Exposure to tobacco smoke increased S. pneumoniae carriage rates in general and for carriage of serotypes included in the conjugate 7-valent vaccine in particular in children. Smoking mothers had a higher S. pneumoniae carriage rate than did nonsmoking mothers. Smoking or exposure to smoking did not increase H. influenzae carriage rates in children and mothers.

Streptococcus pneumoniae and Haemophilus influenzae carriage is a useful index for measuring the emergence of resistance and outcome in vaccination trials. We performed a study to determine which sampling site, nasopharynx (NP) or oropharynx (OP), yields the highest rate of S. pneumoniae and H. influenzae isolation at different ages. Both NP and OP cultures were obtained from 216 children aged <60 months and their mothers. The total S. pneumoniae carriage rate was 68% among children and 15% among mothers (P < 0.001). Using NP alone for the isolation of S. pneumoniae would have missed 2, 2, and 42% and using OP alone would have missed 77, 66, and 45% of S. pneumoniae in children aged 0 to 23 months, 24 to 59 months, and mothers, respectively. Using NP cultures alone for H. influenzae would have missed 23, 24, and 81% of the isolates, respectively. The respective figures for H. influenzae isolation from OP alone are 38, 29, and 9%. In children, S. pneumoniae was carried mainly in the NP while H. influenzae was equally carried in the NP and OP. In mothers, S. pneumoniae was carried equally in the NP and OP while H. influenzae was carried significantly more often in the OP. In children, H. influenzae colonization increased during illness, mainly in the NP. Culturing only one site significantly reduced the recovery of H. influenzae at all ages. NP cultures for S. pneumoniae detected close to 100% of isolates in children but only 58% of isolates in mothers.Streptococcus pneumoniae and Haemophilus influenzae are important bacterial pathogens causing infections in young children and in elderly patients (1,22,23). Both organisms commonly colonize the mucosal membrane of the nasopharynx and throat of healthy children, and most children are colonized at some point during the first 2 years of life (10, 15). Information on the nasopharyngeal (NP) and oropharyngeal (OP) carriage rate of both organisms is crucial to understanding disease epidemiology, since these organisms can spread from colonized sites to adjacent mucosal tissues to cause mucosal infections or, in the case of S. pneumoniae, invade the bloodstream to cause bacteremia and meningitis. In addition to carriage in the upper respiratory tract, the organism can spread from person to person (16,17,24). Furthermore, studying the organisms carried in the upper respiratory tract provides useful information on the emergence of resistance in clinical isolates (18,27). It is also important to evaluate the mucosal carriage of the organisms in vaccine trials as an index of potential herd protection.Nasopharyngeal sampling is considered superior to OP sampling for detecting S. pneumoniae, especially in young children (25), but there are other contradictory results showing that in adults OP sampling yields higher isolation rates (4, 16). Only a few carriage studies have directly compared different sampling methods for the detection of S. pneumoniae and H. influenzae (4, 6, 25; R. Dagan, O. Zamir, M. Sikuler-Cohen, P. Yagupsky, P. Peeters, and M. Hohenboken, Abstr. 41st Intersc...