REPORT OF RIFAMPICIN-RESISTANT PULMONARY TUBERCULOSIS IN AN INFANT IN BRAZIL

Tuberculosis (TB) is a respiratory infection caused by Mycobacterium tuberculosis. In children, especially infants, it can progress severely, with higher risk when caused by resistant strains, such as rifampicin-resistant TB (RR-TB). It is estimated that more than 30,000 children develop RR-TB annually, many after household contact with infected adults. A 10-month-old male patient was referred to the pediatric infectious disease outpatient clinic after household contact with his father, diagnosed with RR-TB in February 2025. Initially asymptomatic, he had only isolated fever, with no changes on physical examination. Initial tests showed PPD 0 mm, normal abdominal ultrasound, and chest radiography without abnormalities. After 8 weeks, there was tuberculin conversion (PPD 18 mm) and peribronchial thickening on follow-up X-Ray. Two gastric lavages were performed: both detected traces of M. tuberculosis by TRM-TB, with AFB absent. Although cultures were ongoing, the finding was considered positive because the child was <10 years old with a pulmonary sample with traces on TRM. The clinical hypothesis was pulmonary TB in an infant contact of RR-TB. Treatment was started with the BLLT regimen (bedaquiline, linezolid, levofloxacin, terizidone), with planned duration of 12 months, which could be adjusted according to evolution. This is a rarely documented profile, especially in this age group, comprising one of only 12 cases notified in children aged 0 to 4 years in Brazil in the last 10 years. The case illustrates the challenges of RR-TB in infants, from diagnosis, hindered by nonspecific presentation, low bacillary load, difficulty collecting sputum, and low positivity in tests, to management, without recommended treatment for the age and limitations in administration due to tablet presentation. The World Health Organization recommends considering molecular tests positive in pulmonary samples from children under 10 years old. The association of tuberculin conversion, household exposure, and radiological findings strengthens clinical suspicion. Early initiation of the appropriate regimen, even before the final culture result, reduces mortality and therapeutic failures. After discussion with the SITE-TB validator and the Ministry of Health, early introduction of BLLT was indicated. Treatment aims to cure the individual and reduce morbidity and mortality in this scenario.