Newborn babies survive exposure to rabies during birth

In a recent report in the Journal of Venomous Animals and Toxins including Tropical Diseases, Chinese physicians describe the unusual occurrence of a pregnant woman with rabies giving birth to a healthy child in Henan Province. The 25-year-old, pregnant woman began to show symptoms on the day she went into labor–pain, agitation and insomnia–with her symptoms worsening the following day. After giving birth to her son by caesarean section, the mother succumbed to the virus within a few days. But the newborn child–along with his father–were administered rabies post-exposure prophylaxis (PEP) immediately after the mother’s death, and they have not shown any signs of infection henceforth.

The mother possibly contracted rabies after a dog bit her foot while walking on her village road when she was four-months pregnant. Her wound was treated, but she did not receive any rabies prophylaxis at the time, nor was she informed of the possibility of rabies transmission. Only when she entered the hospital to deliver her child did she become symptomatic for rabies, passing away two days later in her home after treatments with traditional Chinese medicines, sedatives and antibiotics proved ineffectual.

Once rabies was confirmed as the mother’s cause of death postpartum, the baby and his father were treated with the full course of rabies vaccine. The authors of the paper did not speculate how the baby escaped transmission, but certainly the rapid treatment with anti-rabies vaccine may have played a significant role in preventing the disease from developing. The authors also did not postulate on any additional protections provided by a caesarean versus a vaginal delivery.

Cases of rabid, pregnant women delivering babies are very rare, and cases of mother-to-child transmission of rabies during delivery are even rarer. Another recent study in the journal Vaccine reported a further two cases of probable rabies in mothers near to, or at term (one in Africa and one in Asia) both of whose babies survived. Their review of 14 other documented cases of rabid mothers delivering babies, revealed only one where the baby had contracted rabies. Amongst the surviving babies, some had not received PEP, and some were born vaginally and some by cesarean.

The authors of the Vaccine paper postulated that viral transmission during pregnancy is low because the virus, which travels through the nervous system, is not present in blood and the exposure of the baby’s mucosal tissues to infected maternal fluids is also low in the birth canal, further reducing the possibility of transmission. Additionally, the placenta acts as a barrier and protects the unborn child from infectious maternal fluids; and, the lack of in utero connections to the mother’s nervous system prevents the virus from traveling from the mother to the child.

These papers both remind us that pregnant women who become exposed to rabies through a dog bite should seek treatment immediately. The current cell-culture vaccines used to stop the development of the disease are safe and effective for use, even in pregnant and lactating women and very young children and newborns. The authors also recommend giving PEP as a precautionary measure to any baby born of a mother with rabies.

Submitted by Laura Baker, GARC Newsletter Co-Editor. Summarized from “Survival of a newborn from a pregnant woman with rabies infection” in the Journal of Venomous Animals and Toxins including Tropical Diseases and “Rabies transmission risks during peripartum – Two cases and a review of the literature” in Vaccine.