Tuberculosis Case Detection and Guideline Adherence among Child Contacts in Switzerland: A Retrospective Observational Study.

BACKGROUND: Children exposed to a tuberculosis (TB) index case are at risk of TB infection and disease. OBJECTIVES: The aim of this study was to describe the proportion of child contacts who developed TB infection or disease after exposure and to assess the diagnostic pathways and adherence to current guidelines. METHODS: Retrospective observational study including children ≤16 years of age who had contact to a TB index case between January 2019 and July 2021. Analysis was stratified by age groups 0-4, 5-11, and 12-16 years. RESULTS: Of 401 TB-exposed children, data were available for 380 (95%). Of those, 7 (2%) were diagnosed with TB disease and 35 (9%) with TB infection. We identified several deviations in the management compared to recommendations in national Swiss guidelines: In the children aged 0-4 years, only 82% were examined with an immunodiagnostic test or a chest radiography within 2 weeks after last contact. Recommended prophylactic treatment was prescribed in 66% of the children only. In the children aged 5-11 years, 64% were tested with an immunodiagnostic test in a first examination and 75% in a second examination, 2 weeks and 2 months after last contact, respectively. CONCLUSIONS: Contact investigations of children exposed to a TB index case identified a significant proportion of children with TB infection and disease in a low TB incidence setting. We observed significant deviations from the guidelines in the contact investigations suggesting the need for improved implementation.

Surveillance of Employees of Swiss Federal Asylum Centres for Latent Tuberculosis Infection.

BACKGROUND: Asylum seekers in Switzerland have to register in federal asylum centres (FACs) before formal permission to enter the country. Some of them may have active tuberculosis (TB), exposing fellow refugees and employees. OBJECTIVES: The aim of this study was to assess the risk of TB infection among employees of Swiss FACs. METHODS: Between 2010 and 2018, a free interferon-gamma release assay (IGRA) was offered to all employees of 8 FACs, at employment and at yearly intervals. We defined latent TB infection as IGRA conversion from negative to positive. IGRA-positive employees were referred to a medical centre for further clinical follow-up. RESULTS: 1,427 tests were performed among 737 employees (54.6% male). 403 (55%) persons were tested only once; 330 (44.5%) were tested several times; for 4 (0.5%) persons, the number of IGRA tests is unknown. Twenty employees (2.7%) had a positive IGRA at baseline, 2 (0.6%) converted from negative to positive during follow-up, resulting in an incidence of 22/10,000 person-years. We observed no case of active TB among employees. CONCLUSIONS: The prevalence of latent TB among employees to Swiss FACs and the risk of acquiring TB infection through work-related exposure are low. Yearly IGRA controls in the absence of documented TB exposure seem unnecessary.

Treatment outcomes of multidrug-resistant tuberculosis in Switzerland.

OBJECTIVE: To assess outcomes 24 months after treatment start for multidrug-resistant tuberculosis (MDR-TB). METHODS: Cohort study of all culture-positive MDR-TB cases notified in Switzerland from 01/2003 to 07/2010. RESULTS: Fifty-one cases were observed, with a median age of 26 years (range 2-56). Twenty-seven were male, five of Swiss origin, 46 of foreign origin (Asia 18, Africa 13, former Soviet Union 8), including 21 asylum seekers and refugees. Twelve had received a previous treatment for TB and 24 had not (15 unknown). Forty-four cases were pulmonary of which 25 were known to be sputum smear positive. All but two strains showed additional resistances: 29 to ethambutol, 27 to pyrazinamide, 6 to a fluoroquinolone, 5 to amikacin. None was resistant to both of the latter two classes. Molecular analyses showed three pairs of identical strains. Fluoroquinolones were used in 48 patients and second-line injectable drugs in 37. The median duration of MDR treatment was 18 months (range 1-26). The outcome after 24 months was successful in 39 (76%) and unsatisfactory in 12 (24%) patients: two deaths from TB; two treatments terminated owing to side effects of drugs and one owing to pregnancy; four defaults from treatment at months 0, 4, 8, and 21; two transfers abroad with unknown outcome; one outcome unknown. There was no significant association of unfavourable outcomes with age, sex, origin, previous treatment, treatment delay, resistance pattern, and classes of drugs used. CONCLUSIONS: MDR-TB in Switzerland occurs mostly in persons of foreign origin. Results of decentralised treatments were satisfactory.