Showing papers by "Dean D. Erdman published in 2002"

Virological Features and Clinical Manifestations Associated with Human Metapneumovirus: A New Paramyxovirus Responsible for Acute Respiratory-Tract Infections in All Age Groups

Abstract: The virological features and clinical findings associated with the new human metapneumovirus (HMPV) were examined retrospectively in Canadian patients hospitalized for various respiratory conditions since 1993 Thirty-eight previously unidentified respiratory viruses isolated from rhesus monkey kindey (LLC-MK2) cells were found to be positive for HMPV by reverse-transcription polymerase chain reaction, and those strains clustered in 2 phylogenetic groups Children aged 65 years represented 351% and 459% of the HMPV-infected cases, respectively In hospitalized children, the most frequent diagnoses were pneumonitis (667%) and bronchiolitis (583%), whereas bronchitis and/or bronchospasm (60%) and pneumonitis (40%) were most commonly seen in elderly subjects Of the 15 patients with pneumonitis, 4 (267%) had immunosuppressive conditions and 6 (40%) were infants aged <15 months These findings suggest that HMPV can be associated with severe lower-respiratory-tract infections in very young children, the elderly, and immunocompromised patients

Characterization of Human Metapneumoviruses Isolated from Patients in North America

Abstract: Human metapneumovirus (HMPV) was recently identified in The Netherlands and was linked to acute respiratory tract illness. In this study, 11 isolates from 10 patients with respiratory disease from Quebec, Canada, were tested by a reverse-transcriptase polymerase chain reaction based on the fusion protein gene. Identified sequences were consistent with HMPV. The patients were 2 months to 87 years of age (median age, 58 years) and presented with acute respiratory tract illness during the winter season. Sequence studies of the nucleocapsid, fusion, and polymerase genes identified 2 main lineages of HMPV and cocirculation of both lineages during the same year. These findings support a previous finding that HMPV is a human respiratory pathogen that merits further study.

Prevalence and Quantitation of Species C Adenovirus DNA in Human Mucosal Lymphocytes

Abstract: The common species C adenoviruses (serotypes Ad1, Ad2, Ad5, and Ad6) infect more than 80% of the human population early in life. Following primary infection, the virus can establish an asymptomatic persistent infection in which infectious virions are shed in feces for several years. The probable source of persistent virus is mucosa-associated lymphoid tissue, although the molecular details of persistence or latency of adenovirus are currently unknown. In this study, a sensitive real-time PCR assay was developed to quantitate species C adenovirus DNA in human tissues removed for routine tonsillectomy or adenoidectomy. Using this assay, species C DNA was detected in Ficoll-purified lymphocytes from 33 of 42 tissue specimens tested (79%). The levels varied from fewer than 10 to greater than 2 x 10(6) copies of the adenovirus genome/10(7) cells, depending on the donor. DNA from serotypes Ad1, Ad2, and Ad5 was detected, while the rarer serotype Ad6 was not. When analyzed as a function of donor age, the highest levels of adenovirus genomes were found among the youngest donors. Antibody-coated magnetic beads were used to purify lymphocytes into subpopulations and determine whether viral DNA could be enriched within any purified subpopulations. Separation of T cells (CD4/8- expressing and/or CD3-expressing cells) enriched viral DNA in each of nine donors tested. In contrast, B-cell purification (CD19-expressing cells) invariably depleted or eliminated viral DNA. Despite the frequent finding of significant quantities of adenovirus DNA in tonsil and adenoid tissues, infectious virus was rarely present, as measured by coculture with permissive cells. These findings suggest that human mucosal T lymphocytes may harbor species C adenoviruses in a quiescent, perhaps latent form.

Molecular Epidemiology of Adenovirus Type 7 in the United States, 1966-2000

Abstract: Genetic variation among 166 isolates of human adenovirus 7 (Ad7) obtained from 1966 to 2000 from the United States and Eastern Ontario, Canada, was determined by genome restriction analysis. Most (65%) isolates were identified as Ad7b. Two genome types previously undocumented in North America were also identified: Ad7d2 (28%), which first appeared in 1993 and was later identified throughout the Midwest and Northeast of the United States and in Canada; and Ad7h (2%), which was identified only in the U.S. Southwest in 1998 and 2000. Since 1996, Ad7d2 has been responsible for several civilian outbreaks of Ad7 disease and was the primary cause of a large outbreak of respiratory illness at a military recruit training center. The appearance of Ad7d2 and Ad7h in North America represents recent introduction of these viruses from previously geographically restricted areas and may herald a shift in predominant genome type circulating in the United States.