Cronobacter Support
08-17-2009, 10:39 AM
Enterobacter sakazakii Infections Associated With the Use of Powdered Infant Formula—Tennessee, 2001
JAMA. 2002;287:2204-2205. (posted from jama.ama-assn.org)
MMWR. 2002:51:297-300
Enterobacter sakazakii, a gram-negative, rod-shaped bacterium, is a rare cause of invasive infection with high death rates in neonates.1,2 This report summarizes the investigation of a fatal infection associated with E. sakazakii in a hospitalized neonate, which indicated that the infection was associated with the presence of the organism in commercial powdered formula fed to the infant. The implicated batch of formula has been recalled by the manufacturer. Clinicians should be aware of the potential risk for infection from use of nonsterile enteral formula in the neonatal health-care setting.
In April 2001, a male infant (2 lbs, 13 oz [1,270 grams]) was delivered by cesarean section at 33.5 weeks' gestation and was hospitalized in a neonatal intensive care unit (NICU) because of low birthweight, prematurity, and respiratory distress. The infant had fever, tachycardia, decreased vascular perfusion, and neurologic abnormalities (e.g., suspected seizure activity) at 11 days. Cerebrospinal fluid (CSF) obtained by lumbar puncture was analyzed and revealed a white blood cell count of 32/mm3[normal = 0-0.5/mm3], red blood cell count of 27/mm3 [normal = 0], protein of 292 mg/dL [normal = 15-45 mg/dL], and glucose of 1 mg/dL [normal = 40-70 mg/dL]. Culture of CSF grew E. sakazakii. The infant was treated with intravenous antimicrobials for meningitis; however, neurologic damage was progressive, and the infant died 9 days later. Because the organism was a rare cause of neonatal meningitis, hospital personnel, in collaboration with the Tennessee Department of Health and CDC, investigated the source of infection.
During April 10-20, 2001 (i.e., the study period), enhanced case surveillance was performed to determine if other infants in the NICU were either infected or colonized with E. sakazakii. Patients were assessed for colonization by stool culture; microbiology laboratory records also were reviewed for reports of E. sakazakii growth from clinical specimens during the study period. Confirmed infection was defined as any E. sakazakii-positive culture from a normally sterile site. Suspected infection was defined as an E. sakazakii-positive culture from a nonsterile site with documented deterioration in clinical status (e.g., increased respiratory rate without other evident cause) in the 24 hours before collection of the specimen for culture. Colonization was defined as an E. sakazakii-positive culture from a nonsterile site without documented deterioration in clinical status in the 24 hours before collection of the specimen for culture. A total of 49 infants were screened. Ten E. sakazakii infection or colonization events were identified: one confirmed infection in the index patient (culture-positive from CSF), two suspected infections (both culture-positive from tracheal aspirate), and seven colonizations (six culture-positive from stool, one from urine). One patient was colonized at two sites (urine and stool).
A cohort study was performed on the 49 patients who were screened to determine possible risk factors for acquisition of E. sakazakii infection or colonization. A case-patient was defined as any NICU patient with E. sakazakii infection (confirmed or suspected) or colonization during the study period. Medical records were reviewed to assess possible risk factors during the study period, including gestational age, birthweight, mechanical ventilator use, humidified incubator use, oral medications, and feeding type (total parenteral nutrition, formula [e.g., powdered or liquid], or breast milk) or method (i.e., continuous or intermittent administration). Of the 49 patients identified in the cohort, nine were case-patients and 40 were noncase-patients. Analysis of risk factors identified only use of a specific powdered infant formula product (Portagen [Mead Johnson Nutritionals, Evansville, Indiana]) to be significantly associated with E. sakazakii infection or colonization; all case-patients received Portagen compared with 21 of 40 noncase-patients (p<0.01).
To determine the source of infection, microbiologic studies were performed on samples of commercially sterile water used for formula preparation and from samples of formula taken from opened cans of Portagen from the same two batches used in the NICU during the study period. Environmental swab cultures were taken from surfaces on which the product had been prepared. Cultures also were performed on unopened containers of Portagen supplied by the manufacturer with batch codes matching those of opened cans. The water was cultured using membrane filtration. The powdered infant formula was cultured using a modification of a previously described enrichment method.3 Specifically, for each culture of formula, 100 grams of Portagen were inoculated in phosphate-buffered peptone water, incubated overnight, subcultured, reincubated, and picked and streaked. Colonies that demonstrated a yellow pigment characteristic of E. sakazakii were then picked for identification. Cultures of formula taken from both opened and unopened cans of Portagen from a single batch grew E. sakazakii. Water and all environmental cultures were negative. Pulsed-field gel electrophoresis revealed that isolates of E. sakazakii from the CSF culture of the neonate with meningitis and from the culture of formula from both opened and unopened containers were indistinguishable.
Hospital personnel reviewed NICU infection-control practices, policies, and procedures for preparation, storage, and administration of powdered infant formula. No breaches in infection control were detected. The product was prepared in the NICU according to manufacturer's instructions. Powdered formula was mixed with sterile water and was immediately refrigerated and used within 24 hours of preparation. The infant with E. sakazakii meningitis was given formula by continuous administration; administration or "hang" time (i.e., the amount of time the contents of a formula bag are fed to a patient) did not exceed 8 hours.
To prevent additional infections, the hospital made several policy changes. Principal formula type for NICU patients was changed from powdered formula to a commercially sterile, ready-to-feed liquid formula. Portagen is no longer used; other powdered formula products are reserved for specific needs and, when necessary, are prepared in a designated formula preparation room in the pharmacy. The amount of allowable administration or "hang" time has been reduced from 8 hours to 4 hours. As of April 10, 2002, no additional episodes of infection or colonization have been detected at the reporting hospital.
