Influence of sampling technique on detection of potential pathogens in the nasopharynx.

OBJECTIVES

To determine the optimal approach for nasopharyngeal culture and to establish which approach children tolerate best.

DESIGN

Cross-sectional study.

SETTING

A pediatric otolaryngology department of a Dutch tertiary care hospital.

PATIENTS: A cohort of 42 children with chronic suppurative otitis media.

INTERVENTION: Paired nasopharyngeal samples were collected transorally and transnasally and cultured for potential aerobic pathogens.

MAIN OUTCOME MEASURES: The isolation rate of both samples and the amount of discomfort measured by the visual analog scale.

RESULTS

Forty-six (87%) of 53 samples obtained transnasally were culture positive vs 40 (75%) of 53 samples obtained transorally (P = .20). Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus were found more frequently with the transnasal than with the transoral approach: 34% vs 13% (P = .003), 62% vs 51% (P = .20), 30% vs 19% (P = .15), and 21% vs 11% (P = .18), respectively. Mean (SD) visual analog scale scores were 5.3 (1.0) and 3.4 (1.7) (P<.001) for the transnasal and transoral approaches, respectively.

CONCLUSIONS

Although the transoral approach is better tolerated in children, the isolation rate of the transnasal approach is higher, especially for S. pneumoniae. The transnasal sampling technique should therefore be the preferred approach for detection of potential pathogens in the nasopharynx in children.