Influenza-related hospitalizations in children younger than three years of age

Management of influenza - updated Swedish guidelines for antiviral treatment

Influenza causes seasonal epidemics of respiratory infection in all parts of the world. Manifestations of influenza range from mild upper to severe lower respiratory tract infection. Medical risk groups are defined by factors predisposing for development of severe disease and are recommended annual vaccination as a protective measure. The previous Swedish treatment guidelines for influenza were issued in 2011, and a review of current evidence was deemed relevant. An important reason to revisit the guidelines is the recent approval of a novel drug for influenza treatment, baloxavir. Updated Swedish evidence-based guidelines created by a group of experts from various research areas, for the management of influenza are presented here. The work has been made in collaboration with the Public Health Agency of Sweden and the Swedish Reference Group for AntiViral therapy (RAV). The updated guidelines include guidelines for diagnostics, treatment and prophylaxis in special groups, including management of pregnant women and children with influenza. A new section about infection control has been added. Pharmacological treatment is covered in detail with regards to indication and dosage. Additionally, drug resistance and environmental aspects are discussed.

Influenza in Children With Special Risk Medical Conditions: A Systematic Review and Meta-analysis

BACKGROUND

Children with special risk medical conditions (SRMC) are over-represented in influenza hospitalizations. A systematic review was undertaken to determine whether children with SRMCs experience greater complications or severity following influenza infection.

METHODS

Bibliographies of pertinent articles were searched in MEDLINE and EMBASE (1990 to March 2018) and contact made with the investigators of unpublished studies containing relevant data. Studies of children (aged ≤18 years) with a SRMC hospitalized with influenza were included. Outcomes were pneumonia, intensive care unit (ICU) admission, mechanical ventilation, neurologic outcomes (seizures, encephalopathy), death and length of stay in hospital or ICU.

RESULTS

Twenty-two studies met inclusion criteria. Compared with healthy peers, children with SRMC had higher odds of ICU admission [pooled odds ratio (OR) 1.66 (95% confidence interval (CI): 1.25-2.21)], for mechanical ventilation [pooled OR 1.53 (95% CI: 0.93-2.52)] and death [pooled OR 1.34 (95% CI: 0.74-2.41)]. Additionally, children with SRMC were more likely to develop bacterial pneumonia (crude OR 1.7; 95% CI: 1.1-2.6) or experience prolonged hospital length of stay [adjusted rate ratio 1.75 (95% CI: 1.44-2.11)]. The level of GRADE evidence was low for all outcomes considered in this review.

CONCLUSIONS

While there was evidence that ICU management and bacterial pneumonia increases in children with SRMC, evidence showing an increase in the probability of death or need for mechanical ventilation was inconsistent. Further research using large datasets should evaluate the impact of complications and associated morbidity from influenza in SRMC children.

Unreliable usage of a single influenza virus IgM antibody assay in influenza-like illness: A retrospective study of the 2016-2018 flu epidemic

We retrospectively analyzed serum IgM antibodies (Abs) to influenza viruses from two tertiary hospitals in Beijing from December 2016 to February 2018. Samples from 36,792 patients, aged 0–98 years, were collected and tested. Among the patients, 923 children from two winter flu seasons were assayed with both antigens and IgM Abs to Flu A and Flu B and assigned as paired groups. Another 2,340 adults and 1,978 children with only antigen tested in the 2016 and 2017 winter flu seasons were named as unpaired groups. IgM Abs-positivity rates in children were 0.80% and 36.57% for Flu A and Flu B, respectively, peaking at 4–5 years of age. For adults, the Flu A and Flu B IgM Abs-positivity rates were 10.34% and 21.49%, respectively, peaking at 18–35 years of age. The trend of temporal distribution between the children and the adults was significantly correlated for IgM Abs to Flu B, but not for Flu A. Compared with unpaired groups, the detection rate of Flu A antigen was significantly higher than IgM Abs in children, whereas frequencies of IgM Abs were higher than antigen in adults. Incidence of Flu B antigen was sharply increased in 2017 winter than in the 2016 winter in both children and adults, but no concomitant increase was observed in IgM Abs to Flu B. For paired children groups, incidence of Flu B antigen in the 2017 flu season was significantly higher than that in the 2016 flu season; in contrast, positive rates of IgM Abs in the 2017 flu season were even lower than those in 2016. Considering antigen detection may reflect the Flu A/Flu B epidemic, our results indicate single-assayed IgM Abs were less effective in the diagnosis of acute influenza virus infection, and the use of this assay for epidemiology evaluations was not supported by these findings.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Pneumonia and influenza hospitalizations among children under 5 years of age in Suzhou, China, 2005-2011

BACKGROUND

The disease burden of influenza among children in China has not been well described.

OBJECTIVE

To estimate the influenza-associated excess hospitalization rate and compare the hospitalization length and costs between pneumonia and influenza (P&I) and other community-acquired diseases (CAD) in Suzhou, China.

METHODS

We retrospectively collected hospital discharge data on pediatric patients' discharge diagnosis, hospital costs, and length of hospital stay in Suzhou. P&I hospitalization was defined as a primary discharge diagnosis of pneumonia and influenza disease (ICD-10 codes J09-J18). Other CAD were common community-acquired diseases among children. Negative binomial regression models were used to estimate the weekly P&I hospitalizations in Suzhou. Excess P&I hospitalizations due to influenza were calculated as the difference in P&I hospitalizations between the epidemic period and the baseline period. Baseline was defined as when the influenza-positive rates were <5% for two consecutive weeks.

RESULTS

From October 2005 to September 2011, we identified a total of 180 091 all-cause hospitalizations among children <5 years of age in Suzhou City. The rates of P&I and influenza-associated excess hospitalizations were highest in the 2009-2010 pandemic and 2010-2011 post-pandemic seasons. Infants <6 months of age had the highest P&I hospitalization rates, the longest hospital stays (7.5-8.0 days), and the highest hospitalization costs for P&I. Compared with other CAD, children admitted for P&I had longer hospital stays and higher hospitalization costs.

CONCLUSIONS

The influenza-associated P&I hospitalization rates and economic burden were high among children. Targeted influenza prevention and control strategies for young children in Suzhou may reduce the influenza-associated hospitalizations in this age group.

Hospitalization for Influenza A Versus B

BACKGROUND

The extent to which influenza A and B infection differs remains uncertain.

