A Study on Neonatal Septicemia and Evaluation of a Rapid Test for Early Diagnosis of Neonatal Sepsis.

INTRODUCTION: Sepsis is the commonest cause of neonatal mortality: it is responsible For about 30 – 50 % of the total neonatal deaths in developing countries. It is Estimated that up to 20% of neonates develop sepsis and approximately 1 % Die of sepsis related causes. Sepsis related mortality is largely preventable With rational antimicrobial therapy and aggressive supportive care. Neonatal sepsis is a clinical syndrome characterized by signs and Symptoms of infection with or without accompanying bacteremia in the first 30 days of life. It encompasses various systemic infections of the newborn Such as septicemia, meningitis, pneumonia, arthritis, osteomyelitis and Urinary tract infections. Superficial infections like conjunctivitis and oral Thrush are not usually included under neonatal sepsis. The incidence of neonatal sepsis according to the data from national Neonatal perinatal database (nnpd, 2002-03) is 30 per 1000 live birth. Among intramural births, klebsiella pneumoniae was the most frequently Isolated pathogen (32.5%) followed by staphylococcus aureus (13.6%). Among extramural neonates (referred from community/other hospitals) Klebsiella pneumoniae was again the commonest organism (27%) followed By staphylococcus aureus (15%) and pseudomonas (13%). Through the years, there has been a shift in the microorganisms Responsible for neonatal septicemia. During the 1930’s group a Streptococcus were the predominant organisms. In the 1950’s staphylococci (largely of phage group i) became a major cause of nursery outbreaks Throughout the world. Pseudomonas was predominant during the same Decade, perhaps because of the introduction of respiratory support systems. From the late 1950’s onwards e. Coli has been an important cause of Neonatal sepsis. Finally both group d streptococci and klebsiella have been Relatively recent pathogens, the latter accounting for a high proportion of Antibiotic- resistant organisms that colonize and infect babies in neonatal Intensive care units (goldman et al, 1978). The prevalence rates for a Specific bacterial pathogen vary from nursery to nursery and may change Abruptly in any one unit. The group b streptococcus is the most common gram positive Organism causing septicemia during the first month of life. Vertical Transmissions from mother to infant are the most common route of infection. The incidence of group b streptococcal disease has varied widely from Place to place and from year to year. Group a streptococcal disease is not as Common now as in previous decades. Group d streptococci include the Enterococci and several other species particularly s.bovis, which have been Found in neonatal infection. In the 1950s phage group i staphylococcus aureus was the most Common bacterial agent causing septicemia in neonatal units. More recently, Coagulase positive staphylococcus disease in nurseries has been caused by Organisms of the phage ii group. Coagulase negative staphylococci may be identified in blood Cultures of babies and are frequently dismissed as contaminants. Repeated Isolation of the organism from blood associated with clinical signs of Septicemia should alert the physician to its pathogenic role coagulase Negative staphylococci are frequently, but not always associated with Arterial or venous catheters or ventriculoperitoneal shunts. Eradication of Infection requires removal of the catheter or prosthesis as well as appropriate Antibiotic therapy. E. Coli are the most common gram negative bacteria causing Septicemia during the neonatal period. Approximately 40% of e.coli strains Causing septicemia possess k 1 capsular antigen and strains identical with That in blood can usually be identified in the patient’s nasopharynx or rectal Cultures. The neonate who receives broad spectrum antibiotics while in an Environment potentially contaminated by “water-bugs” (respirators, moist Oxygen) is likely to develop disease caused by pseudomonas species. Klebsiella is the most common bacterial pathogen causing neonatal Sepsis. A high proportion of antibiotic – resistant organisms that colonize And infect babies in neonatal intensive care units are klebsiella species. Among the enterobacter species enterobacter aerogenes, e. Cloacae, e. Sakazakii and e.bormaechei have caused sepsis and a severe form of Necrotizing meningitis in neonates. Contaminated infant formula has been Identified as a source of infection. Parenteral