As cases of coronavirus rise in Mississippi, health officials are warning that schools and extracurricular activities could turn into hot spots.

Several high school sports teams have had to cancel or postpone games due to infections in recent weeks. More than 9,000 students and almost 800 teachers were quarantined for coronavirus exposure in Mississippi last week, according to the state Department of Health. Since the start of the school year, about 4,500 students have tested positive for the virus.

“The schools have become one of the bigger issues this week,” State Epidemiologist Dr. Paul Byers said during an online conversation Friday hosted by the Mississippi State Medical Association. “When we look at what’s going on in the schools, now is not the time to change our course. We need to continue to do those things that we did early on to make sure that we prevent transmission in those settings.”

While students and staff are generally safe during learning time in classrooms, infections are occurring during other hours, like when people are participating in after school activities, gathering for lunch or socializing in school hallways, Byers said.

Tupelo High School and Lafayette County High School both had to forfeit football playoff games this week because of COVID-19 cases within the programs.

The boys’ and girls’ basketball teams at Leflore County High School went into quarantine after Tuesday, when the students might have been exposed to the virus by someone from another team, the Greenwood Commonwealth reported.

“We are just following protocol. It’s the right move right now,” said Clinton Gatewood, athletics director for the Greenwood Leflore Consolidated School District.

Basketball and other indoor activities during the winter season are of particular concern. Dr. Thomas Dobbs, Mississippi’s state health officer, recommended that schools with outbreaks send students home for virtual learning for at least a couple of weeks out of caution. He said if schools move to virtual learning, extracurriculars should be temporarily halted, too.

“For crying out loud, if you go virtual as a school, that needs to include the extracurriculars, and the sports,” he said.

Byers said it’s important that schools stick to the Health Department’s guidelines for in-person learning during the pandemic. He said he has seen some schools talking about no longer mandating that students quarantine if they are exposed to the virus and instead making it a parent’s decision whether or not a child stays home.

“That’s not going to work for us,” Byers said.

The state health department said Saturday that Mississippi, with a population of about 3 million, has reported 1,370 virus cases and at least 21 deaths from COVID-19 as of Friday evening. That’s an increase of 65 cases and 16 deaths from the day before.