lable at ScienceDirect

American Journal of Infection Control 40 (2012) 516-20

Contents lists avai

American Journal of Infection Control

journal homepage: www.aj ic journal .org

American Journal of Infection Control

Major article

An outbreak of Klebsiella pneumoniae late-onset sepsis in a neonatal intensivecare unit in Guatemala

Jennifer Gray MD a,*, Wences Arvelo MPH, MDb, John McCracken MPH, ScD a, Beatriz Lopez BSc a,Fernanda C. Lessa MD c, Brandon Kitchel MSc c, Betty Wong MPH c, Lissette Reyes MDd,e,Kim Lindblade MPH, PhD b

a Center for Health Studies, Universidad del Valle de Guatemala, Guatemala City, GuatemalabUS Centers for Disease Control and Prevention, Regional Office for Central America and Panama, Guatemala City, GuatemalacUS Centers for Disease Control and Prevention, Atlanta, GAdMinistry of Public Health and Social Assistance, Guatemala City, Guatemalae Field Epidemiology Training Program, Guatemala City, Guatemala

Key Words:Hospital-acquired infectionKlebsiella sppNeonatal sepsisCentral America

* Address correspondence to Jennifer Gray, MD, St.State Street, McCall, ID 83638.

E-mail address: jgray@slhs.org (J. Gray).Supported in part by Centers for Disease Control

Agreement UO1 GH000028-02. The findings and cothose of the authors and do not necessarily representDisease Control and Prevention.

These findings were presented in part during theEmerging Infectious Diseases, Atlanta, Georgia, July 1

Conflict of interest: None to report.

0196-6553/$36.00 - Copyright � 2012 by the Associadoi:10.1016/j.ajic.2012.02.031

Background: Gram-negative bloodstream infections are an important cause of neonatal mortality. InOctober 2009, we investigated a Klebsiella spp outbreak in a neonatal intensive care unit in Guatemala.Methods: Probable cases were defined as a Klebsiella spp isolated from blood in neonates aged <28 daysin the neonatal intensive care unit between October 1 and November 10, 2009; confirmed cases wereidentified as Klebsiella pneumoniae. Clinical data were abstracted from medical charts. K pneumoniaeisolates were genotyped by pulsed-field gel electrophoresis (PFGE) and tested for antimicrobialsusceptibility. Infection control practices were inspected.Results: There were 14 confirmed cases. The median age at onset of infection was 3 days (range, 2-8days). Nine patients died (64%). K pneumoniae isolates were resistant to multiple antimicrobials. PFGErevealed 2 distinct clusters. Breaches in infection control procedures included inappropriate intravenoussolution use and inadequate hand hygiene and contact precautions.Conclusions: We report a K pneumoniae outbreak with high neonatal mortality in Guatemala. PFGEclustering suggested a common source possibly related to reuse of a single-use intravenous medicationor solution. The risk for K pneumoniae bloodstream infections in neonates in low-resource settings wheresharing of solutions is common needs to be emphasized.

Copyright � 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc.Published by Elsevier Inc. All rights reserved.

Bloodstream infections (BSIs) are important causes of mortalityand morbidity in neonates and are responsible for an estimatedone-third of the approximately 4 million global neonatal deathsoccurring annually.1 In neonates, these infections are oftenhospital-acquired and are responsible for approximately 62% ofhealth careeassociated infections in neonatal intensive care units

Luke’s McCall Hospital, 1000

and Prevention Cooperativenclusions in this report arethe views of the Centers for

International Conference on0-14, 2010.

tion for Professionals in Infection

(NICUs) worldwide.2 Although data on rates of health careeassociated BSIs in developing countries are limited, the availabledata suggest that neonatal BSI rates are 4 times higher than indeveloped countries, resulting in longer lengths of stay andincreased costs of hospitalization.3 The organisms most commonlyisolated point to inadequate infection control processes as probableprimary sources of infection.4-8 Neonates, particularly those withextremely low birth weight, are inherently at greater risk for healthcareeassociated BSIs based on their prolonged hospitalization andexposure to central venous catheters, mechanical ventilation, totalparenteral nutrition, and long-term antimicrobial therapy withthird-generation cephalosporins.5,9-12

In developing countries, neonatal BSI most commonly resultfrom infection by gram-negative bacteria, such as Klebsiella spp,Escherichia coli, and Pseudomonas aeruginosa.7,13,14 Klebsiella sppare the most commonly implicated pathogen in neonatal sepsis

Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

J. Gray et al. / American Journal of Infection Control 40 (2012) 516-20 517

outbreaks.2,15,16 Klebsiella spp can survive on environmentalsurfaces, health care providers’ skin and also colonize the intestinaltract of neonates, providingmultiple opportunities for transmission.Reported neonatal case fatality rates from BSIs caused by Klebsiellaspp range from 11% to 76%.2,9,15,17,18 There are little reported data onKlebsiella outbreaks in NICUs in Central America. The sparse litera-ture includes NICU Klebsiella outbreaks in Nicaragua andMexico.15,17

Although there are limited data on antimicrobial susceptibilitypatterns of Klebsiella spp in Central America, a high proportion ofisolates with extended-spectrum b-lactamase (ESBL) productionand multidrug resistance has been reported.15,19,20 In settings wheremultidrug-resistant strains are prevalent, more sophisticated inter-ventions directed atmodifying specific antimicrobial usage are oftenmandated to reduce emergence of resistant bacteria.21 Outbreaks ofsepsis due to antimicrobial-susceptible organisms can be controlledby simpler interventions that can be easily implemented inresource-limited settings, such as improving compliance with handhygiene,17 cohorting patients and health care personnel,17,22 prohi-bition of artificial nail use by staff,16 and discontinuation of use ofinadequately chlorinated water for handwashing.23

On October 30, 2009, the Guatemalan Ministry of Public Healthand Social Welfare requested the assistance of the US Centers forDisease Control and Prevention (CDC) and the Universidad del Vallede Guatemala to investigate an increase in rates of neonatal BSI ina regional hospital in the Department of Santa Rosa, Guatemala. Aninitial review of the hospital’s blood culture database revealed anincrease in Klebsiella spp cultures during October 2009, most ofwhich were from patients admitted to the NICU. We initiated aninvestigation to better characterize the epidemiology of theseinfections and assist with control measures.

METHODS

Identification of cases

The National Hospital of Cuilapa, a 176-bed regional referralhospital with a 17-bed NICU, is the only hospital in the Departmentof Santa Rosa (population 308,522). We used the hospital’s bloodculture database to identify cases. The hospital’s protocol forobtaining blood cultures advises clinicians to obtain 1 pediatricblood culture bottle from any neonate suspected of having systemicinfection or with a confirmed diagnosis of pneumonia. A probablecase was defined as Klebsiella spp isolated from blood by thehospital laboratory from an infant aged <28 days who wasadmitted to the NICU between October 1 and November 10, 2009. Aconfirmed case was an isolate identified as K pneumoniae by anal-ysis with the Vitek 2 microbial identification system (bioMérieux,Marcy-l’Etoile, France). The medical charts of patients who met theprobable case definition were reviewed by the investigation team,which included physicians and epidemiologists, using a standard-ized form to collect information on prenatal, birth, and neonatalclinical history, current clinical course (including exposure toindwelling catheters and other procedures, type of alimentation,need formechanical ventilation, duration of intubation, exposure tomedications, and hospital outcome), and demographic information.Prolonged rupture of membranes was defined as >24 hours dura-tion, instrumented vaginal delivery was defined as a vacuum orforceps-assisted delivery, low birthweight was defined as�2,500 g,very low birth weight was defined as �1,500 g, and fever (maternalor neonatal) was defined as an axillary temperature �38�C.

Laboratory tests

The hospital laboratory used an automated BacT/ALERT bloodculture system (bioMérieux). Pediatric bottles inoculated with

1-4 mL of blood were introduced into the BacT/ALERT device, and ifbacterial growth occurred, specimens were plated onto sheep’sblood agar, MacConkey’s agar, and chocolate agar plates. The platesweremonitored for growth, and antimicrobial susceptibility testingwas performed using the disk-diffusion method.

