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Original article
High prevalence of infection and low incidence of disease in child contacts of patients with drug-resistant tuberculosis: a prospective cohort study
  1. Helena Huerga1,
  2. Elisabeth Sanchez-Padilla1,
  3. Nara Melikyan1,
  4. Hakob Atshemyan2,
  5. Armen Hayrapetyan3,
  6. Ani Ulumyan4,
  7. Mathieu Bastard1,
  8. Naira Khachatryan2,
  9. Catherine Hewison5,
  10. Francis Varaine5,
  11. Maryline Bonnet1,6
  1. 1 Epicentre, Paris, France
  2. 2 Médecins Sans Frontières, Yerevan, Armenia
  3. 3 National Tuberculosis Control Centre, Yerevan, Armenia
  4. 4 National TB Center in Abovyan, Yerevan, Armenia
  5. 5 Médecins Sans Frontières, Paris, France
  6. 6 IRD UMI233/University of Montpellier/INSRERM U175, Montpellier, France
  1. Correspondence to Dr Elisabeth Sanchez-Padilla, Epicentre, Paris 75011, France; esanchezpadilla{at}


Objective We aimed to measure the prevalence and incidence of latent tuberculosis infection (LTBI) and tuberculosis (TB) disease in children in close contact with patients with drug-resistant TB (DR-TB) in a country with high DR-TB prevalence.

Design and setting This is a prospective cohort study of paediatric contacts of adult patients with pulmonary DR-TB in Armenia. Children were screened using tuberculin skin test, interferon-gamma release assay and chest X-ray at the initial consultation, and were reassessed every 3–6 months for a period of 24 months. Children did not receive preventive treatment.

Main outcome measures Prevalence and incidence of LTBI and TB disease; factors associated with prevalent LTBI.

Results At initial evaluation, 3 of the 150 children included were diagnosed with TB disease (2.0%). The prevalence of LTBI was 58.7%. The incidence of LTBI was 19.9 per 100 children per year, and was especially high during the first 6 months of follow-up (33.3 per 100 children per year). No additional cases with incident disease were diagnosed during follow-up. After adjustment, prevalent LTBI was significantly associated with the child’s age, sleeping in the same house, higher household density, the index case’s age, positive smear result and presence of lung cavities.

Conclusions Children in close contact with patients with DR-TB or in contact with very contagious patients had an increased risk of prevalent LTBI. Although none of the children developed TB disease during a 2-year follow-up period, screening for symptoms of TB disease, based on the prevalence of disease at recruitment, together with follow-up and repeated testing of non-infected contacts, is highly recommended in paediatric contacts of patients with DR-TB.

  • tuberculosis
  • drug-resistance
  • epidemiology
  • infectious diseases
  • screening

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  • HH and ES-P contributed equally.

  • Contributors HH and ES-P conceptualised and designed the study, coordinated and supervised data collection, drafted the initial manuscript, and reviewed and revised the manuscript. NM and HA collaborated in designing the data collection instruments, interviewed and evaluated the patients, collected the data, and reviewed and revised the manuscript. MBa performed the initial analyses and reviewed and revised the manuscript. CH participated in the study conception and design and interpretation of data, and reviewed and revised the manuscript. AH, AU, NK and FV participated in the study conception and design, and interpretation of data. MBo conceptualised and designed the study and critically reviewed the manuscript for important intellectual content. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

  • Funding This study was funded by Médecins Sans Frontières-France.

  • Competing interests None declared.

  • Ethics approval Ethics approval was obtained from the Comité Consultatif de Protection des Personnes dans la Recherche Médicale in Saint-Germain-en-Laye (France) and from the ethical review board of the Medical University of Yerevan (Armenia).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Obtained.

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