Epidemiology, risk factors, clinical presentation and complications of late-onset neonatal sepsis among preterm neonates in Cyprus: a prospective case-control study.

Background: Late-onset neonatal sepsis (LOS) is common in preterm neonates, with increasing incidence in recent years. In the present study, we examined the epidemiology, clinical presentation, and complications of LOS in Cyprus and quantified possible risk factors for the development of this condition.

Methods: The study subjects were preterm neonates admitted in the Neonatal Intensive Care Unit (NICU) of Archbishop Makarios III Hospital, the only neonatal tertiary centre in Cyprus. A prospective, case-control study was designed, and carried out between April 2017-October 2018. Depending on blood culture results, preterm neonates were classified as "Confirmed LOS": positive blood culture - microorganism isolated and LOS symptoms, "Unconfirmed LOS": negative blood culture and LOS symptoms, and "Controls" group: negative blood culture and absence of LOS symptoms. Comparisons between the 3 groups were performed and the associations between demographic, clinical and treatment characteristics with the likelihood of LOS were assessed using univariate and multivariate logistic regression.

Results: A total of 350 preterm neonates were included in the study and the incidence of LOS was 41.1%. 79 (22.6%) and 65 (18.6%) neonates were classified as "Confirmed LOS", and "unconfirmed LOS" cases respectively while 206 (58.9%) served as controls. The rate of confirmed LOS ranged from 12.2% in moderate to late preterm neonates to 78.6% in extremely preterm neonates. In the multivariate model, we demonstrated an independent association between LOS and duration of hospitalization (OR: 1.06, 95%CI: 1.01-1.10), duration of ventilation (OR: 1.23, 95%CI: 1.07-1.43) and necrotising enterocolitis (OR: 3.41, 95%CI: 1.13-10.25).

Conclusions: The present study highlights the epidemiology of LOS in preterm neonates in Cyprus and its association with the duration of ventilation and hospitalization as well as with necrotizing enterocolitis. Establishment of protocols for the prevention of nosocomial infections during hospitalization in the NICUs and mechanical ventilation of preterm neonates is recommended.