Investigation of Respiratory Syncytial Virus-Associated Deaths Among US Children Aged <2 Years, 2004-2007.

We validated the respiratory syncytial virus-coded deaths of children aged <2 years in 2004-2007 using national/state death data and medical records. There were 48 deaths in 4 states, and hospital records for 32 of them were available; 26 of those 32 (81%) had a laboratory finding of respiratory syncytial virus, and 21 of those 26 (81%) had a potential high-risk condition, most commonly preterm birth (35%).

Molecular characterization of respiratory syncytial viruses infecting children reported to have received palivizumab immunoprophylaxis.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of respiratory infections in children. Palivizumab (PZ) is the only RSV-specific immunoprophylaxis approved by the U.S. Food and Drug Administration. Mutations leading to amino acid substitutions in the PZ binding site of the RSV F protein have been associated with breakthrough RSV infections in patients receiving PZ. OBJECTIVE: To detect PZ resistance conferring mutations in RSV strains from children who received PZ. STUDY DESIGN: Children aged ≤ 24 months on October 31 who were hospitalized or had outpatient visits for respiratory illness and/or fever during October-May 2001-2008 in 3 US counties were included. PZ receipt was obtained from parent interviews and medical records among children subsequently infected with RSV. Archived nasal/throat swab specimens were tested for RSV by real-time RT-PCR. The coding region of the PZ binding site of the RSV F protein was sequenced using both Sanger and pyrosequencing methods. RESULTS: Of 8762 enrolled children, 375 (4.3%) were tested for RSV and had a history of PZ receipt, of which 56 (14.9%) were RSV-positive and 45 of these had available archived specimens. Molecular typing identified 42 partial F gene sequences in specimens from 39 children: 19 single RSV subgroup A, 17 subgroup B and 3 mixed infections. Nucleotide substitutions were identified in 12/42 (28.6%) RSV strains. PZ resistance mutations were identified in 4 (10.2%) of the 39 children, of which one had documented PZ receipt. CONCLUSIONS: Although RSV PZ resistance mutations were infrequent, most RSV-associated illnesses in children with a history of PZ receipt were not due to strain resistance.

Respiratory syncytial virus--United States, July 2012-June 2014.

Respiratory syncytial virus (RSV) causes lower respiratory infection among infants and young children worldwide. Annually in the United States, RSV infection has been associated with an estimated 57,527 hospitalizations and 2.1 million outpatient visits among children aged <5 years. In temperate climate zones, RSV generally circulates during the fall, winter, and spring. However, the exact timing and duration of RSV seasons vary by region and from year-to-year. Knowing the start of the RSV season in any given locality is important to health care providers and public health officials who use RSV seasonality data to guide diagnostic testing and the timing of RSV immunoprophylaxis for children at high risk for severe respiratory infection. To describe RSV seasonality (defined as onset, offset, peak, and duration) nationally, by U.S. Department of Health and Human Services (HHS) regions and for the state of Florida, CDC analyzes RSV laboratory detections reported to the National Respiratory and Enteric Virus Surveillance System (NREVSS). Florida is reported separately because it has an earlier season onset and longer season duration than the rest of the country. For 2012-13, the RSV season onset ranged from late October to late December, and season offset ranged from late December to late April, excluding Florida. For 2013-14, the RSV season onset ranged from late October to late January, and season offset from late January to early April, excluding Florida. Weekly updates of RSV national, regional, and state RSV trends are available from NREVSS at http://www.cdc.gov/surveillance/nrevss.