METHODS

Using active surveillance data from the Canadian Immunization Monitoring Program Active at 12 pediatric hospitals, we compared clinical characteristics and outcomes of children ≤16 years admitted with laboratory-confirmed influenza B or seasonal influenza A. We also examined factors associated with ICU admission in children hospitalized with influenza B.

RESULTS

Over 8 nonpandemic influenza seasons (2004-2013), we identified 1510 influenza B and 2645 influenza A cases; median ages were 3.9 and 2.0 years, respectively (P < .0001). Compared with influenza A patients, influenza B patients were more likely to have a vaccine-indicated condition (odds ratio [OR] = 1.30; 95% confidence interval [CI] = 1.14-1.47). Symptoms more often associated with influenza B were headache, abdominal pain, and myalgia (P < .0001 for all symptoms after adjustment for age and health status). The proportion of deaths attributable to influenza was significantly greater for influenza B (1.1%) than influenza A (0.4%); adjusted for age and health status, OR was 2.65 (95% CI = 1.18-5.94). A similar adjusted OR was obtained for all-cause mortality (OR = 2.95; 95% CI = 1.34-6.49). Among healthy children with influenza B, age ≥10 years (relative to <6 months) was associated with the greatest odds of ICU admission (OR = 5.79; 95% CI = 1.91-17.57).

CONCLUSIONS

Mortality associated with pediatric influenza B infection was greater than that of influenza A. Among healthy children hosptialized with influenza B, those 10 years and older had a significant risk of ICU admission.

Two Birds With One Stone: Estimating Population Vaccination Coverage From a Test-negative Vaccine Effectiveness Case-control Study

Vaccination program evaluation includes assessment of vaccine uptake and direct vaccine effectiveness (VE). Often examined separately, we propose a design to estimate rotavirus vaccination coverage using controls from a rotavirus VE test-negative case-control study and to examine coverage following implementation of the Quebec, Canada, rotavirus vaccination program. We present our assumptions for using these data as a proxy for coverage in the general population, explore effects of diagnostic accuracy on coverage estimates via simulations, and validate estimates with an external source. We found 79.0% (95% confidence interval, 74.3%, 83.0%) ≥2-dose rotavirus coverage among participants eligible for publicly funded vaccination. No differences were detected between study and external coverage estimates. Simulations revealed minimal bias in estimates with high diagnostic sensitivity and specificity. We conclude that controls from a VE case-control study may be a valuable resource of coverage information when reasonable assumptions can be made for estimate generalizability; high rotavirus coverage demonstrates success of the Quebec program.

Healthcare providers as sources of vaccine-preventable diseases

Vaccine-preventable infectious diseases may be introduced into the healthcare setting and pose a serious risk to vulnerable populations including immunocompromised patients. Healthcare providers (HCPs) are exposed to these pathogens through their daily tasks and may serve as a reservoir for ongoing disease transmission in the healthcare setting. The primary method of protection from work-related infection risk is vaccination that protects not only an individual HCP from disease, but also subsequent patients in contact with that HCP. Individual HCPs and healthcare institutions must balance the ethical and professional responsibility to protect their patients from nosocomial transmission of preventable infections with HCP autonomy. This article reviews known cases of HCP-to-patient transmission of the most common vaccine-preventable infections encountered in the healthcare setting including hepatitis B virus, influenza virus, Bordetella pertussis, varicella-zoster virus, measles, mumps and rubella virus. The impact of HCP vaccination on patient care and current recommendations for HCP vaccination against vaccine-preventable infectious diseases are also reviewed.

Complications and associated bacterial coinfections among children hospitalized with seasonal or pandemic influenza, United States, 2003-2010

BACKGROUND

Data on the range and severity of influenza-associated complications among children are limited. We describe the frequency and severity of complications in hospitalized children aged <18 years with seasonal influenza (during 2003-2009) and 2009 pandemic influenza A(H1N1) (during 2009-2010).

METHODS

Population-based surveillance for laboratory-confirmed influenza hospitalizations was conducted among 5.3 million children in 10 states. Complications were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes in medical records.

RESULTS

During 2003-2010, 7293 children hospitalized with influenza were identified, of whom 6769 (93%) had complete ICD-9 code data. Among the 6769 children, the median length of hospitalization was 3 days (interquartile range, 2-4 days), 975 (14%) required intensive care, 359 (5%) had respiratory failure, and 40 (1%) died. The most common complications were pneumonia (in 28% of children), asthma exacerbations (in 22% [793/3616] aged ≥ 2 years), and dehydration (in 21%). Lung abscess/empyema, tracheitis, encephalopathy, bacteremia/sepsis, acute renal failure, and myocarditis were rare (each ≤ 2% of children) but associated with a median hospitalization duration of ≥ 6 days, and 48%-70% of children required intensive care. Bacterial cultures with positive results were identified in 2% of children (107/6769); Staphylococcus aureus and Streptococcus pneumoniae were most commonly identified.

CONCLUSIONS

Complications contribute substantially to the disease burden among children hospitalized with influenza, through intensive care requirements and prolonged hospitalization, highlighting the importance of primary prevention with influenza vaccination.

Vaccination of healthy children against seasonal influenza: a European perspective

Despite ample evidence for the great burden that annual influenza epidemics place on children and society in general, few European countries currently recommend influenza vaccination of healthy children of any age. The most frequently cited reasons for reluctance to extend general vaccine recommendations to children include the view that influenza is a mild illness of limited clinical importance, lack of country-specific data on disease burden, uncertainty about the efficacy and safety of influenza vaccines in children and inadequate evidence of cost-effectiveness of vaccinating children. In recent years, several clinical studies have provided new and important information that help address many of these areas of question and concern. In light of this newly available scientific evidence, influenza vaccine recommendations for children should be properly reevaluated in all European countries. Furthermore, to allow for variation in costs and patterns of healthcare delivery between different countries, cost-effectiveness analyses of influenza vaccination of healthy children should be performed in each country or region. Finally, increased efforts should be made to educate both healthcare professionals and the great public about recent findings and advances in the field of pediatric influenza.

The burden of influenza B: a structured literature review

We reviewed the epidemiology, clinical characteristics, disease severity, and economic burden of influenza B as reported in the peer-reviewed published literature. We used MEDLINE to perform a systematic literature review of peer-reviewed, English-language literature published between 1995 and 2010. Widely variable frequency data were reported. Clinical presentation of influenza B was similar to that of influenza A, although we observed conflicting reports. Influenza B-specific data on hospitalization rates, length of stay, and economic outcomes were limited but demonstrated that the burden of influenza B can be significant. The medical literature demonstrates that influenza B can pose a significant burden to the global population. The comprehensiveness and quality of reporting on influenza B, however, could be substantially improved. Few articles described complications. Additional data regarding the incidence, clinical burden, and economic impact of influenza B would augment our understanding of the disease and assist in vaccine development.

