Babesia During Pregnancy: Two Infants With Congenital Babesia

Welcome to an Inside Lyme case study. One of the best ways to understand Lyme disease and its coinfections is through real clinical cases. In this episode, I discuss two infants who contracted Babesia microti from their mothers during pregnancy. These cases raise important questions about Babesia during pregnancy and congenital babesiosis. This case series will be discussed on my Facebook page and made available on podcast and YouTube.

In this episode, I will be discussing two children who contracted Babesia from their mothers.

These cases were described in the Journal of the Pediatric Infectious Disease Society by Saetre and colleagues in 2017.

Babesia is caused by a parasite called Babesia microti. The infection is typically transmitted through the bite of an infected deer tick. Babesia is also one of the most important Lyme disease coinfections and can occur alongside Lyme disease in patients exposed to tick bites.

Although Babesia is most commonly transmitted by ticks, the parasite can also be passed from mother to baby during pregnancy. This condition is known as congenital babesiosis and, while uncommon, it has been documented in several clinical reports.

In early cases of Babesia, the parasite may be detected in red blood cells using a blood smear under a microscope. In other cases, Babesia can only be detected through PCR testing or antibody testing. In some instances, Babesia may not be detected by any of these tests early in infection.

Babesia infections can range from mild illness to severe disease and, in rare cases, may be fatal. The infection can also be transmitted through blood transfusions.

[bctt tweet=”Babesia can be severe and, in rare cases, fatal. Babesia can also be mild or without symptoms.” username=”DrDanielCameron”]

Let’s get back to the cases.

First Child With Babesia

The first mother from Westchester County, New York, had been diagnosed with Lyme disease during her third trimester at 32 weeks of pregnancy. She developed an erythema migrans rash and was treated with amoxicillin.

Her son was born healthy and initially sent home. At 4½ weeks of age he returned with a fever of 101.7°F, sleepiness, and irritability.

He had scleral icterus — yellowing of the eyes consistent with jaundice. His bilirubin level was 2.8, which represented only a mild elevation. His spleen was enlarged and 2% of his red blood cells showed parasitemia. He was hospitalized.

His blood counts dropped significantly, with a hematocrit of 19.1%, platelets of 24 × 10³ cells per mm³, and an absolute neutrophil count of 100 cells per mm³.

He was treated with azithromycin and atovaquone rather than clindamycin and quinine, as the doctors believed this combination would be better tolerated in infants.

The boy was discharged from the hospital after ten days. He remained well after completing 14 days of treatment, according to the authors.

Second Child With Babesia

A second mother from Putnam County, New York, had been diagnosed with Lyme disease during her third trimester. The mother initially experienced fever and muscle aches for two weeks before developing an erythema migrans rash at 37 weeks of pregnancy. She was treated with amoxicillin.

Her baby girl was born one week later without perinatal complications. Her daughter’s blood test was positive for Babesia microti by PCR. The doctor did not perform a thick smear test looking for Babesia under the microscope. Because the infant had no symptoms, she was sent home without treatment.

The baby returned at 18 days of age with malaise, tachycardia, and pallor. Her blood smear showed Babesia parasites in 0.5% of her red blood cells. She was hospitalized.

Her hematocrit dropped to 20.1 percent. She also developed neutropenia and thrombocytopenia.

She was treated with azithromycin and atovaquone. Because of worsening anemia and persistent parasitemia, clindamycin was added on the fourth day.

The infant also required a blood transfusion due to worsening anemia, pallor, malaise, and tachycardia.

The girl completed 14 days of treatment with the combination therapy.

What Can We Learn From These Cases?

1. Women can contract Babesia during pregnancy.
2. Babesia can be transmitted from mother to baby during pregnancy.
3. There may be a delay in symptom onset after birth.
4. Babesia can cause severe illness in newborn children.

Questions Raised By These Cases

1. How can doctors or parents recognize Babesia and Lyme disease in pregnant women and newborns?
2. Would Babesia have been recognized if the mother had not developed an erythema migrans rash?
3. Would early treatment for Babesia in an infant with a positive PCR test have prevented hospitalization?
4. What happens if a pregnant woman becomes infected earlier in pregnancy before doctors recognize the illness?

Treating Tick-Borne Disease

Diagnosing and treating Babesia in newborns can be challenging. More research is needed to determine the safest and most effective treatment strategies for pregnant women with Lyme disease and Babesia, as well as for infants born with these infections.

These cases highlight the need for clinicians to consider tick-borne infections when evaluating unexplained illness in newborns and infants in endemic areas.

We also need to give doctors the freedom to treat these difficult cases without undue interference by colleagues, insurance companies, medical societies, and medical boards.

Can Babesia be transmitted during pregnancy?

Yes. Although uncommon, Babesia infection can be transmitted from mother to baby during pregnancy. This form of infection, called congenital babesiosis, has been reported in newborns whose mothers were infected during pregnancy.