Bacterial Contamination in Neonatal Intensive Care Unit: A Potential Threat of Nosocomial Infections to Neonates

Abstract

Background: Bacterial contamination in healthcare settings, especially neonatal intensive care units, plays a key role in the spread of nosocomial infections. However, there is limited data on the routine monitoring of contamination on surfaces and instruments in direct contact with neonates, as well as their antimicrobial susceptibility patterns in our setting.
Objective: The study determined the level of bacterial contamination on instruments and surfaces frequently touched or in contact with neonates, and their antimicrobial susceptibility patterns.
Methods: A cross-sectional study was conducted in the neonatal Intensive Care Unit (NICU) at St. Benedict Ndanda Referral Hospital (SBNRH) in Mtwara, Tanzania, over two days in November 2023. Swab samples were collected from surfaces and instruments that are frequently touched or in contact with neonates. Bacterial isolation, identification, and antimicrobial susceptibility testing were conducted according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Multidrug resistance (MDR) was defined as resistance to at least one antibiotic from three or more different classes. Data analysis was conducted using STATA software version 15, with descriptive statistics presented as frequencies and percentages.
Results: Of 57 swab samples, 37 (64.9%) showed bacterial growth, yielding 43 isolates. The majority, 30(69.8%), were gram-negative bacteria. The predominant isolates were coagulasenegative Staphylococci species, accounting for 8 (18.6%), followed by Escherichia coli and Klebsiella pneumoniae, each at 7 (16.3%). The most contaminated areas were nurse stations 2(100.0%), wall sanitizer dispenser 2(100.0%), weighing scale 1(100.0%), neonatal beds 16(88.9%) and door handles 6(85.7%). Enterobacterales were highly resistant to cefotaxime 18(85.7%), ceftriaxone 17 (73.7%) and gentamicin 15(71.4%). Acinetobacter baumanii was resistant to piperacillin 5(100.0%), piperacillin-tazobactam 5(100.0%) and cefotaxime 5(100.0%). Pseudomonas aeruginosa were highly resistant to piperacillin 3(100.0%) and piperacillin-tazobactam 3(100.0%). Most of the gram-negative bacteria were susceptible to meropenem 25(83.3%). Staphylococcus aureus showed resistance to erythromycin 5(100.0%) and tetracycline 4(80.0%). Methicillin resistant Staphylococcus aureus (MRSA) was observed in 4(80.0%) isolated Staphylococcus aureus. Multi-drug resistance (MDR), extended-spectrum beta-lactamase (ESBL) production, and carbapenemase production were observed in 29 (82.9%), 3 (23.1%) and 5 (16.7%) respectively.
Conclusion: The instruments and surfaces in the NICU were contaminated with high-risk pathogens, many of which showed significant resistance to commonly used antibiotics. These findings highlight the urgent need to strengthen infection prevention and control measures and antibiotic stewardship to reduce bacterial colonization and transmission to neonates.