Reductions of Listeria Infections in Infants: Collateral benefit of Prophylaxis against Group B Streptococcus?
Methods: The Pediatric Health Information Systems (PHIS) database from 45 freestanding children’s hospitals across the United States was used. We queried the database for all cases of Listeriosis (ICD9 code 027.0)in patients less than 30 days for the entire timespan of the database (1992-June 2013). We then assessed case rates per 10,000 patients using the total number of patients in that age cohort with data per year. We present incidence rate differences (RD), exact 95% confidence intervals and trend statistic p values.
Results: From 1992-2013, there were 182 cases of Listeria in infants less than 30 days of age. The median age of patients was 13 days (IQR 9, 15) and 53.9% were male. From 1992-1995, the average rate of Listeriosis in this age was 4.79 cases/10,000 patients. For 1996-2002, the rate dropped to 2.24 cases/10,000 (RD: -2.55 (-4.3, -.787), coinciding with implementation of the first published recommendations GBS prophylaxis. From 2003-2013, the rate dropped further to 1.41 cases/10,000 (RD -.83 (-1.5, -.179), coinciding with revision of those recommendations to universal culture-based screening. From 1992-mid 2013 cases of infant Listeria, overall trend statistic p-value was <.0001.
Conclusion: We observed decreases in rates of Listeriosis in infants less than 30 days over the last 20 years. These decreases clearly coincide with expansion of prophylaxis for early onset GBS disease. These results are the first to directly examine this correlation and further suggest that the need for ampicillin in febrile infants should no longer be driven by concerns for Listeria.
R. Jhaveri, None