Sónia T Almeida1, Ana Cristina Paulo1, Filipe Froes2, Hermínia de Lencastre3,4, Raquel Sá-Leão1. 1. Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal. 2. Unidade de Cuidados Intensivos Médico-Cirúrgicos, Departamento do Tórax, Hospital Pulido Valente Centro Hospitalar Universitário Lisboa Norte, Lisboa, Portugal. 3. Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal. 4. Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, USA.
Abstract
BACKGROUND: Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches. METHODS: Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped. RESULTS: Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2-24.2) and 95.9 (95% CI, 62.3-145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6-20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children. CONCLUSIONS: The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.
BACKGROUND: Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches. METHODS: Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped. RESULTS: Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2-24.2) and 95.9 (95% CI, 62.3-145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6-20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children. CONCLUSIONS: The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.
Authors: Estela Moreno-García; Pedro Puerta-Alcalde; Laura Letona; Fernanda Meira; Gerard Dueñas; Mariana Chumbita; Nicole Garcia-Pouton; Patricia Monzó; Carlos Lopera; Laia Serra; Celia Cardozo; Marta Hernandez-Meneses; Verónica Rico; Marta Bodro; Laura Morata; Mariana Fernandez-Pittol; Ignacio Grafia; Pedro Castro; Josep Mensa; José Antonio Martínez; Gemma Sanjuan; Mª Angeles Marcos; Alex Soriano; Carolina Garcia-Vidal Journal: Int J Infect Dis Date: 2022-03-05 Impact factor: 12.074
Authors: Willem R Miellet; Janieke van Veldhuizen; David Litt; Rob Mariman; Alienke J Wijmenga-Monsuur; Paul Badoux; Tessa Nieuwenhuijsen; Rebecca Thombre; Sanaa Mayet; Seyi Eletu; Carmen Sheppard; Marianne Alice van Houten; Nynke Y Rots; Elizabeth Miller; Norman K Fry; Elisabeth A M Sanders; Krzysztof Trzciński Journal: Front Microbiol Date: 2022-04-18 Impact factor: 6.064
Authors: Konstantinos Liatsikos; Angela Hyder-Wright; Sherin Pojar; Tao Chen; Duolao Wang; Kelly Davies; Christopher Myerscough; Jesus Reine; Ryan E Robinson; Britta Urban; Elena Mitsi; Carla Solorzano; Stephen B Gordon; Angela Quinn; Kaijie Pan; Annaliesa S Anderson; Christian Theilacker; Elizabeth Begier; Bradford D Gessner; Andrea Collins; Daniela M Ferreira Journal: BMJ Open Date: 2022-07-07 Impact factor: 3.006
Authors: Sónia T Almeida; A Cristina Paulo; João Babo; João Borralho; Catarina Figueiredo; Bruno Gonçalves; João Lança; Mónica Louro; Hermes Morais; Joana Queiroz; Hermínia de Lencastre; Raquel Sá-Leão Journal: PLoS One Date: 2021-06-30 Impact factor: 3.240
Authors: Joseph A Lewnard; Katia J Bruxvoort; Heidi Fischer; Vennis X Hong; Lindsay R Grant; Luis Jódar; Bradford D Gessner; Sara Y Tartof Journal: J Infect Dis Date: 2022-05-16 Impact factor: 7.759