Provider adoption of pneumococcal conjugate vaccine and the impact of vaccine shortages.

Objectives: To 1) determine the factors associated with provider acceptance of pneumococcal conjugate vaccine and 2) describe how providers prioritize pneumococcal conjugate vaccine during shortages.

Design/methods: During April-November 2002, we conducted a mailed survey of rural and urban Colorado practitioners who provided routine pediatric immunizations. Three groups were surveyed: 1) all immunization providers (n = 51) in 2 geographically large rural areas, identified through a regional immunization registry; 2) all providers (n = 61) from private pediatric practices in metropolitan Denver that were actively participating in the same registry; and 3) all family physicians (n = 244) from the same urban areas as the pediatric practices.

Association mapping of segregating sites in the early trypsin gene and susceptibility to dengue-2 virus in the mosquito Aedes aegypti.

Evidence suggests that midgut trypsins in Aedes aegypti condition the mosquito's ability to become infected with the dengue-2 flavivirus (DEN2). The activity of early trypsin protein peaks approximately 3 h after blood feeding and then drops within a few hours. We use association mapping to test the hypothesis that segregating sites in early trypsin condition midgut susceptibility to DEN2 virus.

Serologic evidence of exposure of wild mammals to flaviviruses in the central and eastern United States.

Serosurveys were conducted to obtain flavivirus and West Nile virus (WNV) seroprevalence data from mammals. Sera from 513 small- and medium-sized mammals collected during late summer and fall 2003 from Colorado, Louisiana, New York, Ohio, and Pennsylvania were screened for flavivirus-specific antibodies. Sera samples containing antibody to flaviviruses were screened for WNV-specific antibodies by epitope-blocking enzyme-linked immunosorbent assays and confirmed with plaque reduction neutralization tests.

Persistence of antibodies to West Nile virus in naturally infected rock pigeons (Columba livia).

Wild caught rock pigeons (Columba livia) with antibodies to West Nile virus were monitored for 15 months to determine antibody persistence and compare results of three serologic techniques. Antibodies persisted for the entire study as detected by epitope-blocking enzyme-linked immunosorbent assay and plaque reduction neutralization test. Maternal antibodies in squabs derived from seropositive birds persisted for an average of 27 days.

Population dynamics of a diverse rodent assemblage in mixed grass-shrub habitat, southeastern Colorado, 1995-2000.

We followed seasonal and year-to-year population dynamics for a diverse rodent assemblage in a short-grass prairie ecosystem in southeastern Colorado (USA) for 6 yr. We captured 2,798 individual rodents (range, one to 812 individuals per species) belonging to 19 species. The two most common species, deer mice (Peromyscus maniculatus) and western harvest mice (Reithrodontomys megalotis), generally had population peaks in winter and nadirs in summer; several other murid species demonstrated autumn peaks and spring nadirs; heteromyids were infrequently captured in winter, and populations generally peaked in summer or autumn.

Epizootiology of Sin Nombre and El Moro Canyon hantaviruses, southeastern Colorado, 1995-2000.

Sin Nombre virus (SNV) is an etiologic agent of hantavirus pulmonary syndrome. To better understand the natural history of this virus we studied population dynamics and temporal pattern of infection of its rodent hosts in southeastern Colorado (USA) from 1995 to 2000. We present evidence for the presence of two hantaviruses, SNV in deer mice (Peromyscus maniculatus) and El Moro Canyon virus in western harvest mice (Reithrodontomys megalotis), at our study sites.

Selection of D2S3, an Aedes aegypti (Diptera: Culicidae) strain with high oral susceptibility to Dengue 2 virus and D2MEB, a strain with a midgut barrier to Dengue 2 escape.

Family-based phenotypic selection was used to breed two genetic strains of Aedes aegypti L. that differ in susceptibility to infection with dengue serotype 2 virus (DEN-2) strain JAM1409. A Dengue 2 Susceptible on 3 chromosomes (D2S3) strain was bred from Ae.

Marriage and ethnicity predict treatment in localized prostate carcinoma.

Background: Primary treatment for early-stage prostate carcinoma includes expectant management or, for curative intent, radical prostatectomy or radiotherapy. Treatment recommendations are generally guided by clinical factors such as Gleason grade, prostate-specific antigen level, comorbid illnesses, and patient age. Sociocultural factors may also have influences on patient and urologist treatment choices.

Quantitative trait loci that control dengue-2 virus dissemination in the mosquito Aedes aegypti.

The mosquito Aedes aegypti is the most important vector of yellow fever and dengue fever flaviviruses. Ae. aegypti eradication campaigns have not been sustainable and there are no effective vaccines for dengue viruses.

Changes in access, utilization, and quality of care after enrollment into a state child health insurance plan.

Background: There currently are few published data evaluating the effect of State Children's Health Insurance Programs on health care outcome measures in children. Colorado's Child Health Plan Plus (CHP+) is a non-Medicaid State Children's Health Insurance Program that began enrollment in April 1998. The objectives of this study were to compare reported (1) access to care, (2) utilization of health care, and (3) quality of care during the year before and the first year after enrollment into CHP+.

Studies on overwintering of bluetongue viruses in insects.

Bluetongue viruses (BTVs) are economically important arboviruses that affect sheep and cattle. The overwintering mechanism of BTVs in temperate climates has eluded researchers for many years. Many arboviruses overwinter in their invertebrate vectors.

Implementation of universal influenza immunization recommendations for healthy young children: results of a randomized, controlled trial with registry-based recall.

Background: An Advisory Committee on Immunization Practices policy of encouraging influenza vaccination for healthy 6- to 23-month-old children was in effect during the 2003-2004 influenza season, which was unusually severe in Colorado. We collaborated with 5 pediatric practices to attempt universal influenza immunization in this age group.