Respiratory syncytial virus infection in Guatemala, 2007-2012.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute respiratory illness (ARI). Little is known about RSV disease among older children and adults in Central America. METHODS: Prospective surveillance for ARI among hospital patients and clinic patients was conducted in Guatemala during 2007-2012. Nasopharyngeal and oropharyngeal swab specimens were tested for RSV, using real-time reverse-transcription polymerase chain reaction. RESULTS: Of 6287 hospitalizations and 2565 clinic visits for ARI, 24% and 12%, respectively, yielded RSV-positive test results. The incidence of RSV-positive hospitalization for ARI was 5.8 cases/10 000 persons per year and was highest among infants aged <6 months (208 cases/10 000 persons per year); among adults, the greatest incidence was observed among those aged ≥ 65 years (2.9 cases/10 000 persons per year). The incidence of RSV-positive clinic visitation for ARI was 32 cases/10 000 persons per year and was highest among infants aged 6-23 months (186 cases/10 000 persons per year). Among RSV-positive hospital patients with ARI, underlying cardiovascular disease was associated with death, moribund discharge, intensive care unit admission, or mechanical ventilation (odds ratio, 4.1; 95% confidence interval, 1.9-8.8). The case-fatality proportion among RSV-positive hospital patients with ARI was higher for those aged ≥ 5 years than for those aged <5 years (13% vs 3%; P < .001). CONCLUSIONS: The incidences of RSV-associated hospitalization and clinic visitation for ARI were highest among young children, but a substantial burden of ARI due to RSV was observed among older children and adults.

Respiratory syncytial virus circulation in seven countries with Global Disease Detection Regional Centers.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in young children globally, with the highest burden in low- and middle-income countries where the association between RSV activity and climate remains unclear. METHODS: Monthly laboratory-confirmed RSV cases and associations with climate data were assessed for respiratory surveillance sites in tropical and subtropical areas (Bangladesh, China, Egypt, Guatemala, Kenya, South Africa, and Thailand) during 2004-2012. Average monthly minimum and maximum temperatures, relative humidity, and precipitation were calculated using daily local weather data from the US National Climatic Data Center. RESULTS: RSV circulated with 1-2 epidemic periods each year in site areas. RSV seasonal timing and duration were generally consistent within country from year to year. Associations between RSV and weather varied across years and geographic locations. RSV usually peaked in climates with high annual precipitation (Bangladesh, Guatemala, and Thailand) during wet months, whereas RSV peaked during cooler months in moderately hot (China) and arid (Egypt) regions. In South Africa, RSV peaked in autumn, whereas no associations with seasonal weather trends were observed in Kenya. CONCLUSIONS: Further understanding of RSV seasonality in developing countries and various climate regions will be important to better understand the epidemiology of RSV and for timing the use of future RSV vaccines and immunoprophylaxis in low- and middle-income countries.

Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age.

BACKGROUND: Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization among infants. However, estimates of the RSV hospitalization burden have varied, and precision has been limited by the use of age strata grouped in blocks of 6 to ≥ 12 months. METHODS: We analyzed data from a 5-year, prospective, population-based surveillance for young children who were hospitalized with laboratory-confirmed (reverse-transcriptase polymerase chain reaction) RSV acute respiratory illness (ARI) during October through March 2000-2005. The total population at risk was stratified by month of age by birth certificate information to yield hospitalization rates. RESULTS: There were 559 (26%) RSV-infected children among the 2149 enrolled children hospitalized with ARI (85% of all eligible children with ARI). The average RSV hospitalization rate was 5.2 per 1000 children <24 months old. The highest age-specific rate was in infants 1 month old (25.9 per 1000 children). Infants ≤ 2 months of age, who comprised 44% of RSV-hospitalized children, had a hospitalization rate of 17.9 per 1000 children. Most children (79%) were previously healthy. Very preterm infants (<30 weeks' gestation) accounted for only 3% of RSV cases but had RSV hospitalization rates 3 times that of term infants. CONCLUSIONS: Young infants, especially those who were 1 month old, were at greatest risk of RSV hospitalization. Four-fifths of RSV-hospitalized infants were previously healthy. To substantially reduce the burden of RSV hospitalizations, effective general preventive strategies will be required for all young infants, not just those with risk factors.

