the 'gold standard'. The secondary outcome measures included length of hospital stay. We identified a total of 155 patients who met the inclusion criteria. Confirmatory tests with SRA on both groups were completed; false positive result was higher in the polyspecific group when compared to the IgG group [60% vs. 5%]. The IgG specific ELISA test yielded a sensitivity of 100% and a specificity of 95% however, the polyspecific ELISA had a low yield for specificity of 24% but maintained 100% sensitivity. In the IgG specific group with HIT-, their median length of stay was halved compared to those who were HIT + ; hospital LOS in days, IQR [30 (27-81) vs. 15 (7-33) p = 0.023] and a shorter median LOS in the ICU, IQR [24 (5-47) vs. 6 (2-14); p = 0.079]. Hospital or ICU LOS was the same in both (HIT+ and HIT-) groups managed with polyspecific ELISA. The IgG specific test had few false positive results and a high sensitivity score. Ensuring appropriate testing can bring a substantial decrease in drug expenditure, reduced length of stay and prevent unnecessary anticoagulation.

Venous Thromboembolism Prophylaxis: A Narrative Review With a Focus on the High-Risk Critically Ill Patient.

Venous thromboembolism (VTE) is a major health concern associated with significant morbidity and mortality. Critically ill patients are at an increased risk of VTE compared to general medical patients due to unique risk factors: prolonged immobilization, invasive lines and devices, certain medications, and acquired thrombophilia. Furthermore, VTE in the critically ill is associated with increased duration of mechanical ventilation, increased length of intensive care unit and hospital stay, and a trend toward increased mortality. Clinical practice guidelines therefore recommend VTE prophylaxis with either subcutaneous heparin or low-molecular-weight heparin for all critically ill patients without contraindication. Yet, many patients will develop VTE despite appropriate pharmacologic prophylaxis, which has led to interest in risk-stratifying critically ill patients for more aggressive prophylaxis strategies. Recent research identified patients at highest risk of failure of thromboprophylaxis and provided insight into the pathophysiologic mechanisms. Obesity and the receipt of vasopressors are 2 risk factors consistently identified in observational studies; further clinical data support decreased absorption of anticoagulant administered via the subcutaneous route as the likely mechanism behind thromboprophylaxis failure in these patient populations. Several studies have investigated novel thromboprophylaxis strategies to circumvent pharmacokinetic limitations in patients who are obese or on vasopressors: increased fixed-dose, weight-based subcutaneous, or continuous intravenous infusion of a prophylactic dose of anticoagulant has shown promise in limited studies; however, the results have yet to demonstrate superiority compared to current standard-of-care. This review discusses observational studies identifying patients at risk of thromboprophylaxis failure and critiques clinical studies evaluating novel thromboprophylaxis strategies in high-risk, critically ill patients with a focus on their limitations. Future studies are currently being conducted that will provide further guidance into the appropriate use of individualized thromboprophylaxis.

Safety and Efficacy of High-Dose Unfractionated Heparin for Prevention of Venous Thromboembolism in Overweight and Obese Patients.

STUDY OBJECTIVE: To determine the safety and efficacy of high-dose subcutaneous unfractionated heparin (UFH) for prevention of venous thromboembolism (VTE) in overweight and obese patients. DESIGN: Single-center retrospective observational cohort study. SETTING: Large academic tertiary care medical center. PATIENTS: A total of 1335 adults who weighed more than 100 kg on admission and received either subcutaneous UFH 7500 units every 8 hours (751 patients [high-dose group]) or 5000 units every 8 hours (584 patients [low-dose group]) for VTE prophylaxis during their hospitalization between January 1, 2013, and August 31, 2014. MEASUREMENTS AND MAIN RESULTS: The incidences of VTE and bleeding complications were assessed in each group. Each group was further divided into four groups based on their body mass index (BMI): overweight (BMI 25-29.9 kg/m(2) ), obese class I (BMI 30-34.9 kg/m(2) ), obese class II (BMI 35-39.9 kg/m(2) ), and obese class III (BMI ≥ 40 kg/m(2) ). The incidence of VTE was similar for patients in the high-dose group versus those in the low-dose group for all BMI categories. Bleeding complications were significantly higher for patients in the high-dose group. The proportion of patients with at least a 2-g/dl hemoglobin drop from admission was higher in patients in the high-dose groups in obese classes II and III: obese class II, 46 (30%) of 152 patients in the high-dose group versus 30 (18%) of 171 patients in the low-dose group (p<0.01); obese class III, 109 (25%) of 432 patients in the high-dose group versus 31 (12%) of 249 patients in the low-dose group (p<0.01). In addition, the proportion of patients who received at least 2 units of packed red blood cell transfusion was significantly higher in patients in the high-dose group who were in obese class III: 47 (11%) of 432 in the high-dose group versus 13 (5%) of 249 in the low-dose group (p<0.01). CONCLUSION: Administering a higher dose of heparin to patients weighing more than 100 kg may not impart additional efficacy in reducing the incidence of VTE. However, it may increase the risk for bleeding.

