Early detection of the universal bacterial and fungal DNA in late neonatal sepsis

Abstract

Background. Sepsis is the leading cause of neonatao morbidity and mortality in the Neonatal Intensive Care Units of developing countries. Early detection of septicemia will lead to early initiation as well as judicious use of antibiotics in the hype of decreasing nenatal mortality. Objective. To determine the sensitivity and specificity of Polymerase Chain Reaction (PCR) using universal DNA sequences for bacterial and for Candidal species in blood cultures of neonates more than three days old. Methods. Blood samples were drawn for both culture and PCR among 61 newborn infants suspected of sepsis DNA sequences universal for bacterial (16s RNA) and Candidal (ITS) species were amplified. Results. Forty six (75%) neonates had a positive blood culture. PCR amplifying the bacterial DNA had a sensitivity of 79% (95% Cl: 60-92), specificity of 100% (95% Cl: 88-100); Positive Predictive Value (PPV), 100%, and Negative Predictive Value, 84%. All false negative PCR results (n=6) had Pseudomonas culture growths. For Candidal pathogens, PCR had a sensitivity of 95% (95% Cl: 76-100), specificity of 95% (95% Cl: 83-99), PPV of 91%,and NPV of 97%. Conclusions. Although some estimates lack precision, PCR is a good screening tool for neonatal sepsis with its high specificity and sensitivity, NPV, and PPV for both bacterial and Candidal species. Modification of DNA extraction technique may further improve the sensitivity of PCR, especially for Pseudomonas sepsis.