Tuberculosis contact investigations in congregate settings in Rome, Italy: contribution of migration

Abstract

Abstract Background In middle to low incidence countries tuberculosis (TB) is known to concentrate in big cities as national incidence falls: in the last decade TB incidence in Rome metropolitan area and in Lazio region has been higher than the national estimates; TB incidence among foreign born fell by more than half despite remaining higher than among Italian born. We aimed to describe the current dynamics of TB transmission among residents of our local health unit in Rome metropolitan area in order to drive specific TB control interventions at local level. Methods We retrospectively evaluated characteristics of TB cases and results of contact investigations among the residents of ASL Roma 2 in congregate settings over year 2018. Results Overall 217 TB cases were notified, of which 70.5% with pulmonary involvement. Male/female ratio was 2.4/1 and age group most affected was 25-44 among foreign born and >65 among natives. During the study period foreign born cases accounted for 65% of the total number of TB cases. 19/141 (13.5%) foreign born patients were hosted in a reception center. 479 exposed close contacts were screened, with no evidence of secondary TB disease transmission. No identifiable links were found among cases occurred in the same immigrant reception center. Conclusions Italian guidelines recommend symptom screening for TB and LTBI testing both of new entrants and of long term residents -including second–generation migrants- from high TB burden countries. These findings suggest that local public health efforts should prioritize the identification of reactivations of remotely acquired latent TB rather than of new postarrival infections acquired in the host county through local transmission. Key messages City-specific data on TB incidence trends among native and foreign-born residents help understanding the wider interaction between migration and TB. To prevent TB incidents in congregate settings remotely acquired latent TB should be targeted.