Taipei Times (01.17.2014)
Taipei Times reported that researchers from National Taiwan University and Taiwan’s Centers for Disease Control created an eight-level prediction score to identify children at increased risk of contracting TB. According to the researchers, Taiwan has had an annual TB incidence of approximately 70 cases per 100,000 people from 1997 to 2005. CDC has focused on decreasing the incidence rates by using contact investigation and preventive care to treat persons with latent TB infection (LTBI). Since young children are very susceptible to the disease, the researchers predicted that the chances of children contracting TB after exposure were about 240 times greater than for children who had not been in contact with an infected person.
The researchers devised a grading system from zero to 12 to categorize children’s risk of developing active TB in three years. The system is meant to assist in identifying and prioritizing preventive care for children at high risk of developing active TB. They then reviewed data from 9,411 children from birth to age 12 years in 2008 and 2009, including measurements of reactions to TB skin tests, smear positivity, residence in high-incidence areas and gender, and categorized the children based on the grading system.
Results showed the risk of developing active TB within three years was 100, 7.8, 4.3, 1.7, and .2 percent for those with risk scores of seven, six, five, four, three, and two, respectively. The researchers estimated that for every 30 children with a risk score of five who received treatment for LTBI, one infection could be prevented. According to Chan Pei-chun, a CDC physician, a child with LTBI who received preventive treatment had a 95 percent chance of preventing active TB. Chan concluded such children should receive preventive treatment.
The full report, “Risk for Tuberculosis in Child Contacts. Development and Validation of a Predictive Score,” was published in the American Journal of Respiratory and Critical Care Medicine (2014; 189 (2): 203-213).