# Examining the influence of Covid-19 restrictions, a nurse strike, and SARS-CoV-2 coinfection on bacteremia mortality: A Danish population-based cohort study (2019–2022)

## TL;DR

This study found that bacteremia mortality decreased during the pandemic's restrictions but increased with SARS-CoV-2 coinfection in Denmark.

## Contribution

The study provides new evidence on how pandemic restrictions and SARS-CoV-2 coinfection influenced bacteremia mortality.

## Key findings

- Bacteremia mortality was significantly lower during the COVID-19 restriction period.
- SARS-CoV-2 coinfection was associated with higher bacteremia mortality.
- The nurse strike's impact on mortality was inconclusive.

## Abstract

Bacteremia is an acute severe infection with high mortality. Changes in healthcare services and coinfections with SARS-CoV-2 may have affected the mortality for bacteremia during the COVID-19 pandemic, which has been reported for other major diseases. In this study we examine the all-cause bacteremia mortality amidst the COVID-19 pandemic.

A population-based cohort study comprised of laboratory confirmed bacteremia episodes in the Capital Region, Denmark (March 2019–February 2022). Cox proportional hazards models were used to calculate hazard ratios (HR) and 95 % confidence intervals (CI) for all-cause bacteremia mortality associated with the Covid-19 restriction period, a strike period, and coinfection with SARS-CoV-2, adjusted for possible confounders.

A total of 14,912 bacteremia episodes were identified in 12,693 patients during the study period. The 30- and 90-day all-cause mortality were 19 % and 27 %, respectively. The fully adjusted HR for 30- and 90-day all-cause mortality associated with the Covid-19 restriction period were 0.91 (95 % CI, 0.84 to 0.99) and 0.90 (95 % CI, 0.84 to 0.96), respectively, compared to the remaining time period. The corresponding HRs associated with SARS-CoV-2 coinfection were 1.29 (95 % CI, 1.11 to 1.50) and 1.36 (95 % CI, 1.20 to 1.55) compared to patients without coinfection. The association between the national nurse strike and all-cause bacteremia mortality was inconclusive.

In this large population-based cohort study, a significant reduction in all-cause mortality for bacteremia was observed during the Covid-19 restriction period in Denmark, while coinfection with SARS-CoV-2 seem to be a substantial risk factor for all-cause bacteremia mortality.

•A Danish population-based cohort study of laboratory confirmed bacteremia.•The 30- and 90-day all-cause mortality were 19 % and 27 %, respectively.•The mortality was significantly lower during the Covid-19 restriction period.•The mortality was significantly higher in those with SARS-CoV-2 coinfection.

A Danish population-based cohort study of laboratory confirmed bacteremia.

The 30- and 90-day all-cause mortality were 19 % and 27 %, respectively.

The mortality was significantly lower during the Covid-19 restriction period.

The mortality was significantly higher in those with SARS-CoV-2 coinfection.