Diagnosis of Tuberculosis in an Asymptomatic Child, Sibling, and Symptomatic Pregnant Mother in New York City by Tuberculin Skin Testing and the Importance of Screening High-Risk Urban Populations for Tuberculosis.

BACKGROUND In 2017, in New York City (NYC), 86% of the cases of tuberculosis (TB) occurred in patients who were born outside the United States (US). This case report illustrates the importance of the use of the tuberculin skin test (TST), and other tests for TB infection (TTBI), in screening high-risk groups, the challenges of diagnosing TB in young children, and highlights the importance of preventing a delay in the diagnosis of TB in family members. CASE REPORT Following a routine TST in an asymptomatic 10-year-old girl, a diagnosis of TB was made, which was confirmed on chest X-ray (CXR) and by the presence of acid-fast bacilli (AFB) in the sputum. Her family had emigrated from China to NYC ten years previously. All the family was screened using the TST, which was positive in her 2-year-old sister and her 37-year-old pregnant mother, and pulmonary TB was confirmed on CXR and by AFBs in the sputum. All three family members and the newborn baby were treated according to current guidelines, with a good clinical outcome. CONCLUSIONS This case report raises awareness about the lack of symptoms in childhood TB and the importance of screening high-risk patients in an urban immigrant population. In children under 5 years of age, a diagnosis of TB can indicate a sentinel event, suggesting a potential undiagnosed or untreated source case, which is usually an adult family member. This report highlights the challenges of diagnosing TB in children, who may be asymptomatic with negative laboratory findings.