Listeriosis: An emerging public health problem especially among the elderly

Objectives: To analyze the incidence trend of listeriosis, its present epidemiology and the potential benefit of aminoglycosides during the last two decades.

Methods: We reviewed all cases of invasive listeriosis detected during a 22-year period in a large tertiary hospital. Two equal periods of 11 years were compared.

Results: We detected 111 cases of listeriosis (32 during the first 11-year period and 79 during the second). Incidence of listeriosis increased significantly (from 4.66/10(6) inhabitants to 10.39/10(6) inhabitants; P = .001). In the second period, there were more patients >65 years (21.9%-45.6%; P = .02) and with no significant underlying diseases (0 vs. 16.5%; P = .02). Comparing clinical presentations between the two periods, primary bacteremia increased (40.6% vs. 55.7%), while central nervous system infections decreased (34.4% vs. 27.8%). Cotrimoxazole (SXT) use increased significantly in the second period (from 6.3% to 40.5%, P = .001) while the administration of aminoglycosides decreased (from 40.6% to 21.5%, P = .04). The use of combination therapy did not have any impact on mortality, however it did increase toxicity.

Conclusions: Listeriosis should be considered an emerging health problem, especially among the elderly, including those with no underlying medical conditions. The use of aminoglycosides does not seem to be justified according to our data.