Reduced transmission of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP) in patients with haematological malignancies hospitalized in an Italian hospital during the COVID-19 pandemic

Objectives: During the lockdown that started in Italy on 10 March 2020 to address the COVID-19 pandemic,aggressive procedures were implemented to prevent SARS-CoV-2 transmission in SARS-CoV-2-negative patientswith haematological malignancies. These efforts progressively reduced Klebsiella pneumonia carbapenemase-producing K. pneumoniae (KPC-KP) spread among these patients. Here we evaluated the potential effects ofmeasures against COVID-19 that reduced KPC-KP transmission.Patients and methods: We analysed KPC-KP spread among 123 patients with haematological malignancies,hospitalized between March and August 2020, who were managed using measures against COVID-19. Theiroutcomes were compared with those of 80 patients hospitalized during the preceding 4 months (November2019–February 2020).Results: During March–August 2020, 15.5% of hospitalized patients were KPC-KP positive, compared with 52.5%in November 2019–February 2020 (P , 0.0001); 8% and 27.5% of patients in these two groups were newly KPC-KP positive, respectively (P " 0.0003). There were eight new KPC-KP-positive patients during January 2020 andnone during June 2020. The weekly rate of hospitalized KPC-KP-positive patients decreased from 50% duringMarch 2020 to 17% during August 2020. Four KPC-KP bloodstream infections (BSIs) were experienced by 123patients (3%) in March–August 2020, and seven BSIs (one fatal) by 80 patients (8%) in November 2019–February2020 (P " 0.02). Consumption and expense of ceftazidime/avibactam administered to KPC-KP-positive patientssignificantly decreased in March–August 2020.Conclusions: Aggressive strategies to prevent SARS-CoV-2 transmission were applied to all hospitalized patients,characterized by high levels of KPC-KP endemicity and nosocomial transmission. Such measures preventedSARS-CoV-2 infection acquisition and KPC-KP horizontal transmission. Reduced KPC-KP spread, fewer associatedclinical complications and decreased ceftazidime/avibactam consumption represented unexpected ‘collateralbenefits’ of strategies to prevent COVID-19.