Parvovirus B19 and Sickle Cell Disease: A 2024 Surge in Aplastic Crises Among Atlanta Children

Human parvovirus B19 is a common virus spread by respiratory droplets. In healthy people it is usually mild. But in people with chronic anemia, including sickle cell disease (SCD), it can halt red blood cell production and cause a sudden, severe anemia — a transient aplastic crisis.

Two siblings

In December 2023, a 10-year-old with SCD died unexpectedly at home, with no fever or other symptoms beforehand. Limited tests showed a hematocrit below 15% (normal is 37%–45%); B19 was not tested for. The autopsy found a massively enlarged spleen, consistent with a splenic sequestration crisis.

Six days later, the child's 14-year-old sibling, who also has SCD, was confirmed to have acute B19 infection, with hemoglobin below 6 g/dL (normal 12.0–16.0) and a reticulocyte count of 7.0 × 10⁹/L (normal 40–102 × 10⁹/L) — the picture of aplastic crisis. After a red blood cell transfusion, the sibling recovered without complications.

Doctors at Children's Healthcare of Atlanta (CHOA), one of the large SCD centers in the southeastern United States, then looked back through their Sickle Cell Clinical Database.

What they found

CHOA tests a patient with SCD for B19 whenever hemoglobin drops by 1 g/dL or more from baseline together with reticulocytopenia (too few young red cells), presuming an aplastic crisis.

From December 2023 to September 30, 2024, it found 55 cases of B19 infection with aplastic crisis — 2 in December 2023 (the sibling and one unrelated child) and 53 in 2024. The report compares these with earlier years of increased cases:

B19-associated aplastic crisis cases (A) and incidence (B) in children with SCD at Children's Healthcare of Atlanta, 2010–September 2024. CDC

More testing was part of the picture: during 2010–2023 a median of 2.9% of SCD patients seen at CHOA were tested for B19 each year (range 1.4%–5.7%), against 6.8% in 2024.

The patients

Complications:

• acute chest syndrome — a blockage of blood vessels in the lungs — 27%
• splenic sequestration — sudden enlargement of the spleen as it traps sickled red cells, lowering blood volume and hemoglobin — 11%
• stroke — 3.6%
• nephrotic syndrome — 1.8%

Apart from the first child, in whom B19 was never confirmed, no patient died with B19 infection.

What clinicians should do

• Know B19 was more active in 2024.
• Suspect it in a child or adolescent with SCD who arrives with anemia and reticulocytopenia — the most common first signs — and keep a low threshold for testing when aplastic crisis seems possible.
• Monitor patients with SCD and B19 for complications: early red blood cell transfusion may prevent serious outcomes.

Sources

Based on Yee MEM, Kalmus GG, Patel AP, Payne JN, Tang A, Gee BE, "Notes from the Field: Increase in Diagnoses of Human Parvovirus B19–Associated Aplastic Crises in Children and Adolescents with Sickle Cell Disease — Atlanta, Georgia, December 14, 2023–September 30, 2024," MMWR volume 73, number 47, Centers for Disease Control and Prevention, by physicians at Children's Healthcare of Atlanta, Emory University and Morehouse School of Medicine; a work of the United States government in the public domain. The report describes the 2024 incidence as 3.6 times that of 2010–2023, but the two rates it gives (35.6 and 7.78 per 1,000 patient-years) do not work out to that ratio, so no ratio is given here.