Vaccine. 2015 Nov 18. pii: S0264-410X(15)01634-5. doi: 10.1016/j.vaccine.2015.11.014. [Epub ahead of print]
Colonization of the upper respiratory tract by Streptococcus pneumoniae is considered prerequisite for pneumococcal disease. Despite high rates of pneumococcal disease in elderly, pneumococcal carriage rates are usually below 5% when detected by the conventional culture method. We assessed pneumococcal carriage in 330 asymptomatic community-dwelling elderly aged 65 years and older. While pneumococci were cultured from 25 (8%) individuals, 65 (20%) elderly were positive for the pneumococcus-specific lytA gene when tested by quantitative-PCR, increasing the overall number of carriers to 75 (22%). Significantly more oropharyngeal samples were pneumococci-positive (18% versus 10%, p<0.001) when tested by the molecular method as compared to nasopharyngeal samples. Our findings indicate that pneumococcal carriage in elderly is higher than previously reported with up to 1 in 5 asymptomatic community-dwelling elderly positive for pneumococcal carriage, when detected by qPCR. The detection of pneumococci by conventional culture alone, greatly underestimates S. pneumoniae colonization in elderly.
Copyright © 2015. Published by Elsevier Ltd.
Colonization; Elderly; Nasopharynx; PCR; Streptococcus pneumoniae
PMID: 26602269 [PubMed - as supplied by publisher]