Congenital tuberculosis in an extremely preterm infant and prevention of nosocomial infection

Management of newborns and healthcare workers exposed to isoniazid-resistant congenital tuberculosis in the neonatal intensive care unit

BACKGROUND

Management of newborns and healthcare workers (HCWs) exposed to congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) has been reported rarely.

AIM

To outline a contact investigation process for individuals exposed to congenital TB in the NICU and investigate nosocomial transmission. Additionally, to assess the efficacy and safety of window prophylaxis in exposed newborns.

METHODS

A baby, born at a gestational age of 28 + 1 weeks, was diagnosed with isoniazid-resistant congenital TB on the 39th day of admission to the level IV NICU. Newborns and HCWs exposed cumulatively for ≥8 h underwent contact investigation and follow-up for a year.

FINDINGS

Eighty-two newborns underwent contact investigation. All newborns displayed normal chest X-rays, and 42 hospitalized newborns tested negative for acid-fast bacilli stain and Xpert® MTB/RIF assay in their endotracheal sputum or gastric juices. Eighty received window prophylaxis: six of 75 on rifampin experienced mild adverse events, and none of the five on levofloxacin. After 12 weeks, five (6.1%) had a positive tuberculin skin test, all of whom had already received the Bacillus Calmette-Guérin vaccine and tested negative on TB interferon-gamma releasing assay. Of 119 exposed HCWs, three (2.5%) were diagnosed with latent TB infection and completed a four-month rifampin therapy. There was no active TB disease among exposed newborns and HCWs during a one-year follow-up.

CONCLUSION

Timely diagnosis of congenital TB is crucial for minimizing transmission among exposed neonates and HCWs in the NICU setting. In cases of isoniazid-resistant index patients, even premature newborns may consider the use of rifampin or levofloxacin for window prophylaxis.

Pathomorphological characteristics of tuberculous placenta and its clinical implication

BACKGROUND

The study of pathologic diagnosis of placental TB is rare. The aim of this study is analyzing the pathomorphological characteristics of tuberculosis (TB) placenta during pregnancy and its clinical significance.

METHODS

Nineteen cases of placental tissue specimens during pregnancy were collected from June 2015 to February 2022 at Shanghai Public Health Clinical Center, the only inpatient center for pregnant women with TB in Shanghai, China. Hematoxylin-eosin staining, acid-fast staining, and molecular testing were applied to analyze them comprehensively in combination with clinical information.

RESULTS

Among the 19 cases, 7 cases caused intrauterine stillbirth, 3 cases received artificial abortion required by the pregnant woman, the other 9 cases received standard delivery and the infants survived, however, 3 of them were low-weight preterm infants, and another 1 case suffered mild intrauterine asphyxia. The 9 surviving infants were followed-up, of which 3 cases got congenital TB. For pathological characteristics of placental tissues under light microscopy, there were 3 cases of epithelioid granuloma formation, 13 cases of acute fetal membranitis, 4 cases of caseous necrosis, 7 cases of inflammatory necrosis, 10 cases of coagulative necrosis, and 6 cases with small focal calcifications. All placental tissues were positive for acid-fast staining and polymerase chain reaction (PCR). Molecular pathological diagnosis showed that 18 cases were positive for Mycobacterium tuberculosis, with 1 case not having received examination.

CONCLUSIONS

Combining acid-fast staining and molecular pathological testing is helpful for accurately diagnosing placental TB.

Risk of tuberculosis transmission by children to healthcare workers - a comprehensive review

Background

Healthcare workers (HCWs) are at increased risk of becoming infected with M. tuberculosis complex (Mtbc).

Objective

To assess the magnitude of Mtbc transmission by children under the age of 15 years to HCW.

Methods

Medline, Google Scholar and Cochrane library were searched to select primary studies in which a child was the presumed index case and exposed HCW were screened for latent TB infection (LTBI).

