Evaluation of Procalcitonin Test for Early Diagnosis of Neonatal Sepsis in Tikrit Teaching Hospital

Abstract

The diagnosis of neonatal infection is challenging because traditional markers of infectionare often misleading instead of diagnosing. This study was conducted to determine Procalcitonin (PCT)level as an early marker for diagnosis of suspected sepsis in neonates in comparison with C-reactiveprotein, blood culture, total and differential white blood cell counts. From August, 2008 till March,2009, 114 blood samples were collected from neonates (males and females) admitted to the pediatricsneonatalwards at Tikrit Teaching Hospital who were clinically suspected with sepsis as diagnosed bythe physician in the hospital with any features suggestive of sepsis. The results of blood cultureshowed that 53 (46%) of samples were positive, of them 32 (60%) were males and 21 (40%) werefemales. The number of negative cases were 61 (54%), of them 31 (51%) were females and 30(49%)were males. The results of identification showed that the most frequent bacterial isolates wereCoagulase Negative Staphylococci and Nocardia spp. (22% for each), followed by Listeriamonocytogenes 17%, Klebsiella pneumoniae, 9% Pseudomonas aeruginosa 6% and Staphylococcusaureus 6%, while (Citrobacter diversus, Serratia marscesens, Serratia liquifascens, Lactobacillus spp.,Peptostreptococcus spp., Micrococcus spp., Streptococcus pyogenes) were frequently less isolatedrecording 2% for each .The antibiotics susceptibility test revealed that Gram negative isolates showed high resistance toantibiotics used in the present study. Each isolate of the Gram positive bacteria showed differentpattern of resistance against the antibiotics used. Results of virulence factor showed that 85%, 100%,100% , 100% and 62% of Gram negative isolates and 61%, 100% , 89%, 94% and 78% of Grampositive isolated produced Urease , Hemolysin, Lipase, Lecithinase and alkaline protease, respectively.Results of routine hematological tests at which the differences were statistically significant showed that33% of culture positive cases had leucopenia, 19% of cases had leukocytosis, while the rest were in thecategory of normal range. For CRP, the differences were not significant among culture positive andculture negative cases. With reference to PCT test which had been measured using theimmunochromatographic semi-quantitative method. The results showed that 21% of culture positivecases were with PCT level <0.5 ng/ml (which were regarded as negative), while the rest which werewith high levels distributed among levels of PCT≥0.5 ≥2 ≥10 ng/ml. As for culture negative cases, 49%of PCT were <0.5 ng/ml, while 51% of cases were in levels of ≥0.5 ≥2 ≥10 ng/ml which means thatsystemic infections cannot be excluded though they were culture negative. In addition PCT results didnot fit with CRP all the time since some cases recorded higher level of PCT ≥10 ng/ml despite theywere negative for CRP. The comparison between results of PCT and WBC for the same performedcases showed that 68% of cases were in the category of normal WBC range, meanwhile they had highlevel of PCT. Only 18% were in the category of leukocytosis, and the rest of percentage were in thecategory of leucopenia. When PCT was compared with other routinely measured parameters used inthis study, It seemed to be significantly more sensitive in sepsis diagnosis. Accordingly, we canconclude that PCT is a more sensitive marker than other traditional tests (blood culture, CRP and WBCcount) that could be used in early diagnosis of bacterial sepsis in neonates