Altered activity-based sleep measures in rhesus monkeys following cocaine self-administration and abstinence.

BACKGROUND: Impairments in sleep and cognitive function have been observed in patients with substance abuse disorders and may be potential factors contributing to drug relapse. In addition, sleep disruption may itself contribute to cognitive deficits. In the present study we examined the impact of prolonged cocaine self-administration and abstinence on actigraphy-based measures of night-time activity in rhesus macaques as an inferential measure of sleep, and determined whether sleep-efficiency correlated with cognitive impairments in the same subjects on drug free days. METHODS: Actigraphy data was obtained from a group of rhesus macaques intravenously self-administering cocaine (n=6) and a control group (n=5). Periods were evaluated during which the mean cumulative doses of cocaine were 3.0+0.0 and 4.5+0.2mg/kg/day for 4days (Tuesday-Thursday) each week. RESULTS: Actigraphy-based sleep efficiency decreased during days of cocaine self-administration in a dose-dependent manner. Consistent with this observation, sleep became more fragmented. Activity-based sleep efficiency normalized during the weekend without cocaine prior to cognitive assessment on Monday. The magnitude of activity-based sleep disruption during self-administration did not correlate with the level of cognitive impairment on drug free days. With continued self-administration, the impact of cocaine on activity-based sleep efficiency declined indicating the development of tolerance. CONCLUSIONS: Cocaine self-administration disrupted sleep efficiency in rhesus macaques as measured by actigraphy, but normalized quickly in the absence of cocaine. The cognitive impairment observed on drug free days was unlikely to be related to disruption of the nightly activity patterns on days of cocaine self-administration.

Time to Blood Pressure Control Before Thrombolytic Therapy in Patients With Acute Ischemic Stroke: Comparison of Labetalol, Nicardipine, and Hydralazine.

BACKGROUND: Elevated blood pressure is common in patients with acute ischemic stroke. Thrombolytic therapy is contraindicated in patients with a systolic blood pressure greater than 185 mmHg or diastolic blood pressure greater than 110 mmHg. Elevated blood pressure can lead to a delay in thrombolytic therapy, which is associated with increased morbidity. There is currently insufficient evidence to support the use of a specific antihypertensive agent in this setting. OBJECTIVE: This study aimed to compare the effects of labetalol, nicardipine, or hydralazine on time to target blood pressure before alteplase administration in patients with acute ischemic stroke. METHODS: A retrospective chart review was conducted to identify patients who received labetalol, nicardipine, or hydralazine to treat elevated blood pressure (systolic blood pressure > 185 or diastolic blood pressure > 110) before intravenous alteplase therapy for ischemic stroke. Data collection included time to blood pressure control, door-to-needle time, total dose administered, and use of additional antihypertensive agent(s). RESULTS: Most patients in this study received labetalol (25/29). Median time to blood pressure control was 10, 22, and 15 minutes in the labetalol, nicardipine, and hydralazine groups, respectively. Among patients who received labetalol, the average time to blood pressure control was 10 minutes longer in those who received 10 mg initially versus those who received 20 mg. Patients who required higher total doses of labetalol tended to achieve blood pressure control more slowly, had longer door-to-needle times, and required additional antihypertensive agents. CONCLUSIONS: Adequate initial dosing of antihypertensive treatment has the potential to reduce time to blood pressure control and possibly time to alteplase therapy. The optimal antihypertensive regimen for controlling blood pressure before alteplase therapy remains unclear.

Profound symptomatic bradycardia requiring transvenous pacing after a single dose of tizanidine.

