A Case-Study of Implementation of Improved Strategies for Prevention of Laboratory-acquired Brucellosis.

BACKGROUND: In 2012, the Alaska Section of Epidemiology investigated personnel potentially exposed to a Brucella suis isolate as it transited through three laboratories. METHODS: We summarize the first implementation of the United States Centers for Disease Control and Prevention 2013 revised recommendations for monitoring such exposures: (1) risk classification; (2) antimicrobial postexposure prophylaxis; (3) serologic monitoring; and (4) symptom surveillance. RESULTS: Over 30 people were assessed for exposure and subsequently monitored for development of illness. No cases of laboratory-associated brucellosis occurred. Changes were made to gaps in laboratory biosafety practices that had been identified in the investigation. CONCLUSION: Achieving full compliance for the precise schedule of serologic monitoring was challenging and resource intensive for the laboratory performing testing. More refined exposure assessments could inform decision making for follow-up to maximize likelihood of detecting persons at risk while not overtaxing resources.

Eighteen Years of Respiratory Syncytial Virus Surveillance: Changes in Seasonality and Hospitalization Rates in Southwestern Alaska Native Children.

BACKGROUND: Alaska Native infants from the Yukon-Kuskokwim Delta (YKD) experienced respiratory syncytial virus (RSV) hospitalization rates 5 times higher and an RSV season twice as long as the general US infant population. We describe trends in hospitalization rates and seasonality during 18 years of continuous RSV surveillance in this population and explore contributions of climate and sociodemographic factors. METHODS: We abstracted clinical and RSV test information from computerized medical records at YKD Regional Hospital and Alaska Native Medical Center from 1994 to 2012 to determine hospitalization rates and RSV season timing. Descriptive village and weather data were acquired through the US Census and Alaska Climate Research Center, University of Alaska, Fairbanks, respectively. RESULTS: During 1994-2012, YKD infant RSV hospitalization rates declined nearly 3-fold, from 177 to 65 per 1000 infants/yr. RSV season onset shifted later, from mid October to late December, contributing to a significantly decreased season duration, from 30 to 11 weeks. In a multivariate analysis, children from villages with more crowded households and lacking plumbed water had higher rates of RSV hospitalizations (relative rate, 1.17; P = 0.0005 and relative rate, 1.45; P = 0.0003). No association of temperature or dew point was found with the timing or severity of RSV season. CONCLUSIONS: Although the RSV hospitalization rate decreased 3-fold, YKD infants still experience a hospitalization rate 3-fold higher than the general US infant population. Overcrowding and lack of plumbed water were associated with RSV hospitalization. Dramatic changes occurred in RSV seasonality, not explained by changes in climate.

Respiratory exacerbations in indigenous children from two countries with non-cystic fibrosis chronic suppurative lung disease/bronchiectasis.

BACKGROUND: Acute respiratory exacerbations (AREs) cause morbidity and lung function decline in children with chronic suppurative lung disease (CSLD) and bronchiectasis. In a prospective longitudinal cohort study, we determined the patterns of AREs and factors related to increased risks for AREs in children with CSLD/bronchiectasis. METHODS: Ninety-three indigenous children aged 0.5 to 8 years with CSLD/bronchiectasis in Australia (n = 57) and Alaska (n = 36) during 2004 to 2009 were followed for > 3 years. Standardized parent interviews, physical examinations, and medical record reviews were undertaken at enrollment and every 3 to 6 months thereafter. RESULTS: Ninety-three children experienced 280 AREs (median = 2, range = 0-11 per child) during the 3-year period; 91 (32%) were associated with pneumonia, and 43 (15%) resulted in hospitalization. Of the 93 children, 69 (74%) experienced more than two AREs over the 3-year period, and 28 (30%) had more than one ARE in each study year. The frequency of AREs declined significantly over each year of follow-up. Factors associated with recurrent (two or more) AREs included age < 3 years, ARE-related hospitalization in the first year of life, and pneumonia or hospitalization for ARE in the year preceding enrollment. Factors associated with hospitalizations for AREs in the first year of study included age < 3 years, female caregiver education, and regular use of bronchodilators. CONCLUSIONS: AREs are common in children with CSLD/bronchiectasis, but with clinical care and time AREs occur less frequently. All children with CSLD/bronchiectasis require comprehensive care; however, treatment strategies may differ for these patients based on their changing risks for AREs during each year of care.