Isolates from probable cases were sent to the CDC laboratories inAtlanta, where the Vitek 2 system (bioMérieux) was used forbacterial identification. Antimicrobial susceptibility testing wasrepeated at the CDC laboratory using the disk-diffusion and brothmicrodilution methods; those results were considered definitive.ESBL production was determined by disk-diffusion for ceftazidimeand cefotaxime with and without clavulanic acid and by brothmicrodilution using cefpodoxime and clavulinic acid. Brothmicrodilution panels were prepared in-house at the CDC laboratoryfollowing Clinical Laboratory and Standards Institute referencemethods,24 and disks for antimicrobial susceptibility testing werecommercially purchased (BD Diagnostic Systems, Sparks, MD).Minimum inhibitory concentrations (MICs) were recorded after16-20 hours of incubation in ambient air at 35�C. E coli AmericanType Culture Collection (ATCC) 25922, P aeruginosa ATCC 27853, Kpneumoniae ATCC 700603, and E coli ATCC 35218 were used for MICquality control; E coli ATCC 25922 and K pneumoniae ATCC 700603were used for disk-diffusion quality control. Pulsed-field gel elec-trophoresis (PFGE) analysis was also performed on all Klebsiella sppisolates as described previously for E coli (http://www.cdc.gov/pulsenet/protocols.htm) using Xbal for digestion of chromosomalDNA and electrophoresis for 21 hours, with switch times of5 seconds and 40 seconds. PFGE patterns were analyzed usingBionumerics software (Applied Maths, Austin, TX). Similarity ofpatterns was based on Dice coefficients, and a dendrogram wasgenerated using the unweighted pair group method.

Infection control observations and environmental investigation

We conducted direct observation of practices within the NICUduring the first 2 days of the investigation. Practices observedincluded the preparation and administration of medications andintravenous (IV) Dice coefficient solutions, hand hygiene practices,adherence to contact precautions, sterilization of ventilator tubing,flushing of IV lines and catheters, aspiration of respiratory secre-tions, spacing of neonates, and maintenance and use of medicalsupplies and instruments. Environmental sampling from equip-ment was performed using cotton swabs that were immersedimmediately in soy trypticase broth and incubated for 4 hours at37�C, and then plated onto MacConkey’s and sheep’s blood agarculture plates. Samples were collected from the following equip-ment: ventilator entry and exit ports, ventilator tubing, aspiratordevice tubing and reservoir, towel for drying hands, and laryngo-scope used for intubating neonates. IV solutions were extractedfrom the IV bags using a sterile syringe and needle and wereincubated using the method described above for environmentalsamples. Additional non-IV solutions were sampled as well,including saline IV flush solution, saline solutions for endotrachealaspiration, water used for mixing formula, and the water bath forformula bottle sterilization.

Human subjects

This investigation was considered a public health response andas such did not require review by an Institutional Review Board. Theinvestigation protocol was approved by the GuatemalanMinistry ofHealth and Welfare. Study questionnaires were stored under lockand key; no nameswere associatedwith reported data. No personalidentifiers were retained.

Table 1Characteristics of 13 patients with confirmed K pneumoniae sepsis during anoutbreak in a Guatemalan NICU, October to November 2009

Characteristic n (%)

Fever at birth* 0 (0)Abnormal white blood cell count in first 24 hours of lifey,z 1 (9)Arterial blood gas pH at birth�7.36 8 (62)7.31-7.35 1 (8)�7.30 4 (31)

Gestational age <37 weeks 9 (69)1-minute Apgar score �5z 3 (27)Birth weight<2,500 g 9 (69)�2,500 g 4 (31)

Meconium aspiration 3 (23)Cesarean delivery 7 (54)Intubation or CPAP at time of birth 7 (54)Intubation or CPAP before blood culture orderx 12 (92)Umbilical venous catheter 9 (69)Orogastric tube 12 (92)Dextrose solution 13 (100)IV normal saline flushes 13 (100)Total parenteral nutrition 7 (54)Orogastric formula feedings 1 (84)Nebulized medication 6 (46)

CPAP, continuous positive airway pressure.*Data available for 10 patients.yAbnormal white blood cell count: �5,500 or �15,500.zData available for 11 patients.xTwo of the 12 patients with CPAP.

J. Gray et al. / American Journal of Infection Control 40 (2012) 516-20518

Data management and analysis

Data from standardized questionnaires were entered intoa Microsoft Excel 2003 spreadsheet (Microsoft, Redmond, WA), andmedians, ranges and frequencies of various potential risk factorsand exposures were calculated. To compare risk factors in neonateswho died and those who survived, Fisher’s exact test was used totest for differences in categorical variables, and the Mann-WhitneyU test was used for continuous variables. A P value <.05 wasconsidered to indicate statistical significance.

