TOPLINE

Herpes simplex virus type 1 (HSV-1) reactivation is common among critically ill patients with COVID treated in the ICU and is independently associated with increased need for organ support and reduced ICU survival.

METHODOLOGY

• A retrospective study analyzed 455 patients (mean age, 57 years; 69% men) with confirmed SARS-CoV-2 infection who were treated at the anesthesiology ICU of University Hospital Essen, Germany, between March 2020 and December 2021.
• Patients underwent routine screening for HSV-1 in bronchoalveolar lavage fluid and cytomegalovirus (CMV) in whole blood; viral reactivation was defined as any positive polymerase chain reaction detection without a viral-load threshold.
• Median time from ICU admission to viral detection was 4 days for both HSV-1 and CMV, with detection rates increasing with longer ICU stays.
• The primary endpoint was to identify independent risk factors associated with ICU mortality; secondary endpoints were 30-day mortality, the crude incidence of HSV-1, CMV, organ failure, need for invasive mechanical ventilation, and veno-venous extracorporeal membrane oxygenation (vvECMO) therapy.

TAKEAWAY

• Overall, 36% of patients developed viral reactivation during their ICU stay: 12% had isolated HSV-1 reactivation, 12% had isolated CMV reactivation, and 13% had both. HSV-1 reactivation was independently associated with reduced ICU survival (odds ratio [OR], 0.35; P = .006).
• Patients with HSV-1 reactivation required invasive mechanical ventilation more than twice as frequently (98% vs 48%; P < .001) and for more than three times longer (463 vs 112 hours; P < .001) compared with those without reactivation.
• vvECMO support was required more than three times as often in patients with HSV-1 reactivation (58% vs 18%; P < .001), and renal replacement therapy was administered more than twice as frequently (57% vs 25%; P < .001).
• Higher neutrophil-lymphocyte ratio (NLR) was independently associated with reduced ICU survival (OR, 0.97; P = .011) and correlated with detection of both HSV-1 and CMV, with a median value of 11.2 in patients positive for HSV-1 vs 8.2 in those without viral reactivation.

IN PRACTICE

"[These findings] support systematic viral monitoring and prospective studies to define clinically meaningful thresholds for antiviral intervention," wrote the authors of the study.

SOURCE

The study was led by Stefanie Michel, Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany. It was published online on July 17 in PLoS One.

LIMITATIONS

The retrospective, single-center design limits both causal inference and generalizability. Viral reactivation was defined virologically without direct clinical correlation, limiting distinction between colonization, reactivation, and invasive infection. The high proportion of secondary referrals for vvECMO therapy introduced potential referral bias through preferential inclusion of patients with the most severe disease.

DISCLOSURES

No specific funding was reported for this work. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.