Decreased incidence of febrile neutropenia in Michigan following masking and social distancing orders for the COVID-19 pandemic: A population based cohort study

Abstract

BACKGROUND It has been theorized that 75%-80% of febrile neutropenia (FN) is caused by endogenous pathogens, while up to 20% of cases are thought to be caused by a viral infection. It is unknown if precautions such as masking and social distancing reduce the risk of FN in susceptible populations. AIM To determine whether coronavirus disease 2019 (COVID-19) infection mitigation efforts, namely masking and social distancing, were associated with a reduction in the incidence of FN. METHODS This was a retrospective population based cohort study comparing the incidence of FN in the 13 mo prior to (Year 0) and 13 mo following (Year 1) the public health executive orders (PHEO) in Michigan. Data was queried for all emergency department (ED) visits from April 1, 2019 to March 31, 2021 from the National Syndromic Surveillance Program, a program which collects data that is voluntarily submitted by approximately 89% of Michigan EDs. The primary study outcome was the incidence of FN as a proportion of ED visits in the 13-mo before and 13-mo after COVID-19 mitigations efforts, namely masking and social distancing. We hypothesized that there would be a significant decrease in the incidence of FN in the period following the PHEO aimed at reducing the spread of the severe acute respiratory syndrome coronavirus 2 virus. RESULTS There was a total of 8979221 total ED visits captured during the study period. In Year 0 there were 5073081 recorded ED visits and 3906140 in Year 1. There was a significant reduction in the proportion of total ED visits with a diagnosis of FN, decreasing 13.3% across periods (0.15% vs 0.13%, P = 0.036). In patients with a hematologic malignancy a more impressive reduction in the incidence of FN was evident following PHEO (22% vs 17%, P = 0.02). CONCLUSION We found a significant association between social distancing and mask guidelines implemented on a large public scale with decreased rates of FN, particularly in those with a hematologic malignancy. These findings may be useful in the design of future research and recommendations regarding the prevention of FN.

Importance of standard precautions to febrile neutropenia prevention in patients with cancer during COVID 19 outbreak

“…At the beginning of our study, there was no report on the relationship between FN and COVID 19 outbreak, however, several recent research results have been reported. The result of each study though similar in some aspect, differed as highlighted in table 5 (19)(20)(21)(22)(23). Nessle et al reported only a reduced incidence of upper respiratory infection associated FN, and not overall FN episodes among pediatric patients with cancer during post-COVID 19 era (19).…”

“…Three other retrospective studies showed a reduction in the overall FN incidence after COVID 19 outbreak in relatively larger dataset. However, these data were derived from heterogeneous disease groups with different tumor types, chemotherapy regimen, patient's characteristics (20,21,23). Furthermore, Baracy et al reported an unexpected nding that FN episodes were reduced only in patients with hematologic malignancies (21).…”

“…However, these data were derived from heterogeneous disease groups with different tumor types, chemotherapy regimen, patient's characteristics (20,21,23). Furthermore, Baracy et al reported an unexpected nding that FN episodes were reduced only in patients with hematologic malignancies (21). Gwak et al reported a reduction in FN episode in a homogenous patient group that received adjuvant docetaxel, adriamycin and cyclophosphamide chemotherapy after breast cancer surgery (22).…”