Neonatal septicaemia remains one of the leading causes of morbidity and mortality both among term and preterm infants.[1] Although advances in neonatal care have improved survival and reduced complications in preterm infants, sepsis still contributes significantly to mortality and morbidity among very-low-birth-weight (VLBW, <1500 g) infants in Neonatal Intensive Care Units (NICUs).[2]

The signs and symptoms of neonatal sepsis are nonspecific.[3] These include fever or hypothermia, respiratory distress including cyanosis and apnea, feeding difficulties, lethargy or irritability, hypotonia, seizures, bulging fontanel, poor perfusion, bleeding problems, abdominal distention, hepatomegaly, gauiac-positive stools, unexplained jaundice, or more importantly, “just not looking right”.[4] Infants with hypoxia–acidosis may gasp in utero and lead to pneumonia and meconium aspiration.[5] 

Definition: National Neonatal Forum of India has defined neonatal sepsis as follows:

Probable (Clinical) Sepsis: In an infant having clinical picture suggestive of septicemia, if there is the presence of any one of the following criteria:

• Existence of predisposing factors: maternal fever or foul-smelling liquor or prolonged rupture of membranes (>24 hrs) or gastric polymorphs (>5 per high power field).

Positive septic screen - presence of two of the four parameters namely, TLC (< 5000/mm), band to total polymorphonuclear cells ratio of>0.2, absolute neutrophil count < 1800/cumm, C-reactive protein (CRP) >1mg/dl and microESR > 10 mm-first hour.

• Radiological evidence of pneumonia.[6]

Culture Positive Sepsis: In an infant having clinical picture suggestive of septicemia, pneumonia or meningitis, if there is presence of either of the following:

• Isolation of pathogens from blood or CSF or urine or abscess (es)
• Pathological evidence of sepsis on autopsy.

Classification

Neonatal sepsis is of two types:

Early onset Sepsis (EOS): Early onset sepsis presents within first 72 hours of life. In severe cases the neonate may be symptomatic in utero(fetal tachycardia, poor beat to beat variability).

Clinically, the neonate usually presents as respiratory distress and pneumonia. Presence of the following risk factors has been associated with an increased risk of EOS:

• Low birth weight (<2500gms) or preterm baby
• Febrile illness in the mother within 2 weeks prior to delivery
• Foul smelling and/or meconium stained liquoramnii.
• Prolonged rupture of membrane (>24 hours).
• More than 3 vaginal examinations during labor.
• Prolonged and difficult delivery with instrumentation.
• Perinatal asphyxia (Apgar score <4 at 1 minute of age) or difficult resuscitation.

Neonates with presence of foul-smelling liquor or three of above-mentioned risk factors should be considered to have EOS & treated with antibiotics.

Presence of ≥2 risk factors should be investigated with sepsis screen and treated accordingly.

Late onset Sepsis (LOS): Late onset sepsis usually presents after 72 hours of age. The source of infection is either nosocomial or community acquired and neonates usually present with septicemia, pneumonia or meningitis.

Risk factors for development of LOS include:

• NICU admission
• Poor hygiene
• Low birth weight (LBW)
• Poor cord care
• Prematurity
• Bottle feeding
• Invasive procedure
• Superficial infection (pyoderma, umbilical sepsis)
• Prelacteal feeding
• Ventilation
• Aspiration of feeds[7]

AIM 

Clinical investigative profile of Neonatal septicaemia and outcome at tertiary care rural hospital

OBJECTIVES

 to study the various clinical features of neonatal septicaemia for its early identification, to study the result of various investigation in identification of early and late onset neonatal septicaemia to identify various factor leading to neonatal septicaemia

A prospective and observational study was carried out Ayaan Institute of Medical Sciences.

