Newborn Exposed to HBV, HCV, HIV, Syphilis, HSV, CMV or Toxoplasmosis

About this tool

This tool gives the newborn plan when the mother has hepatitis B, hepatitis C, HIV, syphilis or active genital herpes, and for congenital cytomegalovirus (CMV) and toxoplasmosis. It follows the AAP Red Book 2024–2027 and the CDC, AAP and US perinatal HIV guidance it endorses.

Hepatitis B results use the mother's HBsAg and the birth weight to time vaccine and HBIG and to plan serology at 9–12 months. Syphilis results follow the four CDC 2021 congenital syphilis scenarios with weight-based penicillin doses. HSV results follow the AAP 2013 algorithm for well infants born to mothers with lesions, plus treatment length for proven disease.

HIV results sort the infant by maternal risk and give the timing of prophylaxis, virologic testing and feeding advice; drug doses follow the perinatal HIV guideline by gestational age. Hepatitis C results give the 2023 RNA testing schedule. CMV results cover who to test, urine or saliva PCR before 21 days, the evaluation, and valganciclovir for 6 months for moderate to severe disease with neutrophil monitoring. Toxoplasmosis results give the serology, eye, imaging and CSF workup and 12 months of pyrimethamine, sulfadiazine and leucovorin. Group B strep points to the Newborn sepsis tool.

Common questions

When should HBIG be given to a newborn?

Within 12 hours of birth with the hepatitis B vaccine when the mother is HBsAg positive. If her status is unknown, give vaccine within 12 hours and HBIG by 7 days if she tests positive, or within 12 hours if the infant weighs under 2000 g.

When should an HCV-exposed infant be tested?

With an HCV RNA test at 2–6 months of age. An undetectable result needs no further testing unless there is a clinical concern. Children 18 months or older who were never tested get anti-HCV with reflex RNA.

How is proven congenital syphilis treated?

Aqueous crystalline penicillin G 50,000 units/kg IV every 12 hours in the first week of life and every 8 hours after, for 10 days in total, or procaine penicillin G 50,000 units/kg IM daily for 10 days.

How long is acyclovir given for neonatal HSV?

20 mg/kg IV every 8 hours for 14 days for skin, eye and mouth disease and at least 21 days for CNS or disseminated disease, followed by oral acyclovir 300 mg/m² three times daily for 6 months.

When should HIV prophylaxis start in an exposed newborn?

As soon as possible, ideally within 6 hours of birth. Low-risk infants get zidovudine alone; high-risk infants get empiric 3-drug therapy with expert advice.

When should a newborn be tested for congenital CMV?

After a failed newborn hearing screen, or with microcephaly, IUGR, petechiae, hepatosplenomegaly, chorioretinitis or maternal primary CMV. Send urine or saliva CMV PCR before 21 days of life; confirm a positive saliva test with urine.

Which infants with congenital CMV get valganciclovir?

Infants with moderate to severe symptomatic disease, including CNS involvement: 16 mg/kg orally twice daily for 6 months, started within the first month, with ANC checks weekly for 6 weeks, at 8 weeks, then monthly. Asymptomatic infants and those with isolated hearing loss are not routinely treated; discuss with a specialist.

How is congenital toxoplasmosis treated?

Pyrimethamine, sulfadiazine and leucovorin for 12 months with pediatric ID, after infant IgG, IgM and IgA serology, an eye exam, head imaging and CSF studies.

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