RESULTS

Description of cases

There were 37 admissions to the NICU between October 1 andNovember 10, 2009. Among those admissions, we identified 16probable cases, of which 14 (38% of admissions) were confirmedcases. Eight cases (57%) occurred in female patients. The averageage at blood culture, the presumed indicator of sepsis onset, was 3days (range, 2-7 days). No blood cultures were drawn before 2 daysof life. Ten of the affected neonates (71%) were born at the hospitalwhere the outbreak occurred, and the other 4 (29%) were trans-ferred from other hospitals.

Clinical charts were available for 13 of the neonates (Table 1). Sixneonates (46%) were born by vaginal delivery and 7 (54%) wereborn by operative delivery. The majority were exposed tomechanical ventilation, orogastric tubes, and umbilical or centralvenous catheters (Table 1). The only common IV solutions ormedications in all patients were saline and dextrose solutions.There was potential simultaneous exposure to IV dobutamine andbicarbonate (intended for single use but used for multiple patients).Among the 12 patients for which data on initial antimicrobialtherapy were available, 10 (83%) were treated with ampicillin andgentamicin (83%) and 3 (25%) were treated with ampicillin,gentamicin, and carbapenem. Nine patients (75%) were treatedwith carbapenem during the NICU admission. Among the 13patients for whom mortality data were available, 9 (69%) died and4 (31%) were discharged alive.

There were no statistically significant differences in gestationalage, birth weight, or 1-minute Apgar scores between the patientswho survived and those who died (data not shown). Although thedifferences were not statistically significant, more of the neonateswho died (5 of 8 with available data; 63%) were intubated at birthcompared with survivors (2 of 5; 40%), and more of the neonateswho died (5 of 8; 75%) demonstrated respiratory distress at birth inthe form of retractions, flaring, or cyanosis compared with thesurvivors (1 of 5; 20%). Antimicrobial treatment data were availablefor 6 of the 9 patients who died and for all 5 of the survivors. Five(83%) of those who died received ampicillin and gentamicin,compared with 5 (100%) survivors, and 6 (100%) of those who diedreceived carbapenem, compared with 4 (80%) of the survivors.

Laboratory data

Antimicrobial susceptibility data demonstrated no carbapenemresistance. We found a 100% resistance to first-, second-, and third-generation cephalosporins with the exception of cefoxitin, towhich6 (43%) isolates were resistant. Some 50% of the cephalosporin-resistant isolates were confirmed to be ESBL producers. All isolateswere resistant to gentamicin, chloramphenicol, trimethoprim/sulfamethoxazole, ampicillin, ampicillin-sulbactam, aztreonam,and piperacillin; 10 isolates (71%) were resistant to piperacillin/tazobactam; and 7 (50%) were resistant to amoxicillin/clavulanate.Two isolates (14%) exhibited resistance to amikacin, 11 (79%) were

resistant to tobramycin, 7 (50%) were resistant to levofloxacin andciprofloxacin, and 2 (14%) were resistant to tetracycline.

PFGE analysis of the 14 isolates revealed a cluster of 7 geneticallyindistinguishable isolates with 94% similarity early in the outbreak(cluster 1), along with a second distinct cluster pattern of 4 isolateswith 86% similarity late in the outbreak (cluster 2). The 2 distinctclusters identified by PFGE also differed in that cluster 1 demon-strated no ESBL production and variable cefoxitin resistance,and cluster 2 had 100% ESBL production and 100% cefoxitinsusceptibility.

The 2 clusters identified occurred in 2 distinct time periods(Fig 1). Only 1 patient from cluster 1 was still hospitalized at theonset of cluster 2; however, there was a period of 9 days betweenthe last culture obtained from cluster 1 and the first cultureobtained from cluster 2. Six of the 7 blood cultures from cluster 1were drawn within a 3-day period, and all blood cultures fromcluster 2 were drawn within a 4-day period. Four patients (57%)from cluster 1 died. One patient from cluster 2 was born at anoutside hospital; K pneumoniae was isolated from that patient’sblood on day 3 of admission.

Environmental investigation

No growth of K pneumoniae was detected in the cultures ofenvironmental surfaces, tubing, medications, or IV solutions.

