High frequency of multidrug-resistant gram-negative rods in 2 neonatal intensive care units in the Philippines

Abstract

Background: Although hospital-acquired infections appear to be a growing threat to the survival of newborns in the developing world, the epidemiology of this problem remains poorly characterized.

Methods: During a 10-month period, we conducted prospective longitudinal surveillance for colonization and bloodstream infection caused by gram-negative rods among all infants hospitalized in the 2 largest neonatal intensive care units in Manila, the Philippines. We determined antibiotic susceptibilities and calculated adjusted odds ratios for risk factors for bacteremia by means of multivariate logistic regression.

Results: Of 1,831 neonates enrolled during a 10-month period, 1,017 (55.5%) became newly colonized and 358 (19.6%) became bacteremic with a drug-resistant gram-negative rod, most commonly Klebsiella species, Enterobacter species, Acinetobacter species, and Pseudomonas aeruginosa. Of the invasive isolates, 20% were resistant to imipenem, 41% to trimethoprim-sulfamethoxazole, 52% to amikacin, 63% to ampicillin-sulbactam, 67% to ceftazidime, and 80% to tobramycin. The factors significantly associated with an increased risk of bacteremia were mechanical ventilation and prematurity. Additionally, colonization with a drug-resistant gram-negative rod was an independent risk factor for bacteremia (odds ratio, 1.4 [95% confidence interval, 1.0-1.9]).

Conclusions: Colonization with a drug-resistant gram-negative rod was an independent risk factor for sepsis. If our data are typical, the unusually high intensity of colonization pressure and disease caused by multidrug-resistant gram-negative rods at these 2 neonatal intensive care units indicates an emerging healthcare crisis in the developing world. Improved infection control methods are therefore critically needed in developing countries.