Tuberculosis In Children Visiting Friends and Relatives

Inclusion Criteria (all criteria must be met): * Informed consent must be obtained from the parents of legal guardian. * Less than 15 years of age. * One or both of the parents is from a country with an elevated incidence of TB. A country is considered to have an elevated incidence of TB when this incidence is 3-fold higher than the incidence in Catalunya, that is approximately 40/100,000 inhabitants. Countries with official reports describing an incidence less than the value proposed but which have regions with \> 40 cases /100,000 inhabitants are also included (Table and figure 1) * The journey to the country of origin is made by at least one of the parents. * The duration of the visit to the country of origin is of at least 21 days. Exclusion Criteria: * Previous TB or LTBI. * Tourist visit to hotels and resorts with scarce contact with the autochthonous population. * Primary or secondary immunodeficiency to treatment with corticosteroids, transplantation, treatment with anti-tumor necrosis factor, chronic renal insufficiency. * Congenital cardiopathy. * Cystic fibrosis of the pancreas and other congenital diseases of pulmonary origin.