Risk factors for intrahospital infection in newborns

Intrahospital infection (IHI) in the newborn (NB) is a morbidity problem that increases mortality rates in this age group because the infecting microorganism is more aggressive. The objective of this study was to compare risk factors for localized or systemic IHIs between groups of NBs with and without IHIs.

This was a retrospective study of two groups of patient records from January 1995 to December 1998. Group A (cases) was made up of 73 patients with documented IHIs and Group B (controls), 105 patients without IHIs. Descriptive and inferential statistics (Student t, Mann-Whitney U, Wilcoxon rank sum, Chi square, and Fisher exact tests) were used. Odds ratio (OR) and multiple logistic regression were used to study risk factors. Statistical significance was considered at p <0.05.

Average gestational age was 35.4 +/- 4.3 weeks in Group A patients and 37.4 +/- 3.2 weeks for Group B patients with p = 0.001. Risk factors studied by means of OR (low birth weight, prematurity of 30 weeks of gestational age or less, prolonged intrahospital stay, etc.) showed statistical significance. Also showing significance were other not-well-studied factors such as higher numbers of diagnoses and blood transfusions. After multivariate analysis, the group of risk factors more associated with IHIs included vein dissection for insertion of central venous catheter, orotracheal intubation, and prolonged intrahospital stay (12 days or more) with an accumulative r of 0.6112.

We conclude that there are several known risk factors for IHIs and others not well described to date that must be avoided to the extent possible in the NB, particularly in the premature newborn population.