Association between semi-quantitative microbial load and respiratory symptoms among Thai military recruits: a prospective cohort study.
BMC Infect Dis
; 18(1): 462, 2018 Sep 14.
Article
en En
| MEDLINE
| ID: mdl-30217168
ABSTRACT
BACKGROUND:
Multiplex real-time polymerase chain reaction assays have improved diagnostic sensitivity for a wide range of pathogens. However, co-detection of multiple agents and bacterial colonization make it difficult to distinguish between asymptomatic infection or illness aetiology. We assessed whether semi-quantitative microbial load data can differentiate between symptomatic and asymptomatic states for common respiratory pathogens.METHODS:
We obtained throat and nasal swab samples from military trainees at two Thai Army barracks. Specimens were collected at the start and end of 10-week training periods (non-acute samples), and from individuals who developed upper respiratory tract infection during training (acute samples). We analysed the samples using a commercial multiplex respiratory panel comprising 33 bacterial, viral and fungal targets. We used random effects tobit models to compare cycle threshold (Ct) value distributions from non-acute and acute samples.RESULTS:
We analysed 341 non-acute and 145 acute swab samples from 274 participants. Haemophilus influenzae type B was the most commonly detected microbe (77.4% of non-acute and 64.8% of acute samples). In acute samples, nine specific microbe pairs were detected more frequently than expected by chance. Regression models indicated significantly lower microbial load in non-acute relative to acute samples for H. influenzae non-type B, Streptococcus pneumoniae and rhinovirus, although it was not possible to identify a Ct-value threshold indicating causal etiology for any of these organisms.CONCLUSIONS:
Semi-quantitative measures of microbial concentration did not reliably differentiate between illness and asymptomatic colonization, suggesting that clinical symptoms may not always be directly related to microbial load for common respiratory infections.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Infecciones del Sistema Respiratorio
/
Reacción en Cadena de la Polimerasa Multiplex
Tipo de estudio:
Diagnostic_studies
/
Etiology_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Female
/
Humans
/
Male
País/Región como asunto:
Asia
Idioma:
En
Revista:
BMC Infect Dis
Asunto de la revista:
DOENCAS TRANSMISSIVEIS
Año:
2018
Tipo del documento:
Article
País de afiliación:
Singapur