Just Added!

Video Lecture Series with Amal Mattu, MD

Watch NowGo

Could It Be Neonatal HSV?

January 17, 2022

Talking About Race in Emergency Medicine

The article summary for today is below. But I am excited to announce that the audio with the authors of Dear White People in Emergency Medicine is available now on the JournalFeed podcast. How fitting on Martin Luther King Day!

Written by John Korducki

Spoon Feed
A risk stratification score for neonates with potential herpes simplex virus (HSV) infection identified very low risk neonates in which testing may be circumvented in an effort to prevent prolonged hospital stays and unnecessary costs and treatments.

Why does this matter?
HSV (especially disseminated) is a potentially devastating disease and must be adequately assessed in every sick neonate and treated when indicated. Mortality in untreated disseminated neonatal HSV has been estimated as high as 85% (1). However, working up and treating HSV for every neonate on the spectrum from mildly to critically ill is not the right approach. HSV testing and monitoring leads to 23% longer hospital stays (2), higher costs for families, and greater hospital resource utilization. Acyclovir also carries with it a small risk of acute kidney injury (3).

Spare the swabs?
This case control study was nested within a 23 center retrospective cohort study from 2005-2013 and examined infants under 60 days presenting with concern for CNS infection and calculated odds ratios for predictive variables to formulate a risk calculator for invasive HSV infection. Examples of factors with increased adjusted odds ratio (aOR) portending HSV infection compared to controls were: vesicular rash (74.3; CI: 31.3—177.6), seizure at home (4.4; CI: 2.0—9.3), and age <14 days (3.3; CI: 1.7—6.4). The Invasive HSV Risk Score utilized 8 factors and ranged from a total score of 0-17, with a score ≥ 3 being deemed “high risk” and a prospective cut point for HSV testing. The cut off ≥ 3 demonstrated a sensitivity of 95.6% (95% CI: 84.9% to 99.5%) and specificity of 40.1% (95% CI: 36.8% to 43.6%). Like all things in medicine, this risk calculator is nuanced. In a well appearing neonate >14 days, a score of 0-1 (rather than the cutoff of 3) using this promising score could be useful as an extra data point in the decision to forgo testing. This risk score needs external validation before using it in practice. For me, HSV is a truly perilous miss for a neonate and their family, while the risk of treatment remains relatively low. Maybe it’s just me, but I won’t be sparing any swabs—at least until further validation.

Predictors of Invasive Herpes Simplex Virus Infection in Young Infants. Pediatrics. 2021 Sep;148(3):e2021050052. doi: 10.1542/peds.2021-050052.

Works Cited
1. Fidler KJ, Pierce CM, Cubitt WD, Novelli V, Peters MJ. Could neonatal disseminated herpes simplex virus infections be treated earlier? J Infect. 2004 Aug;49(2):141-6. doi: 10.1016/j.jinf.2004.03.008. PMID: 15236921.
2. Aronson PL, Cruz AT, Freedman SB, et al. Association of Herpes Simplex Virus Testing with Hospital Length of Stay for Infants ≤60 Days of Age Undergoing Evaluation for Meningitis. J Hosp Med. 2019;14(8):492-495. doi:10.12788/jhm.3202
3. Downes KJ, Boge CLK, Baro E, et al. Acute Kidney Injury During Treatment with Intravenous Acyclovir for Suspected or Confirmed Neonatal Herpes Simplex Virus Infection. J Pediatr. 2020;219:126-132.e2. doi:10.1016/j.jpeds.2019.12.056

Editor’s note: The negative likelihood ratio with a score <3 was 0.11, which means a post-test probability of invasive HSV of 0.05% (5/10,000). The risk of invasive disease is already low, with a pre-test probability of just 0.42% in this study. This is good news, but keep in mind, this score hasn’t been externally validated, and as rare as invasive HSV is, that’s going to be very difficult. However, I think these score variables will find their way into hospital clinical practice guidelines, and for good reason. ~Clay Smith

What are your thoughts?