Testing for Urinary Tract Infection in the Influenza/Respiratory Syncytial Virus-Positive Febrile Infant Aged 2 to 12 Months.

OBJECTIVE: Infants 12 months or younger with influenza and respiratory syncytial virus (RSV) commonly present to the emergency department (ED) with fever. Previous publications have recommended that these patients have a urinalysis and urine culture performed. We aimed to assess the prevalence of urinary tract infection (UTI) in febrile RSV/influenza positive infants aged 2 to 12 months presenting to the ED. We also examined whether the 2011 American Academy of Pediatrics (AAP) UTI clinical practice guidelines could be used to identify patients at lower risk of UTI. METHODS: This was a retrospective chart review examining all infants aged 2 to 12 months with a documented fever of higher than 38°C who presented to our ED from 2009 to 2013 and tested positive for influenza and/or RSV. RESULTS: One thousand seven hundred twenty-four patients were found to meet our inclusion criteria. Of these, 98 were excluded because of known urinary tract anomaly or systemic antibiotic use in the 24 hours preceding evaluation. Of those patients remaining, 10 (0.62%) of 1626 had positive urine cultures (95% confidence interval, 0.3%-1.1%), and 8 (0.49%) of 1626 (95% confidence interval, 0.2%-0.97%) had positive urine cultures with positive urinalyses as defined in the 2011 AAP UTI clinical practice guidelines. All subjects with positive urine cultures as defined by the AAP had risk factors for UTI that placed their risk for UTI above 1%. CONCLUSIONS: Our population of 2- to 12-month-old febrile infants with positive influenza/RSV testing, who did not have risk factors to make their risk of UTI higher than 1%, may not have required evaluation with urinalysis or urine culture.

Genetic Polymorphisms of Toll-like Receptor 4 are Associated with Respiratory Syncytial Virus Infection in a Chinese Infant Population.

BACKGROUND: While genetic polymorphisms in Toll-like Receptor 4 (TLR4) have been demonstrated to play an important role in respiratory syncytial virus (RSV) infections in Western populations, the association between TLR4 polymorphisms and RSV infections has not been investigated in Chinese patient populations. The study presented here identifies TLR4 polymorphisms and investigates the association of TLR4 genetic polymorphism with RSV infection in a Chinese infant patient population. METHODS: One-hundred and ninety-six infants hospitalized with RSV infections and 311 healthy control subjects were enrolled in this study. Genetic polymorphisms in the 5' untranslated region (5'UTR), exons, and 3' untranslated region (3'UTR) of the TLR4 gene were screened using PCR and sequencing analysis. The association between the genetic polymorphisms in TLR4, RSV infection risk, and the related disease severity was investigated using Fisher's Exact Test and the Chi-square test. RESULTS: Fourteen different genetic polymorphisms within the TLR4 gene, including two in the 5'UTR, four in the exons, and eight in the 3'UTR were found in the study population. Two polymorphisms, Asp299Gly and Thr399Ile, typically associated with RSV in Caucasian infants were not observed in the Chinese infants. Of the 14 polymorphisms, only rs41426344 (G/C) in the 3'UTR of the TLR4 gene was found to be associated with RSV infection risk and disease severity. CONCLUSIONS: The TLR4 genetic polymorphism rs41426344 may be a specific genetic risk factor in Chinese infants associated with RSV infection and disease severity.

