Childhood Tuberculosis in Iran: Trends over the 1992 -2005 Period

Children are highly vulnerable to TB and childhood tuberculosis is a sign of TB transmission in community. This study aimed to determine the epidemiologic trend of this disease in Iranian children. A Trend Study was conducted to evaluate all Iranian patients aged below 14 who had been diagnosed with pulmonary or extrapulmonary TB from 1992 to 2005. Statistical relationships were tested using chi square tests (c²) and the software package SPSS (version 11.5). Out of the 6168 cases studied, 2528 (40.1%) were boys. Patients were assigned to three groups based on disease type: there were 1812 (29.4%) sputum- positive, 1920 (31.1%) sputum-negative, and 2449(39.7%) extrapulmonary cases.The incidence of sputum-positive TB declined from 0.8 per 100000 in 1992 to 0.2 per 100000 in 2005. A similar declining trend was observed for the overall TB incidence and in the incidence of sputum-negative and extrapulmonary cases. There was significant difference in TB incidence between girls and boys in the 10-14 year age group (P<0.001), but no sex difference was observed in 0-4y and 5-9y age groups. The incidence of sputum-positive TB decreased by 75 percent over the study period. This could be partly due to improvements in health status, better disease knowledge and the effects of Iran's National TB Control Program. In children aged below 10 years, there was no significant difference in the incidence of tuberculosis between girls and boys. At puberty, the incidence of all types of TB was higher in girls. Based on these findings, further studies are needed to elucidate the gender distribution of childhood tuberculosis in Iran.