Streptococcus pneumoniae and noncapsular Haemophilus influenzae nasal carriage and hand contamination in children: a comparison of two populations at risk of otitis media.

BACKGROUND: Australian Indigenous children living in remote areas have rates of tympanic membrane perforation as high as 60%, almost 100 times the prevalence in urban child care settings (<1%). Relative rates of pneumococcal nasal carriage do not reflect this difference in disease risk.

METHODS: Cross-sectional comparison of nasal carriage and hand contamination in children younger than 4 years of age from urban child-care centers and Indigenous children 3-7 years of age from a remote community. Almost identical methods of nasal swab collection, transport and culture were used. Data on pneumococcal antimicrobial susceptibility patterns and serotypes are also reported.

RESULTS: For Indigenous children compared with children in child care, the relative risk of nasal carriage of either pneumococcus or noncapsular Haemophilus influenzae was <2-fold [relative risk, 1.7; 95% confidence interval (CI), 1.5, 1.9], the risk of simultaneous nasal carriage was almost 3-fold (78% versus 28%; relative risk, 2.9; 95% CI 2.3, 3.5), and the risk of pneumococcal hand contamination was 8-fold higher (37% versus 4%; relative risk, 8.4; 95% CI 4.6, 15.2). For simultaneous hand contamination, the risk was 23-fold (8% versus 0.3%; relative risk, 23.1; 95% CI 2.9, 185.4). Remote Indigenous children also had a more diverse serotype distribution (25 versus 14 serotypes identified).

CONCLUSIONS: Simultaneous nasal carriage of Streptococcus pneumoniae and H. influenzae and hand contamination are simple indicators of risk for use in studies of otitis media in populations at risk for tympanic membrane perforation.