ARTÍCULOS ORIGINALES

The microbiology of neonatal sepsis in a rural Ecuadorian hospital

Lider Pico Menendez [1], Danny Larco[1], David Gaus[2]

1. Hospital Hesburgh, Ecuador
2. Andean Health and Development, Estados Unidos

Doi: https://doi.org/10.16921/pfr.v9i3.331

PRÁCTICA FAMILIAR RURAL│Vol.9│No.3│Noviembre 2024│Recibido: 23/09/2024│Aprobado: 01/11/2024

Compartir en:

. .

Abstract

Introduction: Neonatal sepsis continues to be a public health problem in Latin America. This study aims to describe the bacterial causes of early and late onset neonatal sepsis in a neonatal ICU in a rural hospital in Ecuador.
Methods: A descriptive, retrospective study was conducted using the hospital electronic medical record (EMR) from and all neonates diagnosed with neonatal sepsis were included in this study
Results: 74 neonates were included in the study. Seventeen (17) were characterized as neonatal sepsis within the first week of life (early onset neonatal sepsis) and 57 neonates were diagnosed as late onset neonatal sepsis. Staphylococcus epidermidis and Klebsiella pneumoniae were the most common cause of early onset and late onset neonatal sepsis, respectively.
Conclusions: The most common bacterial causes of neonatal sepsis in this study are distinct from those causes described in the United States. This could influence empiric initial antibiotic therapy decisions and other preventive measures if larger studies demonstrate similar results.

Keywords: neonatal sepsis, infection, Ecuador, rural hospital, microbiology

La microbiología de la sepsis neonatal en un hospital rural ecuatoriano

Resumen

Introducción: La sepsis neonatal continúa siendo un problema de salud pública en América Latina. Este estudio tiene como objetivo describir las causas bacterianas de sepsis neonatal de inicio temprano y tardío en una UCI neonatal en un hospital rural en Ecuador.
Métodos: Se realizó un estudio descriptivo, retrospectivo utilizando la historia clínica electrónica (HCE) del hospital y se incluyeron todos los neonatos diagnosticados con sepsis neonatal.
Resultados: Se incluyeron 74 neonatos en el estudio. Diecisiete (17) fueron caracterizados como sepsis neonatal dentro de la primera semana de vida (sepsis neonatal de inicio temprano) y 57 neonatos fueron diagnosticados como sepsis neonatal de inicio tardío. Staphylococcus epidermidis y Klebsiella pneumoniae fueron las causas más comunes de sepsis neonatal de inicio temprano y de inicio tardío, respectivamente.
Conclusiones: Las causas bacterianas más comunes de sepsis neonatal en este estudio son distintas de las causas descritas en los Estados Unidos. Esto podría influir en las decisiones empíricas sobre el tratamiento antibiótico inicial y otras medidas preventivas si estudios más amplios demuestran resultados similares.

Palabras clave: sepsis neonatal, infección, Ecuador, hospital rural, microbiología

 

Introducción

Neonatal infections, including neonatal sepsis, refer to disease caused by the infection of pathogenic microorganisms in newborns. These organisms include bacteria, virus, and fungi. The mechanism of neonatal susceptibility to infection has been studied extensively. Neonatal immature immunity seen particularly in preterm neonates compared to term newborns appears to be implicated, along with environmental exposure such as maternal exposure to infectious disease and bacterial colonization.1 Neonatal sepsis is one of the major causes of mortality in pediatrics.2  Globally, more than 500,000 neonates die each year from sepsis.3 Sub-Saharan Africa and South Asia had the highest burden of neonatal sepsis in 2016.4 A 2023 study of neonatal sepsis showed that age-standardized incidence rates of neonatal sepsis and other neonatal infections were highest in the Andean Region of South America.5

Neonatal sepsis has been divided into early-onset (less than 7 days) and late-onset (greater than 7 days). The pathophysiology of early-onset neonatal sepsis is distinct from late-onset, and includes very low birth weight, vertical maternal transmission, Group B Streptococcus colonization, and lack of intrapartum antibiotic prophylaxis.6 Late-onset neonatal sepsis pathophysiology includes low birth weight, prematurity, parenteral feeding, central venous catheters, and nosocomial infections.7