Clinical features and outcomes of influenza A and B infections in children

The aim of the study was to describe the course of influenza among children aged 0-59 months. A total of 150 children with influenza-like symptoms (ILI): cough, fever >37.8 °C, and sore throat was included into the observation. All children were tested with both rapid influenza detection test (RIDT) BD Directigen™ EZ Flu A+B® and RT-PCR. Sixty four cases of influenza were diagnosed (incidence rate 40 %): 19 (30 %) cases of influenza caused by type B virus and 45 (70 %) cases caused by type A virus. Children with influenza required more often follow up visits (p < 0.05, OR 1.99, 95 % CI 1.03-3.85) and less often were administrated antibiotic therapy (p < 0.05, OR 0.25, 95 % CI 0.04-0.97). The logistic regression analysis revealed that only positive result of rapid influenza detection test, not any of clinical symptoms, could be found as an independent predictor of influenza (OR 4.37, 95 % CI 2.03-9.43). Patients with influenza type A more often reported muscle ache (p < 0.05) and complications (p < 0.05; OR 6.06, 95 % CI 1.20-60.38). Otitis media occurred more often among patients with than without influenza (p < 0.01; OR 15.50, 95 % CI 2.10-688.5). We conclude that although influenza infections among children younger than 59 months were generally mild and self-limited, pediatric burden of the disease was significant.

Burden of influenza in Latin America and the Caribbean: a systematic review and meta-analysis

OBJECTIVE

Influenza causes severe morbidity and mortality. This systematic review aimed to assess the incidence, etiology, and resource usage for influenza in Latin America and the Caribbean.

DESIGN

Meta-analytic systematic review. Arcsine transformations and DerSimonian Laird random effects model were used for meta-analyses.

SETTING

A literature search from 1980 to 2008 in MEDLINE, Cochrane Library, EMBASE, LILACS, Ministries of Health, PAHO, proceedings, reference lists, and consulting experts.

SAMPLE

We identified 1092 references, of which 31 were finally included, in addition to influenza surveillance reports. We also used information from the 10 reports from the collaborative group for epidemiological surveillance of influenza and other respiratory virus (GROG), and information retrieved from the WHO global flu database FLUNET.

MAIN OUTCOME MEASURES

Incidence, percentage of influenza specimens out of the total received by influenza centers and resource-use outcomes.

RESULTS

A total of 483 130 specimens of patients with influenza were analyzed. Meta-analysis showed an annual rate of 36 080 (95%CI 28 550 43 610) influenza-like illness per 100 000 persons-years. The percentage of influenza out of total specimens received by influenza centers ranged between 4.66% and 15.42%, with type A the most prevalent, and A subtype H3 predominating. The mean length of stay at hospital due to influenza ranged between 5.8 12.9 days, total workdays lost due to influenza-like illnesses were 17 150 days, and the mean direct cost of hospitalization was US$575 per laboratory-confirmed influenza case.

CONCLUSIONS

Our data show that seasonal influenza imposes a high morbidity and economic burden to the region. However, the vaccine-uptake rate has been low in this region. Population-based cohort studies are required to improve the knowledge about incidence and resource utilization, which would inform healthcare authorities for decision making.

Safety and persistence of immunological response 6 months after intramuscular vaccination with an AS03-adjuvanted H1N1 2009 influenza vaccine: an open-label, randomized trial in Japanese children aged 6 months to 17 years

This study evaluated the long-term persistence of immune response and safety of two doses of an A/California/7/2009 H1N1 pandemic influenza vaccine adjuvanted with AS03 (an α-tocopherol oil-in-water emulsion-based Adjuvant System) in Japanese children (NCT01001169). Sixty healthy subjects aged 6 mo-17 y were enrolled (1:1) into two study groups to receive 21 d apart, two doses of 1.9 µg haemagglutinin [HA]+AS03B (5.93 mg α-tocopherol) vaccine (6 mo-9 y) and 3.75 µg HA+AS03A (11.86 mg α-tocopherol) vaccine (10-17 y), respectively. Immunogenicity data (by haemagglutination inhibition [HI] and microneutralisation assays) to six months after the first vaccine dose are reported here. It was observed that following Dose 2, the HI immune response against the vaccine homologous strain induced by the two different dosages of the AS03-adjuvanted vaccine met and exceeded the US and European regulatory guidance criteria for pandemic influenza vaccines (seroprotection rate[SPR]/seroconversion rate[SCR]: 100%/100%; geometric mean fold rise GMFR: 146.8/57.1). Further, the immune response persisted for at least six months after the first vaccine dose wherein these regulatory criteria were still met (SPR: 100%/100%; SCR: 96.4%/89.7%; GMFR: 25.3/23.5). The neutralising antibody response was comparable to the HI immune response at Day 42 (vaccine response rate [VRR]: 100%/100%) and at Day 182 (VRR: 96.4%/82.8%). Overall, both vaccine dosages had a clinically acceptable safety profile. Thus, two doses of a 1.9 µg or 3.75 µg HA AS03-adjuvanted H1N1 2009 pandemic influenza vaccine in children aged 6 mo-17 y induced strong immune responses against the vaccine homologous strain that persisted for at least six months after the first vaccine dose.

MF59™-adjuvanted seasonal influenza vaccine in young children

Influenza is a viral disease of the upper respiratory tract, which is manifested in seasonal epidemic waves associated with excess morbidity and mortality. Although efforts at prevention have traditionally been focused on the elderly, interest is growing on the specific features of influenza disease in children and the opportunities for prevention in this age group. Owing to recent improvements in surveillance schemes and diagnostic tools it has been realized that young children experience a burden of morbidity due to influenza as high or higher than the elderly and that children possibly act as a source of influenza infection and determinants of the intensity and the spread of influenza in the community, and as a result, the proposition that children should be preferentially targeted for influenza vaccination is gaining acceptance in many industrialized countries. Traditional seasonal inactivated influenza vaccines have performed poorly in the very young and the live-attenuated influenza vaccines, which are highly efficacious in this age group, have been associated with a poor safety profile in those less than 2 years of age. MF59™-adjuvanted influenza vaccines that were traditionally used in the elderly show a very promising safety and efficacy profile in the pediatric population that could overcome the limitations of the other currently available influenza vaccines for use in this age group.

Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis

BACKGROUND

The global burden of disease attributable to seasonal influenza virus in children is unknown. We aimed to estimate the global incidence of and mortality from lower respiratory infections associated with influenza in children younger than 5 years.

METHODS

We estimated the incidence of influenza episodes, influenza-associated acute lower respiratory infections (ALRI), and influenza-associated severe ALRI in children younger than 5 years, stratified by age, with data from a systematic review of studies published between Jan 1, 1995, and Oct 31, 2010, and 16 unpublished population-based studies. We applied these incidence estimates to global population estimates for 2008 to calculate estimates for that year. We estimated possible bounds for influenza-associated ALRI mortality by combining incidence estimates with case fatality ratios from hospital-based reports and identifying studies with population-based data for influenza seasonality and monthly ALRI mortality.

FINDINGS

We identified 43 suitable studies, with data for around 8 million children. We estimated that, in 2008, 90 million (95% CI 49-162 million) new cases of influenza (data from nine studies), 20 million (13-32 million) cases of influenza-associated ALRI (13% of all cases of paediatric ALRI; data from six studies), and 1 million (1-2 million) cases of influenza-associated severe ALRI (7% of cases of all severe paediatric ALRI; data from 39 studies) occurred worldwide in children younger than 5 years. We estimated there were 28,000-111,500 deaths in children younger than 5 years attributable to influenza-associated ALRI in 2008, with 99% of these deaths occurring in developing countries. Incidence and mortality varied substantially from year to year in any one setting.

INTERPRETATION

Influenza is a common pathogen identified in children with ALRI and results in a substantial burden on health services worldwide. Sufficient data to precisely estimate the role of influenza in childhood mortality from ALRI are not available.

FUNDING

WHO; Bill & Melinda Gates Foundation.

Severe influenza cases in paediatric intensive care units in Germany during the pre-pandemic seasons 2005 to 2008

BACKGROUND

Data on complications in children with seasonal influenza virus infection are limited. We initiated a nation-wide three-year surveillance of children who were admitted to a paediatric intensive care unit (PICU) with severe seasonal influenza.

METHODS

From October 2005 to July 2008, active surveillance was performed using an established reporting system for rare diseases (ESPED) including all paediatric hospitals in Germany. Cases to be reported were hospitalized children < 17 years of age with laboratory-confirmed influenza treated in a PICU or dying in hospital.

RESULTS

Twenty severe influenza-associated cases were reported from 14 PICUs during three pre-pandemic influenza seasons (2005-2008). The median age of the patients (12 males/8 females) was 7.5 years (range 0.1-15 years). None had received vaccination against influenza. In 14 (70%) patients, the infection had been caused by influenza A and in five (25%) by influenza B; in one child (5%) the influenza type was not reported. Patients spent a median of 19 (IQR 12-38) days in the hospital and a median of 11 days (IQR 6-18 days) in the PICU; 10 (50%) needed mechanical ventilation. Most frequent diagnoses were influenza-associated pneumonia (60%), bronchitis/bronchiolitis (30%), encephalitis/encephalopathy (25%), secondary bacterial pneumonia (25%), and ARDS (25%). Eleven (55%) children had chronic underlying medical conditions, including 8 (40%) with chronic pulmonary diseases. Two influenza A- associated deaths were reported: i) an 8-year old boy with pneumococcal encephalopathy following influenza infection died from cerebral edema, ii) a 14-year-old boy with asthma bronchiale, cardiac malformation and Addison's disease died from cardiac and respiratory failure. For nine (45%) patients, possibly permanent sequelae were reported (3 neurological, 3 pulmonary, 3 other sequelae).

CONCLUSIONS

Influenza-associated pneumonia and secondary bacterial infections are relevant complications of seasonal influenza in Germany. The incidence of severe influenza cases in PICUs was relatively low. This may be either due to the weak to moderate seasonal influenza activity during the years 2005 to 2008 or due to under-diagnosis of influenza by physicians. Fifty% of the observed severe cases might have been prevented by following the recommendations for vaccination of risk groups in Germany.

Complicated features in a young child with influenza B virus pneumonia and co-infection with Stenotrophomonas maltophilia

A 3.5-year-old child with influenza B virus pneumonia developed pneumomediastinum and subcutaneous emphysema on the 3rd day of illness. Bronchoscopy demonstrated obstruction of the left main bronchus by mucopurulent sputum. Culture of the broncho-alveolar lavage yielded Stenotrophomonas maltophilia. After the respiratory complications resolved (11 days), the patient developed neurological symptoms and was diagnosed as acute disseminated encephalomyelitis (ADEM). Stenotrophomonas maltophilia was probably a factor in the development of pneumomediastinum. To our knowledge, this is the first case report of influenza virus infection with Stenotrophomonas maltophilia co-infection associated with spontaneous pneumomediastinum.

Influenza vaccination, diagnosis, and treatment in children

Between 2009 and 2010, the influenza H1N1 pandemic swept across the globe, disproportionately affecting the pediatric population. This pandemic strain is expected to circulate again with other seasonal influenza strains during the 2010-2011 season. This article reviews the new 2010 to 2011 Centers for Disease Control and Prevention and American Academy of Pediatrics recommendations for vaccination against the influenza virus for pediatric patients. It reviews the various testing modalities and the benefits and disadvantage of each test and offers an approach to diagnostic testing. Lastly, it reviews the indications and recommendations for treatment of children with presumed or confirmed influenza infection.

The immunogenicity of a novel A (H1N1) vaccine in HIV-infected children

BACKGROUND

In October 2009, the United Kingdom Department of Health recommended vaccination of high-risk groups, including children with HIV, with a novel, oil-in-water AS03(B) adjuvanted Influenza A (H1N1) vaccine (Pandemrix). There were no published data available regarding the immunogenicity of this vaccine in such children.

OBJECTIVES

This study evaluated the immunogenicity of the adjuvanted Influenza A (H1N1) vaccine in HIV-infected children immunised according to national recommendations and assessed the impact of vaccination on individual CD4 counts and HIV viral loads.

METHODS

HIV-infected children attending outpatient appointments between 01 November and 31 December 2009 were offered two doses of H1N1 vaccine three weeks apart and a blood test before and 3 weeks after the second dose of vaccine. Serum antibody responses were determined by a haemagglutination inhibition (HAI) assay using standard methods.