Results

Of 4,702 abstracts, 15 original case reports covering 16 children with TB were identified. In sum, 1,395 HCW were contact persons and underwent testing. Ten of the studies reported TST conversion, amounting to 35 (2.9%) of the 1,228 HCW tested. In three of the TST-based and both of the studies that used IGRA testing, conversion was absent. 12 of the 15 studies (80%) reported exposure of HCW in neonatal intensive units (NICUs) to premature infants suffering from congenital pulmonary TB. One study including two infants addressed possible pulmonary Mtbc transmission in a general pediatric ward. Extrapulmonary transmission by aerosolized Mtbc was suggested in two patients, an infant with tuberculous peritonitis and a 12-year-old adolescent with pleurisy, and culture-confirmed only after the child had undergone video-assisted thoracoscopic surgery. Routine use of protective facemasks by HCW before exposure was not mentioned in any of the included studies.

Conclusions

The results suggest that the risk of Mtbc transmission from children to HCW is low. Particular attention should be paid to infection risk during respiratory manipulations in NICUs. The consistent wearing of facemasks may further reduce the risk of Mtbc transmission.

Clinical characteristics in 26 children with congenital tuberculosis in Central Southern China: a retrospective study

BACKGROUND

Congenital tuberculosis (CTB) is relatively rare and most patients are described in case reports.

AIM

To investigate the clinical characteristics of CTB in 26 children.

METHODS

A retrospective analysis of 26 children with CTB from January 2013 to December 2021 in Changsha Central Hospital in Central Southern China was undertaken.

RESULTS

The median age at onset was 25 days (17-33) and within 4 weeks of age in approximately 73% of cases. Of 24 mothers (including two mothers of twins), 18 (75.0%) were asymptomatic during pregnancy, and four were diagnosed with tuberculosis prenatally. The numbers of tuberculous meningitis, tuberculous encephalitis and liver TB were 17 (65.4%), five (19.2%) and four (15.4%), respectively. The main symptoms were fever (n = 18, 69.2%) and cough (n = 16, 61.5%). Positive rates of T-SPOT.TB, acid-fast bacilli smear, culture of Mycobacterium tuberculosis and GeneXpert MTB/RIF test were, respectively, 84.2% (16/19), 42.3% (11/26), 43.5% (10/23) and 83.3% (5/6). Radiograph or computed tomography demonstrated typical pulmonary tuberculous lesions in all cases and the head magnetic resonance imaging (MRI) showed marked meningeal enhancement or parenchymal lesions in seven cases (26.9%). One case had drug-resistant TB. During follow-up, nine cases had varying degrees of liver injury, and one had delayed growth and development. Eight died and 18 recovered satisfactorily.

CONCLUSION

Maternal TB status during pregnancy, the epidemiological history, T-SPOT.TB and other TB-related aetiological tests and imaging are important for the early diagnosis and treatment of CTB, and are associated with a favourable outcome.

ABBREVIATIONS

AFB: acid-fast bacilli; Amk: amikacin; Cs: cycloserine; CT: computed tomography; E: ethambutol; GeneXpert MTB/RIF: GeneXpert Mycobacterium tuberculosis and rifampicin resistance; H: isoniazid; IVF-ET: in-vitro fertilization-embryo transfer; Lzd: linezolid; Mfx: moxifloxacin; MTB: Mycobacterium tuberculosis; mNGS: next generation sequencing; MTB-DNA: Mycobacterium tuberculosis-deoxyribonucleic acid; Pto: protionamide; R: rifampicin; TB: tuberculosis; T-SPOT.TB: spot test of mycobacterium TB infection T-lymphocytes; Z: pyrazinamide.

An infant of 26 weeks gestation with congenital miliary tuberculosis complicated by chronic lung disease requiring CPAP was diagnosed on Day 104 of life: congenital tuberculosis was confirmed by detection of calcified ovaries in his mother

INTRODUCTION

Early diagnosis of tuberculosis (TB) in infants is important but is commonly missed because the symptoms are often non-specific.

CASE PRESENTATION

A Nepalese male infant born at 26 weeks gestation and weighing 1227 g (97th centile) was admitted to the neonatal intensive care unit (NICU) immediately after birth for the management of his prematurity. After extubation on Day 8, his oxygen saturation became unstable and he required nasal continuous positive airway pressure with oxygen for 3 months. On Day 104, further detailed evaluation was required because there was no improvement in his respiratory condition. A computed tomography (CT) scan demonstrated scattered miliary nodules in both lung fields. Acid-fast staining for the mycobacteria and TB polymerase chain reaction (PCR) of the sputum obtained directly by laryngeal aspiration confirmed Mycobacterium tuberculosis. On Day 105, he was therefore transferred to a tertiary care hospital for further intensive care. Pathology findings suggested placental involvement with TB owing to chronic endometrial infection. In addition, a maternal abdominal CT scan demonstrated bilateral calcified lesions in the ovaries. He completed antituberculous chemotherapy and was discharged 3 months later. At 18 months of age there are no sequelae and his development is almost normal. None of the infants or medical personnel who were exposed in the NICU developed secondary TB.

