Utility of IRIDICA rapid microbial screening in newborn infections
Research type
Research Study
Full title
Utility of use of IRIDICA rapid microbial screening in early onset infection in newborn
IRAS ID
184196
Contact name
Ajay Sinha
Contact email
Sponsor organisation
Barts Health NHS trust
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Early onset sepsis is an important cause of morbidity and mortality in newborn infants. The clinical problems encountered in newborns requiring admission to neonatal unit are often evaluated for infection and this may be about 10% of all live births. These investigations generally include FBC, CRP and blood cultures. Only a minority of these infants have positive blood cultures and length of antibiotics is often determined on the basis of initial clinical symptoms, clinical response and changes in inflammatory markers. Unfortunately current investigations for sepsis have limitations and have modest sensitivity and specificity for detection of sepsis.
There are consequences of both accurate and inaccurate diagnoses for babies with early onset sepsis. Early and appropriate treatment for babies who truly have sepsis is vital but inaccurate diagnosis (false positive results) or overtreatment would cause unnecessary exposure to antibiotics, hospital stay, anxiety to families and risk of increased antibiotics resistance. Prolonged empirical exposure to antibiotics in preterm infants has been shown to be associated with combined increased risk of necrotizing enterocolitis, late onset sepsis and deaths. Delayed or missed identification and treatment of early onset sepsis in babies who truly have infection can have devastating consequences.
IRIDICA allows rapid identification (within 6-8 hours) of micro-organisms in a sample whereas culture based technology can take up to 48 hours. A recent study in newborns showed that blood samples volume of 0.5 ml allowed bacterial identification with 97% specificity.
Aim: To assess the utility of IRIDICA for diagnosis of infection in blood samples in newborn in comparison with blood culture
To prospectively evaluate if using this method can limit length of use of antibiotics and therefore reduce the length of stay.Lay Summary of Results
Fifty-four infants born at > 34 weeks’ gestational age were enrolled in the study. Forty-three (80%) infants had one or more perinatal risk factors for early-onset infection. The most common risk factors were: premature rupture of membranes (n=36, 67%), parenteral antibiotics given to mother (22, 41%) and intrapartum fever or chorioamnionitis (n = 18, 33%). The common symptoms suggestive of infection in this cohort were: respiratory distress before 4 hours of age (n=21, 38.9%), hypoxia (n=12, 22.2%), jaundice within 24 hours of birth (n=8, 14.8%) and metabolic acidosis with base deficit of greater than 10 mmol/l (n=7, 13%). There were 36 (67%) infants with one or more symptoms of infection. All these infants survived to discharge.
Only one infant in this cohort had a positive blood culture growth of group B streptococcus, whereas 10 infants had bacterial DNA identified by IRIDICA in blood. Bacterial DNA identified by PCR/ESI MS were; Group B Streptococcus 3, Sneathia 1 and propionobacterium 6. All infants with no bacterial DNA detected on PCR/ESI-MS had a negative blood culture result. Infants with bacterial DNA detected by IRIDICA has higher initial C-reactive protein levels and higher C-reactive protein levels at 18-24 hours after birth and higher maximum C-reactive protein levels. Of the 29 neonates with raised maximum CRP of >5 mg/L, 9 (31%) had bacterial DNA detected in the blood sample while only one had bacterial growth on blood culture. Of the 25 neonates with persistently low CRP (<5 mg/L), 24 (96%) had no bacteria detected in the blood using PCR/ESI MS.
PCR/ESI-MS had a high sensitivity of 100%, specificity of 83% and negative predictive value of 100% for diagnosis of Early onset sepsis.Has the registry been updated to include summary results?: No
If yes - please enter the URL to summary results:
If no – why not?: Not applicable
Did you follow your dissemination plan submitted in the IRAS application form (Q A51)?: Yes
If yes, describe or provide URLs to disseminated materials: The study has been presented in international meetings.
Arikana Massiah, Anja Saso, Adela Alcolea-Medina, Priyen Shah, Angela Whiley, Ajay Sinha, Mark Wilks, Michael Millar. Utility of the IRIDICA rapid microbial screening assay in early-onset neonatal infection. Abstract number: 6724, 27th European Congress of Clinical Microbiology and Infectious Diseases, Vienna, Austria.Anja Saso, Arikana Massiah, Priyen Shah, Saba Sheikh, Mark Wilks, Michael Millar, Ajay Sinha. Bacterial detection in blood using IRIDICA in babies with suspected early onset infection: Clinical correlations. ESP17-1201, Page 436, 35th Annual Meeting, European Society of Paediatric Infectious Diseases, Madrid Spain. https:// ESPID-2017-Abstracts.pdf?_ga=2.25308728.424361710.1734006191-992776998.1734006191
The study is currently being submitted for publication.
If pending, date when dissemination is expected:
If no, explain why you didn't follow it:
Have participants been informed of the results of the study?: Pending
If yes, describe and/or provide URLs to materials shared and how they were shared:
If pending, date when feedback is expected: 30/06/2025
If no, explain why they haven't:
Have you enabled sharing of study data with others?: No
If yes, describe or provide URLs to how it has been shared:
If no, explain why sharing hasn't been enabled: The technology that was used for bacterial detection has been decommissioned
Have you enabled sharing of tissue samples and associated data with others?: No
If yes, describe or provide a URL:
If no, explain why: There are no tissue samplesREC name
London - Surrey Borders Research Ethics Committee
REC reference
15/LO/1933
Date of REC Opinion
25 Nov 2015
REC opinion
Favourable Opinion