Frequency of latent tuberculosis infection between age groups in family members of a patient with a pulmonary tuberculosis in Iran

Document Type : Research Paper


1 Pediatric Infections Research Center , Research Institute for Children’s Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

2 Department of Epidemiology, School of Public Health, Iran University of Medical Sciences, Tehran, Iran

3 Center for Communicable Diseases Control, Ministry of Health and Medical Education, Tehran, Iran.

4 Department of immunology, School of public health, Tehran university of medical science, Tehran, Iran.

5 Central Laboratory of deputy of health, Golestan university of medical sciences. Gorgan, Iran

6 Deputy of health, Zabol university of medical science, Zabol, Iran

7 Pediatric Infections Research Center, Research Institute for Children’s Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran


Background: Given that tuberculosis infection is present in one-quarter of the world's population and is more likely to convert to tuberculosis, especially at a young age, its diagnosis and prevention is an important part of the World Health Organization's (WHO) program. The aim of this study is to evaluate the frequency of latent tuberculosis infection (LTBI) in different age groups of family members of pulmonary tuberculosis patients in two provinces of Iran with a high prevalence of tuberculosis during 18 months.
Method: Family members of confirmed pulmonary tuberculosis patients were followed up as a retrospective and prospective study in the cities of Gorgan and Zabol at 0, 3, 12 and 18 months after the starting the study. LTBI was diagnosed by using the QuantiFERON test kit and the Tuberculin skin test (TST).
Results: The number of LTBI cases based on QFT or TST was 354 (52.99%) in the whole study and 33.33% in children under 5 years old. Positive cases of TST, QFT and LTBI in the age group over 18 years were significantly different with 5 to 18 years and less than 5 years, while there was no significant difference between the age groups of less than 5 years and 5 to 18 years.
Conclusion: The results of this study showed that most cases of infection occur before the diagnosis of the index case or in the first phase of study, and there is no significant difference between the diagnosis with TST or QFT.


  1. Behera D. Global Tuberculosis Control 2011, WHO Report 2011. Indian Journal of Medical Research. 2012;136(4):681-3.
  2. Uplekar M, Stop TBP, World Health O. The Stop TB strategy : building on and enhancing DOTS to meet the TB-related Millennium Development Goals. Geneva: World Health Organization; 2006.
  3. World Health O. Latent tuberculosis infection: updated and consolidated guidelines for programmatic management. Geneva: World Health Organization; 2018
  4. Houben RMGJ, Dodd PJ. The Global Burdenof Latent Tuberculosis Infection: A Re-estimation Using Mathematical Modelling. PLoS medicine. 2016;13(10):e1002152-e.
  5. Getahun H, Matteelli A, Abubakar I, Aziz MA, Baddeley A, Barreira D, et al. Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries. The European respiratory journal. 2015;46(6):1563-76.
  6. Kiazyk S, Ball TB. Latent tuberculosis infection: An overview. Canada communicable disease report = Releve des maladies transmissibles au Canada. 2017;43(3-4):62-6.
  7. Houben RM, Dodd PJ. The Global Burden of Latent Tuberculosis Infection: A Re-estimation Using Mathematical Modelling. PLoS medicine. 2016;13(10):e1002152.
  8. Yohhei Hamada, Philippe Glaziou, Charalambos Sismanidis, Haileyesus Getahun. Prevention of tuberculosis in household members: estimates of children eligible for treatment. Bulletin of the World Health Organization, 2019 Aug 1;97(8):534-547D.
  9. Eom JS, Kim I, Kim WY, Jo EJ, Mok J, Kim MH, et al. Household tuberculosis contact investigation in a tuberculosis-prevalent country: Are the tuberculin skin test and interferon-gamma release assay enough in elderly contacts? Medicine. 2018;97(3):e9681.
  10. Morán-Mendoza O, Marion SA, Elwood K, Patrick D, FitzGerald JM. Riskfactors for developing tuberculosis: a 12-year follow-up of contacts of tuberculosis cases. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease. 2010;14(9):1112-9.
  11. Sekandi JN, Neuhauser D, Smyth K, Whalen CC. Active case finding of undetected tuberculosis among chronic coughers in a slum setting in Kampala, Uganda. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease. 2009;13(4):508-13.
  12. Tomas Maria Perez-Porcuna , Hélio Doyle Pereira-da-Silva , Carlos Ascaso , Adriana Malheiro , Samira Bührer, Flor Martinez-Espinosa , Rosa Abellana. Prevalence and Diagnosis of Latent Tuberculosis Infection in Young Children in the Absence of a Gold Standard. PLoS One. 2016 Oct 26;11(10):e0164181.
  13. Peter Auguste, Alexander Tsertsvadze , Joshua Pink, Rachel Court , Noel McCarthy, Paul Sutcliffe, Aileen Clarke. Comparing interferon-gamma release assays with tuberculin skin test for identifying latent tuberculosis infection that progresses to active tuberculosis: Systematic review and meta-analysis. BMC Infectious Diseases. 2017 Mar 9;17(1):200.
  14. Dolla CK, Padmapriyadarsini C, Thiruvengadam K, Lokhande R, Kinikar A, Paradkar M, et al. Age-specific prevalence of TB infection among household contacts of pulmonary TB: Is it time for TB preventive therapy? Transactions of the Royal Society of Tropical Medicine and Hygiene. 2019;113(10):632-40.
  15. Hu Y, Zhao Q, Wu L, Wang W, Yuan Z, Xu B. Prevalence of latent tuberculosis infection and its risk factors in schoolchildren and adolescents in Shanghai, China. European journal of public health. 2013;23(6):1064-9.
  16. Padmapriyadarsini Chandrasekaran , Vidya Mave , Kannan Thiruvengadam , Nikhil Gupte , Shri Vijay Bala Yogendra Shivakumar , Luke Elizabeth Hanna. Tuberculin skin test and QuantiFERON-Gold In Tube assay for diagnosis of latent TB infection among household contacts of pulmonary TB patients in high TB burden setting. Plos one, 2018 Aug 1;13(8):e0199360.
  17. Ghassemieh BJ, Attia EF, Koelle DM, Mancuso JD, Narita M, Horne DJ. Latent Tuberculosis Infection Test Agreement in the National Health and Nutrition Examination Survey. American journal of respiratory and critical care medicine. 2016;194(4):493-500.
  18. Adams S, Ehrlich R, Baatjies R, Dendukuri N, Wang Z, Dheda K. Predictors of discordant latent tuberculosis infection test results amongst South African health care workers. BMC Infectious Diseases. 2019;19(1):131.
  19. Cho H, Kim YW, Suh CH, Jung JY, Um YJ, Jung JH, et al. Concordance between the tuberculin skin test and interferon gamma release assay (IGRA) for diagnosing latent tuberculosis infection in patients with systemic lupus erythematosus and patient characteristics associated with an indeterminate IGRA. Lupus. 2016;25(12):1341-8.