A 28-year-old woman who works as a nurse in a tertiary care hospital in Delhi presents with a 6-week history of persistent cough, malaise, and a 4 kg weight loss. She completed a 6-month course of standard anti-TB therapy 18 months ago for pulmonary TB and was declared cured with sputum conversion. Sputum smear microscopy now shows 1+ acid-fast bacilli. Chest X-ray shows infiltrates in the right upper lobe, different from her previous TB episode. What is the most likely epidemiological classification and what is the primary public health concern in this case?