Infection control observations

IV fluid flush preparation. Central and peripheral IV catheterswere flushed by an ungloved nurse using a nonpreserved salinesolution located at a station in the room with the ill neonates.Flushesweredrawn froma250-mL salinebag locatedona cart in theroomwith the ill neonates and used over several days until emptied.Saline and dextrose for continuous IV infusion were drawn, usinga sterile syringe, from 1-L storage bottles of nonpreserved solutionsthat were also centrally located with the ill neonates.

Fig 1. Timeline of clinical events of K pneumoniae cases for the 2 genetic clusters bydate of isolation from blood, Guatemala, October to November 2009.

J. Gray et al. / American Journal of Infection Control 40 (2012) 516-20 519

Hand hygiene. Hand hygiene was not performed regularly. Ashared hand towel that was changed 3 times daily hung over a sinkwith a hand-operated faucet. Alcohol-based hand hygiene was notavailable or provided by the hospital.

Endotracheal tube aspiration of secretions. The endotrachealtubes were aspirated independently by a physician under non-sterile conditions using a nonpreserved saline solution that wasrepeatedly accessed for all ventilated patients.

Sterilization of ventilator tubing. Ventilator tubing was cleaned,autoclaved, and left to dry in the room with the ill neonates.

Spacing of infants. Well neonates (postcesarean delivery, forobservation only) were kept in an anteroom. All ventilated neonatesand those receiving phototherapy (both ill and otherwise wellpreterm infants) were kept in one room, and nonventilated preterminfants were kept in another room.

Preparation of skin for central line insertion. Physicians report thatthey previously used iodine or thimerosal to prepare their centrallines, but for an undetermined time frame they had been inde-pendently mixing chlorhexidine, resulting in random dilutions andconcentrations.

DISCUSSION

We have examined an outbreak of K pneumoniae BSIs with highmortality in a Guatemalan NICU. Although the neonates had beenin the NICU for varying periods, the temporal clustering of theblood cultures and the corresponding PFGE clustering stronglysuggest a common point source of infection occurring in 2 separateevents. The relatively early onset of the infections and the commonexposure to nonpreserved IV solutions and medications in theneonates suggest that the outbreak was likely a result of contami-nated IV solutions intended for single-use but given to multiplepatients. IV solutions can be a reservoir for K pneumoniae,4,18,25,26

and contamination of IV dextrose solutions has been implicatedin previous NICU outbreaks.22,27

We also found high rates of antimicrobial resistance among the Kpneumoniae isolates in this outbreak, including ESBL production. InCentral America, ESBL-producing Klebsiella spp have been identifiedas important organisms in hospital-acquired infections. Docu-mented ESBL-mediated resistance rates of Klebsiella spp are 2- to3-fold higher in Central America compared with North America andEurope.3,20,28 The typical empiric antimicrobial therapy used in theNICU includesb-lactamantimicrobials, towhich some isolates in thisoutbreak demonstrated resistance.We also report a 100% resistanceof K pneumoniae to gentamicin; this has been noted elsewhere in

Central America28 and confers an additional risk for NICU patientswho commonly receive gentamicin for empiric therapy.

Environmental investigation of the NICU revealed deficienciesthat might have helped propagate the outbreak. Several interven-tions were recommended to address these deficiencies, includingthe single use of nonpreserved IV solution and medications,cohorting of ill neonates, removal of sterilized ventilator equipmentfrom the patient care area, and purchase of an additional aspirator.However, very few of these interventions could be implemented,given the hospital’s limited resources. The interventions deemedfeasible and implemented by the hospital included the use ofdisposable paper towels, use of povidone-iodine to prepare centralline sites, exclusive assignment of nursing personnel to either theacutely ill neonates or the healthier neonates, and disposal ofnonpreserved IV solutions and medication bottles every 24 hours.These interventions, although not the ideal response, might havehelped stop the second cluster of cases from continuing. However,another outbreak of gram-negative BSIs occurred in this NICUwithin 6 months of this investigation, stressing the importance ofadhering to current infection control guidelines and avoiding thesharing of nonpreserved IV medications and solutions intended forsingle use even in resource-limited settings. Although not used inthis outbreak, alcohol-based hand hygiene is another cost-effectiveintervention to address breeches in hand hygiene in low-resourcesettings.