nutrition and bladder Catheterization are identified as risk factors. Citrobacter is an occasional Inhabitant of git and are responsible for disease in neonates and Immunocompromised patients. It causes sporadic and epidemic neonatal Sepsis and meningitis. Neisseria meningitidis, haemophilus influenzae and streptococcus Pneumoniae are relatively uncommon in neonates. S.pneumoniae cause early Onset sepsis that mimic neonatal disease caused by group b. Streptococci. Most people exposed to listeria monocytogenes do not develop illness, but The pregnant women may suffer pregnancy loss and the neonate may Develop sepsis and meningitis. Inhalation of infected amniotic fluid may produce pneumonia and Sepsis in utero, manifested by fetal distress or neonatal asphyxia. Exposure To pathogens at delivery and in the nursery or community is the mechanism Of infection after birth. The physiologic manifestations of the inflammatory Response are mediated by a variety of proinflammatory cytokines, Principally tumor necrosis factor (tnf), inter leukin – 1 (il-1) and il-6 And byproducts of activation of the complement and coagulation systems. Elevated levels of il-6, tnf and platelet activating factor have been Reported in new born infants with neonatal sepsis. Il-6 is the cytokine most Often elevated in neonatal sepsis. Neonatal sepsis can be classified into two major categories depending Up on the onset of symptoms. 1. Early onset of sepsis (eos) presents within the first 72 hours of life. In Severe cases, the neonate may be symptomatic at birth. Infants with eos Usually present with respiratory distress and pneumonia. The source of Infection is generally the maternal genital tract. Some maternal / perinatal Conditions have been associated with an increased risk of eos. Knowledge About these potential risk factors would help in early diagnosis of sepsis. Based on the studies from india, the following risk factors seem to be Associated with an increased risk of early onset sepsis; low birth weight and Prematurity, intrapartum sepsis, rupture of membranes > 24 hrs, prolonged Labor, perinatal asphyxia and foul smelling and/or meconium stained liquor. Presence of foul smelling liquor or three of the mentioned risk factors Warrant initiation of antibiotic treatment. Infants with two risk factors should Be investigated and then treated accordingly. 2. Late onset sepsis (los) presents after 72 hours of age. The source of Infection in los is either nosocomial (hospital acquired) or community Acquired and neonates usually present with septicemia, pneumonia or Meningitis. Various factors that predispose to an increased risk of Nosocomial sepsis include low birth weight, prematurity, admission in Intensive care unit, mechanical ventilation, invasive procedures, Administration of parenteral fluids, and use of stock solutions. Factors that Might increase the risk of community –acquired los include poor hygiene, Poor cord care, bottle feeding, and prelacteal feeds. In contrast, Breastfeeding helps in prevention of infections. The earliest signs of sepsis are often subtle and nonspecific; indeed a High index of suspicion is needed for early diagnosis. Neonates with sepsis May present with one or more of the following symptoms and signs such as Hypothermia or fever, lethargy, poorcry, refusal to suck, poor perfusion, Hypotonia, absent neonatal reflexes, brady / tachycardia, respiratory Distress, apnea and gasping respiration, hypo/hyperglycemia and metabolic Acidosis. A predominance of male infants is apparent in almost all studies of Sepsis in the new born but not among infants infected in utero. The usual Male predominance in neonatal sepsis has suggested the possibility of a sex Linked factor in host susceptibility. A gene located on the x chromosome And involved with function of the thymus or with synthesis of Immunoglobulins has been postulated. The female has double the number of Genes affecting these factors and thus might posses a greater resistance to Infection. Since treatment should be initiated in a neonate suspected to have Sepsis without any delay, only minimal and rapid investigations should be Undertaken. Blood culture is the gold standard for diagnosis of septicemia and Should be performed in all cases of suspected sepsis prior to starting Antibiotics. A positive blood culture with sensitivity of the isolated organism Is the best guide to antimicrobial therapy. Therefore it is very important to Follow the proper procedure for collecting a blood culture. The resident Doctor/ staff should wear sterile gloves prior to the procedure and prepare a Patch of skin approx. 5-cm in diameter over the proposed veni-puncture site. This area should be cleansed thoroughly with alcohol, followed by Povidone- iodine, and followed again by alcohol. Povidone-iodine should be Applied in concentric circles moving outward from the centre. The skin Should be allowed to dry for at least 1 minute before the sample is collected. One-ml sample of blood should be adequate for a blood culture bottle Containing 5-10ml of culture media. Since samples collected from Indwelling lines and catheters are likely to be contaminated, cultures should Be collected only from a fresh veni-puncture site. Many laboratories use their bactec system which measures the Production of carbon-dioxide by metabolizing organisms. Semi-automated And fully automated blood culture systems are available. These advanced Techniques can detect bacteria at a concentration of 1-2 cfu/ml within 12 – 24 hours. Lysis direct plating consists of lysis of 0.5 to 1.5 ml of blood in a Tube containing a cell membrane active lysis agent followed by direct Inoculation of 0.25 ml amounts to one or more agar plates. Positive cultures Are recognized by growth on agar and provide a rapid means to obtain Quantitative blood culture results from pediatric patients. Sucrose 10% to 30% is used as an osmotic stabilizer. Sucrose is especially helpful in dealing With bacteria that have undergone cell wall damage to some extent and the Resultant hypertonicity counteracts the normal bactericidal effect of blood. Growth of cell wall deficient bacteria (e.g., antibiotic damaged organisms, Mycoplasma) may be enhanced by adding osmotic stabilizers like sucrose, Mannitol or sorbose to create a hyperosmotic medium. Rapid diagnosis of Bacteremia in infants can be done by examining a gram stained smear of the Plasma buffy coat layer, obtained by centrifuging anticoagulated capillary Blood. All neonates suspected to have sepsis should have a septic screen to Corroborate the diagnosis. The various components of the septic screen Include total leukocyte count, absolute neutrophil count, immature to total Neutrophil ratio, micro-erythrocyte sedimentation rate and c reactive Protein. The absolute neutrophil count varies considerably in the immediate Neonatal period. The lower limit for normal total neutrophil counts in the Newborn begins at 1800/cmm, rises to 7200/cmm at 12 hours of age and then Declines and persists at 1800/cmm after 72 hours of age. The ratio of Immature to total neutrophils (i/t ratio) is lesser than or equal to 0.16 at Birth and declines to a peak value of 0.12 after 72 hours of age. Presence of Two abnormal parameters in a screen is associated with a sensitivity of 93- 100%, specificity of 83%, positive and negative predictive values of 27% And 100% respectively in detecting sepsis. Hence, if two (or more) Parameters are abnormal, it should be considered as a positive screen and the Neonate should be started on antibiotics. C- reactive protein is a nonspecific acute phase protein that rises in Response to infectious and noninfectious inflammatory processes. It is Synthesized by hepatocytes. Good evidence exists to support the use of crp Measurement in conjunction with other established diagnostic tests (wbc Count, differential count and blood culture) to establish or exclude the Diagnosis of sepsis in full term or near term infants. The three clinical laboratory methods namely 1. Qualitative test, 2. Semi-qualitative test and 3. Quantitative test are carried out to measure Serum crp levels. The qualitative latex agglutination test can be performed rapidly at the Bedside within 10 – 15 minutes. A positive qualitative crp test should Always be followed by a semi-quantitative test which is a more sensitive Measuring method to quantify the concentration of crp. The semiquantitative Latex agglutination assay involves the use of serial dilutions of Serum with saline. Each dilution of serum is mixed with a latex reagent and Observed for agglutination. The highest dilution in which agglutination is Visualized corresponds to an approximate titre or concentration of crp – Ligand complexes. The quantitative immuno assay is the most rapid Sophisticated sensitive method of detecting and measuring crp. The elisa And immunofluorescence test are used in quantitative immuno assay. Increased crp levels can occur in infants for upto three days of life From non-infectious causes. Maternal