Viruses in families.
D002675:Child, Preschool; D006801:Humans; D007223:Infant; D012141:Respiratory Tract Infections / Q000235:genetics* / Q000382:microbiology; D013048:Specimen Handling; D013997:Time Factors; D014777:Virus Diseases / Q000235:genetics*; D014780:Viruses / Q000302:isolation & purification*