RESULTS

Of the 39 children recruited for vaccination, 31 (median age 11.2, range 3.0-17.9 years) received both doses of vaccine and provided pre- and post-vaccination blood samples. Eight children (26%) had baseline HAI titres ≥ 1:32. After vaccination, 29 children (94%, 95% CI, 78.6-99.2%) had HAI titres ≥ 1:32 (seroprotection), of whom 27 (87.1%, 95% CI, 70.1-96.4%) had also had a four-fold rise in titres (seroconversion). In the univariate analysis, post-vaccination geometric mean titres (GMTs) were higher among the 21 children receiving highly active anti-retroviral therapy compared with the 10 treatment-naïve children (GMT 406 [95% CI 218-757] vs. 128 [49-336]; P=0.035), but this was no longer statistically significant when adjusted for prevaccine GMTs. There was no significant impact of vaccination on CD4+ T cell count or HIV viral load.

CONCLUSION

The AS03(B)-adjuvanted pandemic Influenza A (H1N1) vaccine is highly immunogenic and appears to be safe in HIV-infected children.

Admission diagnoses of children 0-16 years of age hospitalized with influenza

The prompt diagnosis of influenza enables the institution of antiviral therapy and adequate cohorting of patients, but scarce data are available to help clinicians correctly suspect influenza in children at the time of admission. This 16-year retrospective study assessed the main admission diagnoses of 401 children aged ≤16 years hospitalized with virologically confirmed influenza. The clinical data were derived from a systematic review of the medical records of the children. Sepsis-like illness was the main reason for admission in 52% of infants aged <6 months and in 7-16% of the older children. Respiratory symptoms accounted for 38% of admissions, and 15% of children were hospitalized due to acute neurologic conditions, primarily febrile convulsions. Wheezing or exacerbation of asthma was the primary reason for admission in 14% of children aged <3 years. No differences were observed in the admission diagnoses between children with influenza A and B infections. The main admission diagnoses vary widely in different age groups of children with influenza, and only a minority of children are hospitalized for respiratory symptoms. The leading role of sepsis-like illness in infants aged <6 months calls for increased efforts to find protective measures against influenza in this age group.

Hospital admissions related to influenza in France during the 2006/2007 epidemic

BACKGROUND

The data available on hospital admissions related to influenza mostly concern in-patients admitted via the emergency department. Severe cases have been collated by intensive care practitioners since 2009. For this survey, we searched French hospital admission databases to estimate the prevalence rate of hospital admissions related to influenza and to record qualitative data.

METHOD

All case studies identified between October 2006 and September 2007 were split into two groups: the first displaying symptoms of clinical influenza and the second suffering from influenza as an associated diagnosis.

RESULTS

We collected 6797 hospital admissions, 2126 of which were closely related to clinical influenza. Fifty percent of cases concerned the elderly and young people. Fifty-six hospital deaths were recorded in which influenza was the underlying cause in 21% of the cases (12). When influenza was an associated diagnosis (44/56), cardiovascular or respiratory diseases were the main causes (26/44).

CONCLUSION

During the same period (2006-2007), the French Sentinel Surveillance identified only 105 hospital admissions related to influenza. Our survey was therefore more exhaustive and was able to record qualitative data. Inclusion of hospital admissions with an associated diagnosis of influenza is debatable because this decreases specificity. The relationship between the principal diagnosis and all the associated diagnoses is difficult to study, although exclusion of this type of hospitalization could significantly underestimate these figures. Despite certain limitations, French hospital admissions databases should complement French Sentinel Surveillance data.

Burden of severe 2009 pandemic influenza A (H1N1) infection in children in Southeast Spain

INTRODUCTION

Most of the published studies on patients admitted with 2009 pandemic influenza are not population based. We have compiled the clinical information regarding all children admitted with 2009 pandemic influenza A (H1N1) infection during the season 2009-2010 in our defined population, in order to have an unbiased view of the most severe side of the clinical spectrum of the infection and to quantify its burden.

METHODS

Children <15 years-old admitted to any of 3 hospitals in South-East Spain with 2009 pandemic influenza A (H1N1) detected by means of reverse transcriptase polymerase chain reaction. High quality data were extracted from clinical records specially designed for the pandemic.

RESULTS

Eighty two children fulfilled the inclusion criteria. The hospitalization rate was 68 per 100,000 children <15 years-old; in those <5 years-old the rate was of 131 and in <1 year-old, 234 per 100,000. An estimated 0.7% of the children who suffered from pandemic influenza were admitted (1.7% in <5 years-old). Intensive care was required for 5% of the hospitalized patients living in the study area. Mortality was roughly estimated about 1 per 100,000 children <15 years-old and was associated with the presence of very severe comorbidities or co-infections. Only 20% of the admitted children were ≥ 5 years-old and without risk factors. The disease followed a generally benign course despite the modest use of oseltamivir (49% of the patients).

CONCLUSIONS

Clinical and epidemiological data are very similar to those observed in other places and in interpandemic seasons with a high influenza activity.

Impact of rotavirus vaccination on hospital-acquired rotavirus gastroenteritis in children

OBJECTIVE

Data show that after the implementation of routine rotavirus vaccination for infants in the United States, community-acquired (CA) rotavirus cases declined substantially in the 2007-2008 season. The impact of community-based rotavirus vaccination on the substantial burden of hospital-acquired (HA) rotavirus has not been documented.

PATIENTS AND METHODS

We assessed CA and HA rotavirus, respiratory syncytial virus, and influenza infections at Children's Memorial Hospital for 5 winter seasons (defined as occurring from September through May) from 2003 to 2008. We also report rotavirus data from the 2008-2009 season.

RESULTS

A similar dramatic decline (>60% compared with the median of previous seasons) occurred in the rates of cases of both CA (P < .0001) rotavirus hospitalizations and HA (P < .01) rotavirus infections in the 2007-2008 season compared with previous seasons, whereas the rates of CA and HA influenza and respiratory syncytial virus, respectively, remained stable. Improvements in hand-hygiene compliance did not correlate with a reduction in the transmission rate of rotavirus in the hospital. Both CA and HA rotavirus rates remained much lower in the 2008-2009 than in the 2003-2007 seasons.

CONCLUSIONS

Community-based rotavirus vaccination is associated with a substantial reduction in the number of children who are admitted with rotavirus. These data also indicate that routine community-based rotavirus infant vaccination protects hospitalized children from acquiring rotavirus. Vaccination efforts should be encouraged as a strategy to affect the substantial burden of HA rotavirus.