Field evaluation of TaqMan Array Card (TAC) for the simultaneous detection of multiple respiratory viruses in children with acute respiratory infection.

BACKGROUND: Multipathogen reverse transcription real-time PCR (RT-qPCR) platforms have proven useful in surveillance for acute respiratory illness (ARI) and study of respiratory outbreaks of unknown etiology. The TaqMan(®) Array Card (TAC, Life Technologies™), can simultaneously test 7 clinical specimens for up to 21 individual pathogens (depending on arrangement of controls and use of duplicate wells) by arrayed singleplex RT-qPCR on a single assay card, using minimal amounts of clinical specimens. A previous study described the development of TAC for the detection of respiratory viral and bacterial pathogens; the assay was evaluated against well-characterized analytical materials and a limited collection of human clinical specimens. OBJECTIVES: We wished to compare TAC assay performance against standard individual RT-qPCR assays for respiratory viral detection, focusing on 10 viruses (adenovirus, human metapneumovirus, human parainfluenza viruses 1-4, influenza viruses A and B, respiratory syncytial virus, and rhinovirus) from a larger collection of human specimens. STUDY DESIGN: We used specimens from 942 children with ARI enrolled systematically in a population-based, ARI surveillance study (New Vaccine Surveillance Network, NVSN). RESULTS: Compared with standard individual RT-qPCR assays, the sensitivity of TAC for the targeted viruses ranged from 54% to 95% (54%, 56%, and 75% for adenovirus, human parainfluenza viruses-1 and -2, respectively, and 82%-95% for the other viruses). Assay specificity was 99%, and coefficients of variation for virus controls ranged from 1.5% to 4.5%. CONCLUSION: The TAC assay should prove useful for multipathogen studies and rapid outbreak response.

Disparities between black and white children in hospitalizations associated with acute respiratory illness and laboratory-confirmed influenza and respiratory syncytial virus in 3 US counties--2002-2009.

Few US studies have assessed racial disparities in viral respiratory hospitalizations among children. This study enrolled black and white children under 5 years of age who were hospitalized for acute respiratory illness (ARI) in 3 US counties during October-May 2002-2009. Population-based rates of hospitalization were calculated by race for ARI and laboratory-confirmed influenza and respiratory syncytial virus (RSV), using US Census denominators. Relative rates of hospitalization between racial groups were estimated. Of 1,415 hospitalized black children and 1,824 hospitalized white children with ARI enrolled in the study, 108 (8%) black children and 111 (6%) white children had influenza and 230 (19%) black children and 441 (29%) white children had RSV. Hospitalization rates were higher among black children than among white children for ARI (relative rate (RR) = 1.7, 95% confidence interval (CI): 1.6, 1.8) and influenza (RR = 2.1, 95% CI: 1.6, 2.9). For RSV, rates were similar among black and white children under age 12 months but higher for black children aged 12 months or more (for ages 12-23 months, RR = 1.7, 95% CI: 1.1, 2.5; for ages 24-59 months, RR = 2.2, 95% CI: 1.3, 3.6). Black children versus white children were significantly more likely to have public insurance or no insurance (85% vs. 43%) and a history of asthma/wheezing (28% vs. 18%) but not more severe illness. The observed racial disparities require further study.

The burden of influenza in young children, 2004-2009.

