Epidemic listeriosis associated with Mexican-style cheese.

In Los Angeles County, California, 142 cases of human listeriosis were reported from January 1 through August 15, 1985. Ninety-three cases (65.5 percent) occurred in pregnant women or their offspring, and 49 (34.5 percent) in nonpregnant adults. There were 48 deaths: 20 fetuses, 10 neonates, and 18 nonpregnant adults. Of the nonpregnant adults, 98 percent (48 of 49) had a known predisposing condition. Eighty-seven percent (81 of 93) of the maternal/neonatal cases were Hispanic. Of the Listeria monocytogenes isolates available for study, 82 percent (86 of 105) were serotype 4b, of which 63 of 86 (73 percent) were the same phage type. A case-control study implicated Mexican-style soft cheese (odds ratio, 5.5; 95 percent confidence interval, 1.2 to 24.8) as the vehicle of infection; a second case-control study showed an association with one brand (Brand A) of Mexican-style soft cheese (odds ratio, 8.5; 95 percent confidence interval, 2.4 to 26.2). Laboratory study confirmed the presence of L. monocytogenes serogroup 4b of the epidemic phage type in Brand A Mexican-style cheese. In mid-June, all Brand A cheese was recalled and the factory was closed. An investigation of the cheese plant suggested that the cheese was commonly contaminated with unpasteurized milk. We conclude that the epidemic of listeriosis was caused by ingestion of Brand A cheese contaminated by one phage type of L. monocytogenes serotype 4b.

Prophylactic oral nystatin and fungal infections in very-low-birthweight infants.

Prevention of systemic fungal infection in the very-low-birthweight infant is important since it is associated with a high morbidity and mortality. To determine if oral nystatin administration could prevent fungal colonization and infection, we evaluated 67 preterm infants with birthweights less than 1250 gm. Thirty-three infants received 1 ml (100,000 units/ml) of nystatin inside the mouth every 8 hours until 1 week after extubation. Oropharyngeal, rectal, blood, and urine cultures were obtained on the 1st day of life and weekly. Endotracheal cultures were obtained three times a week from intubated infants. Four (12%) of the 33 nystatin-treated infants had positive cultures, two (6%) developed systemic infection. The control group consisted of 34 infants, 15 (44%) had positive fungal cultures and 11 (32%) developed systemic infection. Fungi isolated were Candida species and Torulopsis glabrata. Colonized infants were dependent on the respirator (P less than 0.001), had indwelling catheters (P less than 0.01), and received antibiotics (P less than 0.05) for a longer period than infants free from fungi and their mortality was significantly higher (P less than 0.05). We conclude that prophylactic administration of oral nystatin reduces fungal colonization and infection in very-low-birthweight infants.

Clinical manifestations of epidemic neonatal listeriosis.

We report the broad spectrum of clinical manifestations in 23 infants with positive cultures for Listeria monocytogenes who were treated in our hospital during a recent epidemic. The majority of infants (70%) were preterm and none was small for gestational age. Thirteen (56%) had respiratory distress at birth with evidence of congenital pneumonia. Four of the 5 deaths occurred among these infants. Four infants considered healthy after resuscitation developed fever and lethargy within 36 hours after birth. Only one of these infants had evidence of pneumonia. We conclude that congenital pneumonia with respiratory distress at birth is the major cause of mortality and morbidity from L. monocytogenes infection in the neonate.

Perinatal mortality associated with intrauterine infection due to pseudomonads.

Pseudomonads are common causes of nosocomial infections but are rarely implicated in perinatal disease. In a retrospective autopsy study we found that 9% of all acute congenital bacterial infections were due to Pseudomonas species. Premature rupture of membranes occurred in half the cases and clinical maternal amnionitis in two-thirds. One case was apparently nosocomial in origin. No known risk factors were implicated in any other case. Seven infants were stillborn and two died within a few hours. Congenital pneumonia, funisitis, and chorioamnionitis were found at autopsy. Intrauterine infection due to the pseudomonads poses a serious problem that has not been previously recognized.