None of the current biomarkers have sufficient sensitivity and specificity to replace blood cultures as the gold standard for neonatal sepsis. However, there are significant clinical challenges around ill-appearing newborns with negative blood cultures.8

The microbiology of early-onset neonatal sepsis includes Streptococcus agalactiae [Group B Strep (GBS)], Escherichia coli, Listeria monocytogenes, non-Enterococcal Group D streptococcus, Staphylococcus aureus, Streptococcus viridans, Enterococcus, Acinetobacter baumannii.

The pathogens of late-onset neonatal sepsis include KJebsiella pneumonia, Acinetobacter baumannii, gram negative bacteria, coagulase-negative staphylococci. Viruses, Fungi (Candida).

To prevent severe complications and death, preventive measures, early diagnosis, and appropriate antibiotic administration are critical. Primary Care Physicians in rural Latin America are frequently confronted with febrile newborns and are responsible for initial management of neonatal sepsis. Multiple factors in the health system are necessary for appropriate care of a neonatal with sepsis and mortality is highest in low-income and middle-income countries.9 An understanding of the likely pathogens informs the decision around empiric antimicrobial therapy.

The objective of this study is to determine the microbiological causes of neonatal sepsis at a rural neonatal intensive care unit in Ecuador, South America.

Methodology

Hospital Hesburgh is a 55-bed hospital in the city of Santo Domingo, Ecuador. A 10-unit neonatal intensive care unit staffed with neonatologists receives patients transferred from the public health system from around the region. As part of a high-risk obstetrics service at Hesburgh Hospital, newborns are also managed following maternal care. 

A descriptive, retrospective study was conducted using the hospital electronic medical record (EMR) from all neonates diagnosed with neonatal sepsis were included in this study. Inclusion criteria were newborns between 1-28 days of life, an established diagnosis of neonatal sepsis, and a positive blood culture to determine etiology.

Results

A total of 74 neonates were included in the study. Seventeen (17) were characterized as neonatal sepsis within the first week of life (early onset neonatal sepsis) and 57 neonates were diagnosed as late onset neonatal sepsis.

Staphylococcus no aureus (coagulase negative, generally S. epidermidis) was responsible for the greatest number of cases (41.2%) of early onset neonatal sepsis (Figure 1). Other microbiological etiologies included K. pneumoniae, S. aureus, Enterococcus sp., E. coli, and S. agalactiae (Streptococcus Grupo B).

Figure 1. Microbiological causes of early onset neonatal sepsis

A much greater number of cases of neonatal sepsis identified in the study were late onset neonatal sepsis. Of the fifty-seven (57) positive blood cultures in this group, K. pneumoniae was the most common bacteria isolated with twenty-six (26) cases (figure 2).  Other causes included S. aureus, S. no aureus, Enterococcus spp., E. coli, and Streptococcus agalactiae.

Figure 2. Microbiological causes of late onset neonatal sepsis

Discussion

In the United States, the two most common causes of early onset neonatal sepsis are Streptococcus agalactiae (Group B Strep) and E. coli.10 However Group B Strep sepsis is decreasing due to preventive measures such as maternal prenatal genital cultures looking for colonization and intrapartum antibiotic therapy. In the current retrospective study, Group B Strep was an uncommon cause of early neonatal sepsis, despite an absence of preventive measures as seen in the United States. Furthermore, E. coli in this study was also an uncommon cause of early neonatal sepsis, distinct from what has been observed in the United States.

Although a very small, focused population, this current study would suggest that preventive measures for Group B Strep early neonatal sepsis might not be warranted in Ecuador. Certainly, larger studies are required to determine if the low incidence of Group B Strep neonatal early sepsis is a national phenomenon.
With Staphylococcus (aureus and coagulase negative), Klebsiella pneumoniae, and Enterococcus spp as the leading causes of early neonatal sepsis in this hospital, antibiotic sensitivity patterns of these organisms require further analysis to determine if traditional empiric antimicrobial therapy, Ampicillin and Gentamicin, remain appropriate first line treatments.

