Effect of ventilation improvement during a tuberculosis outbreak in underventilated university buildings.
Indoor Air
; 30(3): 422-432, 2020 05.
Article
em En
| MEDLINE
| ID: mdl-31883403
ABSTRACT
The role of ventilation in preventing tuberculosis (TB) transmission has been widely proposed in infection control guidance. However, conclusive evidence is lacking. Modeling suggested the threshold of ventilation rate to reduce effective reproductive ratio (ratio between new secondary infectious cases and source cases) of TB to below 1 is corresponding to a carbon dioxide (CO2 ) level of 1000 parts per million (ppm). Here, we measured the effect of improving ventilation rate on a TB outbreak involving 27 TB cases and 1665 contacts in underventilated university buildings. Ventilation engineering decreased the maximum CO2 levels from 3204 ± 50 ppm to 591-603 ppm. Thereafter, the secondary attack rate of new contacts in university dropped to zero (mean follow-up duration 5.9 years). Exposure to source TB cases under CO2 >1000 ppm indoor environment was a significant risk factor for contacts to become new infectious TB cases (P < .001). After adjusting for effects of contact investigation and latent TB infection treatment, improving ventilation rate to levels with CO2 <1000 ppm was independently associated with a 97% decrease (95% CI 50%-99.9%) in the incidence of TB among contacts. These results show that maintaining adequate indoor ventilation could be a highly effective strategy for controlling TB outbreaks.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tuberculose
/
Ventilação
Tipo de estudo:
Guideline
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
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Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article