title: Carriage of Streptococcus pneumoniae in aged adults with influenza-like-illness.
abstract: Incidence of pneumococcal disease is disproportionally high in infants and elderly. Nasopharyngeal colonisation by Streptococcus pneumoniae is considered a prerequisite for disease but unlike in children, carriage in elderly is rarely detected. Here, we tested for S. pneumoniae in nasopharyngeal and saliva samples collected from community-dwelling elderly with influenza-like-illness (ILI). Trans-nasal nasopharyngeal, trans-oral nasopharyngeal and saliva samples (n = 270 per sample type) were collected during winter/spring 2011/2012 from 135 persons aged 60-89 at onset of ILI and 7-9 weeks later following recovery. After samples were tested for pneumococci by conventional culture, all plate growth was collected. DNA extracted from plate harvests was tested by quantitative-PCRs (qPCR) specific for S. pneumoniae and serotypes included in the 13-valent pneumococcal conjugated vaccine (PCV13). Pneumococci were cultured from 14 of 135 (10%) elderly with none of the sampled niches showing superiority in carriage detection. With 76/270 (28%) saliva, 31/270 (11%) trans-oral and 13/270 (5%) trans-nasal samples positive by qPCR, saliva was superior to nasopharyngeal swabs (p<0.001) in qPCR-based carriage detection. Overall, from all methods used in the study, 65 of 135 (48%) elderly carried pneumococci at least once and 26 (19%) at both study time points. The difference between carriage prevalence at ILI (n = 49 or 36%) versus recovery (n = 42 or 31%) was not significant (p = 0.38). At least 23 of 91 (25%) carriage events in 19 of 65 (29%) carriers were associated with PCV13-serotypes. We detected a large reservoir of pneumococci in saliva of elderly, with PCV13-serotype distribution closely resembling the contemporary carriage of serotypes reported in the Netherlands for PCV-vaccinated infants.
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Cassandra L
authors: CL
authors: Krone
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Anne L
authors: AL
authors: Wyllie
authors: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors: Josine
authors: J
authors: van Beek
authors: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors: Nynke Y
authors: NY
authors: Rots
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Anna E
authors: AE
authors: Oja
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Mei Ling J N
authors: ML
authors: Chu
authors: Regional Laboratory of Public Health, Haarlem, The Netherlands.
authors: Jacob P
authors: JP
authors: Bruin
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Debby
authors: D
authors: Bogaert
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Elisabeth A M
authors: EA
authors: Sanders
authors: Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Krzysztof
authors: K
authors: Trzciński
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004269:DNA, Bacterial / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000235:genetics / Q000382:microbiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000235:genetics* / Q000382:microbiology; D012463:Saliva / Q000382:microbiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D004269:DNA, Bacterial