Indigenous children from three countries with non-cystic fibrosis chronic suppurative lung disease/bronchiectasis.

OBJECTIVE: Indigenous children in developed countries are at increased risk of chronic suppurative lung disease (CSLD), including bronchiectasis. We evaluated sociodemographic and medical factors in indigenous children with CSLD/bronchiectasis from Australia, United States (US), and New Zealand (NZ). METHODS: Indigenous children aged 0.5-8 years with CSLD/bronchiectasis were enrolled from specialist clinics in Australia (n = 97), Alaska (n = 41), and NZ (n = 42) during 2004-2009, and followed for 1-5 years. Research staff administered standardized parent interviews, reviewed medical histories and performed physical examinations at enrollment. RESULTS: Study children in all three countries had poor housing and sociodemographic circumstances at enrollment. Except for increased household crowding, most poverty indices in study participants were similar to those reported for their respective local indigenous populations. However, compared to their local indigenous populations, study children were more often born prematurely and had both an increased frequency and earlier onset of acute lower respiratory infections (ALRIs). Most (95%) study participants had prior ALRI hospitalizations and 77% reported a chronic cough in the past year. Significant differences (wheeze, ear disease and plumbed water) between countries were present. DISCUSSION: Indigenous children with CSLD/bronchiectasis from three developed countries experience significant disparities in poverty indices in common with their respective indigenous population; however, household crowding, prematurity and early ALRIs were more common in study children than their local indigenous population. Addressing equity, especially by preventing prematurity and ALRIs, should reduce risk of CSLD/bronchiectasis in indigenous children.

Longitudinal nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in indigenous Australian and Alaska native children with bronchiectasis.

BACKGROUND: Indigenous children in Australia and Alaska have very high rates of chronic suppurative lung disease (CSLD)/bronchiectasis. Antibiotics, including frequent or long-term azithromycin in Australia and short-term beta-lactam therapy in both countries, are often prescribed to treat these patients. In the Bronchiectasis Observational Study we examined over several years the nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in these two PCV7-vaccinated populations. METHODS: Indigenous children aged 0.5-8.9 years with CSLD/bronchiectasis from remote Australia (n = 79) and Alaska (n = 41) were enrolled in a prospective cohort study during 2004-8. At scheduled study visits until 2010 antibiotic use in the preceding 2-weeks was recorded and nasopharyngeal swabs collected for culture and antimicrobial susceptibility testing. Analysis of respiratory bacterial carriage and antibiotic resistance was by baseline and final swabs, and total swabs by year. RESULTS: Streptococcus pneumoniae carriage changed little over time. In contrast, carriage of Haemophilus influenzae declined and Staphylococcus aureus increased (from 0% in 2005-6 to 23% in 2010 in Alaskan children); these changes were associated with increasing age. Moraxella catarrhalis carriage declined significantly in Australian, but not Alaskan, children (from 64% in 2004-6 to 11% in 2010). While beta-lactam antibiotic use was similar in the two cohorts, Australian children received more azithromycin. Macrolide resistance was significantly higher in Australian compared to Alaskan children, while H. influenzae beta-lactam resistance was higher in Alaskan children. Azithromycin use coincided significantly with reduced carriage of S. pneumoniae, H. influenzae and M. catarrhalis, but increased carriage of S. aureus and macrolide-resistant strains of S. pneumoniae and S. aureus (proportion of carriers and all swabs), in a 'cumulative dose-response' relationship. CONCLUSIONS: Over time, similar (possibly age-related) changes in nasopharyngeal bacterial carriage were observed in Australian and Alaskan children with CSLD/bronchiectasis. However, there were also significant frequency-dependent differences in carriage and antibiotic resistance that coincided with azithromycin use.

Comparison of nasopharyngeal flocked swabs and nasopharyngeal wash collection methods for respiratory virus detection in hospitalized children using real-time polymerase chain reaction.

