ST. LOUIS — Two Washington University physicians and two Washington University students have tested positive for COVID-19, the university said Wednesday evening.

In a letter to students, the university said one of the doctors lives in St. Louis and the other lives in St. Louis County. Both doctors are quarantined in their homes and are not treating patients.

One of the doctors is the second reported case in St. Louis, as 5 On Your Side reported earlier Wednesday, sources told 5 On Your Side's Casey Nolen.

St. Louis County said it is their fifth case. The release said the person was between 30 and 40 years old and recently traveled. Where the person traveled is still under investigation. 

RELATED: Missouri reports 9 new coronavirus cases Wednesday, bringing total to 24

RELATED: Second confirmed case of the coronavirus in City of St. Louis is Barnes Jewish employee, sources say

"We’re working as diligently and quickly as possible with public health officials who are focused on identifying and communicating with anyone who may have had contact with the physicians," the letter said.

The letter to students also said two students who were studying abroad in Denmark tested positive for COVID-19. Those students are quarantining out of the state and did not return to campus after returning from their study abroad program ended.

"While this news is certainly troubling, and we are concerned for our employees and students, it is not entirely unexpected that we would have cases confirmed in our community," the letter said. "This is something we’ve been preparing for as the virus has continued to spread and as testing has become more readily available, and we have plans in place for responding."

Washington University has a web page set up for students to get coronavirus information as it becomes available.

This story will be updated when more information becomes available.

More coronavirus coverage:

RELATED: Coronavirus live blog: Trump to marshal private sector against virus

RELATED: List of restaurants in the St. Louis area offering curbside pickup

RELATED: Illinois confirms 128 new coronavirus cases in 1 day

RELATED: Gatherings limited to 10 people in St. Louis City