JAMA. 2002;287:2204-2205. (posted from jama.ama-assn.org)
MMWR. 2002:51:297-300
Enterobacter sakazakii, a gram-negative, rod-shaped bacterium, is a rare cause of invasive infection with high death rates in neonates.1,2 This report summarizes the investigation of a fatal infection associated with E. sakazakii in a hospitalized neonate, which indicated that the infection was associated with the presence of the organism in commercial powdered formula fed to the infant. The implicated batch of formula has been recalled by the manufacturer. Clinicians should be aware of the potential risk for infection from use of nonsterile enteral formula in the neonatal health-care setting.
In April 2001, a male infant (2 lbs, 13 oz [1,270 grams]) was delivered by cesarean section at 33.5 weeks' gestation and was hospitalized in a neonatal intensive care unit (NICU) because of low birthweight, prematurity, and respiratory distress. The infant had fever, tachycardia, decreased vascular perfusion, and neurologic abnormalities (e.g., suspected seizure activity) at 11 days. Cerebrospinal fluid (CSF) obtained by lumbar puncture was analyzed and revealed a white blood cell count of 32/mm3[normal = 0-0.5/mm3], red blood cell count of 27/mm3 [normal = 0], protein of 292 mg/dL [normal = 15-45 mg/dL], and glucose of 1 mg/dL [normal = 40-70 mg/dL]. Culture of CSF grew E. sakazakii. The infant was treated with intravenous antimicrobials for meningitis; however, neurologic damage was progressive, and the infant died 9 days later. Because the organism was a rare cause of neonatal meningitis, hospital personnel, in collaboration with the Tennessee Department of Health and CDC, investigated the source of infection.
During April 10-20, 2001 (i.e., the study period), enhanced case surveillance was performed to determine if other infants in the NICU were either infected or colonized with E. sakazakii. Patients were assessed for colonization by stool culture; microbiology laboratory records also were reviewed for reports of E. sakazakii growth from clinical specimens during the study period. Confirmed infection was defined as any E. sakazakii-positive culture from a normally sterile site. Suspected infection was defined as an E. sakazakii-positive culture from a nonsterile site with documented deterioration in clinical status (e.g., increased respiratory rate without other evident cause) in the 24 hours before collection of the specimen for culture. Colonization was defined as an E. sakazakii-positive culture from a nonsterile site without documented deterioration in clinical status in the 24 hours before collection of the specimen for culture. A total of 49 infants were screened. Ten E. sakazakii infection or colonization events were identified: one confirmed infection in the index patient (culture-positive from CSF), two suspected infections (both culture-positive from tracheal aspirate), and seven colonizations (six culture-positive from stool, one from urine). One patient was colonized at two sites (urine and stool).
A cohort study was performed on the 49 patients who were screened to determine possible risk factors for acquisition of E. sakazakii infection or colonization. A case-patient was defined as any NICU patient with E. sakazakii infection (confirmed or suspected) or colonization during the study period. Medical records were reviewed to assess possible risk factors during the study period, including gestational age, birthweight, mechanical ventilator use, humidified incubator use, oral medications, and feeding type (total parenteral nutrition, formula [e.g., powdered or liquid], or breast milk) or method (i.e., continuous or intermittent administration). Of the 49 patients identified in the cohort, nine were case-patients and 40 were noncase-patients. Analysis of risk factors identified only use of a specific powdered infant formula product (Portagen [Mead Johnson Nutritionals, Evansville, Indiana]) to be significantly associated with E. sakazakii infection or colonization; all case-patients received Portagen compared with 21 of 40 noncase-patients (p<0.01).
To determine the source of infection, microbiologic studies were performed on samples of commercially sterile water used for formula preparation and from samples of formula taken from opened cans of Portagen from the same two batches used in the NICU during the study period. Environmental swab cultures were taken from surfaces on which the product had been prepared. Cultures also were performed on unopened containers of Portagen supplied by the manufacturer with batch codes matching those of opened cans. The water was cultured using membrane filtration. The powdered infant formula was cultured using a modification of a previously described enrichment method.3 Specifically, for each culture of formula, 100 grams of Portagen were inoculated in phosphate-buffered peptone water, incubated overnight, subcultured, reincubated, and picked and streaked. Colonies that demonstrated a yellow pigment characteristic of E. sakazakii were then picked for identification. Cultures of formula taken from both opened and unopened cans of Portagen from a single batch grew E. sakazakii. Water and all environmental cultures were negative. Pulsed-field gel electrophoresis revealed that isolates of E. sakazakii from the CSF culture of the neonate with meningitis and from the culture of formula from both opened and unopened containers were indistinguishable.
Hospital personnel reviewed NICU infection-control practices, policies, and procedures for preparation, storage, and administration of powdered infant formula. No breaches in infection control were detected. The product was prepared in the NICU according to manufacturer's instructions. Powdered formula was mixed with sterile water and was immediately refrigerated and used within 24 hours of preparation. The infant with E. sakazakii meningitis was given formula by continuous administration; administration or "hang" time (i.e., the amount of time the contents of a formula bag are fed to a patient) did not exceed 8 hours.
To prevent additional infections, the hospital made several policy changes. Principal formula type for NICU patients was changed from powdered formula to a commercially sterile, ready-to-feed liquid formula. Portagen is no longer used; other powdered formula products are reserved for specific needs and, when necessary, are prepared in a designated formula preparation room in the pharmacy. The amount of allowable administration or "hang" time has been reduced from 8 hours to 4 hours. As of April 10, 2002, no additional episodes of infection or colonization have been detected at the reporting hospital.