OBJECTIVE: To characterize the health care burden of influenza from 2004 through 2009, years when influenza vaccine recommendations were expanded to all children aged ≥6 months. METHODS: Population-based surveillance for laboratory-confirmed influenza was performed among children aged <5 years presenting with fever and/or acute respiratory illness to inpatient and outpatient settings during 5 influenza seasons in 3 US counties. Enrolled children had nasal/throat swabs tested for influenza by reverse transcriptase-polymerase chain reaction and their medical records reviewed. Rates of influenza hospitalizations per 1000 population and proportions of outpatients (emergency department and clinic) with influenza were computed. RESULTS: The study population comprised 2970, 2698, and 2920 children from inpatient, emergency department, and clinic settings, respectively. The single-season influenza hospitalization rates were 0.4 to 1.0 per 1000 children aged <5 years and highest for infants <6 months. The proportion of outpatient children with influenza ranged from 10% to 25% annually. Among children hospitalized with influenza, 58% had physician-ordered influenza testing, 35% had discharge diagnoses of influenza, and 2% received antiviral medication. Among outpatients with influenza, 7% were tested for influenza, 7% were diagnosed with influenza, and <1% had antiviral treatment. Throughout the 5 study seasons, <45% of influenza-negative children ≥6 months were fully vaccinated against influenza. CONCLUSIONS: Despite expanded vaccination recommendations, many children are insufficiently vaccinated, and substantial influenza burden remains. Antiviral use was low. Future studies need to evaluate trends in use of vaccine and antiviral agents and their impact on disease burden and identify strategies to prevent influenza in young infants.

Adherence to guidelines for respiratory syncytial virus immunoprophylaxis among infants with prematurity or chronic lung disease in three United States counties.

Among infants with prematurity and/or chronic lung disease for whom respiratory syncytial virus immunoprophylaxis is recommended, we examined adherence in infants enrolled during healthcare visits for acute respiratory illness in 3 U.S. counties from 2001 to 2007. Immunoprophylaxis among infants who met national criteria for prophylaxis increased from 33% to 83% over the 6-year period; 17% (11/65) of infants who received immunoprophylaxis did not meet eligibility criteria.

Human coronavirus in young children hospitalized for acute respiratory illness and asymptomatic controls.

BACKGROUND: Human coronaviruses (HCoVs) have been detected in children with upper and lower respiratory symptoms, but little is known about their relationship with severe respiratory illness. OBJECTIVE: To compare the prevalence of HCoV species among children hospitalized for acute respiratory illness and/or fever (ARI/fever) with that among asymptomatic controls and to assess the severity of outcomes among hospitalized children with HCoV infection compared with other respiratory viruses. METHODS: From December 2003 to April 2004 and October 2004 to April 2005, we conducted prospective, population-based surveillance of children <5 years of age hospitalized for ARI/fever in 3 US counties. Asymptomatic outpatient controls were enrolled concurrently. Nasal/throat swabs were tested for HCoV species HKU1, NL63, 229E, and OC43 by real-time reverse-transcription polymerase chain reaction. Specimens from hospitalized children were also tested for other common respiratory viruses. Demographic and medical data were collected by parent/guardian interview and medical chart review. RESULTS: Overall, HCoV was detected in 113 (7.6%) of 1481 hospitalized children (83 [5.7%] after excluding 30 cases coinfected with other viruses) and 53 (7.1%) of 742 controls. The prevalence of HCoV or individual species was not significantly higher among hospitalized children than controls. Hospitalized children testing positive for HCoV alone tended to be less ill than those infected with other viruses, whereas those coinfected with HCoV and other viruses were clinically similar to those infected with other viruses alone. CONCLUSIONS: In this study of children hospitalized for ARI/fever, HCoV infection was not associated with hospitalization or with increased severity of illness.

Validity of parental report of influenza vaccination in young children seeking medical care.