Efficacy of motavizumab for the prevention of respiratory syncytial virus disease in healthy Native American infants: a phase 3 randomised double-blind placebo-controlled trial.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infections in children. We aimed to assess the safety and efficacy of an anti-RSV monoclonal antibody (motavizumab) in healthy term (≥36 weeks' gestational age) infants for the prevention of medically attended RSV acute lower respiratory tract infections. METHODS: This phase 3, double-blind, placebo-controlled, randomised trial enrolled healthy Native American infants aged 6 months or younger who were born at 36 weeks' gestational age in southwestern USA, on the Navajo Nation, the White Mountain Apache reservation, and the San Carlos Apache Indian reservation. Participants were randomly assigned (2:1) to receive either five monthly intramuscular doses of motavizumab (15 mg/kg) or placebo. They were followed up for 150 days after the first dose, and the primary endpoints were respiratory admission to hospital with a positive result for RSV by RT-PCR and death caused by RSV. Participants were followed up for medically attended wheezing until they reached age 3 years. Analysis was by intention to treat (ITT). This trial is registered with ClinicalTrials.gov, number NCT00121108. FINDINGS: During the autumn seasons (October to December) between 2004 and 2007, 2127 infants of the 2596 infants enrolled were randomly assigned to receive either motavizumab (1417) or placebo (710). After ITT analysis, motavizumab resulted in an 87% relative reduction (relative risk [RR] 0·13, 95% CI 0·08-0·21) in the proportion of infants admitted to hospital with RSV (21 [2%] of 1417 participants who received motavizumab; 80 [11%] of 710 participants who received placebo, p<0·0001). Serious adverse events were less common in particpants taking motavizumab (212 [15%]) than particpants on placebo (148 [21%]). Six deaths occurred in study participants (motavizumab, n=4 [0·3%]; placebo, n=2 [0·3%]); none were deemed to be related to the study product. Hypersensitivity events were more common in patients given motavizumab (208 [14·7%]) than in placebo recipients (87 [12·3%]; p=0·14). There was no effect on rates of medically attended wheezing in children aged 1-3 years (190 [14·9%] of participants randomly assigned to receive motavizumab vs 90 [14·0%] participants randomly assigned to receive placebo). INTERPRETATION: To our knowledge, this is the only trial of an anti-RSV antibody to prevent serious RSV disease in healthy term infants. Motavizumab significantly reduced the RSV-associated inpatient and outpatient burden and set a benchmark for the efficacy of RSV prevention strategies. The findings do not support a direct, generalisable, causal association between RSV lower respiratory tract infection and subsequent long-term wheezing in term infants. FUNDING: MedImmune.

Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection.

Guidance from the American Academy of Pediatrics (AAP) for the use of palivizumab prophylaxis against respiratory syncytial virus (RSV) was first published in a policy statement in 1998. Guidance initially was based on the result from a single randomized, placebo-controlled clinical trial conducted in 1996-1997 describing an overall reduction in RSV hospitalization rate from 10.6% among placebo recipients to 4.8% among children who received prophylaxis. The results of a second randomized, placebo-controlled trial of children with hemodynamically significant heart disease were published in 2003 and revealed a reduction in RSV hospitalization rate from 9.7% in control subjects to 5.3% among prophylaxis recipients. Because no additional controlled trials regarding efficacy were published, AAP guidance has been updated periodically to reflect the most recent literature regarding children at greatest risk of severe disease. Since the last update in 2012, new data have become available regarding the seasonality of RSV circulation, palivizumab pharmacokinetics, the changing incidence of bronchiolitis hospitalizations, the effects of gestational age and other risk factors on RSV hospitalization rates, the mortality of children hospitalized with RSV infection, and the effect of prophylaxis on wheezing and palivizumab-resistant RSV isolates. These data enable further refinement of AAP guidance to most clearly focus on those children at greatest risk.

Increased risk for respiratory syncytial virus-associated, community-acquired alveolar pneumonia in infants born at 31-36 weeks of gestation.

