Congenital Tuberculosis in Preterm Infants in a High-Burden Setting of Southwest China: A Single-Center Cross-Sectional Study

Xiaoling Zhuang¹Wanting Xu²Wen Xu²Yan Shi¹Mei Xiao¹Awai Rihe¹Dong Wen Bin^2*Chengpeng Bian^1*

• ¹Department of Pediatrics, First People's Hospital of Liangshan Yi Autonomous Prefecture, Xichang, China
• ²Department of Neonatology, Children's Medical Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China

Background: Congenital tuberculosis (CTB) is an extremely rare, potentially life-threatening, infection in premature infants that is frequently misdiagnosed. There is still a lack of thorough characterization of this condition in preterm in high TB burdens areas. Methods: Premature infants with CTB were identified from medical records in the hospital from January 2016 to December 2023 in a high-burden, resource-limited NICU in Southwest China according to etiology and clinical evidence. Hospital medical record for each patient was extracted, which included demographics, maternal history of tuberculosis (TB) exposure, symptoms, laboratory markers, microbiological findings, typical images, treatments, and prognosis evaluated during the pre-diagnosis, diagnosis, and post-treatment stages. Results: A total of eleven premature infants with CTB were included using data from medical records in the hospital. Maternal TB was common in our cohort, seven of the eleven mothers were diagnosed with TB infection following in vitro fertilization and embryo transfer. Clinical manifestations were atypical and consisted primarily of non-specific symptoms, including low fever, shortness of breath, poor reaction, eating less, and coughing. Laboratory findings during the active phase of CTB revealed statistically significant elevations in C-reactive protein levels (P = 0.001), thrombocytopenia (P = 0.007), hyponatremia (P = 0.040), hypocalcemia (P = 0.022), and hypomagnesemia (P = 0.025). Sputum AFB smear positivity was four out of eleven, while gastric juice AFB smear positivity was six out of eleven. Mycobacterial liquid culture produced the highest positivity with seven out of eleven, followed by solid culture and interferon-gamma release assays with five out of eleven. All nucleic acid amplification tests were positive, and chest CT scans showed abnormalities in each patient. Among the patients, 5 experienced liver function impairment after anti-TB treatment, as evidenced by elevated alanine aminotransferase levels. Conclusions: In this study, preterm infants with CTB frequently demonstrated non-specific clinical signs with a reversible pattern of inflammation, anemia, thrombocytopenia, and electrolyte disturbances that normalized after anti-TB therapy. These patterns, together with maternal TB risk or IVF-ET history, may raise clinical suspicion and justify the early nucleic-acid testing (NAAT), and generalizability outside this setting requires larger, controlled cohorts.