TY - JOUR
T1 - Incident Mycobacterium tuberculosis infection in household contacts of infectious tuberculosis patients in Brazil
AU - Jones-López, Edward C.
AU - Acuña-Villaorduña, Carlos
AU - Fregona, Geisa
AU - Marques-Rodrigues, Patricia
AU - White, Laura F.
AU - Hadad, David Jamil
AU - Dutra-Molina, Lucilia Pereira
AU - Vinhas, Solange
AU - McIntosh, Avery I.
AU - Gaeddert, Mary
AU - Ribeiro-Rodrigues, Rodrigo
AU - Salgame, Padmini
AU - Palaci, Moises
AU - Alland, David
AU - Ellner, Jerrold J.
AU - Dietze, Reynaldo
N1 - Funding Information:
This work was supported by the National Institute of Allergy and Infectious Diseases at the National Institutes of Health awards [UO1 AI065663–01 (International Collaboration in Infectious Diseases Research)] and [U19AI111276 (TB Research Unit Network)]; and funds from the Section of Infectious Diseases at Boston Medical Center; and Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.”
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/8/18
Y1 - 2017/8/18
N2 - Background: In household contact investigations of tuberculosis (TB), a second tuberculin skin test (TST) obtained several weeks after a first negative result consistently identifies individuals that undergo TST conversion. It remains unclear whether this delay in M. tuberculosis infection is related to differences in the infectious exposure, TST boosting, partial host resistance, or some other factor. Methods: We conducted a household contact study Vitória, Brazil. Between 2008 and 2013, we identified culture-positive pulmonary TB patients and evaluated their household contacts with both a TST and interferon gamma release assay (IGRA), and identified TST converters at 8-12 weeks post study enrollment. Contacts were classified as TST-positive (≥10 mm) at baseline, TST converters, or persistently TST-negative. We compared TST converters to TST-positive and to TST-negative contacts separately, using generalized estimating equations. Results: We enrolled 160 index patients and 838 contacts; 523 (62.4%) were TST+, 62 (7.4%) TST converters, and 253 (30.2%) TST'. TST converters were frequently IGRA' at 8-12 weeks. In adjusted analyses, characteristics distinguishing TST converters from TST+ contacts (no contact with another TB patient and residence ownership) were different than those differentiating them from TST' contacts (stronger cough in index patient and contact BCG scar). Conclusions: The individual risk and timing of M. tuberculosis infection within households is variable and dependent on index patient, contact and environmental factors within the household, and the surrounding community. Our findings suggest a threshold effect in the risk of infection in humans.
AB - Background: In household contact investigations of tuberculosis (TB), a second tuberculin skin test (TST) obtained several weeks after a first negative result consistently identifies individuals that undergo TST conversion. It remains unclear whether this delay in M. tuberculosis infection is related to differences in the infectious exposure, TST boosting, partial host resistance, or some other factor. Methods: We conducted a household contact study Vitória, Brazil. Between 2008 and 2013, we identified culture-positive pulmonary TB patients and evaluated their household contacts with both a TST and interferon gamma release assay (IGRA), and identified TST converters at 8-12 weeks post study enrollment. Contacts were classified as TST-positive (≥10 mm) at baseline, TST converters, or persistently TST-negative. We compared TST converters to TST-positive and to TST-negative contacts separately, using generalized estimating equations. Results: We enrolled 160 index patients and 838 contacts; 523 (62.4%) were TST+, 62 (7.4%) TST converters, and 253 (30.2%) TST'. TST converters were frequently IGRA' at 8-12 weeks. In adjusted analyses, characteristics distinguishing TST converters from TST+ contacts (no contact with another TB patient and residence ownership) were different than those differentiating them from TST' contacts (stronger cough in index patient and contact BCG scar). Conclusions: The individual risk and timing of M. tuberculosis infection within households is variable and dependent on index patient, contact and environmental factors within the household, and the surrounding community. Our findings suggest a threshold effect in the risk of infection in humans.
KW - Brazil
KW - Household contact study
KW - Latent tuberculosis infection
KW - M. tuberculosis infection
KW - TST conversion
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U2 - 10.1186/s12879-017-2675-3
DO - 10.1186/s12879-017-2675-3
M3 - Article
C2 - 28821234
AN - SCOPUS:85027495014
SN - 1471-2334
VL - 17
JO - BMC infectious diseases
JF - BMC infectious diseases
IS - 1
M1 - 576
ER -