BACKGROUND: We report a case of profound symptomatic bradycardia after a single dose of tizanidine. CASE REPORT: A 93-year-old female became altered and was found to have hypotension and profound symptomatic bradycardia 30 min post ingestion of a single 4-mg dose of tizanidine at her physician's office. Emergency Medical Services was called to scene and patient was transported to our tertiary medical center. In the emergency department, the patient required intubation, vasopressor support, and transcutaneous pacing. An electrocardiogram revealed atrial fibrillation with slow ventricular response with a heart rate of 19 beats/min. The patient was transferred to the intensive care unit and subsequently taken for cardiac catheterization, where a transvenous pacer was placed. During the next few days, her vital signs and mental status improved, allowing for successful extubation. Before discharge, the patient received a single-chamber pacemaker. DISCUSSION: Profound symptomatic bradycardia from a single dose of tizanidine has not been reported. A review of the patient's medications did not reveal a significant cytochrome P450 drug interaction to result in an adverse effect as previously reported in the literature. CONCLUSIONS: Tizanidine should be used cautiously in elderly population and drug interactions screening should be performed.

Rotavirus disease burden among children <5 years of age--Santa Rosa, Guatemala, 2007-2009.

OBJECTIVES: To assess the burden of rotavirus disease in Guatemala, in view of the recent introduction of a national rotavirus vaccination programme. METHODS: We examined data from an active, facility-based surveillance system in Santa Rosa, Guatemala, from October 2007 through September 2009 among children <5years of age presenting to the hospital or ambulatory clinics with diarrhoea (≥3 loose stools in 24 h during the last 7 days). Demographic and epidemiological data were collected, and specimens were tested for rotavirus via enzyme immunoassay. Genotyping was performed via reverse transcriptase polymerase chain reaction. RESULTS: We enrolled 347 hospitalized patients <5 years of age with diarrhoea and 1215 from ambulatory clinics. Specimens from 275 (79%) hospitalized children and 662 (54%) from ambulatory visits were tested for rotavirus. Rotavirus accounted for 32% of hospitalizations and 9% of ambulatory visits for diarrhoea, resulting in adjusted annual rates of 36 hospitalizations and 372 ambulatory visits per 10 000 children. Ninety-one per cent of hospitalizations and 81% of ambulatory visits for rotavirus diarrhoea occurred in children <2 years. G1P8 represented 71% and 95% of rotavirus genotypes for 2007-2008 and 2008-2009 rotavirus seasons, respectively. CONCLUSIONS: Rotavirus is a major cause of diarrhoea in children <5 years of age in Santa Rosa, Guatemala, highlighting the potential health benefits of vaccination and the need for continued surveillance to assess impact and effectiveness of the rotavirus vaccination programme in Guatemala.

Rotavirus vaccine and health care utilization for diarrhea in U.S. children.

BACKGROUND: Routine vaccination of U.S. infants with pentavalent rotavirus vaccine (RV5) began in 2006. METHODS: Using MarketScan databases, we assessed RV5 coverage and diarrhea-associated health care use from July 2007 through June 2009 versus July 2001 through June 2006 in children under 5 years of age. We compared the rates of diarrhea-associated health care use in unvaccinated children in the period from January through June (when rotavirus is most prevalent) in 2008 and 2009 with the prevaccine rates to estimate indirect benefits. We estimated national reductions in the number of hospitalizations for diarrhea, and associated costs, by extrapolation. RESULTS: By December 31, 2008, at least one dose of RV5 had been administered in 73% of children under 1 year of age, 64% of children 1 year of age, and 8% of children 2 to 4 years of age. Among children under 5 years of age, rates of hospitalization for diarrhea in 2001-2006, 2007-2008, and 2008-2009 were 52, 35, and 39 cases per 10,000 person-years, respectively, for relative reductions from 2001-2006 by 33% (95% confidence interval [CI], 31 to 35) in 2007-2008 and by 25% (95% CI, 23 to 27) in 2008-2009; rates of hospitalization specifically coded for rotavirus infection were 14, 4, and 6 cases per 10,000 person-years, respectively, for relative reductions in the rate from 2001-2006 by 75% (95% CI, 72 to 77) in 2007-2008 and by 60% (95% CI, 58 to 63) in 2008-2009. In the January-June periods of 2008 and 2009, the respective relative rate reductions among vaccinated children as compared with unvaccinated children were as follows: hospitalization for diarrhea, 44% (95% CI, 33 to 53) and 58% (95% CI, 52 to 64); rotavirus-coded hospitalization, 89% (95% CI, 79 to 94) and 89% (95% CI, 84 to 93); emergency department visits for diarrhea, 37% (95% CI, 31 to 43) and 48% (95% CI, 44 to 51); and outpatient visits for diarrhea, 9% (95% CI, 6 to 11) and 12% (95% CI, 10 to 15). Indirect benefits (in unvaccinated children) were seen in 2007-2008 but not in 2008-2009. Nationally, for the 2007-2009 period, there was an estimated reduction of 64,855 hospitalizations, saving approximately $278 million in treatment costs. CONCLUSIONS: Since the introduction of rotavirus vaccine, diarrhea-associated health care utilization and medical expenditures for U.S. children have decreased substantially.

