Investigation of a suspected nosocomial infection outbreak in a neonatology department, China

Abstract

Objective: To describe the successful management of a multi-strain outbreak of Pseudomonas aeruginosa (Pae) in the neonatal unit, combined with a case control study to identify risk factors. Materials and Methods: The management measures including outbreak investigations and controls were taken to prevent further cases. To analyze the risk factors of infection, neonates were divided into case group and control group. The case group consisted of the 5 infected neonates. The control group consisted of 10 premature infants without infection, but with similar gestational age, body weight, and with >48 hours stay in the hospital. The two groups were matched with the ratio of 1:2. t and chi-square tests were used for comparison between the two groups and P<0.05 was considered significant. Environmental samples were collected from the faucet, sewer, staff hand, body surface of medical instrument, on 15th October, 2020. Cultures were initiated to detect sources of infectious agents. Results: The outbreak comprised of 5 infections over time period. The results were that samples from the environment identified the infection source. It was hypothesized that the organism being transferred from the source to the patients via water. The outbreak was halted by successful control measures. The cases differed from controls only by antibiotic application (type and duration of treatment), length of hospital stays, PICC catheterization time and gastric tube in-dwelling time (P<0.05). When logistic regression was used to analyze relationships between neonatal infection and various variables, all variables were not included in the regression equation (probably due to our small sample size). Pae was identified from the sputum and skin cultures, and from multiple faucet samples. Blood culture analyses indicated inflammation. The Pae outbreaks were associated with exogenous water sources but the infectious agent had different drug resistant patterns. Conclusion：The conclusion is that this was an multi strain outbreak of Pae arising probable from biofilm in faucet water sources, streptococcus, enterococcus, coagulase negative staphylococcus were cultured from the faucet. It was controlled by pre-determined protocols and expert personnel to handle the suspected outbreak efficiently, and successful prevention and intervention processes. The data, therefore, allowed us to exclude the infection as NI outbreak but to conclude exogenous NIs. Furthermore, new hygienic protocols were developed to prevent such occurrences.