A respiratory virus linked to paralysis in children is spreading across the United States, raising concerns about a possible surge in cases of a rare disease such as polio.

Wastewater monitoring has revealed a significant increase in enterovirus D68 (EV-D68), which is known to cause severe neurological symptoms in children.

EV-D68 is usually associated with mild respiratory problems, such as runny nose, cough, and headache. However, in rare cases, it can cause acute flaccid myelitis (AFM), a condition that affects the nervous system and causes muscle weakness, especially in the arms and legs.

This condition mainly affects young children and can result in long-term disability.

“We are now detecting EV-D68 nucleic acid in wastewater across the country, and the levels are rising,” said Alexandria Boehm, program director for WastewaterScan, a nonprofit network that monitors viruses, and a professor at Stanford University.

An increase in virus levels in wastewater is a key early indicator of a possible increase in AFM cases.

Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security, told NBC News that the timing of this increase is particularly concerning, as September has historically seen the highest number of AFM cases.

“It’s the right time of year,” he said, adding that there are other signs pointing to a possible rise in cases.

EV-D68 first gained attention in 2014, when an unexpected surge in pediatric AFM cases was seen in the US. That year, 120 children were diagnosed with the condition, which has no known cure or specific treatment.

Even after intensive physical therapy, many children are left with long-term or permanent disabilities.

Enteroviruses such as EV-D68 are common and usually cause mild symptoms, but the association of this virus with AFM has raised concern.

Experts continue to urge vigilance, as more research is needed to understand how the virus leads to this rare and serious outcome.

Although the situation is being closely monitored, health officials are emphasizing the importance of taking caution and staying informed about the spread of the virus.

According to the US Centers for Disease Control and Prevention, as of September 3, 2024, 13 AFM cases have been confirmed among 22 patients under investigation (PUI), and 18 cases have been confirmed among 40 PUI in 2023.

Since the CDC began tracking AFM in August 2014, 758 cases have been confirmed.

There is currently no treatment or vaccine against EV-D68. Researchers are studying the virus to understand its long-term effects.

Prevention includes following basic hygiene, such as frequent hand washing, avoiding contact with sick people, and seeking medical attention for children with respiratory problems.