Decline in diarrhea mortality and admissions after routine childhood rotavirus immunization in Brazil: a time-series analysis.

BACKGROUND: In 2006, Brazil began routine immunization of infants <15 wk of age with a single-strain rotavirus vaccine. We evaluated whether the rotavirus vaccination program was associated with declines in childhood diarrhea deaths and hospital admissions by monitoring disease trends before and after vaccine introduction in all five regions of Brazil with varying disease burden and distinct socioeconomic and health indicators. METHODS AND FINDINGS: National data were analyzed with an interrupted time-series analysis that used diarrhea-related mortality or hospitalization rates as the main outcomes. Monthly mortality and admission rates estimated for the years after rotavirus vaccination (2007-2009) were compared with expected rates calculated from pre-vaccine years (2002-2005), adjusting for secular and seasonal trends. During the three years following rotavirus vaccination in Brazil, rates for diarrhea-related mortality and admissions among children <5 y of age were 22% (95% confidence interval 6%-44%) and 17% (95% confidence interval 5%-27%) lower than expected, respectively. A cumulative total of ~1,500 fewer diarrhea deaths and 130,000 fewer admissions were observed among children <5 y during the three years after rotavirus vaccination. The largest reductions in deaths (22%-28%) and admissions (21%-25%) were among children younger than 2 y, who had the highest rates of vaccination. In contrast, lower reductions in deaths (4%) and admissions (7%) were noted among children two years of age and older, who were not age-eligible for vaccination during the study period. CONCLUSIONS: After the introduction of rotavirus vaccination for infants, significant declines for three full years were observed in under-5-y diarrhea-related mortality and hospital admissions for diarrhea in Brazil. The largest reductions in diarrhea-related mortality and hospital admissions for diarrhea were among children younger than 2 y, who were eligible for vaccination as infants, which suggests that the reduced diarrhea burden in this age group was associated with introduction of the rotavirus vaccine. These real-world data are consistent with evidence obtained from clinical trials and strengthen the evidence base for the introduction of rotavirus vaccination as an effective measure for controlling severe and fatal childhood diarrhea.

Disease transmission and passenger behaviors during a high morbidity Norovirus outbreak on a cruise ship, January 2009.

BACKGROUND: Norovirus continues to pose a significant burden on cruise ships, causing an average of 27 confirmed outbreaks annually over the past 5 years. In January 2009, the report of a suspected norovirus outbreak among passengers on a cruise ship prompted an investigation. METHODS: A retrospective cohort study among passengers was conducted on board the ship. Questionnaires about health care-seeking behaviors, hygiene practices, and possible norovirus exposures were placed in every cabin. Stool samples from several ill passengers were tested for norovirus by quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) and confirmed by sequence analysis. RESULTS: Of 1842 passengers, 1532 (83.2%) returned questionnaires, and 236 (15.4% of participants) met the case definition. Of these, 95 (40%) did not report to the infirmary. Case passengers were significantly more likely to have an ill cabin mate (relative risk [RR] = 3.0; P < .01) and to have witnessed vomiting during boarding (RR = 2.8; P = .01). Over 90% of all passengers reported increased hand hygiene practices following the outbreak; 38% of ill passengers and 11% of well passengers decreased participation in public activities. Of 14 samples tested, 12 were positive for norovirus by RT-qPCR; 5 of these were confirmed by sequence analysis and typed as GII.4 Minerva. CONCLUSIONS: Person-to-person transmission, including an incident of public vomiting during boarding, likely contributed to this high morbidity outbreak. Infirmary surveillance detected only 60% of acute gastroenteritis (AGE) cases involved in this outbreak. Adjustments to outbreak reporting thresholds may be needed to account for incomplete voluntary AGE reporting and to more rapidly implement control measures.

