Neonatal listeriosis: experience in Suffolk

Antimicrobial chemotherapy of human infection due to Listeria monocytogenes

Listeriosis is an uncommon infection, but when it occurs it carries a high mortality rate. Early diagnosis is essential and thereafter appropriate antimicrobial chemotherapy. Ampicillin or penicillin plus gentamicin remains the treatment of choice for most manifestations of listeriosis, and adequate doses must be given, i.e. greater than 6g/day of ampicillin or penicillin. Co-trimoxazole appears to be an excellent alternative agent with good penetration into the cerebrospinal fluid. Vancomycin is an appropriate agent for the treatment of primary bacteraemia but does not cross the blood-brain barrier sufficiently well to be useful in meningitis, while erythromycin may be used to treat listeriosis in cases of pregnancy. Treatment of bacteraemia requires one to two weeks' therapy, while meningitis cases may need to be treated for longer; for example, it has been found that most patients with acute meningitis in the UK were treated for 20 days. Infective endocarditis needs treatment for six to eight weeks. Doses should be varied with patients' altered organ function and antimicrobial serum monitoring performed when appropriate.

A 10 year survey of the epidemiology and clinical aspects of listeriosis in a provincial English city

Between January 1983 and December 1992 29 cases of human listeriosis were recorded in Bristol, giving an incidence for the decade of 0.35 infections/10(5) population/annum. For those less than a year old the incidence was 5.2/10(5) population/annum and for adults increased from 0.029/10(5)/annum for those aged 20-49 years to 0.65/10(5)/annum for those over 80 years of age. Social classes I and II were over represented in those infected while classes IV and V were under represented when compared to the general population. Infection was seasonal with most infections occurring in October and 75.9% cases in the last two quarters of the year. Altogether, 13 (45%) cases were associated with pregnancy while 16 (55%) arose in non-pregnant persons. The incidence of pregnancy-associated infection was 1.23 per 10(4) births. In the first half of the decade, pregnancy-associated infection (62.5%) was more common than infection in non-pregnant adults or juveniles but this preponderance was reversed in the second half (23.1%). Among juvenile/adult infections not associated with pregnancy, bacteraemia became more common than CNS infection as the decade progressed. Among the pregnancy-associated infections were five infected abortions, seven neonatal infections (six systemic and one local) and one maternal infection during pregnancy in which the baby was not infected. The juvenile and adult infections in non-pregnant adults presented as primary bacteraemia in 10 (62.5%) patients and CNS infection in six (37.5%) patients. The overall mortality, excluding abortions, was 27.6% (8/29), being 14.3% (1/7) among affected neonates and 37.5% (6/16) among juveniles and non-pregnant adults. Sequelae of infection were not noted in the neonates but a third of the juveniles or adults with CNS infection were left with residual defects.