Study Population

A total of 130 febrile subjects aged up to 28 days with clinical features such as Babies with birth asphyxia and congenital anomalies were excluded from the study. Informed consent was obtained from parents of the neonates in the study. Detailed maternal, birth, postnatal histories were recorded in a pre-set proforma. The following signs were looked for in the neonates: lethargy, refusal of feeds, respiratory distress (>60/ min), grunt, vomiting, abdominal distension, jaundice, apnoea, seizures, central cyanosis, bradycardia (HR(HR>160/min), hypothermia (rectal temperature 37.5°C), sclerema. All neonates underwent sepsis screen testing that included total leucocyte count, absolute neutrophil count, Immature to total ratio, serum CRP, micro ESR. blood culture and sensitivity was done in all neonates under aseptic precautions as per standard protocol. The neonates were categorised as (a) proven sepsis- blood culture positive and clinical signs and symptoms of sepsis, (b) Probable sepsis- clinical signs and symptoms of sepsis with two or more parameters of sepsis screen positive and no growth in blood culture. All neonates were stabilised and managed as per standard NICU protocols. Data was analysed using descriptive analytical tools.

Sample Collection

One milliliter (mL) of blood samples were collected aseptically by clinicians or trained nurse using sterile syringe and needle by venipuncture and immediately the blood samples were carefully transferred into 9 mL of Brain Heart Infusion (BHI) broth and labeled with the patient’s name, age/sex, identification number, date, and time of collection.

Bacteriological Processing

The BHI broth inoculated with blood sample was transported to the laboratory and incubated at 37°C in aerobic condition. Subcultures were made into sheep blood agar, chocolate agar, and MacConkey agar after overnight of aerobic incubation. Blood agar and MacConkey agar plates were incubated overnight at 37°C in aerobic atmosphere while chocolate agar plates were incubated overnight at 37°C in 5% CO2 atmosphere. Thereafter, culture bottles were observed for turbidity for up to 10 days. Final blind subcultures were done before reporting the sample negative. Growth obtained was identified by standard methods [16]. A purity plate was employed to ensure that the inoculum used for the biochemical tests was pure.

Antibiotic Susceptibility Testing

All the isolates grown were subjected to antibiotic susceptibility testing by modified Kirby-Bauer disk diffusion method in compliance with Clinical and Laboratory Standards Institute (CLSI) guidelines using Mueller-Hinton agar standard media. The inhibition zone standards for antimicrobial susceptibility were considered from tables for interpretative zone diameters of CLSI.[8]

Antibiotic disks (HiMedia Laboratories, Pvt. Limited, India) used were oxacillin (1 μg), erythromycin (15 μg), clindamycin (2 μg), vancomycin (30 μg), teicoplanin (30 μg), penicillin (10 U), cephalexin (30 μg), cotrimoxazole (25 μg), gentamicin (10 μg), amikacin (30 μg), ofloxacin (5 μg), cefixime (5 μg), cefotaxime (30 μg), ceftazidime (30 μg), piperacillin (100 μg), piperacillin-tazobactam (100/10 μg), carbenicillin (100 μg), and ampicillin (10 μg).

Staphylococcus aureus ATCC 25923 and Escherichia coli 25922 were used as a control organisms for antibiotic sensitivity testing.

Gender-Wise Distribution of Cases

Of total 130 enrolled neonates, 68.4% were males and 31.5% were females. Among total enrolled cases, among which EOS was found in 89 (68.4%) neonates while LOS was found in 41 (31.5%) neonates (Table 1).

Table 1: Sex-wise distribution of total and septicaemia cases.

Table 2: Clinical features in neonates.

The clinical signs and symptoms seen in the neonates are shown in Table 2. The most common symptoms seen were lethargy and refusal of feeds in 61.66% and 55.9% respectively, followed by apnoea and respiratory distress in 34.17% and 21.67% respectively. Lethargy, refusal of feeds, apnoea, grunt, respiratory distress and seizures were more common in neonates with proven sepsis than in those with probable sepsis; vomiting and abdominal distension were seen to a greater extent in probable sepsis group than in proven sepsis group.

Isolates Distribution

Among a total of 130 bacterial isolates recovered, 74 (63.8%) were Gram-positive isolates and 42 (36.2%) were Gram-negative isolates. Of total positive cases, CoNS were recovered from nearly half of the cases (46.6%) followed by S. aureus (14.6%), Acinetobacter spp. (9.5%), and Klebsiellapneumoniae (7.7%) whereas viridans streptococci was recovered from a single case. E. coli and Proteus mirabilis were recovered from LOS cases but not from EOS cases while Enterococcus spp., viridans streptococci, and Burkholderia spp. were recovered from EOS case but not from LOS cases (Table 3).

