Abstract
Background: Thailand is among the 30 countries with high tuberculosis (TB) prevalence. Cases of TB in Secondary schools have been reported and aggregated adolescents in school are at risk of TB transmission. Children with latent TB may develop TB diseases later on. Nevertheless, studies of TB diseases and latent TB prevalence in schoolchildren in Thailand are scarce. Method: We did an observational cross-sectional study in Secondary school children grade 7-12 in a school in Bangkok and a school in another province of Thailand. We used the Symptoms scoring questionnaire developed by the Bureau of Tuberculosis and Chest radiography to screen for pulmonary TB to identify the TB prevalence. And we used tuberculin skin test (TST) at a 10 mm. cut-off to identify latent TB infection in grade 7 students. Also, 80 students were undergone QuantiFERON® TB Gold (QFT) blood test together with TST. Furthermore, we did a survey on knowledge, attitude, and practice (KAP) of TB in school among personnel of the 2 schools using a structured questionnaire. Results: A total of 1,005 from 5,113 students from 2 schools were enrolled, 496 from Nawaminthrachinuthit Bodindecha School in Bangkok and 509 from Chonburi Sukkhabot School in Chonburi province. Three hundred and fifty-four, 176, 154, 176, 141, and 153 students were from Grade 1, 2, 3, 4, 5, and 6 respectively. The mean age was 14.6±1.8 years. Forty-six and 21.8 percent had the household incomes of 20,000-40,000 and less than 20,000 Thai Baht per month. Twelve percent had the history of TB exposure in the past. The screening with Symptoms scoring questionnaire and chest radiography revealed no TB disease in this survey. Meanwhile, 270 first grade students were screened for latent TB and 13 were positive, resulted in latent TB prevalence of 4.8% (95% Confidence Interval (CI), 2.3-7.4%) Of them, none developed TB disease during the 1-year follow-up. The TST at 10 mm. cut-off had the sensitivity 50% (95% CI 6.8-98.2) and specificity 98.7 (95% CI, 92.9-100%) compared to QFT. Furthermore, the results of KAP survey among the school personnel showed lower percentage (11-39%) of correct answers to knowledge of TB symptoms in children, transmission, and prevention of TB in community. Most personnel had positive attitude to learn about TB and help students to receive treatment (78-99%). However, 55% tended to separate students with TB from others even the students already receiving treatment and 29% would not be a personal tutor for students with TB after the treatment. Conclusion: The prevalence of TB disease and latent TB in Thai school children is not high. The routine TB screening in Thailand may target other population groups with higher TB rate. However, the protocol for reporting and investigation should be put forward for schoolchildren who develop TB diseases along with school personnel education on TB transmission and prevention.
