Skin test screening for tuberculosis among healthcare students: a retrospective cohort study

Screening for Tuberculosis in Health Care Workers: Experience in an Italian Teaching Hospital

Health care workers (HCW) are particularly at risk of acquiring tuberculosis (TB), even in countries with low TB incidence. Therefore, TB screening in HCW is a useful prevention strategy in countries with both low and high TB incidence. Tuberculin skin test (TST) is widely used although it suffers of low specificity; on the contrary, the in vitro enzyme immunoassay tests (IGRA) show superior specificity and sensitivity but are more expensive. The present study reports the results of a three-year TB surveillance among HCW in a large teaching hospital in Rome, using TST (by standard Mantoux technique) and IGRA (by QuantiFERON-TB) as first- and second-level screening tests, respectively. Out of 2290 HCW enrolled, 141 (6.1%) had a positive TST; among them, 99 (70.2%) underwent the IGRA and 16 tested positive (16.1%). The frequency of HCW tested positive for TB seems not far from other experiences in low incidence countries. Our results confirm the higher specificity of IGRA, but, due to its higher cost, TST can be considered a good first level screening test, whose positive results should be further confirmed by IGRA before the patients undergo X-ray diagnosis and/or chemotherapy.

Posterior mediastinal tuberculous lymphadenitis with dysphagia as the main symptom: a case report and literature review

INTRODUCTION

Mediastinal tuberculous lymphadenitis (MTL) is mostly seen in primary tuberculosis in children, uncommon observed in adults. It usually presents the toxic symptoms of tuberculosis but rarely with symptoms characteristic of esophageal compression, such as dysphagia. Such patients can easily be misdiagnosed as esophageal neoplasm and get delayed or faulty treatment.

CASE REPORT

A 32-year-old man presented with dull chest pain of one month and dysphagia of five days. CRP was elevated, and a skin test was strongly positive. At upper endoscopy, a protruding lesion covered by normal mucosa was seen at 26 cm from the upper incisor. Barium swallow showed visible external compressive stricture on the middle-lower esophagus with normal mucosal pattern. Chest computed tomography (CT) scan showed a subcarinal mass adjacent to the esophageal wall in posterior mediastinum. An endoscopic ultrasonography (EUS) revealed a hypoechoic lesion suspected of esophageal stromal tumor in the fourth layer. A tissue was obtained by ultrasound-guided fine-needle aspiration (EUS-FNA), but cytopathology, bacilliculture and PCR test had no special findings. The patient required experimental antitubercular treatment and the protruding lesion shrank gradually during therapy period.

CONCLUSIONS

MTL could not be ignored in the differential diagnosis of posterior mediastinal mass with dysphagia. Analyzing and evaluating test results comprehensively is the key to make correct diagnosis and timely treatment. The experimental antituberculous treatment should be used if MTL is highly suspected.