Objectives: The objectives were (1) to assess the maximal influenza immunization rates that could be achieved for healthy young children in private practice settings, (2) to evaluate the efficacy of registry-based reminder/recall for influenza vaccination, and (3) to describe methods used by private practices to implement the recommendations.

RNA interference acts as a natural antiviral response to O'nyong-nyong virus (Alphavirus; Togaviridae) infection of Anopheles gambiae.

RNA interference (RNAi) is triggered in eukaryotic organisms by double-stranded RNA (dsRNA), and it destroys any mRNA that has sequence identity with the dsRNA trigger. The RNAi pathway in Anopheles gambiae can be silenced by transfecting cells with dsRNA derived from exon sequence of the A. gambiae Argonaute2 (AgAgo2) gene.

Introduction of the American/Asian genotype of dengue 2 virus into the Yucatan State of Mexico.

A dengue (DEN) outbreak occurred in the Yucatan State of Mexico in 2002. Three isolates were obtained from patients presenting with DEN-like symptoms, and examined by partial nucleotide sequencing and phylogenetic analysis. The isolates were identified as DEN-2 viruses of the American-Asian genotype; this is the first report of this genotype in the Yucatan State.

Differences in fat and lean mass proportions in normal and growth-restricted fetuses.

Objective: The purpose of this study was to assess fetal subcutaneous fat and lean mass areas as predictors of fetal growth restriction.

Study Design: Seventeen severe fetal growth-restricted (abdominal circumference, < 2 SD) fetuses and 20 control fetuses underwent ultrasound measurements of subcutaneous fat, lean mass, and standard biometry. Thigh subcutaneous fat and lean mass were measured on enlarged ultrasound axial images (subcutaneous fat area = total cross sectional area - lean mass area [bone + muscle areas]).

Characterization of an endogenous gene expressed in Aedes aegypti using an orally infectious recombinant Sindbis virus.

Sindbis virus expression vectors have been used successfully to express and silence genes of interest in vivo in several mosquito species, including Aedes aegypti, Ae. albopictus, Ae. triseriatus,Culex pipiens, Armigeres subalbatus and Anopheles gambiae.

Phylogenetic analysis of West Nile virus, Nuevo Leon State, Mexico.

West Nile virus RNA was detected in brain tissue from a horse that died in June 2003 in Nuevo Leon State, Mexico. Nucleotide sequencing and phylogenetic analysis of the premembrane and envelope genes showed that the virus was most closely related to West Nile virus isolates collected in Texas in 2002.

Outcomes and characteristics of patients discharged alive from hospice.

Objectives: To describe outcomes and characteristics of patients discharged alive from hospice.

Design: Prospective cohort study using a telephone survey.

Setting: Hospices (n=18) participating in the Population-Based Palliative Care Research Network during the 1-year study period.

The regional immunization registry as a public health tool for improving clinical practice and guiding immunization delivery policy.

Objectives: We assessed the distribution of immunization records among 3 health care delivery sectors and the impact of a regional immunization registry on "up to date" rates.

Methods: Immunization registry records in 2 regions were categorized as having originated in private practices, community health centers, or public health clinics. "Up to date" rates were calculated after we sequentially added immunization records from the 3 sectors.

Using RNA interference to develop dengue virus resistance in genetically modified Aedes aegypti.

Diseases caused by arthropod-borne viruses are significant public health problems, and novel methods are needed to control pathogen transmission. We hypothesize that genetic manipulation of Aedes aegypti mosquitoes can profoundly and permanently reduce vector competence and subsequent transmission of dengue viruses (DENV) to human hosts. We have identified RNA interference (RNAi) as a potential anti-viral, intracellular pathway in the vector that can be triggered by expression of virus-specific, double stranded RNAs (dsRNAs) to reduce vector competence to DENV.

Genetic relatedness of deer mice (Peromyscus maniculatus) infected with Sin Nombre virus.

The deer mouse (Peromyscus maniculatus) is the primary rodent host of Sin Nombre virus (SNV), the principal etiologic agent of hantavirus pulmonary syndrome in the United States. Many characteristics of SNV infections of deer mice are unknown. To better understand the transmission mechanisms of SNV in deer mice, we conducted mark-recapture sampling and genetic analyses to study deer mouse population density and genetic relatedness from 2001 to 2002.

The cost of giving childhood vaccinations: differences among provider types.

Objective: To describe costs to providers of delivering childhood immunizations.

Methods: We collected variable costs--costs that vary with the amount of services rendered--including cost of practitioner and staff time and supplies, using a cost accounting method, from 12 practices (4 pediatric practices, 4 family practices, and 4 public health agencies) in rural and urban areas in Colorado. For private practices, we estimated fixed costs--costs that do not vary with the amount of services, eg, rent and insurance).

Quality improvement in immunization delivery following an unsuccessful immunization recall.

Objectives: Within a clinic serving disadvantaged children, 1) to evaluate a multifaceted quality improvement (QI) project to improve immunization (IZ) up-to-date (UTD) rates and 2) to assess the efficacy of IZ reminder/recall performed following QI.

Methods: A year-long QI project followed by a trial of reminder/recall. QI interventions were targeted at previously identified barriers to IZ and were designed specifically to improve the efficacy of reminder/recall.

RNA interference, arthropod-borne viruses, and mosquitoes.

RNA interference (RNAi) probably functions as an antiviral mechanism in most eukaryotic organisms. Variations in the activity of this antiviral pathway in mosquitoes could explain, in part, why some mosquitoes are competent vectors of medically important, arthropod-borne viruses (arboviruses) and others are not. There are three lines of evidence that show the RNAi pathway exists in Aedes species that transmit arboviruses.