fever, prom, fetal distress, Pneumothorax and meconium aspiration pneumonitis could cause elevated Crp levels. The crp levels do not always rise above 10 mg / lit in preterm infants Or those infants with overwhelming sepsis, resulting in a false negative test Result. Procalcitonin is a 116 aminoacid peptide that has an approximate Mw of 14.5 kda and belongs to the calcitonin super family of peptides. Its Level increases significantly in severe systemic infections, as compared to Other parameters of microbial infection. The short half- life (25-30 hours in plasma) of pct, coupled with its Virtual absence in health and specificity for bacterial infections, gives it a Clear advantage over the other markers of bacterial infection. Studies have Also shown that an increase in pct levels is minimal in viral infections While levels increase rapidly after a single injection with endotoxin. Increased pct levels comparable to what is observed in severe sepsis were Also seen in addisonian crisis, transplant patients receiving t-cells antibody Therapy. The incidence of meningitis in neonatal sepsis has varied from 0.3- 3% in various studies. Lumbar puncture is indicated in the presence of a Positive blood culture or if the clinical picture is consistent with septicemia. Chest x-ray should be considered in the presence of respiratory Distress or apnea. An abdominal x-ray is indicated in the presence of Abdominal signs suggestive of necrotizing enterocolitis (nec). Neurosonogram and computed tomography (ct scan) should be performed In all patients diagnosed to have meningitis. In early onset sepsis, urine cultures have a low yield and are not Indicated. Urine cultures obtained by suprapubic puncture or bladder Catheterization have been recommended in all cases of los. Adequate and proper supportive care is crucial in a sick neonate with Sepsis. He/she should be nursed in a thermo-neutral environment taking care To avoid hypo/hyperthermia. Oxygen saturation should be maintained in the Normal range; mechanical ventilation may have to be initiated if necessary. If the infant is hemodynamically unstable, intravenous fluids should be Administered and the infant is to be monitored for hypo/hyperthermia. There Cannot be a single recommendation for the antibiotic regimen of neonatal Sepsis for all settings. The choice of antibiotics depends on the prevailing flora in the given Unit and their antimicrobial sensitivity. Decision to start antibiotics is based Upon the clinical features and / or a positive septic screen. However duration Of antibiotic therapy is dependent upon the presence of a positive blood Culture and meningitis. Sadana et al., (1997), have evaluated the role of double volume Exchange transfusion in septic neonates with sclerema and demonstrated a 50% reduction in sepsis related mortality in the treated group. Non-specific Pooled intravenous immuno globulin has not been found to be useful. Treatment with granulocyte - macrophage colony stimulating factor (gm – Csf) is still on experimental stage. Aggressive management of suspected maternal chorioamnionitis with Antibiotic therapy during labor along with rapid delivery of the infant Reduces the risk of early – onset neonatal sepsis. Vertical transmission of Group b streptococcal sepsis is significantly reduced by selective Intrapartum chemoprophylaxis. Principles for the prevention of nosocomial infection include Adherence to universal precautions with all patient contact, avoiding nursery Crowding, strict compliance with hand washing, meticulous neonatal skin Care, minimizing the risk of catheter contamination, decreasing the number Of veni-punctures and mechanical ventilation days and providing education And feedback to nursery personnel. This study is aimed at finding a technically easy, rapid and sensitive Test that would help reduce turn around time and enable early initiation of Appropriate management. Aim and objectives: The study on neonatal septicemia and Evaluation of a rapid test for early Diagnosis of neonatal sepsis was done at Government rajaji hospital (grh) for a period of one year from June 2009 to may 2010. The study was aimed 1. To know the prevalence of neonatal septicemic cases at Government rajaji hospital, madurai according to the A) age B) sex C) place of birth. 2. To know the risk factors involved in neonatal sepsis. 3. To know the common clinical features of neonatal sepsis. 4. To evaluate a rapid, easily available and non laborious test For the early diagnosis of neonatal septicemi