BACKGROUND: We compared hospitalization and pediatric intensive care unit (PICU) admission rates for community-acquired alveolar pneumonia (CAAP) and respiratory syncytial virus (RSV)-associated CAAP (RSV-CAAP) in non-RSV-immunized children <24-month-old born at 31-36 weeks gestational age (GA) versus those born at term (>36 weeks GA). METHODS: Nasopharyngeal samples for RSV were obtained prospectively (2004-2011) during RSV season, from hospitalized children with radiographic-diagnosed CAAP. Soroka University Medical Center is the only hospital in the region, enabling population-based rate calculation. Relative risks (RR) and 95% confidence intervals (95% CI) were calculated comparing RSV-CAAP incidence in 31-36 weeks GA with >36 weeks GA children. RESULTS: CAAP hospitalization incidences (per 1000 population) were 23.6 and 9.4 (RR: 2.52; 95% CI: 2.13-2.68), respectively; the respective incidences of PICU admission for overall CAAP were 1.8 and 0.2 (RR: 7.88; 95% CI: 4.59-11.83). The RRs (and 95% CI) for RSV-CAAP hospitalizations and PICU admission rates were (after extrapolation) 15.2 and 5.8 (RR: 2.79; 95% CI: 2.31-3.06) and 1.1 and 0.1 (RR: 9.14; 95% CI: 4.93-16.96), respectively. In a multiregression analysis in patients with RSV-CAAP versus CAAP, 31-36 weeks GA was an independent risk factor for hospitalization (RR: 1.485; 95% CI: 1.03-2.14). CONCLUSIONS: Children <24-month-old born at 31-36 weeks GA are at increased risk for hospitalization and PICU admission for both overall CAAP and RSV-associated CAAP compared with those born at >36 weeks GA. Moreover, in late premature children, RSV represented a 50% increased risk for CAAP compared with infants born at term.

The real-life effectiveness of palivizumab for reducing hospital admissions for respiratory syncytial virus in infants residing in Nunavut.

UNLABELLED: BACKGROUND/ OBJECTIVE: Nunavut has the highest hospitalization rates for respiratory syncytial virus (RSV) worldwide, with rates of 166 per 1000 live births per year <1 year of age. Palivizumab was implemented in Nunavut primarily for premature infants, or those with hemodynamically significant cardiac or chronic lung disease; however, the effectiveness of the program is unknown. The objective of the present multisite, hospital-based surveillance study was to estimate the effectiveness of palivizumab in infants <6 months of age in Nunavut for the 2009 and 2010 RSV seasons. METHODS: Infants identified as palivizumab candidates who were <6 months of age were compared with all admissions for lower respiratory tract infection through multisite, hospital-based surveillance documenting the adequacy of palivizumab prophylaxis, admission for lower respiratory tract infection and the results of RSV testing. The OR for RSV admission in unprophylaxed infants was compared with those who were prophylaxed, and the effectiveness of palivizumab was estimated. RESULTS: Within the study cohort (n=101) during the two RSV seasons, five of the 10 eligible infants who did not receive adequate prophylaxis were admitted with RSV while two of the 91 infants <6 months of age eligible for palivizumab who were adequately prophylaxed were hospitalized with RSV (OR 22.3 [95% CI 3.8 to 130]; P=0.0005). The estimated effectiveness of palivizumab for the cohort was as high as 96%. Eight eligible infants were missed by the program and did not receive prophylaxis. CONCLUSION: Palivizumab was highly effective in reducing hospitalizations due to RSV infection in Nunavut. Further efforts need to be made to ensure that all eligible infants are identified.

Experiences of Alaskan parents with children hospitalized for respiratory syncytial virus treatment.

The purpose of this study was to describe the experiences of Alaskan parents with children hospitalized for the treatment of the respiratory syncytial virus (RSV). Six parents participated in a qualitative descriptive study composed of individual interviews. Using content analysis, three major themes emerged: "RSV is scary," "Lots of stress; little rest" and "At what point does it become a Bingo? He's going to the hospital." Findings provided further insight into the educational needs of the participants. Advanced practice registered nurses can translate insights provided by the participants into crucial knowledge needed for the care of families at heightened risk and currently experiencing RSV.

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.

A high burden of respiratory syncytial virus associated pneumonia in children less than two years of age in a South East Asian refugee population.

