Association of Laboratory Methods, Colonization Density, and Age With Detection of Streptococcus pneumoniae in the Nasopharynx.
Am J Epidemiol
; 188(12): 2110-2119, 2019 12 31.
Article
en En
| MEDLINE
| ID: mdl-31509184
ABSTRACT
Culture-based methods for detecting Streptococcus pneumoniae in the nasopharynx lack sensitivity. In this study, we aimed to compare the performance of culture and molecular methods in detecting pneumococcus in the nasopharynx of healthy individuals and to evaluate the associations of age and colonization density with detection. Between 2010 and 2012, nasopharyngeal specimens were collected from healthy individuals living on Navajo Nation and White Mountain Apache Tribal lands in the United States. Pneumococci were detected by means of broth-enrichment culture and autolysin-encoding gene (lytA) quantitative polymerase chain reaction (qPCR). Among 982 persons evaluated (median age, 18.7 years; 47% male), 35% were culture-positive and an additional 27% were qPCR-positive. Agreement between culture and qPCR was 70.9% but was higher among children (age <18 years) (75.9%-84.4%) than among adults (age ≥18 years) (61.0%-74.6%). The mean density of colonization was lower for culture-negative samples (3.14 log10 copies/mL) than for culture-positive samples (5.02 log10 copies/mL), overall and for all age groups. The percent culture-positive increased with increasing density, exceeding 80% at densities of ≥10,000 copies/mL. Mean colonization density decreased with age. Use of qPCR improved detection of pneumococcus in the nasopharynx of healthy individuals. This finding was most notable among adults, probably because of improved detection of low-density colonization.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Streptococcus pneumoniae
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Nasofaringe
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Técnicas de Cultivo
Tipo de estudio:
Diagnostic_studies
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Evaluation_studies
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Observational_studies
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Prevalence_studies
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Risk_factors_studies
Límite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
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Middle aged
Idioma:
En
Revista:
Am J Epidemiol
Año:
2019
Tipo del documento:
Article