[Neonatal septicemia caused by Listeria monocytogenes: report of 6 cases].

OBJECTIVE

Neonatal listeriosis is a relatively rare but serious disease with a high mortality rate. This study was conducted to analyze the clinical features, treatment, and outcome of 6 cases with Listeria monocytogenes septicemia confirmed by positive blood cultures.

METHODS

Totally 12,538 live births delivered in the hospital from January 1, 2004 to June 30, 2006 were investigated. Differences in the time of onset of the disease, clinical presentation, illness severity, laboratory data, management, and prognosis were compared between preterm and full-term infants.

RESULTS

The incidence of neonatal listeriosis was 4.8% in this study. All the cases with listeriosis were found to have early onset and the disease was transmitted from the mother to the fetus, 4 of the cases were delivered via cesarean section, 2 were born via normal spontaneous vaginal delivery. Maternal infection before parturition presented with fever in 4, diarrhea in 1; 5 had abnormal white blood cell counts and total neutrophil counts; 1 had positive result of Listeria monocytogenes in intrauterine contents culture. Three premature infants showed signs and symptoms of severe bacterial septicemia at birth, such as reduced activity, respiratory distress, poor skin color and poor peripheral perfusion; the enlarged liver was palpable 2 - 3 cm below the right costal margin and 5 cm below the xiphoid in one; congestive rashes over the body and muscular hypotonia. Abnormal results of laboratory tests included peripheral blood white cell count (21.6 - 33.8 x 10(9))/L, total neutrophil count 0.77 - 0.83; platelet count (102 - 59 x 10(9))/L; C-reactive protein (CRP) > (160 - 118) mg/L(24 - 72 h after birth). Three preterm infants who received intensive care, accompanied by pathological changes of lungs indicated by chest X ray required assisted mechanical ventilation and 2 of them survived without sequelae but the other one died at 51 h of life. The initial clinical signs of septicemia in 3 full-term infants appeared later than preterm newborn within 62 h, 63 h and 165 h, respectively after birth. They only had fever, T 38 - 39 degrees C, with lower activity in contrast to normal newborn and without other signs and symptoms of septicemia. Accurate diagnosis of listeriosis was established by positive bacterial blood cultures. Intravenous treatment of neonatal listeriosis with ampicillin or penicillins for 1 - 2 weeks was more effective, but cephalosporins were not effective.

CONCLUSIONS

There are sporadic cases with Listeria monocytogenes infection among pregnant women in this country, resulting in severe illness of their newborn infants. Early differential diagnosis, early detection of causative organisms, especially in newborn infants infected with Listeria monocytogenes, early treatment with sensitive antibiotics can decrease the mortality rate and improve neonatal outcome. It is necessary to enhance nationwide surveillance for listeriosis.