Background: Due to a shortage of individualized erythromycin ointment (IEO), we switched to shared erythromycin drops (SED). Following this change, nurses claimed observing more cases of eye discharge. 

Objectives: To test whether switching from IEO to SED affected the rate of neonatal conjunctivitis (NC).

Methods: The study group included 14,916 neonates > 35 weeks of gestation, further divided into two birth periods of 12 months each: 1 January 2013 to 31 December 2013 (IEO) and 1 February 2014 to 31 January 2015 (SED). We compared the two birth periods with regard to three variables: clinical NC (number of conjunctival swabs/1000 neonates), bacterial NC (number of culture-positive swabs/1000 neonates), and bacterial growth percentage (number of culture-positive swabs/100 samples).  

Results: Compared to 2012–2013, the period 2014–2015 included fewer cesarean deliveries and shorter length of stay (LOS). Clinical NC, bacterial NC and bacterial-growth percentage were not different between the two periods. Variables that were independently significantly associated with increased clinical NC included male gender (OR 1.48, CI 1.21–1.81) and LOS (OR 1.24, CI 1.18–1.29). LOS was associated with bacterial NC (OR 1.19, CI 1.11–1.28). Coagulase-negative staphylococci, Escherichia coli and Pseudomonas aeruginosa were the prevalent pathogens, though without difference between periods. 

Conclusions: Rates of clinical NC, bacterial NC and bacterial-growth percentage were not different between the study periods. Switching from IEO to SED had no effect on the NC rate.