Federal health officials are warning doctors to keep watch for a respiratory virus, known as parvovirus B19, as infection rates tick up in the United States. Parvovirus B19 has existed for decades, and its symptoms are typically mild or nonexistent among children and healthy adults. But it can also lead to serious complications for people who are pregnant or immunocompromised or who have certain blood disorders.
In a health advisory issued this week, the Centers for Disease Control and Prevention reported seeing a spike in the proportion of people who tested positive for antibodies — indicating a recent infection — especially among children ages 5 to 9. This year, public health authorities in 14 European countries also reported observing an unusually high number of cases, according to the CDC. Infections generally pop up during late winter, spring and early summer, while minor outbreaks appear every three to four years.
This year, the infection is spreading as back to school gets underway. Here's what to know about the virus. Parvovirus B19 spreads from person to person three ways: respiratory droplets, blood or during pregnancy from mother to fetus.
(Canine parvovirus, which affects dogs, is different from parvovirus B19, and it cannot pass from pet to person or vice versa.) Most people who are infected with parvovirus B19 are asymptomatic. For those who do show symptoms, they can vary depending on age.
In children, the illness can first cause flu-like symptoms, includin.