BACKGROUND: Despite frequent use of self-reported information to determine pediatric influenza vaccination coverage, little data are available on the validity of parental reporting of their child's influenza vaccination status and on factors affecting its accuracy. METHODS: We compared parent reported influenza vaccination of children to documented reports of vaccination collected from medical records (the criterion standard) among children aged 6-59 months who presented to selected hospitals, emergency departments, and clinics in three U.S. counties with acute respiratory illness during three influenza seasons (November through May of 2004-2007). Demographic and epidemiologic data were collected from chart reviews and parental surveys. RESULTS: Among 3072 children aged 6-59 months, 47.5% were reported by the parent to have received influenza vaccine and 39.5% of children had medical record verification of influenza vaccination. Sensitivity and specificity of parental reporting was 92.1% and 82.3%, respectively, when compared to the immunization record. However, 17.7% of children whose parents reported vaccination had no influenza vaccination documented in their medical records, and this proportion was even higher at 28.6%, among children with an underlying high-risk medical condition. Greater reporting accuracy was associated with younger age of child (6-23 months vs. 24-59 months), white non-Hispanic race/ethnicity, having health insurance, and having a mother with a college education. CONCLUSIONS: Our findings indicate that although parental report of influenza vaccination is fairly reliable (∼76-96%), over reporting by parents often occurs and immunization record review remains the preferable method for determining vaccination status in children.

Human rhinovirus species associated with hospitalizations for acute respiratory illness in young US children.

BACKGROUND: The contribution of human rhinovirus (HRV) to severe acute respiratory illness (ARI) is unclear. OBJECTIVE: To assess the association between HRV species detection and ARI hospitalizations. METHODS: Children <5 years old hospitalized for ARI were prospectively enrolled between December 2003 and April 2005 in 3 US counties. Asymptomatic controls were enrolled between December 2003 and March 2004 and between October 2004 and April 2005 in clinics. Nasal and throat swab samples were tested for HRV and other viruses (ie, respiratory syncytial virus, human metapneumovirus, parainfluenza virus, and influenza virus) by reverse-transcription-polymerase chain reaction, and genetic sequencing identified HRV species and types. HRV species detection was compared between controls and patients hospitalized during months in which controls were enrolled. RESULTS: A total of 1867 children with 1947 ARI hospitalizations and 784 controls with 790 clinic visits were enrolled and tested for HRV. The HRV-A detection rate among participants ≥24 months old was 8.1% in the hospitalized group and 2.2% in the control group (P = .009), and the HRV-C detection rates among those ≥6 months old were 8.2% and 3.9%, respectively (P = .002); among younger children, the detection rates for both species were similar between groups. The HRV-B detection rate was ≤1%. A broad diversity of HRV types was observed in both groups. Clinical presentations were similar among HRV species. Compared with children infected with other viruses, children with HRV detected were similar for severe hospital outcomes and more commonly had histories or diagnoses of asthma or wheezing. CONCLUSIONS: HRV-A and HRV-C were associated with ARI hospitalization and serious illness outcomes.

The burden of respiratory syncytial virus infection in young children.

BACKGROUND: The primary role of respiratory syncytial virus (RSV) in causing infant hospitalizations is well recognized, but the total burden of RSV infection among young children remains poorly defined. METHODS: We conducted prospective, population-based surveillance of acute respiratory infections among children under 5 years of age in three U.S. counties. We enrolled hospitalized children from 2000 through 2004 and children presenting as outpatients in emergency departments and pediatric offices from 2002 through 2004. RSV was detected by culture and reverse-transcriptase polymerase chain reaction. Clinical information was obtained from parents and medical records. We calculated population-based rates of hospitalization associated with RSV infection and estimated the rates of RSV-associated outpatient visits. RESULTS: Among 5067 children enrolled in the study, 919 (18%) had RSV infections. Overall, RSV was associated with 20% of hospitalizations, 18% of emergency department visits, and 15% of office visits for acute respiratory infections from November through April. Average annual hospitalization rates were 17 per 1000 children under 6 months of age and 3 per 1000 children under 5 years of age. Most of the children had no coexisting illnesses. Only prematurity and a young age were independent risk factors for hospitalization. Estimated rates of RSV-associated office visits among children under 5 years of age were three times those in emergency departments. Outpatients had moderately severe RSV-associated illness, but few of the illnesses (3%) were diagnosed as being caused by RSV. CONCLUSIONS: RSV infection is associated with substantial morbidity in U.S. children in both inpatient and outpatient settings. Most children with RSV infection were previously healthy, suggesting that control strategies targeting only high-risk children will have a limited effect on the total disease burden of RSV infection.

