Bocavirus: A genus in the subfamily PARVOVIRINAE comprising three species: Bovine parvovirus, Canine minute virus, and HUMAN BOCAVIRUS.Human bocavirus: A member of the family PARVOVIRIDAE, subfamily PARVOVIRINAE, originally isolated from human nasopharyngeal aspirates in patients with respiratory disease.Parvoviridae Infections: Virus infections caused by the PARVOVIRIDAE.Parvovirinae: A subfamily of DNA vertebrate viruses, in the family PARVOVIRIDAE. There are three genera: PARVOVIRUS; ERYTHROVIRUS; and DEPENDOVIRUS.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Nasopharynx: The top portion of the pharynx situated posterior to the nose and superior to the SOFT PALATE. The nasopharynx is the posterior extension of the nasal cavities and has a respiratory function.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Parvovirus: A genus of the family PARVOVIRIDAE, subfamily PARVOVIRINAE, infecting a variety of vertebrates including humans. Parvoviruses are responsible for a number of important diseases but also can be non-pathogenic in certain hosts. The type species is MINUTE VIRUS OF MICE.Gastroenteritis: INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Viruses: Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.Metapneumovirus: A genus of the subfamily PNEUMOVIRINAE, containing two members: Turkey rhinotracheitis virus and a human Metapneumovirus. Virions lack HEMAGGLUTININ and NEURAMINIDASE.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Parvovirus B19, Human: The type species of ERYTHROVIRUS and the etiological agent of ERYTHEMA INFECTIOSUM, a disease most commonly seen in school-age children.Virus Diseases: A general term for diseases produced by viruses.Pneumonia, Viral: Inflammation of the lung parenchyma that is caused by a viral infection.Child, Hospitalized: Child hospitalized for short term care.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.