Risk of Healthcare-Associated Transmission of Sever Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitalized Cancer Patients

Abstract

Background: There is limited information on the risk of hospital-acquired coronavirus disease 2019 (COVID-19) among high-risk hospitalized patients after exposure to an infected patient or healthcare worker (HCW) in a nonoutbreak setting.

Methods: This study was conducted at a tertiary care cancer center in New York City from 10 March 2020 until 28 February 2021. In early April 2020, the study institution implemented universal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing at admission and retesting every 3 days through the hospital stay. Contact tracing records were reviewed for all exposures to SARS-CoV-2 positive patients and HCWs.

Results: From 10 March 2020 to 28 February 2021, 11 348 unique patients who were SARS-CoV-2 polymerase chain reaction (PCR) negative at the time of admission underwent 31 662 postadmission tests during their hospitalization, and 112 tested positive (0.98%). Among these, 49 patients housed in semiprivate rooms during admission resulted in 74 close contacts and 14 secondary infections within 14 days, for an overall attack rate of 18.9%. Among those exposed to a roommate undergoing an aerosol-generating procedure (AGP), the attack rate was 35.7%. Whole genome sequencing (WGS) corroborated transmission in 6/8 evaluated pairs. In addition, three transmission events occurred in 214 patients with significant exposure to 105 COVID-19 positive healthcare workers (1.4%).

Conclusions: The overall risk of hospital-acquired COVID-19 is low for hospitalized cancer patients, even during periods of high community prevalence. However, shared occupancy with an unrecognized case is associated with a high secondary attack rate in exposed roommates.

Keywords: COVID-19; SARS-CoV-2; cancer; hospital-acquired.

Figure 1.

A, Timing of 14 secondary cases (gray dots) among exposed roommates depicted against all laboratory confirmed patient cases diagnosed at the study institution. B, Shared room duration by hours with the index case. Abbreviation: MSK, Memorial Sloan Kettering. Color figures available online.

Figure 2.

Attack rate among close contact exposures examined by shared room occupancy duration in days.

Figure 3.

COVID-19 transmission among 74 close contacts by shared room duration and N1 target Ct value of index patient. Abbreviations: COVID-19, coronavirus disease 2019; Ct, cycle threshold.

Figure 4.

Phylogenetic tree of available SARS-CoV-2 sequences for each pair of index (I) cases, their roommates (R) or the healthcare worker (HCW) and patient (P). Abbreviation: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 5.

Similarity matrix of all pairs with available sequences. Gray: No Single Nucleotide Polymorphism Differences between pairs.*Pairs with SNP ≥2. Pair 11R-13I represents one patient. Positive after exposure to Index 11 but was briefly housed in a semi-private room prior to Index 11’s detection. Patient was relabeled as Index 13 with roommate exposure. Abbreviations: HCW, healthcare worker; I, index; P, patient; R, roommates; SNP, single nucleotide polymorphism. Color figures available online.