BACKGROUND: Pneumonia is a major cause of childhood mortality and morbidity approximately 1.6 million deaths and 150 million episodes occur annually in children <5 years. Respiratory syncytial virus (RSV) may be responsible for up to 25% of cases and 12% of deaths making it an important potential vaccine target, although data from South East Asia is scarce. METHODS: We followed a birth cohort of Burmese refugee children, born over a one year period, for two years. Pneumonia episodes were diagnosed using WHO criteria. A chest radiograph, nasopharyngeal aspirate and non-specific markers of infection were taken during each episode. RESULTS: The incidence of RSV-associated pneumonia was 0.24 (95% CI 0.22-0.26) episodes per child year. All children with pneumonia received antibiotic treatment, following WHO guidelines. The highest incidence was in the 2-12 month age group. The commonest diagnosis in a child with RSV-associated pneumonia was non-severe pneumonia (239/362:66.0%), however the incidence of RSV-associated severe or very severe pneumonia was 0.08 (95% CI 0.01-0.10) episodes per child year. Birth in the wet season increased the risk of severe disease in children who had their first episode of RSV-associated pneumonia aged 2-11 months (OR 28.7, 95% CI 6.6-125.0, p<0.001). RSV episodes were highly seasonal being responsible for 80.0% of all the pneumonia episodes occurring each October and November over the study period. CONCLUSIONS: There was a high incidence of RSV associated pneumonia in this refugee population. Interventions to prevent RSV infection have the potential to reduce the incidence of clinically diagnosed pneumonia and hence unnecessary antibiotic usage in this population.

Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants.

BACKGROUND: Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published. MATERIAL AND METHOD: The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS: Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between July and October (42-76%). RSV patients were more likely to present with higher temperature than the negative RT-PCR patients (p = .031). Oseltamivir was prescribed in 7.7% of influenza infections. Intravenous antibiotics were prescribed in 69.2%, 56.7% and 60.7% of the influenza, RSV and negative group respectively (p = .736). Percentages of patients requiring mechanical ventilation were 3.8, 6.7 and 6.3% among the influenza, RSV and negative group respectively (p = .861). Three patients died: 2 from RSV and 1 from the negative group. All three fatality cases had existing co-morbidity. CONCLUSION: A high proportion of RSV was detected in infants hospitalized with LRTI especially during July to October. High proportion of antibiotic prescription and relatively low rate of oseltamivir treatment were identified. Surveillance data and the availability of a rapid and reliable viral diagnostic test may help guide treatment, thereby improve outcome of this vulnerable population.

Respiratory syncytial virus infections in Central Australia.

BACKGROUND: Little is known about the epidemiology of respiratory syncytial virus (RSV) infection in arid desert regions and in the Aboriginal population. We describe the seasonality and epidemiology of RSV infection in Central Australia, an arid area with a large Aboriginal population. METHODS: Five-year retrospective study from 2000 through 2004 of children less than 2 years old admitted to Alice Springs Hospital with documented RSV infection. RESULTS: RSV infection was documented in 173 children <2 years old admitted over a 5-year period, 165 community-acquired and 8 nosocomial. The annual incidence rate of community-acquired RSV infection in hospitalised Central Australian children <2 years old was 20.4 per 1000. The rate in Aboriginal children of 29.6 per 1000 children was significantly greater than in non-Aboriginal children of 10.9 per 1000 (P < 0.0001). Associated risk factors were common; 52% of infected children had at least one other comorbidity. Younger children had more severe illness and longer duration of hospital stay. RSV-related illness peaked in winter but infections occurred throughout the year, and the winter predominance was less marked than in temperate climates. CONCLUSIONS: In the arid, desert region of Central Australia, RSV infection occurs throughout the year, but is more frequent in winter and more common in Aboriginal children. These data are important for understanding RSV epidemiology in desert regions, and for planning active or passive RSV immunoprophylaxis in these and other similar populations.

The cost effectiveness of palivizumab in term Inuit infants in the Eastern Canadian Arctic.

