Active tuberculosis among Iraqi schoolchildren with positive skin tests and their household contacts.

In a prospective cohort study in Iraq, schoolchildren with a positive tuberculin skin test during the nationwide survey in 2000 were followed up in 2002 to determine prevalence of latent tuberculosis (TB) infection and risk factors among household contacts. Of 205 children, 191 remained skin-test positive in 2002. Based on X-ray and clinical examination, 9 children (4.4%) were active TB cases. Among 834 household contacts, there were 144 new TB cases, giving a cumulative incidence of 17.3%. Risk factors for TB among household contacts were: age > or = 15 years; technical/professional job; smoking; low body mass index; diabetes mellitus; steroid therapy; and closeness of contact with the index cases. Based on past history of TB in index children and their contacts, 77.2% of new TB cases were attributable to household contacts.