# Impact of Blood Herpes Simplex Virus Polymerase Chain Reaction Testing in Neonatal Management of Herpes Simplex Virus Infection: An Institutional Experience

## TL;DR

This study found that blood HSV PCR testing does not significantly affect the management of neonatal herpes infections when results take too long to return.

## Contribution

The study evaluates the clinical impact of blood HSV PCR testing in neonatal HSV management in an institution with delayed test results.

## Key findings

- Blood HSV PCR results did not significantly influence clinical decisions for neonatal HSV management.
- Acyclovir was often discontinued before blood HSV PCR results were available.
- Turnaround time for blood HSV PCR results was too slow to impact treatment decisions.

## Abstract

Background: The evaluation of neonatal herpes simplex virus (HSV) includes HSV culture and/or polymerase chain reaction (PCR) of different surfaces, cerebrospinal fluid (CSF), and blood. However, the impact of blood HSV PCR for the management of neonatal HSV infections has not been well-established.

Objective: To evaluate the impact of blood HSV PCR results in the management (i.e., clinical decision-making regarding treatment) of neonatal HSV infections at our institution, where this test is performed at an outside facility.

Methods: We retrospectively reviewed the medical records of all neonates tested for HSV DNA in blood from January 1, 2018, to July 31, 2023, at our children’s hospital.

Results: A total of 149 medical records were analyzed, of which seven had positive blood HSV PCR. These seven patients and five of 142 patients with negative blood HSV PCR had a positive HSV PCR result from another site, and they were managed according to those results. The mean turnaround time (TAT) for the results of blood HSV PCR was three and a half days for positive results and four days for negative results. In most patients with negative PCR from other sites, including CSF, acyclovir was discontinued before the blood HSV PCR results were back. Acyclovir was not discontinued until the results were available in only 12 of 134 neonates who had all negative results and available information about management. Statistical analysis showed that blood HSV PCR did not significantly impact the management of these neonates.

Conclusions: Our study does not support the use of blood HSV PCR in the evaluation of neonatal HSV infection specifically in institutions where the test is not performed in-house, because the test results are not available in a timely fashion to have an impact on the management of these neonates.