September Week 4 Answers
You are at VHC and a labor and delivery nurse calls to tell you about a new baby born to an HIV positive mom. Per usual, she does not know what information you would like regarding mom’s history.
Q. What information do you ask her for and why is it important?
A. Was mom on ART? (if on ART antenatally, should continue) What was mom’s viral load (determines need for intrapartum zidovudine)? Did she receive intrapartum zidovudine (reduces transmission by 66% in mom’s with HIV RNA >400). Mode of delivery (risk stratification, recommend sched c/s @ 38WGA for all women with RNA >1000 or RNA level unknown). Any coinfections? (Do you need to evaluate the baby for other infections i.e. herpes simplex virus, hepatitis B, hepatitis C, syphilis, toxoplasmosis, or tuberculosis.).
Q. What would you order for the baby while they are in the nursery if mom was on ART and had good viral suppression? What would you do differently if mom was not on ART prior to delivery?
A. Check a CBC & start 6 week course of zidovudine ASAP (preferably within 12 hours of delivery, no proven benefit if started >48 hours after delivery); if mom was not on ART also give 3 doses of nevirapine given during the first week of life (first dose at birth–48 hours, second dose 48 hours after first dose, and third dose 96 hours after second dose); some experts advise more intensive laboratory monitoring, including serum chemistry and transaminases at birth
Q. What side effects would you watch for from the HIV prophylaxis regimen
A. Anemia/neutropenia – Zidovudine; Rash, hepatotoxicity – nevirapine
Q. You are now following this baby in CYAS. What diagnostic testing would you order and when ?
A. HIV virologic testing (HIV DNA PCR) should be performed within the first 14 to 21 days of life, at 1 to 2 months, and at 4 to 6 months of age.
Q. What prophylaxis is recommended for babies born to mothers with known HIV and when do you give it? In what circumstances would you not proceed with the prophylaxis?
A. All infants born to women with HIV infection should begin PCP prophylaxis at ages 4 to 6 weeks, after completing their ARV prophylaxis regimen, unless there is adequate test information to presumptively exclude HIV infection
Q. What test results would allow you to exclude a diagnosis of HIV in the infant?
A. HIV may be presumptively excluded with two or more negative tests, one at age 14 days or older and the other at age 1 month or older. Definitive exclusion of HIV in non-breastfed infants can be based on two negative virologic tests at age 1 month or older and at age 4 months or older. If non-subtype B HIV infection is suspected based on maternal origins, then newer HIV RNA assays that have improved ability to detect non-subtype B HIV should be used as part of the initial diagnostic algorithm. Many experts confirm HIV-negative status with an HIV antibody test at ages 12 to 18 months.
Q. What changes would you make to the vaccine schedule for this baby?
A. The baby should receive routine vaccines on schedule. If HIV is confirmed, then changes in the administration if live vaccines may be made.
Q. What anticipatory guidance should you provide regarding feeding practices.
A. It is safest not to breastfeed, even in mothers with good viral suppression on ARV. Premasticating food has also been linked to the transmission of HIV and should be avoided.
Q. What further testing is recommended in an infant found to be HIV positive?
A Any newly diagnosed infant should undergo viral resistance testing by genotype and/or phenotype to assess for susceptibility to combination antiretroviral therapy.