CONCLUSION

In neonates with persistent respiratory distress, neonatologists should consider TB infection as a differential diagnosis.

ABBREVIATIONS

CLD: chronic lung disease; CRP: C-reactive protein; CT: computed tomography; IGRA: interferon-γ release assay; IVF-ET: in vitro fertilisation-embryo transfer; N-CPAP: nasal continuous positive airway pressure; NICU: neonatal intensive care unit; PCR: polymerase chain reaction; PROM: premature rupture of membranes; TB: tuberculosis; WBC: white blood cells.

Involvement of dopamine signaling pathway in neurodevelopmental toxicity induced by isoniazid in zebrafish

AIMS

This study evaluated the neurodevelopmental toxicity of isoniazid (INH) in zebrafish embryos and the underlying mechanism.

METHODS

Zebrafish embryos were exposed to different concentrations (2 mM, 4 mM, 8 mM, 16 mM, 32 mM) INH for 120 hpf. During the exposure period, the percentage of embryo/larva mortality, hatching, and morphological malformation were checked every 24 h until 120 hpf. The development of blood vessels in the brain was observed at 72 hpf and 120 hpf, and behavioral capacity and acridine orange (AO) staining were measured at 120 hpf. Alterations in the mRNA expression of apoptosis and dopamine signaling pathway related genes were assessed by real-time quantitative PCR (qPCR).

RESULTS

INH considerably inhibited zebrafish embryo hatching and caused zebrafish larval malformation (such as brain malformation, delayed yolk sac absorption, spinal curvature, pericardial edema, and swim bladder defects). High concentration of INH (16 mM, 32 mM) even induced death of zebrafish. In addition, INH exposure markedly restrained the ability of the zebrafish autonomous movement, shortened the length of dopamine neurons and inhibited vascular development in the brain. No obvious apoptotic cells were observed in the control group, whereas considerable numbers of apoptotic cells appeared in the head of INH-treated larvae at 120 hpf. PCR results indicated that INH significantly raised the transcription levels of caspase-3, -8, -9, and bax and significantly decreased bcl-2 and bcl-2/bax in the zebrafish apoptotic signaling pathway. INH also markedly decreased the genes related to dopamine signaling pathway (th1, dat, drd1, drd2a, drd3, and drd4b).

CONCLUSIONS

Experimental results indicated that INH had obvious neurodevelopmental toxicity in zebrafish. Persistent exposure to INH for 120 h caused apoptosis, decreased dopaminergic gene expression, altered vasculature, and reduced behaviors.

Preterm Twins Born to a Mother with Miliary Tuberculosis: Importance of Early Recognition and Prompt Response in Infection Control to Manage Congenital Tuberculosis Exposure in a Neonatal Intensive Care Unit

Delayed diagnosis of congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) is a serious problem in terms of infection control. Here, we report our preemptive infection control activities implemented after the diagnosis of miliary TB in a mother of preterm twins (index twins, NB1 and NB2) in the NICU. In addition, we reviewed previous case reports of congenital TB exposure in the NICU setting. Immediately after diagnosing miliary TB in the mother, the index twins were isolated before their TB diagnosis and received preemptive anti-TB medication; contact investigations were also conducted. Eventually, NB1 was diagnosed with congenital TB at 29 days of age, and NB2 showed no definite evidence of TB. Through contact investigation, 11 of the 16 exposed infants received isoniazid prophylaxis and no positive tuberculin skin test results were obtained after 3 months. One of the 31 exposed healthcare workers showed new interferon-gamma release assay conversion. Moreover, our case showed a much shorter contagious period compared to that in previous reports (8 versus 17-102 days). This suggests that a high index of suspicion and prompt measures can help prevent congenital TB outbreaks and reduce the burden of infection control activities in the NICU.