Risk of developing tuberculosis after brief exposure in Norwegian children: results of a contact investigation

Abstract

ObjectiveProlonged exposure to adults with pulmonary tuberculosis is a risk factor for infecting children. We have studied to what extent a brief exposure may increase the risk of being infected in children.DesignObservational study of a tuberculosis contact investigation.Setting7 day-care centres and 4 after-school-care centres in Norway.Participants606 1-year-old to 9-year-old children who were exposed briefly to a male Norwegian with smear-positive pulmonary tuberculosis.Main outcome measuresNumber of children with latent and active tuberculosis detected by routine clinical examination, chest x-ray and use of a Mantoux tuberculin skin test (TST) and an interferon-γ release assay (IGRA).ResultsThe children were exposed to a mean of 6.9 h (range 3–18 h). 2–3 months after the exposure, 11 children (1.8%) had a TST ≥6 mm, 6 (1.0%) had TST 4–5 mm, and 587 (97.2%) had a negative TST result. Two children (0.3%) with negative chest x-rays who were exposed 4.75 and 12 h, respectively, had a positive IGRA test result, and were diagnosed with latent tuberculosis. None developed active tuberculosis.ConclusionsChildren from a high-income country attending day-care and after-school-care centres had low risk of being infected after brief exposure less than 18 h to an adult day-care helper with smear-positive pulmonary tuberculosis.

Reducing tuberculosis transmission: a consensus document from the World Health Organization Regional Office for Europe

“…The risk of children becoming TST positive following exposure to sputum smear-positive adults at day care or after-school care facilities was considered low in a Norwegian study: <3% of children underwent TST conversion after a median contact period of 6.9 h [65]. However, a recent Italian study demonstrated that children can become infected within a rather shorter exposure time.…”

Difficulties in diagnosis of tuberculosis without bacteriologic confirmation in a 15-year-old boy from contact with a patient with tuberculosis: A case report

“…Studies have shown that the different countries have different percentage of illness after the contact. The highest percentage of TB after the contact was found in the Netherlands study 6 whereas much lower inciden-Kostić G, et al Vojnosanit Pregl 2018; 75(5): 516-520. ce of 3% was reported in a Chinese study 7 , followed by considerably lower results in a Vietnam study (0.7%) 8 and 0.3% in a Norway study 10 . These data indicate that the contact with the patient is not sufficient per se for the development of disease.…”

“…According to Serbian Report on Tuberculosis, the morbidity rate in all age groups is 17 : 100,000, whereas the morbidity rate in children population is 6.425 : 100,000 with specific morbidity rate of 8.5 : 100,000 in the population aged 15-19 years 21 . After the contact with an adult suffering from pulmonary TB, the possibility of developing active disease is created in 1%-16% of previously healthy children with preserved immunity [6][7][8][9][10] . Studies have shown that the different countries have different percentage of illness after the contact.…”

“…After the contact of previously healthy children with people suffering from tuberculosis (TB), the possibility of development of active illness is 1%-16%. The highest risk is during the first two years after the infection and declines over time [6][7][8][9][10] . The symptoms of TB may arise from the respiratory tract, the cough longer than 2-3 weeks, chest pain, shortness of breath, blood coughing, or non-specific loss of appetite, fatigue, prolonged fever, chills, weight loss, night sweats [1][2][3][4][5]11 .…”

Empfehlungen für die Umgebungsuntersuchungen bei Tuberkulose – Update 2023

“…B. durch direktes Anhusten), jedoch keinesfalls aus. Bei Kindern unter 5 Jahren und immunsupprimierten Kontaktpersonen (siehe 2.5) kann u. U. eine geringere kumulative Gesamtexpositionszeit in Betracht gezogen werden [23].…”