Well-quantified tuberculosis exposure is a reliable surrogate measure of tuberculosis infection
Date
2012
Authors
Mandalakas A.M.
Kirchner H.L.
Lombard C.
Walzl G.
Grewal H.M.S.
Gie R.P.
Hesseling A.C.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
SETTING: Cape Town, South Africa. OBJECTIVE: To develop a standardized, reliable measure of household tuberculosis (TB) exposure that considers child-specific risk factors. DESIGN: We assessed TB exposure in 536 children. Children were considered Mycobacterium tuberculosis infected if two of three tests of infection were positive. Principal component analysis identified a discrete set of components that collectively described exposure and contributed to a composite contact score. Logistic regression assessed the odds of having M. tuberculosis infection given increasing contact score while controlling for age and past TB treatment. RESULTS: Four components described 68% of data variance: 1) maternal TB and sleep proximity, 2) index case infectivity, 3) duration of exposure, and 4) exposure to multiple index cases. Components were derived from 10 binary questions that contributed to a contact score (range 1-10, median 5, 25th-75th interquartile range [IQR] 4-7). Among children aged 3 months to 6 years with household exposure, the odds of being M. tuberculosis-infected increased by 74% (OR 1.74, 95%CI 1.42-2.12) with each 1-point increase in the contact score. CONCLUSIONS: Well-quantified TB exposure is a good surrogate measure of M. tuberculosis infection in child household contacts in a high-burden setting, and could guide targeted preventive treatment in children at highest risk of M. tuberculosis infection. © 2012 The Union.
Description
Article
Keywords
Children, Contact tracing, Latent tuberculosis infection, Pediatrics, Preventive therapy
Citation
International Journal of Tuberculosis and Lung Disease
16
8
1033
1039
16
8
1033
1039