Determinants of late neonatal nosocomial infection: a case-control study in Ceará.

Objectives: To assess the determining factors of late healthcare-associated infections (HAIs) and bacterial multiple drug resistance in neonatal intensive care.
Methods: This is a case-control study, conducted between January 2013 and December 2017, in a neonatal intensive care unit in the state of Ceará, Brazil. Newborns showing late HAIs were considered cases and those without infection, the control. Variables with p-values ≤ 0.05 in our initial bivariate regressive analysis were included in a non-conditional hierarchical logistic model for multivariate analysis. P-values below 0.01 were considered significant.
Results: Of the 1,132 participants, 427 (37.7%) showed late healthcare-associated infections. Of these, 54 (12.6%), positive blood cultures, of which 14.9% contained multidrug-resistant bacteria. Bivariate analysis showed the protective effect of the feminine phenotype (OR = 0.71; 95%CI: 0.56-0.90) and of gestational ages ≥ 34 weeks (OR = 0.48; 95%CI: 0.30-0.75). In earlier-born preterm infants, late infections were 18 times more likely in those with less than 30 week-gestations (OR = 18.61; 95%CI: 9.84-35.22) and four times higher in those weighing less than 1,500 g (OR = 4.18; 95%CI: 3.12-5.61). Mechanical ventilation increased infection odds by more than seven times (OR = 7.14; 95%CI: 5.26-9.09); as did parenteral nutrition (OR = 5.88; 95%CI: 4.54-7.69); central venous catheters (OR = 10.00; 95%CI: 6.66-16.66); the number of catheters used (OR = 3.93; 95%CI: 3.02-5.12); surgery (OR = 4.00; 95%CI: 2.27-7.14); and hospitalization time (OR = 1.06; 95%CI: 1.05-1.07). The association between preterm infants with less than 30 week-gestations (OR = 5.62; 95%CI: 1.83-17.28); mechanical ventilation (OR = 1.84; 95%CI: 1.26-2.68); central venous catheters (OR = 2.48; 95%CI: 1.40-4.37); and hospitalization time (OR = 1.06; 95%CI: 1.05-1.07) remained significant after adjustment. Among deaths, 41 (55.4%) were associated with late infections.
Conclusion: Better practices should be adopted in caring for the premature, as well as in the rational use of procedures, to avoid late healthcare-associated infections, preventable deaths, and risks of bacterial multiple drug resistance and environmental contamination.