Parainfluenza virus infection of young children: estimates of the population-based burden of hospitalization.

OBJECTIVE: To determine the population-based inpatient disease burden of parainfluenza virus in children <5 years of age. STUDY DESIGN: The New Vaccine Surveillance Network (NVSN) enrolled children <5 years of age who were hospitalized with febrile or acute respiratory illnesses. Surveillance hospitals admitted >95% of all hospitalized children from each county. Combined nasal turbinate/throat swabs were tested for parainfluenza virus (PIV), respiratory syncytial virus, and influenza virus with culture and reverse-transcription-polymerase chain reaction. Both parental interviews and medical chart reviews were conducted. Age-specific population-based hospitalization rates were calculated. RESULTS: From October 2000 through September 2004, 2798 children were enrolled. A total of 191 PIVs were identified from 189 children (6.8% of enrolled: 73 PIV type 1, 23 PIV type 2, and 95 PIV type 3), compared with 521 respiratory syncytial viruses and 159 influenza viruses. Mean PIV hospitalization rates were 3.01, 1.73, 1.53, 0.39, and 1.02 per 1000 children per year for ages 0 to 5 months, 6 to 11 months, 12 to 23 months, 24 to 59 months, and 0 to 59 months, respectively. CONCLUSIONS: PIV accounted for 6.8% of all hospitalizations for fever, acute respiratory illnesses, or both in children <5 years of age. The pediatric PIV inpatient burden is substantial and highlights the need to find an effective vaccine candidate.

A novel group of rhinoviruses is associated with asthma hospitalizations.

BACKGROUND: Although recent studies have identified new group C human rhinoviruses (HRVCs), their spectrum of pediatric disease is unknown. OBJECTIVE: We sought to determine the presentation and burden of disease caused by HRVCs among young hospitalized children. METHODS: We conducted prospective population-based surveillance in 2 US counties among children less than 5 years of age hospitalized with acute respiratory illness or fever from October 2001 through September 2003. Nasal/throat swabs were obtained and tested for HRVs, as determined by means of RT-PCR and then characterized by means of partial sequencing. RESULTS: Of 1052 children enrolled and tested during the 2-year period, 167 (16%) had HRVs detected. Of 147 samples successfully sequenced, 64 were group A HRVs, 6 were group B HRVs, and 77 were HRVCs. Children with HRVCs were significantly more likely than those with group A HRVs to have underlying high-risk conditions, such as asthma (42% vs 23%, P = .023) and to have had a discharge diagnosis of asthma (55% vs 36%, P = .022). CONCLUSIONS: Overall, HRVCs were detected in 7% of children hospitalized for fever or respiratory conditions and constituted almost half of all rhinovirus-associated hospitalizations, suggesting that this novel group causes a substantial burden of pediatric disease.

Vaccine effectiveness against laboratory-confirmed influenza in children 6 to 59 months of age during the 2003-2004 and 2004-2005 influenza seasons.

OBJECTIVE: The goal was to estimate the effectiveness of influenza vaccination against laboratory-confirmed influenza during the 2003-2004 and 2004-2005 influenza seasons in children 6 to 59 months of age. METHODS: We conducted a case-control study with children with medically attended, acute respiratory infections who received care in an inpatient, emergency department, or outpatient clinic setting during 2 consecutive influenza seasons. All children residing in Monroe County, New York, Davidson County, Tennessee, or Hamilton County, Ohio, were enrolled prospectively at the time of acute illness and had nasal/throat swabs tested for influenza with cultures and/or polymerase chain reaction assays. Children with laboratory-confirmed influenza were case subjects and children who tested negative for influenza were control subjects. Child vaccination records from the parent and the child's physician were used to determine and to validate influenza vaccination status. Influenza vaccine effectiveness was calculated as (1 - adjusted odds ratio) x 100. RESULTS: We enrolled 288 case subjects and 744 control subjects during the 2003-2004 season and 197 case subjects and 1305 control subjects during the 2004-2005 season. Six percent and 19% of all study children were fully vaccinated according to immunization guidelines in the respective seasons. Full vaccination was associated with significantly fewer influenza-related inpatient, emergency department, or outpatient clinic visits in 2004-2005 (vaccine effectiveness: 57%) but not in 2003-2004 (vaccine effectiveness: 44%). Partial vaccination was not effective in either season. CONCLUSIONS: Receipt of all recommended doses of influenza vaccine was associated with halving of laboratory-confirmed influenza-related medical visits among children 6 to 59 months of age in 1 of 2 study years, despite suboptimal matches between the vaccine and circulating influenza strains in both years.