The most common causes of late onset neonatal sepsis in the United States are coagulase negative Staphylococcus (S. epidermidis), gram negative bacilli (E. coli, Klebsiella pneumoniae, Enterobacter spp, Pseudomonas spp), and in some regions, Candida spp.11 In our study, gram negative bacilli were much more frequent than S. epidermidis as causes of late onset neonatal sepsis. S. epidermidis is less virulent than gram negative bacilli but is associated with cognitive and visual impairment and cerebral palsy, particularly in extremely low-birth weight neonates.12

Conclusion
The most common causes of bacterial early onset neonatal sepsis in this hospital neonatal ICU were Staphylococcus epidermidis, K. pneumoniae, S. aureus, Enterococcus sp., E. coli, and S. agalactiae (Group B Streptococcus). However, E. coli and Group B Streptococcus were a much less common etiology compared to early onset neonatal sepsis causes in the United States. Furthermore, gram negative bacilli were the predominant cause of late onset neonatal sepsis in this study compared to S. epidermidis that predominates in the United States. 
This study would suggest that careful consideration should be given around recommendations in Ecuador to implement broad scale preventive measures against Group B Streptococcus infections in neonates given its lower incidence. If these results were reproduced at a broader, national level, antibiotic sensitivity of these organisms should be studied to determine the most effective, empiric, initial antibiotic therapy for these neonates.

Referencias

2 Kim F, Polin RA, Hooven TA. Neonatal sepsis. Br Med J. (2020) 371:m3672. doi: 10.1136/bmj.m3672

3 Lawn JE, Blencowe H, Oza S, You D, Lee ACC, Waiswa P, et al. Every Newborn: Progress, priorities, and potential beyond survival. Lancet. (2014) 384:189–205. doi: 10.1016/S0140-6736(14)60496-7

4 Chaurasia S, Sivanandan S, Agarwal R, Ellis S, Sharland M, Sankar MJ. Neonatal sepsis in South Asia: Huge burden and spiralling antimicrobial resistance. Br Med J. (2019) 364:k5314. doi: 10.1136/bmj.k5314

5 Li J, Shen L, Qian K. Global, regional, and national incidence and mortality of neonatal sepsis and other neonatal infections, 1990-2019. Front. Public Health. (2023) 11:1139832.doi: 10.3389/fpubh.2023.1139832

6 Antibiotic regimens for early-onset neonatal sepsis. Korang SK, Safi S, Nava C, et al. Cochrane Database Syst Rev. 2021;5:0.

7  Pathophysiology of neonatal sepsis. Wynn JL, Wong HR. Fetal Neonatal Physiol. 2017;2:1536–1552.

8 Celik IH et al. What Are the Cut-Off Levels for Il-6 and Crp in Neonatal Sepsis? J Clin Lab Anal 24, 407–412 (2010).

9 Neonatal sepsis and mortality in low-income and middle-income countries from a facility-based birth cohort: an international multisite prospective observational study. Milton R, Gillespie D, Dyer C, et al. Lancet Glob Health. 2022;10:0–72.

10 Centers for Disease Control, USA: Early onset neonatal sepsis surveillance and trends. https://www.cdc.gov/abcs/reports/neonatal-sepsis.html

11 Dong Y, Speer CP. Late-onset neonatal sepsis: recent developments. Arch Dis Child Fetal Neonatal Ed. 2015 May;100(3):F257-63. doi: 10.1136/archdischild-2014-306213. Epub 2014 Nov 25. PMID: 25425653; PMCID: PMC4413803.

12 Stoll BJ, Hansen NI, Adams-Chapman I, et al. . Neurodevelopmental and growth impairment among extremely low-birth-weight infants with neonatal infection. JAMA 2004;292:2357–65.