INTRODUCTION: Canadian, Inuit, full term infants have the highest rate of respiratory syncytial virus (RSV) infection globally, which results in substantial costs associated hospitalisation. METHODS: Decision-analytical techniques were used to estimate the incremental cost-effectiveness ratio (ICER) for palivizumab compared to no prophylaxis for Inuit infants of all gestational age. The time horizon was that of life-time follow-up, and costs and effectiveness were discounted at 5% per year. Costs (2007 CAD$) for palivizumab, hospitalisation (including medical evacuation, intensive care unit [ICU]), physician visits, and transportation were calculated based on the Canadian payer's perspective. Benefits on decreasing RSV hospitalisation were expressed as quality-adjusted life-years (QALYs). One-way and probabilistic sensitivity analysis (PSA) were conducted, varying: mortality rates, utilities, length of stay in hospital and ICU. RESULTS: For all of Baffin Island infants (<1 year), the ICER was $39,435/QALY. However, when infants were grouped by age and area of residence, those residing in Iqaluit (<1 year) had an ICER of $152,145/QALY, while those residing in rural areas (outside of Iqaluit) had an ICER of $24,750/QALY. Prophylaxis was a dominant strategy (cost saving) for rural infants under 6 months of age, with the PSA demonstrating that it was dominant 98% of the time. CONCLUSIONS: The ICERs suggested that palivizumab is a cost-effective option for the prevention of RSV for Inuit infants on Baffin Island compared to no prophylaxis. Palivizumab is highly cost effective in Arctic infants <1 year of age specifically residing outside of Iqaluit and is a dominant strategy for those under 6 months of age in rural areas. However, palivizumab is not cost effective compared to no treatment for infants of all ages residing in Iqaluit.

Comparison of the cost of hospitalization for respiratory syncytial virus disease versus palivizumab prophylaxis in Canadian Inuit infants.

BACKGROUND: The objectives were to compare actual respiratory syncytial virus (RSV) hospitalization rates and costs in a cohort of Inuit infants to hypothetical palivizumab prophylaxis strategies for infants of all gestational ages in the Eastern Canadian Arctic. METHODS: Incidence and costs of RSV hospitalization were collected for infants admitted to the Baffin Regional Hospital in 2002, before the initiation of palivizumab. There was a comparison of the actual costs to the costs associated with 8 palivizumab strategies stratified by age (<6 months, <1 year) and location (overall, town [Iqaluit], rural communities). It was assumed that each category would receive universal palivizumab prophylaxis resulting in a 78% decrease in RSV admissions. The net costs incurred, number needed to treat (NNT), and incremental costs per hospitalization avoided were calculated for each comparison. RESULTS: There was a great variation in the rates and costs associated with RSV admissions between Iqaluit and the communities. For infants <1 year of age residing in Iqaluit, the mean admission cost was $3915, and palivizumab prophylaxis had an NNT of 20.4 and cost of $162,551 per admission avoided. For rural infants <6 months, the mean cost of admission was $23,030, and palivizumab prophylaxis resulted in an NNT of 3.9 to 2.5 and cost savings of up to $8118 per admission avoided. CONCLUSIONS: Due to the high rates and costs associated with RSV admissions, administration of palivizumab in rural communities in the Canadian Arctic to infants less than 6 months of age could result in net cost savings.

The relationship between in-home water service and the risk of respiratory tract, skin, and gastrointestinal tract infections among rural Alaska natives.

OBJECTIVES: We investigated the relationship between the presence of in-home piped water and wastewater services and hospitalization rates for respiratory tract, skin, and gastrointestinal tract infections in rural Alaska. METHODS: We determined in-home water service and hospitalizations for selected infectious diseases among Alaska Natives by region during 2000 to 2004. Within 1 region, infant respiratory hospitalizations and skin infections for all ages were compared by village-level water services. RESULTS: Regions with a lower proportion of home water service had significantly higher hospitalization rates for pneumonia and influenza (rate ratio [RR] = 2.5), skin or soft tissue infection (RR = 1.9), and respiratory syncytial virus (RR = 3.4 among those younger than 5 years) than did higher-service regions. Within 1 region, infants from villages with less than 10% of homes served had higher hospitalization rates for pneumonia (RR = 1.3) and respiratory syncytial virus (RR = 1.2) than did infants from villages with more than 80% served. Outpatient Staphylococcus aureus infections (RR = 5.1, all ages) and skin infection hospitalizations (RR = 2.7, all ages) were higher in low-service than in high-service villages. CONCLUSIONS: Higher respiratory and skin infection rates were associated with a lack of in-home water service. This disparity should be addressed through sanitation infrastructure improvements.

