Neonatal Babesiosis: Transfusion Risk in Premature Infants
Can a single blood donor transmit infection to multiple newborns?
Neonatal babesiosis is a rare but serious threat—particularly in premature infants receiving transfusions.
Researchers at Yale School of Medicine described three premature infants in one neonatal intensive care unit who contracted Babesia from a single 24-year-old donor.
The report was published in the Pediatric Infectious Diseases Journal.
How Neonatal Babesiosis Spread in One NICU
Babesia can be unknowingly transmitted through blood transfusions. Current screening methods are not fully reliable.
“Screening questionnaires are clearly insufficient given the growing number of cases of transfusion-transmitted babesiosis,” writes Glanternik.
The Connecticut donor passed all FDA-mandated screening and was approved by the American Red Cross, despite being infected.
This case highlights ongoing concerns about Babesia in the blood supply.
Three Infants Infected
All three premature infants developed measurable parasitemia:
- Infant A: 13.4%
- Infant B: 12.5%
- Infant C: 6.8%
These levels are clinically significant. In adults, parasitemia above 10% often warrants exchange transfusion.
Treatment Approach
The infants were treated with azithromycin and atovaquone, rather than clindamycin and quinine.
Quinine is often avoided in neonates due to dosing challenges and potential toxicity.
All three infants received 14 days of therapy—longer than the 7–10 days recommended in guidelines.
Relapse After Treatment
One infant relapsed 48 days after treatment, with 1% parasitemia detected on routine smear.
After retreatment for 23 days, the infection cleared.
This pattern is consistent with persistent Babesia infection requiring longer therapy.
Why Diagnosis Is Challenging
Neonatal babesiosis is difficult to recognize.
Symptoms are often nonspecific and may resemble complications of prematurity.
Clinicians should maintain a high index of suspicion in infants who have received transfusions.
Clinical Questions Raised
- Would longer initial treatment reduce relapse risk?
- Can low-level parasitemia be missed on standard smears?
- How should clearance be confirmed in newborns?
Clinical Perspective
This case highlights two important concerns: limitations in blood donor screening and the potential for relapse despite treatment.
A single donor—without symptoms and with negative routine screening—was able to infect three vulnerable infants.
For clinicians, transfusion history should be considered when evaluating unexplained illness in neonates, particularly in endemic areas.
Clinical Takeaway
Neonatal babesiosis can be transmitted through blood transfusion and may relapse after standard therapy. Careful monitoring and individualized treatment are essential.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
