Abby Parks, a 27-year-old special education teacher from Springfield, Illinois, had never heard of parvovirus until she started experiencing flu-like symptoms in late April, which were soon followed by joint pain and a rash. At 18 weeks pregnant, Parks had been feeling unwell with a persistent fever for several days, but tests for Covid and strep throat were negative.

The school nurse, noticing that several students had “really rosy, red cheeks,” suggested that Parks might be dealing with the same illness.

“I kept getting worse,” Parks recalled. “I was bedridden with a fever for four or five days straight.”

In early May, blood tests performed by her OB-GYN confirmed she had parvovirus B19. She was then referred to a maternal-fetal medicine specialist, who discovered that the virus had infected her fetus, causing it to develop anemia—a condition that can be life-threatening. The fetus received a blood transfusion while still in the womb.

Cases of parvovirus B19, commonly known as Fifth disease or “slapped cheek syndrome” due to the red rash it causes, are on the rise in the U.S. On Tuesday, the Centers for Disease Control and Prevention (CDC) issued an alert, urging healthcare providers to be vigilant for signs of this highly contagious seasonal virus.

The CDC noted that most infections are occurring in children aged 5 to 9. Since March, parvovirus has been spreading at unusually high rates across Europe, according to the European Centre for Disease Prevention and Control.

Although most adults have already been infected as children and are immune, the CDC warned that pregnant women and individuals with sickle cell disease who haven’t been exposed before are at risk of severe illness.

Dr. Kathy Bligard, an OB-GYN at Barnes Jewish Hospital in St. Louis, commented: “Abby isn’t the only patient whose fetus needed a blood transfusion due to parvovirus. It’s something I used to see maybe once every other year, but I’ve encountered several cases in the past few months.”

Bligard explained that parvovirus is especially dangerous for pregnant women because it can cross the placenta, infect the fetus, and cause anemia, which may lead to fetal death.

While Parks has recovered from the virus, her pregnancy remains at risk.

On Wednesday morning, an ultrasound revealed that the fetus wasn’t receiving sufficient blood from the placenta, prompting Parks’ admission to a hospital in Springfield for further care.

“I believe the earlier transfusion saved the fetus’s life,” Parks said from her hospital bed. “If the anemia had continued, the baby could have died due to low blood count.”

Bligard noted that parvovirus hampers the fetus’s ability to produce new red blood cells. “Red blood cells are crucial for delivering oxygen to vital organs. A deficiency can lead to heart failure or even death,” she explained.

Although Fifth disease primarily affects children, adults who contract it can experience more severe symptoms, such as joint pain and anemia, resulting from difficulties in producing red blood cells, said Dr. Vincent Iannelli, a pediatrician in the Dallas area. These symptoms can cause pregnancy complications.

Patients with sickle cell disease are also at heightened risk.

“We’ve been seeing more cases over the past couple of months,” Iannelli observed. Typically, he would encounter one case of Fifth disease per month; now, he’s seeing one to two cases per week, noting that the virus is more prevalent in the spring and summer.

Symptoms of Fifth Disease

In children, Fifth disease is usually mild. It often presents with a fever and respiratory symptoms, followed by a distinctive red rash on the cheeks, then a lacy rash on the body, which may be itchy.

The rash appears toward the end of the illness and typically fades within seven to 10 days, although it can last several weeks. Importantly, a person with Fifth disease is no longer contagious once the rash emerges. “By the time you realize your child has it, they’re no longer contagious,” Iannelli said.

The rash may become more pronounced in heat and sunlight, but this doesn’t worsen the infection, Iannelli added.

Pregnant women who experience symptoms like joint pain or issues with red blood cell production should contact their doctors immediately, especially if they’ve been in contact with someone infected with Fifth disease.

Iannelli stressed that the rise in cases is not cause for alarm.

“Most pregnant women have already had the infection in childhood, so they’re immune. But occasionally, we do see adults with it,” he said.

Ultimately, “if you’re healthy, it’s a mild illness,” Iannelli added. “If you have immune system issues or are early in your pregnancy, you should inform your doctor. But for everyone else, it’s essentially just a rash.”

Iannelli emphasized that the CDC alert was meant to increase awareness among healthcare providers, not to alarm the public.

Why is it Called Fifth Disease?

In the early 1900s, doctors created a list of common childhood rashes to improve diagnostic accuracy. They identified six major rashes:

  1. Measles, a highly contagious virus causing rash, high fever, and respiratory symptoms.
  2. Scarlet fever, a bacterial infection caused by group A streptococcus.
  3. Rubella, a viral infection also known as German measles. If contracted during pregnancy, it can lead to miscarriage or stillbirth. The CDC recommends two doses of the MMR (measles-mumps-rubella) vaccine for children.
  4. Filatov-Dukes, no longer considered a distinct disease.
  5. Fifth disease, or parvovirus B19, also known as erythema infectiosum.
  6. Roseola, a viral infection sometimes called Sixth disease, which can cause high fever and rash.

Although there are now more recognized childhood rashes, such as chickenpox, the numbering system has fallen out of use—except for Fifth disease.

Now at 30 weeks pregnant, Parks is under close monitoring in the hospital. She wants other pregnant women to be aware of the virus and get tested if they believe they’ve been exposed.

“This has been the most challenging experience,” Parks said. “The fetus’s survival wasn’t guaranteed due to the anemia.”