Table 3: Distribution of isolated organisms.

Antibiotic Resistance Characteristics of Isolates Recovered from EOS Septicemia

Vancomycin and colistin showed 100% efficacy against Gram-positive isolates. Most of the Gram-positive isolates were resistant to penicillin, erythromycin, and gentamicin whereas amikacin showed a promising efficacy among tested antibiotics. Among Gram-negative isolates, nearly all the isolates were resistant to ampicillin and most of the isolates were resistant to cefixime and cefotaxime while amikacin, meropenem and linezolid was found to be most effective among tested antibiotics.

Antibiotic Resistance Characteristics of Isolates Recovered from LOS

Of isolates recovered from LOS cases, most of the Gram-positive isolates were resistant to erythromycin, penicillin, and cephalexin while vancomycin and colistin showed 100% efficacy and amikacin showed better efficacy among all the antibiotics tested. Among Gram-negative isolates, nearly all the isolates were resistant to ampicillin whereas nearly all Citrobacter spp. and Proteus mirabilis were susceptible to most of the antibiotic tested. Nearly all isolates of Enterobacter spp., up to 50% E. coli isolates, and 33.3% of the Klebsiella spp. were resistant to most of the antibiotic tested.

Neonatal sepsis remains a dreaded cause of neonatal mortality and morbidity. The blood culture positivity in LOS in the present study was 42.5%, while 57.5% had probable sepsis. Roy et al had a blood culture positivity of 47.5% in their study. [9] In other Indian studies, the blood culture yield has ranged from as low as 25% to as high as 64.87% in neonates with sepsis. [10] Among hospitalised neonates, an incidence of LOS varying between 0.4% to 14.2% has been reported. [11]Tallur et al in their study of neonatal sepsis reported that 16.5% had late onset sepsis. [12]

In the present study, lethargy, refusal of feeds and apnoea were the predominant symptoms noted among neonates with LOS. Kar SS et al in their study in 2013 found apnoea as the most common followed by lethargy and tachycardia in neonates with LOS. [13] Cardiorespiratory signs and jaundice were the most frequent clinical features reported by Tallur SS et al. [12]The signs and symptoms of sepsis are non-specific and demand a high degree of suspicion for early diagnosis. [14]

The commonest organism causing LOS in the present study was Klebsiella followed by Staphylococcus aureus and coagulase negative Staphylococcus. Waters et al in their review of the etiology of community acquired neonatal sepsis in low and middle income countries found Klebsiella to be highly prevalent in South-East Asia. In developing countries, they found potential similarities in major causative organisms between hospital-acquired and community acquired neonatal sepsis. [15]Tallur et al reported also reported Klebsiella species as the most common organism in their study. [12]Vishwanathan R et al in their study in a rural NICU set up, reported 46.3% blood culture positivity with predominant gram negative isolates, Klebsiella being the most common organism followed by E coli. They also noted that profile of organisms causing early and late onset sepsis was similar in their study. [16]

In 2012, Hammoud MS et al in Kuwait reported CONS as the most common causative organism in 35.7% of LOS; Klebsiella was the most common gram negative organism in 18.8% of LOS. [17]Tsai MH et al reported that rates of LOS were inversely proportional to birth weight and gestational age. Increased risk of mortality and morbidity was associated with Pseudomonas and Candida SPP in LOS. [18] CONS account for 35.5% - 47.4% of LOS in some developing nations and a higher percentage in industrial countries. CONS is emerging as the most common causative organism in LOS. As the pattern of isolates in LOS changes over time and regions, this should be regularly re-evaluated to guide management. [19]

The clinical features of neonatal sepsis being non-specific, pose a great challenge for prompt diagnosis. Lethargy, refusal of feeds and apnoea were the most common clinical features  in this study. Klebsiella was the predominant gram negative organism and Staphylococcus aureus and CONS were the predominant gram positive isolates from blood culture in EOS and LOS.

