title: Quantification of nasopharyngeal bacteria for diagnosis of respiratory tract infection in children.
abstract: Agreement between clinical signs of bacterial respiratory tract infections and quantities of respiratory tract pathogens in nasopharynx was studied in 77 children, aged 6-13 years. Specimens were obtained from 27 clinically bacterial and 51 clinically non-bacterial respiratory tract infections, and in 124 instances from healthy children. Viable counts of Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis, and beta-haemolytic streptococci were made from swab specimens suspended in saline before being plated on agar media. The frequency of these species in children with clinically bacterial, non-bacterial and no signs of respiratory tract infections were 85%, 47% and 26%, respectively. Bacterial counts greater than 10(4) colony-forming units (CFU)/ml of the pathogens occurred in 59% of clinically bacterial infections, as compared with 18% in clinically non-bacterial infections (p less than 0.001), the corresponding figures for counts greater than 10(3) CFU/ml being 85% and 41% (p less than 0.01), respectively. At neither level of bacterial count (i.e. greater than 10(4) or greater than 10(3], was there a significant difference between the healthy and those with a clinically non-bacterial infection. The quantification of bacteria in nasopharyngeal samples may thus be of clinical diagnostic value.
authors.affiliation: Department of Health Sciences Centre, University of Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Söderström
authors.forename: B
authors.initials: B
authors.lastname: Hovelius
authors.forename: K
authors.initials: K
authors.lastname: Prellner
authors.forename: C
authors.initials: C
authors.lastname: Schalén
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D002353:Carrier State / Q000175:diagnosis*; D002648:Child; D015169:Colony Count, Microbial; D006193:Haemophilus influenzae / Q000254:growth & development; D006801:Humans; D001936:Moraxella catarrhalis / Q000254:growth & development; D009305:Nasopharynx / Q000382:microbiology*; D015203:Reproducibility of Results; D012141:Respiratory Tract Infections / Q000175:diagnosis*; D013048:Specimen Handling; D013291:Streptococcus / Q000254:growth & development; D013296:Streptococcus pneumoniae / Q000254:growth & development