Orange County officials declared a health emergency because of rapidly spreading viral infections that have caused record numbers of pediatric hospitalizations and daily emergency room visits. The emergency proclamations allow the county to use state and federal resources and get mutual aid from other counties.

Why now? During the last two-plus years of masking and social distancing and other precautions people took to protect themselves from COVID-19, fewer people ended up in the hospital because of common respiratory viruses like RSV and the flu. Now that those precautions have largely been lifted, these viruses are spreading fast again, hitting babies and other young children especially hard because RSV tends to make kids sickest the first time they get it. 

Source: Orange County Declares Health Emergency Due To Respiratory Infections | LAist