An outbreak of New Delhi metallo-β-lactamase-1 (NDM-1) producing Enterobacteriaceae in a South African hospital: a case-control study
Year: 2014
Type: dissertation
Study design: Observational Study
Abstract: Objective: New Delhi metallo-β-lactamase (NDM)-producing Gram-negative bacteria have spread globally and pose a significant public health threat. There is a need to better define risk factors and outcomes of NDM-1 clinical infection. We assessed risk factors for nosocomial infection with NDM-1-producers and associated in-hospital mortality. Methods: A matched case-control study was conducted during a nosocomial outbreak of NDM-1-producers in South Africa. All patients from whom NDM-1-producers were identified were considered (n=105). Cases included patients admitted during the study period in whom NDM-1 producing Gram-negative bacteria were isolated from clinical specimens collected ≥48 hours after admission, and where surveillance definitions for healthcare-associated infections were met. Controls were matched for age, sex, date of hospital admission and intensive-care admission. Conditional logistic regression was used to identify risk factors for NDM-1 clinical infection and associated in-hospital mortality. Findings: 38 cases and 68 controls were included. Klebsiella pneumoniae was the most common NDM-1-producer (28/38, 74%). Cases had longer mean hospital stays (44.0 vs 13.3 days; P < 0.001) and ICU stays (32.5 vs 8.3 days; P < 0.001). Adjusting for co-morbid disease, the in-hospital mortality of cases was significantly higher than controls (55.3% vs 14.7%; AOR, 11.29; P < 0.001). Higher Charlson co-morbidity index score (5.2 vs 4.1; AOR, 1·59; CI 95 % 1.15 – 2.18), more mechanical ventilation days (7.47 vs 0.94 days; AOR, 1.32; CI 95 % 1.10 – 1.59) and piperacillin/tazobactam exposure (11.03 vs 1.05 doses; AOR, 1.08; CI 95 % 1.02 – 1.15) were associated with NDM-1 infection on multivariate analysis. Cases had a significantly higher likelihood of in-hospital mortality when the NDM-1-producer was Klebsiella pneumoniae (AOR, 16.57; CI 95 % 2.12 – 129.6), or when they had a bloodstream infection (AOR, 8.84; CI 95 % 1.09 – 71.55). Conclusion: NDM-1 infection is associated with significant in-hospital mortality. Risk factors for hospital-associated infection include the presence of co-morbid disease, mechanical ventilation and piperacillin/tazobactam exposure. Rational use of intensive care, medical devises and antibiotics are essential in reducing the transmission and emergence of NDM-1 and other drug resistance Gram-negative bacteria.
Author: Pieter de Jager
Language: English
Subfield: Microbiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1886076298