PHOENIX (AP) — As schools reopen for another year, they are focused on improving student attendance. But back-to-school is hitting just as COVID-19 cases are increasing, raising the question: When is a child too sick for school? School absences surged during the pandemic and have yet to recover. Nearly 1 in 4 students remains chronically absent, defined as missing 10% or more of the academic year, according to the latest data analyzed by The Associated Press.

One reason for continued high absences: After years of COVID-19 quarantines, parents are more cautious about sending children to school when they might be contagious with an illness. When a child misses school, even for an excused absence like a sick day, it's harder for them to stay on track academically . So schools and health experts are trying to change the culture around sick days.

Here's what they want parents to know. During the pandemic, the Centers for Disease Control and Prevention urged people who tested positive for COVID-19 to isolate at home for a set number of days and to quarantine after exposure to the coronavirus. In some settings, people with any mild illness were urged to remain home until symptoms were clear.

Those standards, and the caution behind them, remained for years after schools reopened to in-person instruction. That meant children often missed large portions of school after contracting or being exposed to COVID-19 or other illnesses. This spring, COVID-19 guidance officially changed.

Now,.