1. Neonatal Group of Chinese Medical Science Branch, Editorial Board of Chinese Journal of Pediatrics, Chinese Medical Association. "Neonatal Sepsis Diagnosis and Treatment Program." Chin J Pediatr, vol. 41, 2003, pp. 897–899.
2. Weston, E. J., et al. "The Burden of Invasive Early-Onset Neonatal Sepsis in the United States, 2005-2008." Pediatric Infectious Disease Journal, vol. 30, no. 11, 2011, pp. 937–941.
3. Chiabi, A., et al. "The Clinical and Bacteriological Spectrum of Neonatal Sepsis in a Tertiary Hospital in Yaoundé, Cameroon." Iranian Journal of Pediatrics, vol. 21, no. 4, 2011, pp. 441–448.
4. Wang, Y., and S. Qian. "Relevant Explanation of the Expert Consensus for Neonatal Sepsis Shock (Infectious Shock)." Chin J Pediatr, vol. 53, 2015, pp. 584-585.
5. Wen, Y., et al. "Diagnostic Value of Combined Detection of Serum PCT and CRP in Patients with Sepsis." Exp Lab Med, vol. 34, 2016, pp. 231–233.
6. Fan, H., X. Han, and X. Yin. "Research Progress of Neonatal Sepsis." Chin Pediatric Emerg Med, vol. 21, 2014, pp. 539–542.
7. Angus, D. C., et al. "Epidemiology of Severe Sepsis in the United States: Analysis of Incidence, Outcome, and Associated Costs of Care." Critical Care Medicine, vol. 29, no. 7, 2001, pp. 1303–1310.
8. Martin, G. S., D. M. Mannino, and M. Moss. "The Effect of Age on the Development and Outcome of Adult Sepsis." Critical Care Medicine, vol. 34, no. 1, 2006, pp. 15–21.
9. Goldstein, B., B. Giroir, and A. Randolph. "International Pediatric Sepsis Consensus Conference: Definitions for Sepsis and Organ Dysfunction in Pediatrics." Pediatric Critical Care Medicine, vol. 6, no. 1, 2005, pp. 2–8.
10. Jiang, Y. "Progress in Diagnosis and Treatment of Neonatal Septicemia." Chin J Neonatol, vol. 25, 2010, p. 60.
11. Carvalho, P. R. A., et al. "Prevalence of Systemic Inflammatory Syndromes at a Tertiary Pediatric Intensive Care Unit." Jornal de Pediatria, vol. 81, no. 2, 2005, pp. 143–148.
12. Drassinower, D., et al. "Prolonged Latency of Preterm Premature Rupture of Membranes and Risk of Neonatal Sepsis." American Journal of Obstetrics and Gynecology, vol. 214, no. 6, 2016, pp. 743–743.e6.
13. Srinivasa, S., and D. Arunkumar. "Bacterial Isolates and Their Antibiotic Susceptibility Patterns in Neonatal Sepsis." Current Pediatric Research, vol. 18, no. 2, 2014, pp. 83–86.
14. Behnes, M., et al. "Diagnostic and Prognostic Utility of Soluble CD14 Subtype (Presepsin) for Severe Sepsis and Septic Shock During the First Week of Intensive Care Treatment." Critical Care, vol. 18, no. 5, 2014, article no. 507.
15. Liu, B., et al. "Role of Presepsin (sCD14-ST) and the CURB65 Scoring System in Predicting Severity and Outcome of Community-Acquired Pneumonia in an Emergency Department." Respiratory Medicine, vol. 108, no. 8, 2014, pp. 1204–1213.
16. Leante-Castellanos, J. L., et al. "The Value of Lipopolysaccharide Binding Protein for Diagnosis of Late-Onset Neonatal Sepsis in Very Low Birth Weight Infants." Journal of Perinatal Medicine, vol. 43, no. 2, 2015, pp. 253–257.
17. Wu, Y. "Distribution and Drug Resistance of Pathogenic Bacteria in Blood Culture of Children." Chin J Nosocomiology, vol. 16, 2006, pp. 463–465.
18. Chen, X., and C. Jiang. "Research Progress on Diagnostic Index of Bacterial SIRS in Newborns." Int J Pediatr, vol. 40, 2013, pp. 148–151.
19. Li, M., L. Dong, and X. Cui. "The 13-Year Changes of Blood Cultures in Children with Septicemia and the Results of Drug Sensitivity Test." J Clin Pediatr, vol. 21, 2003, pp. 85–90.