Population-based surveillance of neonatal herpes simplex virus infection in Australia, 1997-2011.
BACKGROUND
Neonatal herpes simplex virus (HSV) infection is uncommon, but mortality after disseminated disease and morbidity after encephalitis are high. For the last decade, increased dose and duration of acyclovir has been advised to prevent disease progression and recurrence. We sought to determine prospectively the epidemiologic, clinical, and secular trends of this condition in Australia.


METHODS
This was prospective national active surveillance for neonatal HSV disease through the Australian Paediatric Surveillance Unit from 1997 to 2011. Case notification triggered a questionnaire requesting de-identified data from the pediatric clinician.


RESULTS
We identified 131 confirmed cases of neonatal HSV disease in 15 years from 261 notifications (95% response). The reported incidence (3.27 cases per 100 000 live births overall; 95% confidence interval [CI], 2.73-3.86) was stable. Overall mortality was 18.8% (95% CI, 12.1-25.5); the mortality rate was significantly lower in the latter part of the study period, 2005-2011, compared with 1997-2004 (P = .04). There were significantly more young mothers (<20 years of age) compared with Australian birth record data (18.5% vs 4.8%; P < .001). HSV-1 infection was more common than HSV-2 (62.7% vs 37.3%; P < .001), and the rate of HSV-1 infections increased significantly over the surveillance period (P < .05). From 2002, most infants received high-dose acyclovir. The time from symptom onset to initiation of therapy in survivors did not change over time.


CONCLUSIONS
Mortality from neonatal HSV infection has fallen but remains high. HSV-1 is the major serotype causing neonatal disease in Australia. Young mothers represent an important target group for prevention.
Discipline of Paediatrics and Child Health, Sydney Medical School The Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney Department of Microbiology and Infectious Diseases, The Children's Hospital at Westmead Centre for Perinatal Infection Research, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.
Cheryl A
CA
Jones
Discipline of Paediatrics and Child Health, Sydney Medical School Centre for Perinatal Infection Research, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.
Camille
C
Raynes-Greenow
Discipline of Paediatrics and Child Health, Sydney Medical School Department of Microbiology and Infectious Diseases, The Children's Hospital at Westmead.
David
D
Isaacs
D000212:Acyclovir / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D004363:Drug Utilization; D062665:Epidemiological Monitoring; D005260:Female; D006561:Herpes Simplex / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology* / Q000821:virology; D018259:Herpesvirus 1, Human / Q000302:isolation & purification*; D018258:Herpesvirus 2, Human / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology* / Q000821:virology; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D055815:Young Adult
D000998:Antiviral Agents; D000212:Acyclovir
adolescent mothers; genital herpes; herpes simplex virus; neonatal herpes simplex virus infection; vertical transmission