Latent tuberculosis infection in rural China: who will develop tuberculosis?

Abstract

Screening people at risk of developing tuberculosis because of latent infection and offering preventive treatment to those with positive results is now regarded as one of the components of the WHO End TB Strategy. 1 Getahun H Matteelli A Abubakar I et al. Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries. Eur Respir J. 2015; 46: 1563-1576 Crossref PubMed Scopus (392) Google Scholar In The Lancet Infectious Diseases, Lei Gao and colleagues 2 Gao L Li X Liu J et al. Incidence of active tuberculosis in individuals with latent tuberculosis infection in rural China: follow-up results of a population-based, multicentre, prospective cohort study. Lancet Infect Dis. 2017; (published online July 14.)http://dx.doi.org/10.1016/S1473-3099(17)30402-4 Google Scholar present the results of a 2-year follow-up study in four rural regions of China, assessing patients with latent tuberculosis infection, defined by a positive tuberculin skin test (TST) or a positive interferon-γ release assay (IGRA) QuantiFERON-TB Gold In-Tube (QFT), which has been described in previous publications. 3 Gao L Lu W Bai L et al. Latent tuberculosis infection in rural China: baseline results of a population-based, multicentre, prospective cohort study. Lancet Infect Dis. 2015; 15: 310-319 Summary Full Text Full Text PDF PubMed Scopus (149) Google Scholar , 4 Gao L Bai L Liu J et al. Annual risk of tuberculosis infection in rural China: a population-based prospective study. Eur Respir J. 2016; 48: 168-178 Crossref PubMed Scopus (26) Google Scholar The authors report an incidence rate of tuberculosis of 0·87 (95% CI 0·68–1·07) per 100 person-years in people with QFT positivity and 0·50 (0·38–0·63) per 100 person-years in the group with a positive TST. 2 Gao L Li X Liu J et al. Incidence of active tuberculosis in individuals with latent tuberculosis infection in rural China: follow-up results of a population-based, multicentre, prospective cohort study. Lancet Infect Dis. 2017; (published online July 14.)http://dx.doi.org/10.1016/S1473-3099(17)30402-4 Google Scholar The main risk factors for the development of active tuberculosis during the observation period are male sex and a history of tuberculosis. Gao and colleagues conclude that targeted screening of population groups with a high risk of tuberculosis and provision of a preventive treatment might reduce the pool of future tuberculosis cases. Incidence of active tuberculosis in individuals with latent tuberculosis infection in rural China: follow-up results of a population-based, multicentre, prospective cohort studyOur results suggest that high-risk populations in communities in rural China, such as individuals at a high risk of disease reactivation from previous tuberculosis, should be targeted for latent infection screening and treatment with an interferon-γ releasing assay rather than a TST. Full-Text PDF