Incidence of influenza-related hospitalizations in different age groups of children in Finland: a 16-year study

BACKGROUND

children are frequently hospitalized with influenza-associated illnesses. Few virologically confirmed population-based studies of pediatric hospitalizations performed during several consecutive seasons are vailable.

METHODS

this 16-year retrospective study consisted of all children ≤ 16 years of age who were treated for virologically confirmed influenza at the Department of Pediatrics, Turku University Hospital, Finland, between July 1, 1988 and June 30, 2004. Calculation of the population-based rates of hospitalization in different age cohorts was based on children (n = 69,068) who lived within the 38 municipalities whose acute pediatric care was provided solely by Turku University Hospital.

RESULTS

during the study period, 401 children were hospitalized with virologically confirmed influenza. The average annual incidences of influenza-related hospitalizations were highest among children <6 months (276 [95% confidence interval, 220–336] per 100,000) and 6 to 11 months (173 [95% confidence interval, 129–220] per 100,000) of age. For both influenza A and B, the rates of hospitalization were highest among children younger than 1 year of age. Influenza A accounted for 82% and influenza B for 18% of all hospitalizations. A total of 40 (10.0%) children received treatment at the intensive care unit. Of all 401 children with confirmed influenza infection, only 216 (53.9%) had a discharge International Classification of Diseases code related to influenza.

CONCLUSIONS

the high incidence of influenza-associated hospitalization among infants less than 6 months of age underscores the need to find effective ways to prevent influenza in this age group, in which influenza vaccines are not currently licensed for use.

Influenza vaccination rates among pharmacists

OBJECTIVES

To quantify influenza vaccination rates and determine perceived barriers to influenza vaccination among U.S. pharmacists from various practice settings.

DESIGN

Prospective study.

SETTING

United States in 2008.

PARTICIPANTS

1,028 respondents, including 895 pharmacists.

INTERVENTION

A survey request was distributed manually at the 2008 National Community Pharmacists Association annual meeting, and an initial e-mail was sent with two follow-up e-mails to all pharmacists who receive e-mails via Pharmacist e-link.

MAIN OUTCOME MEASURES

Vaccination rates and barriers to vaccination among pharmacists.

RESULTS

Pharmacists reported an influenza vaccination rate of 78%, with coverage varying across practice settings: hospital (88%), academia (86%), clinic (83%), and community (75%). Employers infrequently required the influenza vaccine as a condition of employment (7%), and slightly more than one-half (58%) compensated pharmacists for being vaccinated; both of these were significantly associated with higher influenza vaccination rates (P < 0.001 for both). One-quarter of pharmacists (26%) expressed at least one issue regarding the influenza vaccine. Pharmacists were significantly less likely to be vaccinated if they expressed a concern (91% vs. 43%, P < 0.0001). Community pharmacists were significantly less likely to be compensated for receiving the influenza vaccination and significantly more likely to express one or more concerns than pharmacists from any other practice setting.

CONCLUSION

Pharmacists reported high influenza vaccination rates overall, with slight variability among practice settings. Although employers infrequently required influenza vaccination, approximately one-half of employers compensated their pharmacists for being vaccinated. Employer incentives and pharmacist attitudes were highly correlated with influenza vaccination.

Influenza and parainfluenza associated pediatric ICU morbidity

OBJECTIVES

To investigate if morbidity in young children admitted to a pediatric intensive care unit (PICU with a laboratory proven diagnosis of influenza and parainfluenza infection) had increased.

METHODS

Retrospective study from January 2003 through December 2009 was carried out. Every child in the PICU with a laboratory-confirmed influenza or parainfluenza infection was included.

RESULTS

18 influenza (influenza A =13 and influenza B = 5) and 17 parainfluenza admissions were identified over the 7-year period. Parainfluenza type 3 (n = 9) was the commonest subtype of parainfluenza infection. The median age of children admitted with influenza was higher than parainfluenza (4.5 vs 1.7 years, p = 0.044). Admissions associated with proven influenza and parainfluenza infections accounted for 2% of PICU annual admissions. There was only one death in 2003. 51% of these patients required ventilatory support, 45% received systemic corticosteroids, and 91% received initial broad spectrum antibiotic coverage. Bacterial co-infections were identified in 25% of these patients. The incidence of influenza admissions had not increased significantly in 2009 (H1N1 pandemic) when compared with 2003 (SARS epidemic) (p = 0.3). There were only two PICU cases of pandemic H1N1 in 2009 and both survived. The annual incidence of severe PICU cases of influenza and parainfluenza were 0.94 and 0.88 per 100,000 children per annum, respectively.

CONCLUSIONS

Pandemic H1N1, influenza and parainfluenza viruses may be associated with significant childhood morbidity and PICU admissions.

Influenza-associated pneumonia in children hospitalized with laboratory-confirmed influenza, 2003-2008

BACKGROUND

Pneumonia is one of the most common complications in children hospitalized with influenza. We describe hospitalized children with influenza-associated pneumonia and associated risk indicators.

METHODS

Through Emerging Infections Program Network population based surveillance, children aged <18 years hospitalized with laboratory confirmed influenza with a chest radiograph during hospitalization were identified during the 2003-2008 influenza seasons. A case with radiologically confirmed influenza-associated pneumonia was defined as a child from the surveillance area hospitalized with: (1) laboratory-confirmed influenza and (2) evidence of new pneumonia on chest radiograph during hospitalization. Hospitalized children with pneumonia were compared with those without pneumonia by univariate and multivariate analysis.

RESULTS

Overall, 2992 hospitalized children with influenza with a chest radiograph were identified; 1072 (36%) had influenza-associated pneumonia.When compared with children hospitalized with influenza without pneumonia, hospitalized children with influenza-associated pneumonia were more likely to require intensive care unit admission (21% vs. 11%, P < 0.01), develop respiratory failure (11% versus 3%, P < 0.01), and die(0.9% vs. 0.3% P 0.01). In multivariate analysis, age 6 to 23 months(adjusted OR: 2.1, CI: 1.6 -2.8), age 2 to 4 years (adjusted OR: 1.7, CI:1.3-2.2), and asthma (adjusted OR: 1.4, CI: 1.1-1.8) were significantly associated with influenza-associated pneumonia.