Influenza-like illness in a community surrounding a school-based outbreak of 2009 pandemic influenza A (H1N1) virus-Chicago, Illinois, 2009.

In April 2009, following the first school closure due to 2009 pandemic influenza A (H1N1) (pH1N1) in Chicago, Illinois, area hospitals were inundated with patients presenting with influenza-like illness (ILI). The extent of disease spread into the surrounding community was unclear. We performed a household survey to estimate the ILI attack rate among community residents and compared reported ILI with confirmed pH1N1 cases and ILI surveillance data (ie, hospital ILI visits, influenza testing, and school absenteeism). The estimated ILI attack rate was 4.6% (95% confidence interval, 2.8%-7.4%), with cases distributed throughout the 5-week study period. In contrast, 36 (84%) of 43 confirmed pH1N1 cases were identified the week of the school closure. Trends in surveillance data peaked during the same week and rapidly decreased to near baseline. Public awareness and health care practices impact standard ILI surveillance data. Community-based surveys are a valuable tool to help assess the burden of ILI in a community.

Reduction of diarrhea-associated hospitalizations among children aged < 5 Years in Panama following the introduction of rotavirus vaccine.

BACKGROUND: In March 2006, rotavirus vaccine (Rotarix, RV1) was introduced into the Panamanian national immunization program. We assessed the effect of vaccine on diarrhea-associated hospitalizations among young Panamanian children. METHODS: We obtained monthly numbers of diarrhea-associated hospitalizations among children aged ≤ 5 years during 2003 and 2008 from 5 health regions in Panama, representing 53% of the birth cohort. We compared the number of diarrhea-associated hospitalizations during the postvaccine years of 2007 and 2008 with the prevaccine mean numbers 2003-2005 among children < 1 year and those 1 to 4 years of age. Administrative data were used to estimate national rotavirus vaccine coverage. RESULTS: During prevaccine years, diarrhea-associated hospitalizations among children < 5 years in the 5 regions averaged 4057 annually. After the vaccine introduction, a decrease in diarrhea-associated hospitalizations of 22% (898 fewer) occurred in 2007 and 37% (1502 fewer) in 2008. Greater reductions were observed during January through June, the months presumed to have high rotavirus activity in prevaccine years (33% reduction in 2007 and 58% in 2008, compared with prevaccine mean). Reduction estimates were similar among infants and those aged 1-4 years of age, even though only 25% of the latter group was likely to have received vaccine by early 2008. Estimated coverage with ≥ 1 dose of rotavirus vaccine among infants increased from 63% at the end of 2006 to 94% at the end of 2008. CONCLUSIONS: RV1 appears to have had a substantial impact on diarrhea-associated hospitalizations among young children in Panama.

Sustained decline in rotavirus detections in the United States following the introduction of rotavirus vaccine in 2006.

BACKGROUND: Following implementation of the rotavirus vaccination program in 2006, rotavirus activity in the United States declined dramatically in 2007-2008 but increased slightly in 2008-2009, despite greater vaccine uptake. To further evaluate impact of the vaccine program, we assessed trends in rotavirus testing and detection during 2009-2010. METHODS: We examined rotavirus testing data from July 2000 to June 2010 from the National Respiratory and Enteric Viruses Surveillance System to compare rotavirus season timing and peak activity in the pre- and postvaccine introduction eras. Rotavirus season onset was defined as the first of 2 consecutive weeks during which the percentage of specimens testing positive for rotavirus was ≥ 10%. To assess trends in rotavirus testing and detection, we restricted the analyses to 25 laboratories that reported for ≥ 26 weeks per season from 2000 to 2010. RESULTS: During 2009-2010, the threshold for the start of the rotavirus season was never achieved nationally or in the North, Midwest, or West. Activity in the South met this threshold but the season duration was substantially shorter and of lower magnitude than in all previous pre- and postvaccine introduction seasons. Nationally and within each region, the peak week was more delayed and the peak proportion of positive tests was substantially lower than all previous seasons. The total number of tests performed declined by 23%, and the number of positive tests declined by 86%. CONCLUSIONS: Rotavirus activity was substantially diminished during the 2009-2010 rotavirus season compared with the prevaccine baseline and the 2 previous postvaccine introduction seasons. These sustained declines over 3 rotavirus seasons reaffirm the health benefits of the US rotavirus vaccination program.

Uptake, impact, and effectiveness of rotavirus vaccination in the United States: review of the first 3 years of postlicensure data.