Surveillance for BSIs in resource-limited settings can allow forthe early detection of outbreaks and can provide valuable oppor-tunities to institute simple infection control measures. Antimicro-bial susceptibility data should be presented regularly to cliniciansand should factor into their appropriate selection of antimicrobials.In the event that resources dictate the need to share nonpreservedIV solutions and medications, temporary changes in this practiceduring an outbreak can be effective in preventing further cases.

The outbreak reported here reinforces the need to implementevidence-based infection control guidelines in countries withlimited resources. The loss of life and increased costs associatedwith treating these patients with health careeassociated infectionsoutweigh any perceived benefits derived from hospital policiespromoting the sharing of IV medications and solutions to reducecosts. Increased attention should be given to ensuring safe injectionpractices and limiting sharing of medications and solutionswhenever possible. This can be accomplished by using prefilledsyringes or single-dose vials or dedicating multidose vials toa single patient. Adoption of existing guidelines is essential tominimize medication contamination and ensure patient safety inhealth care facilities around the globe.

Acknowledgment

We thank all of the physicians, residents, and nurses at theNational Hospital of Cuilapa. We especially acknowledge thesupport of Dr. Tegualda Gaette, neonatologist, Dr. Motta, hospitalepidemiologist, and Dra. Margarita Cortes, hospital director. Wealso thank Soledad Reyes and Leticia Ruiz for assistance with datacollection. We acknowledge the scientific contributions of theCenters for Disease Control and Prevention, particularly KateEllingson, Dan Garcia, Alexander Kallen, Brandi Limbago, Jean Patel,and David Lonsway, and the Universidad del Valle, particularlyAleida Roldan, Enio Martinez, and Christopher Bernart.

References

1. Thaver D, Zaidi AK. Burden of neonatal infections in developing countries:a review of evidence from community-based studies. Pediatr Infect Dis J 2009;28(1 Suppl):S3-9.

J. Gray et al. / American Journal of Infection Control 40 (2012) 516-20520

2. Gastmeier P, Loui A, Stamm-Balderjahn S, Hansen S, Zuschneid I, Sohr D, et al.Outbreaks in neonatal intensive care units: they are not like others. Am J InfectControl 2007;35:172-6.

3. Rosenthal VD, Maki DG, Jamulitrat S, Medeiros EA, Todi SK, Gomez DY, et al.International Nosocomial Infection Control Consortium (INICC) report, datasummary for 2003-2008, issued June 2009. Am J Infect Control 2009;38:95-104.

4. Macias AE, Munoz JM, Herrera LE, Medina H, Hernandez I, Alcantar D, et al.Nosocomial pediatric bacteremia: the role of intravenous set contamination indeveloping countries. Infect Control Hosp Epidemiol 2004;25:226-30.

5. Pessoa-Silva CL, Dharan S, Hugonnet S, Touveneau S, Posfay-Barbe K, Pfister R,et al. Dynamics of bacterial hand contamination during routine neonatal care.Infect Control Hosp Epidemiol 2004;25:192-7.

6. Raad I. Gram-negative bacillary bacteremia and intravenous therapy practices.Infect Control Hosp Epidemiol 2004;25:189-91.

7. Zaidi AK, Thaver D, Ali SA, Khan TA. Pathogens associated with sepsis innewborns and young infants in developing countries. Pediatr Infect Dis J 2009;28(1 Suppl):S10-8.

8. Won SP, Chou HC, Hsieh WS, Chen CY, Huang SM, Tsou KI, et al. Handwashingprogram for the prevention of nosocomial infections in a neonatal intensivecare unit. Infect Control Hosp Epidemiol 2004;25:742-6.

9. Ayan M, Kuzucu C, Durmaz R, Aktas E, Cizmeci Z. Analysis of three outbreaksdue to Klebsiella species in a neonatal intensive care unit. Infect Control HospEpidemiol 2003;24:495-500.

10. Brady MT. Health careeassociated infections in the neonatal intensive careunit. Am J Infect Control 2005;33:268-75.

11. Linkin DR, Fishman NO, Patel JB, Merrill JD, Lautenbach E. Risk factors forextended-spectrum b-lactamaseeproducing Enterobacteriaceae in a neonatalintensive care unit. Infect Control Hosp Epidemiol 2004;25:781-3.

12. Singh N. Large infection problems in small patients merit a renewed emphasison prevention. Infect Control Hosp Epidemiol 2004;25:714-6.

