Predictors of Invasive Herpes Simplex Virus Infection in Young Infants

OBJECTIVES

To identify independent predictors of and derive a risk score for invasive herpes simplex virus (HSV) infection.

METHODS

In this 23-center nested case-control study, we matched 149 infants with HSV to 1340 controls; all were ≤60 days old and had cerebrospinal fluid obtained within 24 hours of presentation or had HSV detected. The primary and secondary outcomes were invasive (disseminated or central nervous system) or any HSV infection, respectively.

RESULTS

Of all infants included, 90 (60.4%) had invasive and 59 (39.6%) had skin, eyes, and mouth disease. Predictors independently associated with invasive HSV included younger age (adjusted odds ratio [aOR]: 9.1 [95% confidence interval (CI): 3.4-24.5] <14 and 6.4 [95% CI: 2.3 to 17.8] 14-28 days, respectively, compared with >28 days), prematurity (aOR: 2.3, 95% CI: 1.1 to 5.1), seizure at home (aOR: 6.1, 95% CI: 2.3 to 16.4), ill appearance (aOR: 4.2, 95% CI: 2.0 to 8.4), abnormal triage temperature (aOR: 2.9, 95% CI: 1.6 to 5.3), vesicular rash (aOR: 54.8, (95% CI: 16.6 to 180.9), thrombocytopenia (aOR: 4.4, 95% CI: 1.6 to 12.4), and cerebrospinal fluid pleocytosis (aOR: 3.5, 95% CI: 1.2 to 10.0). These variables were transformed to derive the HSV risk score (point range 0-17). Infants with invasive HSV had a higher median score (6, interquartile range: 4-8) than those without invasive HSV (3, interquartile range: 1.5-4), with an area under the curve for invasive HSV disease of 0.85 (95% CI: 0.80-0.91). When using a cut-point of ≥3, the HSV risk score had a sensitivity of 95.6% (95% CI: 84.9% to 99.5%), specificity of 40.1% (95% CI: 36.8% to 43.6%), and positive likelihood ratio 1.60 (95% CI: 1.5 to 1.7) and negative likelihood ratio 0.11 (95% CI: 0.03 to 0.43).

CONCLUSIONS

A novel HSV risk score identified infants at extremely low risk for invasive HSV who may not require routine testing or empirical treatment.

Herpes Simplex Virus Infection in Infants Undergoing Meningitis Evaluation

BACKGROUND

Although neonatal herpes simplex virus (HSV) is a potentially devastating infection requiring prompt evaluation and treatment, large-scale assessments of the frequency in potentially infected infants have not been performed.

METHODS

We performed a retrospective cross-sectional study of infants ≤60 days old who had cerebrospinal fluid culture testing performed in 1 of 23 participating North American emergency departments. HSV infection was defined by a positive HSV polymerase chain reaction or viral culture. The primary outcome was the proportion of encounters in which HSV infection was identified. Secondary outcomes included frequency of central nervous system (CNS) and disseminated HSV, and HSV testing and treatment patterns.

RESULTS

Of 26 533 eligible encounters, 112 infants had HSV identified (0.42%, 95% confidence interval [CI]: 0.35%-0.51%). Of these, 90 (80.4%) occurred in weeks 1 to 4, 10 (8.9%) in weeks 5 to 6, and 12 (10.7%) in weeks 7 to 9. The median age of HSV-infected infants was 14 days (interquartile range: 9-24 days). HSV infection was more common in 0 to 28-day-old infants compared with 29- to 60-day-old infants (odds ratio 3.9; 95% CI: 2.4-6.2). Sixty-eight (0.26%, 95% CI: 0.21%-0.33%) had CNS or disseminated HSV. The proportion of infants tested for HSV (35%; range 14%-72%) and to whom acyclovir was administered (23%; range 4%-53%) varied widely across sites.

CONCLUSIONS

An HSV infection was uncommon in young infants evaluated for CNS infection, particularly in the second month of life. Evidence-based approaches to the evaluation for HSV in young infants are needed.

Accuracy of non-contact infrared thermometry versus rectal thermometry in young children evaluated in the emergency department for fever

OBJECTIVE

We evaluated the accuracy of a non-contact infrared thermometer compared with a rectal thermometer.

METHODS

Two hundred patients, ages 1 month to 4 years, were included in the study. Each child underwent contemporaneous standard rectal thermometry and mid forehead non-contact infrared thermometry. Clinical features, including chief complaint, recently administered antipyretic agents, and ambient temperature at the time of measurement, were included.

ANALYSIS

Linear models were used to compare agreement between the 2 techniques, as well as to determine bias of infrared thermometry at different rectal temperatures. Multivariate linear models were used to evaluate the impact of clinical variables and ambient temperature.

RESULTS

A linear relationship between rectal and infrared temperature measurements was observed; however, the coefficient of determination (r(2)) value between was only 0.48 (P < 0.01). Infrared thermometry tended to overestimate the temperature of afebrile children and underestimate the temperature of febrile patients (P < .01). Ambient temperature and child age did not affect the accuracy of the device.

CONCLUSION

In this study, non-contact infrared thermometry did not sufficiently agree with rectal thermometer to indicate its routine use.