Respiratory syncytial virus season and hospitalizations in the Alaskan Yukon-Kuskokwim Delta.

From 1993 to 1996, Alaska Native infants younger than 1 year of age from the Yukon-Kuskokwim Delta region in Alaska experienced a respiratory syncytial virus (RSV) hospitalization rate 5 times higher than the U.S. general infant population rate. This article describes the trends in hospitalization and prolonged annual season of RSV hospitalizations in Yukon-Kuskokwim children from 1993 to 2004 and discusses factors associated with high rates of RSV hospitalization and the impact of interventions to decrease RSV hospitalizations in this population.

Hospitalization for respiratory syncytial virus among California infants: disparities related to race, insurance, and geography.

OBJECTIVES: To evaluate population-based rates of Respiratory Syncytial Virus (RSV)-associated infant hospitalizations related to race/ethnicity, payer source, and geography in California. STUDY DESIGN: Retrospective analysis of RSV-coded infant hospitalizations were performed using the California patient discharge data for 1999 to 2003. All discharge records for infants younger than 1 year of age with an ICD-9-CM code for any RSV-related illness (466.11, 480.1, or 079.6) among any of the diagnosis fields were selected for analysis (n = 45,330). Rates were expressed as the number of RSV-associated hospitalizations per 1000 live births in the same calendar year. RESULTS: Infants enrolled in MediCal (California's version of the United States' national Medicaid program) had a relative risk of 2.03 (95% CI, 1.99 to 2.06) compared with non-MediCal payers (24.3 vs 12.0/1000 live births, respectively). The 1999 to 2003 rates per 1000 live births of RSV-associated hospitalizations for MediCal payers by race/ethnicity were: non-Hispanic white (34.9), African-American (27.9), Hispanic (21.8), Asian/Pacific Islander (12.5), and American Indian/Alaska Native (12.2). CONCLUSIONS: RSV was the leading cause of infant hospitalizations in California between 1999 and 2003. RSV hospitalization rates were highest among non-Hispanic white MediCal insured infants.

Costs associated with infant bronchiolitis in the Baffin region of Nunavut.

UNLABELLED: OBJECTIVE. Although infants living in the north of Canada have been reported to have one of the highest rates of hospital admission for bronchiolitis in the world, the economic effects of this condition have not been reported. Passive immunization against the Respiratory Syncytial Virus, the most common causative agent of infant bronchiolitis, is available. METHODS: We tabulated transportation, in-hospital care and family accommodation costs for infants of less than 12 months of age residing in the Baffin Region of Nunavut aged who were admitted to Baffin Regional Hospital in Iqaluit, Nunavut, and the Children's Hospital of Eastern Ontario in Ottawa, Ontario, with a primary diagnosis of bronchiolitis or viral pneumonia, over a 36-month period, between April 1999 and March 2002. RESULTS: One hundred fifty-nine infants were admitted a total of 210 times, with 196 admissions to Baffin Regional Hospital, and 14 to the Children's Hospital of Eastern Ontario, during the study period. The overall, annual, population-based admission rate for the Baffin Region of Nunavut was 197 admissions per thousand infants per year. Total costs were $2,997,373 ($2,357,747 for Baffin Regional Hospital, $639,625 for the Children's Hospital of Eastern Ontario). Overall average costs were $14,273 per admission, $12,029 for infants admitted to Baffin Regional Hospital and $45,688 for infants admitted to the Children's Hospital of Eastern Ontario. CONCLUSIONS: Infant bronchiolitis in the Baffin Region of Nunavut represents a significant burden on the territorial health care system.