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Published on: February 17, 2014
Risk of tuberculosis among household contacts in Salvador, Bahia
Antonio Carlos Lemos1, Eliana D Matos, Diana B Pedral-Sampaio
1Prof. Edgard Santos Universitary Hospital, Federal University of Bahia, Rua João das Botas, S/N 6o andar, Sala 1124-Canela, 40110-160 Salvador, Bahia, Brazil.
Unlabelled:
Tuberculosis is one of the most important infectious diseases in the world. Only 68% of the estimated new tuberculosis (TB) cases in Brazil are diagnosed. Our aim was to determine the risk of infection among household contacts.
Study Design:
Cohort of tuberculin-negative household contacts followed for 12 months.
Methods:
Household contacts of randomly selected index acid-fast bacilli (AFB)-positive TB cases were evaluated through clinical examination, thorax X-ray, tuberculin, AFB smear and culture. Contacts with a negative response to the tuberculin test (less than 10 mm diameter) were retested after 90 days. Tuberculin reversal (used as a parameter of infection risk) was defined as an increase of at least 10 mm from the last measurement.
Results:
269 household contacts were followed. The prevalence of disease in this population was 3.7%. The prevalence of infection after the 12-month follow-up period was 63.9%. The risk of infection was 31.1% within 120 +/- 48 days.
Conclusion:
Household contacts of AFB positive tuberculosis patients have a very high prevalence and risk of tuberculosis infection. TB preventive or therapeutic measures directed towards this group should be implemented in Brazil.
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