Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Early-onset neonatal disease Signs of sepsis a few hours after birth in an infant born with fetal distress and hepatosplenomegaly; maternal fever Late-onset neonatal disease Meningitis, sometimes with monocytosis in the CSF and peripheral blood Onset at age 9–30 days Immunosuppressed patients Fever and meningitis +++ General Considerations ++ Listeria monocytogenes causes systemic infections in newborn infants and immunosuppressed older children In pregnant women, infection is relatively mild, with fever, aches, and chills, but is accompanied by bacteremia and sometimes results in intrauterine or perinatal infection with grave consequences for the fetus or newborn Listeria is present in the stool of approximately 10% of the healthy population Persons in contact with animals are at greater risk Outbreaks of listeriosis have been traced to contaminated cabbage in coleslaw, soft cheese, hot dogs, luncheon meats, and milk +++ Clinical Findings +++ Symptoms and Signs ++ In the early neonatal form Symptoms usually appear on the first day of life and always by the third day Fetal distress is common Infants frequently have signs of severe disease at birth Respiratory distress, diarrhea, and fever occur Hepatosplenomegaly and a papular rash are seen A history of maternal fever is common Meningitis may accompany the septic course Late neonatal form Usually occurs after age 9 days and can occur as late as 5 weeks Meningitis is common, characterized by irritability, fever, and poor feeding Listeria infections are rare in older children and usually are associated with immunodeficiency +++ Differential Diagnosis ++ Early-onset neonatal disease resembles Hemolytic disease of the newborn Group B streptococcal (GBS) sepsis Severe cytomegalovirus infection Rubella Toxoplasmosis Late-onset disease must be differentiated from Meningitis due to echovirus and coxsackievirus GBS Gram-negative enteric bacteria +++ Diagnosis ++ WBC count is elevated, with 10–20% monocytes in all patients except those receiving white cell depressant drugs When meningitis is found, the characteristic CSF cell count is high (> 500/μL) with a predominance of polymorphonuclear neutrophils in 70% of cases Monocytes may predominate in up to 30% of cases Gram-stained smears of CSF are usually negative, but short gram-positive rods may be seen The chief pathologic feature in severe neonatal sepsis is miliary granulomatosis with microabscesses in liver, spleen, CNS, lung, and bowel Culture results are frequently positive from multiple sites, including blood from the infant and the mother +++ Treatment ++ Ampicillin (150–300 mg/kg/d every 6 hours intravenously) is the drug of choice Gentamicin (2.5 mg/kg every 8 hours intravenously) Has a synergistic effect with ampicillin Should be given in serious infections and to patients with immune deficits Vancomycin may be substituted for ampicillin when empirically treating meningitis If ampicillin cannot be used, trimethoprim-sulfamethoxazole (TMP-SMX) is effective Treatment duration Severe disease: continue for at ... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth