Pregnancy-associated listeriosis

Infection by Listeria monocytogenes in pregnant women may result in fetal loss or invasive disease in the newborn. We examined listeriosis cases reported through the U.S. Listeria Initiative during 2004-2007. Cases were classified as pregnancy-associated if illness occurred in a pregnant woman or an infant aged <28 days. Of 758 reported Listeria cases, 128 (16.9%) were pregnancy-associated. Maternal infection resulted in four neonatal deaths and 26 (20.3%) fetal losses. Invasive illnesses in newborns (n = 85) were meningitis (32.9%) and sepsis (36.5%). Pregnant women with Listeria were more likely to report Hispanic ethnicity (52.8% vs. 25.6%, respectively; OR 3.3 95% CI 2.2-4.8) than mothers giving live birth in the USA during 2005 and were more likely to report consumption of Mexican-style cheese (OR 2.6, 95% CI 1.6-4.2) than were non-pregnant patients with Listeria infection. Pregnant woman comprised a considerable proportion of reported listeriosis cases. Further declines in pregnancy-associated listeriosis will require education about avoiding high-risk foods, and continued regulatory and industry efforts to decrease Listeria in foods.