Respiratory tract infections are the main cause of children's morbidity and mortality both in the developing and the developed countries. An accurate understanding of the epidemiology of these diseases, identification of risk factors, etiology and seasonality are critical for successful treatment and/or prevention program. Evidence Acquisition: This article aims at offering clinicians a brief update on the recent epidemiology of respiratory infections in pediatrics. It also underlines the fact that any evidence-based recommendation needs more research in different areas. Results: Almost 150 million new episodes of pneumonia are identified per year worldwide more than 90% of which occur in developing countries. Nearly 30% of total annual deaths occur in children younger than 5 years old. Viruses remain the most common cause of RTIs. S. pneumonia and HIB are the main causes of bacterial pneumonia in the world; however, infections due to many of these pathogens can be prevented. Conclusions: Widespread immunization against influenza, measles, bacilli calmette-guerin (BCG) and now pneumococcus have been related to the decline of the LRTIs in children.

ObjectiveTo identify the pattern of the clinical, radiological, diagnostic procedures and loss to follow-up of the diagnosed cases of active tuberculosis (TB) adolescents.MethodsThis study was a retrospective analysis of the medical records of 143 adolescents aged 10 to 18 years with tuberculosis who were admitted TB wards of National Research Institute of Tuberculosis and Lung Disease (NRITLD) in Tehran, Iran, between March 2006 and March 2011.ResultsOf the 143 patients identified, 62.9% were females. Median age of the patients was 16 years. The contact source was identified in 47.5%. The most common presenting symptom was cough (86%). Isolated pulmonary TB (PTB) was detected in 113 patients (79%), 21 patients (14.7%) had extrapulmonary TB(EPTB), and 9 patients (6.3%) had PTB and EPTB. The most common site of EPTB was pleural (14%). The most common radiographic finding was infiltration (61%). Positive acid fast smears were seen in 67.6%. Positive cultures for Mycobacterium tuberculosis (M. TB) were seen in 44.7%. Positive Polymerase chain reaction (PCR) results were seen in 60%. The adolescents aged 15 to 18 years were more likely to lose weight (p=0.001), smear positive (p=0.001), culture positive (p<0.001) and have positive PCR results (p=0.009). The type of TB (p=0.017) was a significant factor influencing loss to follow-up.ConclusionsThe study has revealed that the clinical and radiological findings of TB in adolescents are combination as identified in children and adults. The TB control programs should pay more attention to prevention and treatment of TB in adolescents.

Most children with BCG complications had a local disease in our study. A higher rate of disseminated disease was also observed. In addition, PID was identified in most children with disseminated disease. Development of more appropriate BCG vaccines and changing the current vaccination programme in cases with suspected PID are required in our country.