Epidemiological trend in tuberculosis in the Italian region of Liguria: impact of immigration and AIDS

Abstract

Background: Tuberculosis (TB) uniformly decreased in all industrialized countries from 1950 to 1985. However, since 1985 an upsurge of the disease has been observed, probably due to the increases in AIDS and immigration. It is for this reason that in the last decade all industrialized countries have intensified their controls on TB and a new reduction has been recently observed.

Methods: In this study we collected epidemiological data (mortalities and reported cases) for the region of Liguria over the last 15 years. We then calculated the incidence rate of TB per 100,000 residents according to age, HIV infection and nationality, making a distinction between European Union (EU) citizens and immigrants coming from countries outside the EU.

Results: The rate of mortality, after the last peak at the end of the Second World War, has progressively decreased from 1946 to today, so much so that presently we record fewer than two cases per 100,000 people. We observed a consistent downward trend in the incidence rate up to 1987, but from 1988 onwards this trend stopped and, in subsequent years, we detected an increase in the incidence rate, which peaked in 1996. This led to increased interventions, which has resulted in a considerably decreased overall rate of cases of TB during the last few years. The number of TB cases specifically among foreigners increased considerably during the last 5 years, whereas there was a drastic reduction in the number of total TB cases, as well as an interesting reduction in AIDS cases. During the same period there was a progressive decrease in tuberculin skin positivity in all school classes.

Conclusions: The reduction in TB notifications is probably due to an increase in surveillance and control of social and health conditions. These results show that immigrant workers are considered to be a high-risk group, whereas the risk has progressively decreased in the HIV group.