What is the appropriate treatment for a neonate with suspected Herpes Simplex Virus (HSV) meningitis, given a maternal history of HSV-2 (Herpes Simplex Virus type 2) and valacyclovir (valacyclovir) prophylaxis during pregnancy?

From the Guidelines

For a neonate with suspected HSV meningitis with maternal HSV-2 history and valacyclovir prophylaxis during pregnancy, immediate treatment with intravenous acyclovir at 60 mg/kg/day divided every 8 hours is recommended. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of prompt treatment in reducing morbidity and mortality associated with neonatal HSV infections 1.

Key Considerations

• A full sepsis workup should be performed, including lumbar puncture for CSF analysis and HSV PCR, blood HSV PCR, surface swabs (eyes, mouth, nasopharynx), and lesion swabs if present.
• The initial treatment duration is 14 days for skin/mucous membrane disease, but should be extended to 21 days for CNS involvement or disseminated disease, as guided by the CDC recommendations 1.
• Serial CSF HSV PCR testing should be performed to ensure clearance of the virus before discontinuing therapy.
• Despite maternal valacyclovir prophylaxis during pregnancy, neonatal HSV infection can still occur, particularly during primary maternal infections or with viral shedding at delivery 1.
• Close monitoring for clinical signs including seizures, lethargy, poor feeding, temperature instability, and skin vesicles is essential.

Treatment and Prophylaxis

• After completing intravenous therapy, oral suppressive therapy with acyclovir (300 mg/m²/dose three times daily) for six months is recommended to improve neurodevelopmental outcomes.
• The use of suppressive acyclovir or valacyclovir during pregnancy has been shown to decrease the risk of viral shedding, recurrences, and cesarean deliveries in women with a history of genital herpes 1.
• However, the safety of HSV antivirals during pregnancy should be considered, with a case-control study suggesting an increased risk of gastroschisis among women who used antiherpes medications between the month prior to conception and the third month of pregnancy 1.

Conclusion is not needed as per the guidelines, the above information is sufficient to make a clinical decision.

From the FDA Drug Label

Neonatal Herpes Simplex Virus Infection Acyclovir for Injection is indicated for the treatment of neonatal herpes infections.

Given the clinical scenario of a three-week-old infant presenting with fever and initial findings consistent with acute pyelonephritis, and a maternal history of HSV-2 with valacyclovir prophylaxis during pregnancy, treatment for HSV meningitis should be considered.

• The infant's symptoms and maternal history suggest a possible risk of neonatal herpes infection.
• Although a lumbar puncture could not be obtained, empiric treatment with acyclovir may be warranted due to the potential severity of neonatal herpes infections 2.
• It is essential to exercise caution and consider the possibility of HSV meningitis, even without a definitive diagnosis, given the maternal history and the infant's clinical presentation.

From the Research

Clinical Presentation and Diagnosis

• The patient is a three-week-old infant presenting with fever and initial findings consistent with acute pyelonephritis, with a maternal history of HSV-2 and valacyclovir prophylaxis during pregnancy 3.
• The clinical question is whether this patient should be treated for HSV meningitis, given the maternal history and the inability to obtain a lumbar puncture.
• Neonatal herpes is rare and mainly due to HSV-1, but can also be caused by HSV-2, especially in cases where the mother has a history of genital herpes 3, 4.

Treatment and Management

• Any newborn with suspected neonatal herpes should be treated with intravenous acyclovir (20 mg/kg 3 times daily) before the PCR results are available 3.
• The duration of treatment depends on the clinical form, and suppressive treatment with valacyclovir may not be effective in preventing recurrent meningitis 5.
• Acyclovir or valacyclovir is commonly administered for a median of 10 days in cases of HSV-2 meningitis 6.

Risk Factors and Prevention

• The major risk factor for transmission of HSV to the neonate is the type of maternal infection, with primary and non-primary infections carrying a higher risk than recurrent infections 4.
• Antiviral prophylaxis, such as valacyclovir, can be offered to women with a history of genital herpes during pregnancy to reduce the risk of transmission 3.
• Cesarean delivery is recommended in cases where a first episode of genital herpes is suspected or confirmed at the onset of labor, or if it occurred less than 6 weeks before delivery 3.