This paper describes the molecular detection of respiratory viruses from nasopharyngeal flocked swabs (flocked swabs) and nasopharyngeal washes (washes) in a clinical setting. Washes and flocked swabs collected from children<3 years old hospitalized with a lower respiratory tract infection were tested for parainfluenza virus 1-3, respiratory syncytial virus, influenza A and B and metapneumovirus (Group 1) and adenovirus, rhinovirus and coronavirus (Group 2) using real-time reverse transcriptase PCR (rRT-PCR). A consensuses standard was used to determine sensitivity and compare cycle thresholds (C(T)) of washes and flocked swabs for each virus and group of viruses. Sensitivities ranged from 79 to 89% and 69 to 94% for flocked swabs and washes, respectively, excluding AdV which had a sensitivity of 35% for flocked swabs. When the flocked swabs and washes of Group 1 viruses were collected on the day of admission, the sensitivity of both sample types was 100%. Wash specimens had a lower C(T) value and higher sensitivity than flocked swabs; however there was no statistical difference in the sensitivity of a flocked swab (89%) versus wash (93%) for the detection of Group 1 viruses, particularly when samples were collected on the same day. Flocked swabs may be a useful alternative to washes for detection of respiratory viruses in clinical settings.

Risk factors for hospitalization with lower respiratory tract infections in children in rural Alaska.

OBJECTIVE: Lower respiratory tract infections (LRTIs) are a major cause of morbidity for children worldwide and particularly for children from developing and indigenous populations. In this study, we evaluated risk factors for hospitalization with LRTI in a region in southwest Alaska. METHODS: The study was conducted from October 1, 2006, to September 30, 2007, in the Yukon Kuskokwim Delta region of Alaska. Cases were recruited from children <3 years of age hospitalized with LRTI. Controls were recruited during visits to the surrounding communities in the region and matched posthoc to cases on the basis of subregion, season, and age. Parents were interviewed for potential risk factors, and medical records were reviewed. Participants had a nasopharyngeal swab sample taken for polymerase chain reaction (PCR) testing for a panel of respiratory viruses. Samples positive for respiratory syncytial virus, human metapneumovirus, or parainfluenza type 3 were quantitated by reverse transcriptase real-time quantitative PCR. RESULTS: One hundred twenty-eight cases were matched to 186 controls. In a multivariable conditional logistic regression model, significantly (P < .05) increased risk of hospitalization was associated with medically high-risk status, having a woodstove in the house, being bottle fed, and vomiting after feeding; living in a house that had 2 or more rooms with sinks was a protective factor. Viral loads in hospitalized cases were significantly higher than those in controls, but a strict cutoff level was not observed. CONCLUSIONS: Several risk factors for LRTI hospitalization were identified in this high risk population. Some factors are amenable to environmental and behavioral interventions.

Performance of a rapid antigen test (Binax NOW® RSV) for diagnosis of respiratory syncytial virus compared with real-time polymerase chain reaction in a pediatric population.

BACKGROUND: Infants from Alaska's Yukon-Kuskokwim Delta (YKD) have a high respiratory syncytial virus (RSV) hospitalization rate (104/1000/yr). Appropriate patient management requires rapid and accurate RSV diagnosis. Antigen-based methods are often used in clinical settings, but these tests can lack sensitivity. OBJECTIVE: We compared Binax NOW(®) RSV (BN) used for RSV diagnosis in the YKD hospital with a real-time polymerase chain reaction assay (RT-qPCR) used for viral surveillance. STUDY DESIGN: Between October 2005 and September 2007 we obtained nasopharyngeal washes (NPW) from children <3 years hospitalized with a lower respiratory tract infection. The NPW were tested using BN and RT-qPCR. RESULTS: 79/311 (25%) children had RSV infection as determined by RT-qPCR. As compared with RT-qPCR, sensitivity and specificity of BN were 72% and 97%, respectively. The sensitivity of BN was higher in children <1 year compared with children ≥ 1 year (79% vs. 52%; p=0.025), children with bronchiolitis compared with children without bronchiolitis (89% vs. 38%; p<0.001), and children with a shorter duration of symptoms before testing (0-1 (92%) vs. 2-4 (78%) vs. 5+ (65%) days; p=0.04). The median RSV viral load in NPW positive by BN and RT-qPCR was 1.01 × 10(9)copies/mL vs. a median of 5.25 × 10(7)copies/mL for NPW positive by RT-qPCR only (p<0.001). CONCLUSION: RT-qPCR is more sensitive than BN in detecting RSV infection. BN sensitivity is high in children with bronchiolitis, but the sensitivity is low when children present with a non-bronchiolitis illness, especially after a longer duration of symptoms before testing.