13. Fedler KA, Biedenbach DJ, Jones RN. Assessment of pathogen frequency andresistance patterns among pediatric patient isolates: report from the 2004SENTRY Antimicrobial Surveillance Program on 3 continents. Diagn MicrobiolInfect Dis 2006;56:427-36.

14. Qazi SA, Stoll BJ. Neonatal sepsis: a major global public health challenge.Pediatr Infect Dis J 2009;28(1 Suppl):S1-2.

15. Amaya E, Caceres M, Fang H, Ramirez AT, Palmgren AC, Nord CE, et al.Extended-spectrum b-lactamaseeproducing Klebsiella pneumoniae ina neonatal intensive care unit in Leon, Nicaragua. Int J Antimicrob Agents 2009;33:386-7.

16. Gupta A, Della-Latta P, Todd B, San Gabriel P, Haas J, Wu F, et al. Outbreak ofextended-spectrum b-lactamaseeproducing Klebsiella pneumoniae in a neonatal

intensive care unit linked to artificial nails. Infect Control Hosp Epidemiol 2004;25:210-5.

17. Martinez-Aguilar G, Alpuche-Aranda CM, Anaya C, Alcantar-Curiel D, Gayosso C,Daza C, et al. Outbreak of nosocomial sepsis and pneumonia in a newbornintensive care unit by multiresistant extended-spectrum b-lactamaseeproducing Klebsiella pneumoniae: high impact on mortality. Infect Control HospEpidemiol 2001;22:725-8.

18. Moore KL, Kainer MA, Badrawi N, Afifi S, Wasfy M, Bashir M, et al. Neonatalsepsis in Egypt associated with bacterial contamination of glucose-containingintravenous fluids. Pediatr Infect Dis J 2005;24:590-4.

19. Nordmann P, Cuzon G, Naas T. The real threat of Klebsiella pneumoniaecarbapenemase-producing bacteria. Lancet Infect Dis 2009;9:228-36.

20. Sader HS, Biedenbach DJ, Jones RN. Global patterns of susceptibility for 21commonly utilized antimicrobial agents tested against 48,440 Enter-obacteriaceae in the SENTRY Antimicrobial Surveillance Program (1997-2001).Diagn Microbiol Infect Dis 2003;47:361-4.

21. Velasco C, Rodriguez-Bano J, Garcia L, Diaz P, Lupion C, Duran L, et al. Eradi-cation of an extensive outbreak in a neonatal unit caused by two sequentialKlebsiella pneumoniae clones harbouring related plasmids encoding anextended-spectrum b-lactamase. J Hosp Infect 2009;73:157-63.

22. Richards C, Alonso-Echanove J, Caicedo Y, Jarvis WR. Klebsiella pneumoniaebloodstream infections among neonates in a high-risk nursery in Cali,Colombia. Infect Control Hosp Epidemiol 2004;25:221-5.

23. Pegues DA, Arathoon EG, Samayoa B, Del Valle GT, Anderson RL, Riddle CF, et al.Epidemic gram-negative bacteremia in a neonatal intensive care unit inGuatemala. Am J Infect Control 1994;22:163-71.

24. Clinical and Laboratory Standards Institute. Performance standards for anti-microbial susceptibility testing; 19th informational supplement. M100eS19.Wayne [PA]: Clinical and Laboratory Standards Institute; 2009.

25. Maki DG, Martin WT. Nationwide epidemic of septicemia caused by contami-nated infusion products, IV: growth of microbial pathogens in fluids forintravenous infusions. J Infect Dis 1975;131:267-72.

26. Garrett DO, McDonald LC, Wanderley A, Wanderley C, Miller P, Carr J, et al. Anoutbreak of neonatal deaths in Brazil associated with contaminated intrave-nous fluids. J Infect Dis 2002;186:81-6.

27. Lebessi E, Dellagrammaticas H, Tassios PT, Tzouvelekis LS, Ioannidou S,Foustoukou M, et al. Extended-spectrum b-lactamaseeproducing Klebsiellapneumoniae in a neonatal intensive care unit in the high-prevalence area ofAthens, Greece. J Clin Microbiol 2002;40:799-804.

28. Biedenbach DJ, Moet GJ, Jones RN. Occurrence and antimicrobial resistancepattern comparisons among bloodstream infection isolates from the SENTRYAntimicrobial Surveillance Program (1997-2002). Diagn Microbiol Infect Dis2004;50:59-69.