One of the things that I have wondered about over the years is whether infants who appear to be infected, but who have negative cultures, might have viral infections.
A new study suggests that this is not rare. Kidszun A, et al. Viral Infections in Neonates with Suspected Late-Onset Bacterial Sepsis-A Prospective Cohort Study. American journal of perinatology. 2016. In this study all the infants who were having a sepsis work-up also had evaluation for respiratory viruses (using a nasopharyngeal aspirate for a PCR multiplex) and enteral viruses using a stool sample for PCR of various viruses including an enterovirus screen. There were 88 babies with 137 sepsis screens. None of the babies who had positive blood cultures for bacteria had positive screens for viruses. 9 of the 113 sepsis evaluations which had negative blood cultures were positive for respiratory viruses, none for enteric viruses. So in this NICU at that period about 8% of sepsis-like episodes were associated with positive viral screens, some of those episodes had an increase in CRP, some had more than 5 days of antibiotic treatment. Basically all the indicators that are used to define culture-negative sepsis were present at times.
Similar data were published from 2 US NICUs a couple of years ago Ronchi A, et al. Viral respiratory tract infections in the neonatal intensive care unit: the VIRIoN-I study. The Journal of pediatrics. 2014;165(4):690-6. A similar incidence of positive tests for respiratory viruses were found with routine PCR multiplex screening added to traditional sepsis screens, of 6% among over 130 sepsis screens. They also had no patients with a positive viral screen who also had a positive blood culture.
I think there is value in doing this, the results can be obtained rapidly, could be used to stop antibiotics faster (although that doesn’t seem to have happened in either of these studies). Spread of viruses in the NICU can be reduced by good hand hygiene measures, knowing a baby is infected might make people do a better job of washing, but I’m not too hopeful about that.