CONCLUSIONS

Hospitalized children with influenza-associated pneumonia were more likely to have a severe clinical course than other hospitalized children with influenza, and children aged 6 months to 4 years and those with asthma were more likely to have influenza-associated pneumonia.Identifying children at greater risk for influenza-associated pneumonia will inform prevention and treatment strategies targeting children at risk for influenza complications.

Immunogenicity and safety of AS03-adjuvanted 2009 influenza A H1N1 vaccine in children 6-35 months

We report on the evaluation of the immunogenicity and reactogenicity/safety of AS03-adjuvanted vaccine against pandemic influenza A/H1N1/2009 in young children. In this open-label, randomized study, 157 healthy children aged 6-35 months received two doses (21 days apart) of split-virion inactivated A/California/7/2009 H1N1 vaccine containing either (i) 1.9microg hemagglutinin (HA) and AS03(B) (5.93mg tocopherol) (N=104) or (ii) 3.75mug HA and AS03(A) (11.86mg tocopherol) (N=53). At 21 days following the first dose of AS03(B)-adjuvanted vaccine (1.9microg HA) the percentage of children with hemagglutination-inhibition titers of >or=40 against the vaccine strain rose from 3.0% before vaccination to 100%. The seroconversion rate was 99% and the geometric mean titer (GMT) increased from 6 to 313. After the second dose the GMT increased further to 2008. The higher dose AS03(A)-adjuvanted 3.75microg HA vaccine did not further increase the immune response. Solicited symptoms reported within 7 days following vaccination were mainly mild to moderate. After the first dose of AS03(B)-adjuvanted vaccine (1.9microg HA) the most common solicited symptoms were pain at the injection site (35.6%) and irritability (31.7%). Fever (axillary >or=37.5 degrees C) was reported with an incidence of 20.2%. After the second dose reactogenicity tended to increase (injection site pain: 41.3%; irritability: 46.2%; fever >or=37.5 degrees C: 67.3%). Spontaneously reported adverse events with an intensity that prevented normal activities were documented for 2.9-6.7% of doses with only one event (vomiting) considered related to vaccination. There was one serious adverse event reported in the AS03(A)-adjuvanted 3.75microg HA vaccine group (traumatic brain injury) which was not considered as related to vaccination. In conclusion, these data suggest that a first dose of AS03(B)-adjuvanted A/H1N1/2009 vaccine containing 1.9microg HA in children 6-35 months old is highly immunogenic and that the overall reactogenicity profile is acceptable although reactions including fever tend to increase after a second dose.

Community acquired influenza requiring hospitalization: vaccine status is unrelated to morbidity in children with cancer

BACKGROUND

Community acquired influenza can be severe and there are few data regarding hospitalization for children with cancer and influenza. Association between prior vaccination and infection severity has not been studied, although vaccination is standard practice.

PROCEDURE

Patients with malignancy or prior stem cell transplant (SCT) were identified using a database of children with laboratory confirmed influenza (2000-2005). Other data collected included receipt of vaccine, absolute neutrophil count (ANC) and absolute lymphocyte count (ALC). These were compared with intensive care unit (ICU) stay, respiratory complications and hospital days.

RESULTS

There were 39 patients with laboratory-confirmed influenza with a median age of 6.9 years. Twenty-four (62%) were on cancer therapy at time of infection and 18 (46%) had received the influenza vaccination that season. Measures of immune status included ANC at time of infection (median 1,530 cells/microl; inter-quartile range, 315, 4347), presence of graft versus host disease 2 (5%) and steroid therapy 4 (10%) patients. All had a low ALC (median 448 cells/microl; IQR 189, 861). Respiratory complications occurred in 8 (20%), ICU admissions in 4 (10%) and death in 2 (5%) patients. Median hospital stay was 2 days. All ICU admissions occurred in unvaccinated patients (P = 0.1). Vaccine status, ANC (<1,000 cells/microl vs. >1,000) and ALC (<500 cells/microl vs. >500) were not associated with length of stay or respiratory complications.

CONCLUSIONS

Influenza infection can be severe in children with cancer and complications occur despite vaccination. Prospective evaluation of vaccine response is worthy of future study.

Influenza-related hospitalisations in children

AIM

To describe the disease burden, clinical pattern and outcome of influenza-related hospitalisations in children.

METHODS

This is a retrospective study carried out in a regional hospital in Hong Kong. Children hospitalised with established diagnosis of influenza infection from January to June of 2005 were studied. Length of hospitalisation, demographic characteristics, symptoms, clinical diagnosis and complications of influenza infection were analysed.

RESULTS

Influenza A infection accounted for 93.5% of these hospitalisations. Children less than 5 years of age comprised 70% of admission. Highest rate of admission occurred in May and April. One fourth of emergency admission during the study period and over 70% in the peak season was a result of influenza-related illness. Underlying medical disease was observed in 14.6% of children. Mean duration of hospitalisation was 3.0 days. Fever was the commonest presenting symptoms. Fever lasting for 7 days or more was observed in one-fifth of patients. Respiratory tract diseases (upper and lower) were the most frequent non-neurological diagnosis. Febrile convulsion was the complication observed in 27.6% of admission. One patient died as a result of acute necrotising encephalopathy.

CONCLUSION

Influenza contributed to heavy health-care burden. Mortality was rare but did occur. Hospitalisations occurred in both healthy children and those with underlying chronic illness. Young children played an important role in such hospitalisations. Means to prevent influenza-associated morbidity and mortality especially among young children are needed.

The burden of influenza in East and South-East Asia: a review of the English language literature

Abstract  While human infections with avian influenza A (H5NI) viruses in Asia have prompted concerns about an influenza pandemic, the burden of human influenza in East and Southeast Asia has received far less attention. We conducted a review of English language articles on influenza in 18 countries in East and Southeast Asia published from 1980 to 2006 that were indexed on PubMed. Articles that described human influenza‐associated illnesses among outpatients or hospitalized patients, influenza‐associated deaths, or influenza‐associated socioeconomic costs were reviewed. We found 35 articles from 9 countries that met criteria for inclusion in the review. The quality of articles varied substantially. Significant heterogeneity was noted in case definitions, sampling schemes and laboratory methods. Early studies relied on cell culture, had difficulties with specimen collection and handling, and reported a low burden of disease. The recent addition of PCR testing has greatly improved the proportion of respiratory illnesses diagnosed with influenza. These more recent studies reported that 11–26% of outpatient febrile illness and 6‐14% of hospitalized pneumonia cases had laboratory‐confirmed influenza infection. The influenza disease burden literature from East and Southeast Asia is limited but expanding. Recent studies using improved laboratory testing methods and indirect statistical approaches report a substantial burden of disease, similar to that of Europe and North America. Current increased international focus on influenza, coupled with unprecedented funding for surveillance and research, provide a unique opportunity to more comprehensively describe the burden of human influenza in the region.