BACKGROUND: Rotavirus vaccine was recommended for routine use in US infants in 2006. Before the introduction of vaccine, rotavirus was the most common cause of severe gastroenteritis in children <5 years of age in the United States. METHODS: We reviewed published data to summarize the US experience during the first 3 years of its rotavirus vaccination program. RESULTS: Rotavirus seasons have been delayed and diminished in magnitude during the postvaccine era compared with the prevaccine era. Hospitalizations, emergency department visits, and outpatient visits due to gastroenteritis have declined dramatically in children < 5 years of age including in children age-ineligible to have received vaccine, suggesting indirect benefits of vaccination. Rotavirus vaccine has been widely accepted by pediatricians. Vaccine coverage is steadily increasing but remains lower than coverage levels of other routine infant immunizations. CONCLUSIONS: The implementation of routine childhood immunization against rotavirus has rapidly and dramatically reduced the large health burden of rotavirus gastroenteritis in US children. Continued monitoring of rotavirus diarrhea is needed to determine if immunity wanes as vaccinated children get older and to better quantify the indirect benefits of vaccination. Ongoing surveillance will also enable monitoring of the long-term impact of vaccination on rotavirus epidemiology.

Likely transmission of norovirus on an airplane, October 2008.

BACKGROUND: On 8 October 2008, members of a tour group experienced diarrhea and vomiting throughout an airplane flight from Boston, Massachusetts, to Los Angeles, California, resulting in an emergency diversion 3 h after takeoff. An investigation was conducted to determine the cause of the outbreak, assess whether transmission occurred on the airplane, and describe risk factors for transmission. METHODS: Passengers and crew were contacted to obtain information about demographics, symptoms, locations on the airplane, and possible risk factors for transmission. Case patients were defined as passengers with vomiting or diarrhea (> or =3 loose stools in 24 h) and were asked to submit stool samples for norovirus testing by real-time reverse-transcription polymerase chain reaction. RESULTS: Thirty-six (88%) of 41 tour group members were interviewed, and 15 (41%) met the case definition (peak date of illness onset, 8 October 2008). Of 106 passengers who were not tour group members, 85 (80%) were interviewed, and 7 (8%) met the case definition after the flight (peak date of illness onset, 10 October 2008). Multivariate logistic regression analysis showed that sitting in an aisle seat (adjusted relative risk, 11.0; 95% confidence interval, 1.4-84.9) and sitting near any tour group member (adjusted relative risk, 7.5; 95% confidence interval, 1.7-33.6) were associated with the development of illness. Norovirus genotype II was detected by reverse-transcription polymerase chain reaction in stool samples from case patients in both groups. CONCLUSIONS: Despite the short duration, transmission of norovirus likely occurred during the flight.

Trends in healthcare utilization for diarrhea and rotavirus disease in privately insured US children <5 years of age, 2001-2006.

BACKGROUND: To assess impact of the new US rotavirus immunization program initiated in 2006, robust baseline data on diarrhea and rotavirus disease burden are needed. While several studies have assessed burden in inpatient settings, few data are available for emergency department (ED) and outpatient settings. METHODS: We used the MarketScan databases, a large claims-based data repository, to analyze the health and economic burden of diarrhea-related healthcare encounters in children <5 years in inpatient, ED, and outpatient settings from 2001 to 2006. Because rotavirus testing and coding are not routinely performed, rotavirus burden was estimated by calculating excess diarrhea events during winter compared with summer baseline (winter residual method). RESULTS: Between 2001 and 2006, the average annual rate of healthcare utilization for diarrhea was 1561 per 10,000 children <5 years, with a hospitalization rate of 50 per 10,000, ED visit rate of 180 per 10,000, and outpatient visit rate of 1332 per 10,000. The winter residual method attributed 53% of inpatient, 41% of ED, and 23% of outpatient diarrhea events to rotavirus. By age 5, we estimated that 1 in 74 children are admitted, 1 in 27 require ED care, and 1 in 7 are treated in outpatient settings for rotavirus illness. Median payments for rotavirus in inpatient, ED, and outpatient settings were $3135, $332, and $90, respectively. CONCLUSIONS: Rotavirus causes substantial health and economic burden in US children, especially in ED and outpatient settings. Future monitoring through claims-based data sources should allow assessment of rotavirus vaccine impact on healthcare utilization for diarrhea.