Influenza burden for children with asthma.

OBJECTIVE: The goal was to estimate the influenza disease burden among children with asthma and among healthy children by using active, laboratory-confirmed, population-based surveillance. METHODS: Children 6 to 59 months of age residing in 3 US counties who were hospitalized with acute respiratory illnesses or fever were enrolled prospectively from 2000 through 2004. Similar children who presented to clinics and emergency departments during 2 of the influenza seasons (2002-2004) were enrolled. Rates of influenza-attributable outpatient visits and hospitalizations for children with asthma and for healthy children were estimated. History of asthma and receipt of influenza vaccine for the study children were determined through parental report. The prevalence of asthma in the surveillance population was assumed to be 6.2% for children 6 to 23 months of age and 12.3% for children 24 to 59 months of age. RESULTS: Of 81 children 6 to 59 months of age with influenza-confirmed hospitalizations in 2000 to 2004, 19 (23%) had asthma. Average annual influenza-attributable hospitalization rates were significantly higher among children with asthma than among healthy children 6 to 23 months of age (2.8 vs 0.6 cases per 1000 children) but not children 24 to 59 months of age (0.6 vs 0.2 case per 1000 children). Of 249 children 6 to 59 months of age with influenza-confirmed outpatient visits in 2002 to 2004, 38 (15%) had asthma. Estimated outpatient influenza-attributable visit rates were higher among children with asthma than among healthy children 6 to 23 months of age (316 vs 152 cases per 1000 children) and 24 to 59 months of age (188 vs 102 cases per 1000 children) in 2003 to 2004. Few parents reported that their children had been vaccinated, including <30% of children with asthma. CONCLUSION: Influenza-attributable health care utilization is high among children with asthma and is generally higher than among healthy children.

Assessing influenza vaccine utilization in physician offices serving adult patients: experience during a season of vaccine delays and shortages.

BACKGROUND: Influenza vaccination among US adults has plateaued at suboptimal levels. Severe delays and shortages of influenza vaccine prompted revised guidances to prioritize vaccine first to persons at greatest risk for serious influenza complications and to create vaccine stockpiles. OBJECTIVES: (1) Pilot an assessment of influenza vaccine use in a large sample of physician offices with adult patients. (2) Apply the method to assess vaccine receipt by age and risk groups. METHODS: Influenza vaccination and risk status for the 2000-2001 season were obtained from record review conducted in November 2001 to April 2002 for adult patients in a sample of physicians' offices in eight states. Participating physicians also completed a questionnaire. RESULTS: The assessment method was feasible to implement. One hundred eighteen physicians participated. They administered more than 83 percent of doses to prioritized groups in October and November compared with 74 percent of doses during the entire season. Office-based vaccination coverage was less than 40 percent in all age and risk groups. More than 50 percent of participating physicians reported unused doses. CONCLUSIONS: Office-based assessments of vaccine utilization can be a valuable evaluation tool. Vaccine distribution was consistent with recommendations to target early vaccination to priority groups. Results highlight the difficulty distributing vaccine late in the season and the need for strategies to improve vaccination coverage, particularly when vaccine supply is inadequate.