Seasonal influenza in adults and children--diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America

Guidelines for the treatment of persons with influenza virus infection were prepared by an Expert Panel of the Infectious Diseases Society of America. The evidence-based guidelines encompass diagnostic issues, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal (interpandemic) influenza. They are intended for use by physicians in all medical specialties with direct patient care, because influenza virus infection is common in communities during influenza season and may be encountered by practitioners caring for a wide variety of patients.

2009 update in prevention, evaluation, and outpatient treatment of influenza

BACKGROUND

Influenza A and B virus infections account for substantial morbidity and mortality and adversely affect quality of life and productivity in millions of Americans every year. Because of antigenic drifts and shifts, influenza is difficult to manage, presenting primary care clinicians with two major challenges every year: 'Who should be vaccinated?' and 'How should patients who present with symptoms of influenza be managed?'

METHODS

A search from 1995 to 2008 of the National Library of Medicine, the Cochrane Database of Systematic Reviews, the US Centers for Disease Control and Prevention (CDC) website, and the reference lists of retrieved articles was conducted to identify the most current and relevant information to address these two major challenges and the questions they generate in primary care. Emphasis was placed on influenza vaccination and antiviral agents.

FINDINGS

In all, 275 articles met the search criteria. Emphasis was placed on recommendations developed by the Advisory Committee on Immunization Practices for 2008-2009, as well as several advisories issued by the US Food and Drug Administration and the US CDC.

DISCUSSION

Eighty-five percent of the US population is eligible for influenza vaccination. Several measures have been demonstrated to improve vaccination rates. Diagnosis of influenza should be confirmed with testing such as a rapid viral test. Management of persons with influenza includes treatment with neuraminidase inhibitors and symptom-specific therapy.

CONCLUSION

The implementation of more aggressive measures is needed in the primary care setting to prevent and treat influenza.

Increasing burden and risk factors for bronchiolitis-related medical visits in infants enrolled in a state health care insurance plan

OBJECTIVES

The goals were to estimate the year-round burden of health care visits attributable to bronchiolitis and to identify risk factors for bronchiolitis in term healthy infants.

METHODS

We conducted a population-based, retrospective cohort study of 103 670 term, non-low birth weight infants enrolled in Tennessee Medicaid in 1995-2003. We monitored infants through the first year of life. Risk factors for bronchiolitis during infancy and rates of inpatient, emergency department, and outpatient visits during the study period were calculated by using claims data.

RESULTS

Over the 9 study years, rates of bronchiolitis visits were 238 outpatient visits per 1000 infant-years, 77 emergency department visits per 1000 infant-years, and 71 hospitalizations per 1000 infant-years. Average annual rates of bronchiolitis visits increased 41%, from 188 visits per 1000 infant-years to 265 visits per 1000 infant-years, from 1996-1997 to 2002-2003. Analysis of the linear trend in 500-g increments demonstrated a negative association between increasing birth weight and bronchiolitis diagnosis. There was a significant negative trend between maternal age and infant bronchiolitis diagnosis. Compared with infants of mothers 20 to 29 years of age, infants of mothers 15 to 19 years of age had a small increase in risk of having a bronchiolitis visit, whereas infants of older mothers (30-39 or 40-44 years of age) were less likely to have a visit.

CONCLUSIONS

The disease burden of bronchiolitis is substantial, with increasing rates of all types of visits among term, otherwise-healthy infants enrolled in Tennessee Medicaid between 1995 and 2003. Protective factors in this cohort of term infants included higher birth weight and older maternal age.

Shedding of live vaccine virus, comparative safety, and influenza-specific antibody responses after administration of live attenuated and inactivated trivalent influenza vaccines to HIV-infected children

HIV-infected children (N=243), >or=5 to <18 years old, receiving stable antiretroviral therapy, were stratified by immunologic status and randomly assigned to receive intranasal live attenuated influenza vaccine (LAIV) or intramuscular trivalent inactivated influenza vaccine (TIV). The safety profile after LAIV or TIV closely resembled the previously reported tolerability to these vaccines in children without HIV infection. Post-vaccination hemagglutination inhibition (HAI) antibody responses and shedding of LAIV virus were also similar, regardless of immunological stratum, to antibody responses and shedding previously reported for children without HIV infection. LAIV should be further evaluated for a role in immunizing HIV-infected children.

Premorbid factors and outcome associated with respiratory virus infections in a pediatric intensive care unit

OBJECTIVES

The purpose of this study was to report the clinical features and outcome of all children with a laboratory proven diagnosis of respiratory virus infection admitted to a university Pediatric Intensive Care Unit (PICU).

METHODS

Retrospective study between January 2003 and April 2007 was carried out in the PICU. Every child with a laboratory-confirmed viral infection was included.

RESULTS

54 viruses were identified in 49 children (27 M, 22 F) over a 52-month period. The three respiratory virus species, respiratory syncytial virus (RSV) (n = 17), influenza (n = 13) and parainfluenza (n = 12), accounted for 86% of these 49 cases. PICU admissions due to influenza A (n = 10) were more common than influenza B (n = 3), whereas parainfluenza type 3 (n = 7) was the commonest subtype of parainfluenza infection. Comparing these three common viruses, the mean age of children admitted with RSV was lower than with influenza or parainfluenza (1.2 years vs. 5.6 years vs. 2.4 years, P = 0.003). Pre-existing conditions such as prematurity and chronic lung disease were only present in children with RSV infection. These respiratory viruses caused both upper (croup) and lower respiratory tract diseases (bronchiolitis, pneumonia). Extrapulmonary presentations were less prevalent and included encephalitis, seizures, cardiac arrest, coexisting diabetes ketoacidosis and acute lymphoblastic leukemia. One patient with RSV and another with influenza A died during their PICU stay. Nearly half of these patients required ventilatory support or received systemic corticosteroids, and 88% received initial broad spectrum antibiotic coverage. Approximately one in five of them had nebulised adrenaline, airway endoscopies or bacterial co-infections. Adenovirus was isolated in four patients and two (both with adenovirus type 3) died during the PICU stay.

CONCLUSIONS

In PICU, respiratory viral infections were associated with significant morbidity and life-threatening conditions.